This document summarizes new features and bugfixes in each stable release of Tor. If you want to see more detailed descriptions of the changes in each development snapshot, see the ChangeLog file. Changes in version 0.4.7.13 - 2023-01-12 This version contains three major bugfixes, two for relays and one for client being a security fix, TROVE-2022-002. We have added, for Linux, the support for IP_BIND_ADDRESS_NO_PORT for relays using OutboundBindAddress. We strongly recommend to upgrade to this version considering the important congestion control fix detailed below. o Major bugfixes (congestion control): - Avoid incrementing the congestion window when the window is not fully in use. Thia prevents overshoot in cases where long periods of low activity would allow our congestion window to grow, and then get followed by a burst, which would cause queue overload. Also improve the increment checks for RFC3742. Fixes bug 40732; bugfix on 0.4.7.5-alpha. o Major bugfixes (relay): - When opening a channel because of a circuit request that did not include an Ed25519 identity, record the Ed25519 identity that we actually received, so that we can use the channel for other circuit requests that _do_ list an Ed25519 identity. (Previously we had code to record this identity, but a logic bug caused it to be disabled.) Fixes bug 40563; bugfix on 0.3.0.1-alpha. Patch from "cypherpunks". o Major bugfixes (TROVE-2022-002, client): - The SafeSocks option had its logic inverted for SOCKS4 and SOCKS4a. It would let the unsafe SOCKS4 pass but not the safe SOCKS4a one. This is TROVE-2022-002 which was reported on Hackerone by "cojabo". Fixes bug 40730; bugfix on 0.3.5.1-alpha. o Minor feature (authority): - Reject 0.4.6.x series at the authority level. Closes ticket 40664. o Minor features (fallbackdir): - Regenerate fallback directories generated on January 12, 2023. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2023/01/12. o Minor features (relays): - Set the Linux-specific IP_BIND_ADDRESS_NO_PORT option on outgoing sockets, allowing relays using OutboundBindAddress to make more outgoing connections than ephemeral ports, as long as they are to separate destinations. Related to issue 40597; patch by Alex Xu (Hello71). o Minor bugfixes (relay, metrics): - Fix typo in a congestion control label on the MetricsPort. Fixes bug 40727; bugfix on 0.4.7.12. o Minor bugfixes (sandbox, authority): - With the sandbox enabled, allow to write "my-consensus- {ns|microdesc}" and to rename them as well. Fixes bug 40729; bugfix on 0.3.5.1-alpha. o Code simplifications and refactoring: - Rely on actual error returned by the kernel when choosing what resource exhaustion to log. Fixes issue 40613; Fix on tor-0.4.6.1-alpha. Changes in version 0.4.7.12 - 2022-12-06 This version contains a major change that is a new key for moria1. Also, new metrics are exported on the MetricsPort for the congestion control subsystem. o Directory authority changes (moria1): - Rotate the relay identity key and v3 identity key for moria1. They have been online for more than a decade and refreshing keys periodically is good practice. Advertise new ports too, to avoid confusion. Closes ticket 40722. o Minor feature (Congestion control metrics): - Add additional metricsport relay metrics for congestion control. Closes ticket 40724. o Minor features (fallbackdir): - Regenerate fallback directories generated on December 06, 2022. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/12/06. o Minor bugfixes (cpuworker, relay): - Fix an off by one overload calculation on the number of CPUs being used by our thread pool. Fixes bug 40719; bugfix on 0.3.5.1-alpha. Changes in version 0.4.7.11 - 2022-11-10 This version contains several major fixes aimed at helping defend against network denial of service. It is also extending drastically the MetricsPort for relays to help us gather more internal data to investigate performance and attacks. We strongly recommend to upgrade to this version especially for Exit relays in order to help the network defend against this ongoing DDoS. o Directory authority changes (dizum, Faravahar): - Change dizum IP address. Closes ticket 40687. - Remove Faravahar until its operator, Sina, set it back up online outside of Team Cymru network. Closes ticket 40688. o Major bugfixes (geoip data): - IPFire informed us on August 12th that databases generated after (including) August 10th did not have proper ARIN network allocations. We are updating the database to use the one generated on August 9th, 2022. Fixes bug 40658; bugfix on 0.4.5.13. o Major bugfixes (onion service): - Set a much higher circuit build timeout for opened client rendezvous circuit. Before this, tor would time them out very quickly leading to unnecessary retries meaning more load on the network. Fixes bug 40694; bugfix on 0.3.5.1-alpha. o Major bugfixes (OSX): - Fix coarse-time computation on Apple platforms (like Mac M1) where the Mach absolute time ticks do not correspond directly to nanoseconds. Previously, we computed our shift value wrong, which led us to give incorrect timing results. Fixes bug 40684; bugfix on 0.3.3.1-alpha. o Major bugfixes (relay): - Improve security of our DNS cache by randomly clipping the TTL value. TROVE-2021-009. Fixes bug 40674; bugfix on 0.3.5.1-alpha. o Minor feature (Mac and iOS build): - Change how combine_libs works on Darwin like platforms to make sure we don't include any `__.SYMDEF` and `__.SYMDEF SORTED` symbols on the archive before we repack and run ${RANLIB} on the archive. This fixes a build issue with recent Xcode versions on Mac Silicon and iOS. Closes ticket 40683. o Minor feature (metrics): - Add various congestion control counters to the MetricsPort. Closes ticket 40708. o Minor feature (performance): - Bump the maximum amount of CPU that can be used from 16 to 128. Note that NumCPUs torrc option overrides this hardcoded maximum. Fixes bug 40703; bugfix on 0.3.5.1-alpha. o Minor feature (relay): - Make an hardcoded value for the maximum of per CPU tasks into a consensus parameter. - Two new consensus parameters are added to control the wait time in queue of the onionskins. One of them is the torrc MaxOnionQueueDelay options which supersedes the consensus parameter. Closes ticket 40704. o Minor feature (relay, DoS): - Apply circuit creation anti-DoS defenses if the outbound circuit max cell queue size is reached too many times. This introduces two new consensus parameters to control the queue size limit and number of times allowed to go over that limit. Closes ticket 40680. o Minor feature (relay, metrics): - Add DoS defenses counter to MetricsPort. - Add congestion control RTT reset counter to MetricsPort. - Add counters to the MetricsPort how many connections, per type, are currently opened and how many were created. - Add relay flags from the consensus to the MetricsPort. - Add total number of opened circuits to MetricsPort. - Add total number of streams seen by an Exit to the MetricsPort. - Add traffic stats as in number of read/written bytes in total. - Related to ticket 40194. o Minor features (fallbackdir): - Regenerate fallback directories generated on November 10, 2022. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/11/10. o Minor bugfixes (authorities, sandbox): - Allow to write file my-consensus- to disk when sandbox is activated. Fixes bug 40663; bugfix on 0.3.5.1-alpha. o Minor bugfixes (dirauth): - Directory authorities stop voting a consensus "Measured" weight for relays with the Authority flag. Now these relays will be considered unmeasured, which should reserve their bandwidth for their dir auth role and minimize distractions from other roles. In place of the "Measured" weight, they now include a "MeasuredButAuthority" weight (not used by anything) so the bandwidth authority's opinion on this relay can be recorded for posterity. Lastly, remove the AuthDirDontVoteOnDirAuthBandwidth torrc option which never worked right. Fixes bugs 40698 and 40700; bugfix on 0.4.7.2-alpha. o Minor bugfixes (onion service client): - A collapsing onion service circuit should be seen as an "unreachable" error so it can be retried. Fixes bug 40692; bugfix on 0.3.5.1-alpha. o Minor bugfixes (onion service): - Make the service retry a rendezvous if the circuit is being repurposed for measurements. Fixes bug 40696; bugfix on 0.3.5.1-alpha. o Minor bugfixes (relay overload statistics): - Count total create cells vs dropped create cells properly, when assessing if our fraction of dropped cells is too high. We only count non-client circuits in the denominator, but we would include client circuits in the numerator, leading to surprising log lines claiming that we had dropped more than 100% of incoming create cells. Fixes bug 40673; bugfix on 0.4.7.1-alpha. o Code simplification and refactoring (bridges): - Remove unused code related to ExtPort connection ID. Fixes bug 40648; bugfix on 0.3.5.1-alpha. Changes in version 0.4.7.10 - 2022-08-12 This version updates the geoip cache that we generate from IPFire location database to use the August 9th, 2022 one. Everyone MUST update to this latest release else circuit path selection and relay metrics are badly affected. o Major bugfixes (geoip data): - IPFire informed us on August 12th that databases generated after (including) August 10th did not have proper ARIN network allocations. We are updating the database to use the one generated on August 9th, 2022. Fixes bug 40658; bugfix on 0.4.7.9. Changes in version 0.4.7.9 - 2022-08-11 This version contains several major fixes aimed at reducing memory pressure on relays and possible side-channel. It also contains a major bugfix related to congestion control also aimed at reducing memory pressure on relays. Finally, there is last one major bugfix related to Vanguard L2 layer node selection. We strongly recommend to upgrade to this version especially for Exit relays in order to help the network defend against this ongoing DDoS. o Major bugfixes (congestion control): - Implement RFC3742 Limited Slow Start. Congestion control was overshooting the congestion window during slow start, particularly for onion service activity. With this fix, we now update the congestion window more often during slow start, as well as dampen the exponential growth when the congestion window grows above a capping parameter. This should reduce the memory increases guard relays were seeing, as well as allow us to set lower queue limits to defend against ongoing DoS attacks. Fixes bug 40642; bugfix on 0.4.7.5-alpha. o Major bugfixes (relay): - Remove OR connections btrack subsystem entries when the connections close normally. Before this, we would only remove the entry on error and thus leaking memory for each normal OR connections. Fixes bug 40604; bugfix on 0.4.0.1-alpha. - Stop sending TRUNCATED cell and instead close the circuit from which we received a DESTROY cell. This makes every relay in the circuit path to stop queuing cells. Fixes bug 40623; bugfix on 0.1.0.2-rc. o Major bugfixes (vanguards): - We had omitted some checks for whether our vanguards (second layer guards from proposal 333) overlapped. Now make sure to pick each of them to be independent. Also, change the design to allow them to come from the same family. Fixes bug 40639; bugfix on 0.4.7.1-alpha. o Minor features (dirauth): - Add a torrc option to control the Guard flag bandwidth threshold percentile. Closes ticket 40652. - Add an AuthDirVoteGuard torrc option that can allow authorities to assign the Guard flag to the given fingerprints/country code/IPs. This is a needed feature mostly for defense purposes in case a DoS hits the network and relay start losing the Guard flags too fast. - Make UPTIME_TO_GUARANTEE_STABLE, MTBF_TO_GUARANTEE_STABLE, TIME_KNOWN_TO_GUARANTEE_FAMILIAR WFU_TO_GUARANTEE_GUARD tunable from torrc. o Minor features (fallbackdir): - Regenerate fallback directories generated on August 11, 2022. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/08/11. o Minor bugfixes (congestion control): - Add a check for an integer underflow condition that might happen in cases where the system clock is stopped, the ORconn is blocked, and the endpoint sends more than a congestion window worth of non- data control cells at once. This would cause a large congestion window to be calculated instead of a small one. No security impact. Fixes bug 40644; bugfix on 0.4.7.5-alpha. o Minor bugfixes (defense in depth): - Change a test in the netflow padding code to make it more _obviously_ safe against remotely triggered crashes. (It was safe against these before, but not obviously so.) Fixes bug 40645; bugfix on 0.3.1.1-alpha. o Minor bugfixes (relay): - Do not propagate either forward or backward a DESTROY remote reason when closing a circuit in order to avoid a possible side channel. Fixes bug 40649; bugfix on 0.1.2.4-alpha. Changes in version 0.4.7.8 - 2022-06-17 This version fixes several bugfixes including a High severity security issue categorized as a Denial of Service. Everyone running an earlier version should upgrade to this version. o Major bugfixes (congestion control, TROVE-2022-001): - Fix a scenario where RTT estimation can become wedged, seriously degrading congestion control performance on all circuits. This impacts clients, onion services, and relays, and can be triggered remotely by a malicious endpoint. Tracked as CVE-2022-33903. Fixes bug 40626; bugfix on 0.4.7.5-alpha. o Minor features (fallbackdir): - Regenerate fallback directories generated on June 17, 2022. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/06/17. o Minor bugfixes (linux seccomp2 sandbox): - Allow the rseq system call in the sandbox. This solves a crash issue with glibc 2.35 on Linux. Patch from pmu-ipf. Fixes bug 40601; bugfix on 0.3.5.11. o Minor bugfixes (logging): - Demote a harmless warn log message about finding a second hop to from warn level to info level, if we do not have enough descriptors yet. Leave it at notice level for other cases. Fixes bug 40603; bugfix on 0.4.7.1-alpha. - Demote a notice log message about "Unexpected path length" to info level. These cases seem to happen arbitrarily, and we likely will never find all of them before the switch to arti. Fixes bug 40612; bugfix on 0.4.7.5-alpha. o Minor bugfixes (relay, logging): - Demote a harmless XOFF log message to from notice level to info level. Fixes bug 40620; bugfix on 0.4.7.5-alpha. Changes in version 0.4.7.7 - 2022-04-27 This is the first stable version of the 0.4.7.x series. This series includes several major bugfixes from previous series and several features including one massive new one: congestion control. Congestion control, among other things, should improve traffic speed and stability on the network once a majority of Exit upgrade. You can find more details about it in proposal 324 in the torspec.git repository. Below are all the changes of the 0.4.7.x series: o Major features (congestion control): - Implement support for flow control over congestion controlled circuits. This work comes from proposal 324. Closes ticket 40450. o Major features (relay, client, onion services): - Implement RTT-based congestion control for exits and onion services, from Proposal 324. Disabled by default. Enabled by the 'cc_alg' consensus parameter. Closes ticket 40444. o Major features (directory authority): - Add a new consensus method to handle MiddleOnly specially. When enough authorities are using this method, then any relay tagged with the MiddleOnly flag will have its Exit, Guard, HSDir, and V2Dir flags automatically cleared, and will have its BadExit flag automatically set. Implements part of proposal 335. - Authorities can now be configured to label relays as "MiddleOnly". When voting for this flag, authorities automatically vote against Exit, Guard, HSDir, and V2Dir; and in favor of BadExit. Implements part of proposal 335. Based on a patch from Neel Chauhan. o Major features (Proposal 332, onion services, guard selection algorithm): - Clients and onion services now choose four long-lived "layer 2" guard relays for use as the middle hop in all onion circuits. These relays are kept in place for a randomized duration averaging 1 week. This mitigates guard discovery attacks against clients and short-lived onion services such as OnionShare. Long-lived onion services that need high security should still use the Vanguards addon (https://github.com/mikeperry-tor/vanguards). Closes ticket 40363; implements proposal 333. o Major bugfix (relay, metrics): - On the MetricsPort, the DNS error statistics are not reported by record type ("record=...") anymore due to a libevent bug (https://github.com/libevent/libevent/issues/1219). Fixes bug 40490; bugfix on 0.4.7.1-alpha. o Major bugfixes (bridges): - Make Tor work reliably again when you have multiple bridges configured and one or more of them are unreachable. The problem came because we require that we have bridge descriptors for both of our first two bridges (else we refuse to try to connect), but in some cases we would wait three hours before trying to fetch these missing descriptors, and/or never recover when we do try to fetch them. Fixes bugs 40396 and 40495; bugfix on 0.3.0.5-rc and 0.3.2.1-alpha. o Major bugfixes (client): - Stop caching TCP connect failures to relays/bridges when we initiated the connection as a client. Now we only cache connect failures as a relay or bridge when we initiated them because of an EXTEND request. Declining to re-attempt the client-based connections could cause problems when we lose connectivity and try to reconnect. Fixes bug 40499; bugfix on 0.3.3.4-alpha. o Major bugfixes (onion service, congestion control): - Fix the onion service upload case where the congestion control parameters were not added to the right object. Fixes bug 40586; bugfix on 0.4.7.4-alpha. o Major bugfixes (relay, DNS): - Lower the DNS timeout from 3 attempts at 5 seconds each to 2 attempts at 1 seconds each. Two new consensus parameters were added to control these values. This change should improve observed performance under DNS load; see ticket for more details. Fixes bug 40312; bugfix on 0.3.5.1-alpha. o Major bugfixes (relay, overload state): - Relays report the general overload state for DNS timeout errors only if X% of all DNS queries over Y seconds are errors. Before that, it only took 1 timeout to report the overload state which was just too low of a threshold. The X and Y values are 1% and 10 minutes respectively but they are also controlled by consensus parameters. Fixes bug 40491; bugfix on 0.4.6.1-alpha. o Major bugfixes (relay, overload): - Do not trigger a general overload on DNS timeout. Even after fixing 40527, some code remained that triggered the overload. Fixes bug 40564; bugfix on 0.4.7.1-alpha. - Change the MetricsPort DNS "timeout" label to be "tor_timeout" in order to indicate that this was a DNS timeout from tor perspective and not the DNS server itself. - Deprecate overload_dns_timeout_period_secs and overload_dns_timeout_scale_percent consensus parameters as well. They were used to assess the overload state which is no more now. - Don't make Tor DNS timeout trigger an overload general state. These timeouts are different from DNS server timeout. They have to be seen as timeout related to UX and not because of a network problem. Fixes bug 40527; bugfix on 0.4.6.1-alpha. o Minor feature (authority, relay): - Reject End-Of-Life relays running version 0.4.2.x, 0.4.3.x, 0.4.4.x and 0.4.5 alphas/rc. Closes ticket 40480. - Reject End-Of-Life relays running version 0.3.5.x. Closes ticket 40559. o Minor feature (onion service v2): - Onion service v2 addresses are now not recognized anymore by tor meaning a bad hostname is returned when attempting to pass it on a SOCKS connection. No more deprecation log is emitted client side. Closes ticket 40476. - See https://blog.torproject.org/v2-deprecation-timeline for details on how to transition from v2 to v3. o Minor feature (reproducible build): - The repository can now build reproducible tarballs which adds the build command "make dist-reprod" for that purpose. Closes ticket 26299. o Minor features (bridge testing support): - Let external bridge reachability testing tools discard cached bridge descriptors when setting new bridges, so they can be sure to get a clean reachability test. Implements ticket 40209. o Minor features (compilation): - Give an error message if trying to build with a version of LibreSSL known not to work with Tor. (There's an incompatibility with LibreSSL versions 3.2.1 through 3.4.0 inclusive because of their incompatibility with OpenSSL 1.1.1's TLSv1.3 APIs.) Closes ticket 40511. o Minor features (control port): - Provide congestion control fields on CIRC_BW and STREAM control port events, for use by sbws. Closes ticket 40568. o Minor features (fallbackdir): - Regenerate fallback directories generated on April 27, 2022. o Minor features (fuzzing): - When building with --enable-libfuzzer, use a set of compiler flags that works with more recent versions of the library. Previously we were using a set of flags from 2017. Closes ticket 40407. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/04/27. o Minor features (logging, heartbeat): - When a relay receives a cell that isn't encrypted properly for it, but the relay is the last hop on the circuit, the relay now counts how many cells of this kind it receives, on how many circuits, and reports this information in the log. Previously, we'd log each cell at PROTOCOL_WARN level, which is far too verbose to be useful. Fixes part of ticket 40400. o Minor features (portability): - Try to prevent a compiler warning about printf arguments that could sometimes occur on MSYS2 depending on the configuration. Closes ticket 40355. o Minor features (testing configuration): - When TestingTorNetwork is enabled, skip the permissions check on hidden service directories. Closes ticket 40338. - On a testing network, relays can now use the TestingMinTimeToReportBandwidth option to change the smallest amount of time over which they're willing to report their observed maximum bandwidth. Previously, this was fixed at 1 day. For safety, values under 2 hours are only supported on testing networks. Part of a fix for ticket 40337. - Relays on testing networks no longer rate-limit how frequently they are willing to report new bandwidth measurements. Part of a fix for ticket 40337. - Relays on testing networks now report their observed bandwidths immediately from startup. Previously, they waited until they had been running for a full day. Closes ticket 40337. o Minor features (testing): - We now have separate fuzzers for the inner layers of v3 onion service descriptors, to prevent future bugs like 40392. Closes ticket 40488. o Minor bugfix (CI, onion service): - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500; bugfix on 0.3.2.1-alpha. o Minor bugfix (logging): - Update a log notice dead URL to a working one. Fixes bug 40544; bugfix on 0.3.5.1-alpha. o Minor bugfix (pluggable transport): - Do not kill a managed proxy if one of its transport configurations emits a method error. Instead log a warning and continue processing method arguments. Fixes bug 7362; bugfix on 0.2.3.6-alpha. o Minor bugfix (relay): - Remove the HSDir and HSIntro onion service v2 protocol versions so relay stop advertising that they support them. Fixes bug 40509; bugfix on 0.3.5.17. o Minor bugfixes (bridges): - When we don't yet have a descriptor for one of our bridges, disable the entry guard retry schedule on that bridge. The entry guard retry schedule and the bridge descriptor retry schedule can conflict, e.g. where we mark a bridge as "maybe up" yet we don't try to fetch its descriptor yet, leading Tor to wait (refusing to do anything) until it becomes time to fetch the descriptor. Fixes bug 40497; bugfix on 0.3.0.3-alpha. o Minor bugfixes (cell scheduling): - Avoid writing empty payload with NSS write. - Don't attempt to write 0 bytes after a cell scheduling loop. No empty payload was put on the wire. Fixes bug 40548; bugfix on 0.3.5.1-alpha. o Minor bugfixes (circuit padding): - Don't send STOP circuit padding cells when the other side has already shut down the corresponding padding machine. Fixes bug 40435; bugfix on 0.4.0.1-alpha. o Minor bugfixes (compatibility): - Fix compatibility with the most recent Libevent versions, which no longer have an evdns_set_random_bytes() function. Because this function has been a no-op since Libevent 2.0.4-alpha, it is safe for us to just stop calling it. Fixes bug 40371; bugfix on 0.2.1.7-alpha. o Minor bugfixes (compilation): - Fix compilation error when __NR_time is not defined. Fixes bug 40465; bugfix on 0.2.5.5-alpha. Patch by Daniel Pinto. - Fix our configuration logic to detect whether we had OpenSSL 3: previously, our logic was reversed. This has no other effect than to change whether we suppress deprecated API warnings. Fixes bug 40429; bugfix on 0.3.5.13. - Resume being able to build on old / esoteric gcc versions. Fixes bug 40550; bugfix on 0.4.7.1-alpha. o Minor bugfixes (compiler warnings): - Fix couple compiler warnings on latest Ubuntu Jammy. Fixes bug 40516; bugfix on 0.3.5.1-alpha. o Minor bugfixes (congestion control, client side logs): - Demote a warn about 1-hop circuits using congestion control down to info; Demote the 4-hop case to notice. Fixes bug 40598; bugfix on 0.4.5-alpha. o Minor bugfixes (control, sandbox): - Allows the control command SAVECONF to succeed when the seccomp sandbox is enabled. Makes SAVECONF keep only one backup file, to simplify implementation. Fixes bug 40317; bugfix on 0.2.5.4-alpha. Patch by Daniel Pinto. o Minor bugfixes (controller, path bias): - When a circuit's path is specified, in full or in part, from the controller API, do not count that circuit towards our path-bias calculations. (Doing so was incorrect, since we cannot tell whether the controller is selecting relays randomly.) Resolves a "Bug" warning. Fixes bug 40515; bugfix on 0.2.4.10-alpha. o Minor bugfixes (dirauth, bandwidth scanner): - Add the AuthDirDontVoteOnDirAuthBandwidth dirauth config parameter to avoid voting on bandwidth scanner weights to v3 directory authorities. Fixes bug 40471; bugfix on 0.2.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (DNSPort, dormant mode): - A request on the DNSPort now wakes up a dormant tor. Fixes bug 40577; bugfix on 0.3.5.1-alpha. o Minor bugfixes (fragile-hardening, sandbox): - When building with --enable-fragile-hardening, add or relax Linux seccomp rules to allow AddressSanitizer to execute normally if the process terminates with the sandbox active. This has the side effect of disabling the filtering of file- and directory-open requests on most systems and dilutes the effectiveness of the sandbox overall, as a wider range of system calls must be permitted. Fixes bug 11477; bugfix on 0.2.5.4-alpha. o Minor bugfixes (heartbeat): - Adjust the heartbeat log message about distinct clients to consider the HeartbeatPeriod rather than a flat 6-hour delay. Fixes bug 40330; bugfix on 0.2.6.3-alpha. o Minor bugfixes (logging): - If a channel has never received or transmitted a cell, or seen a client, do not calculate time diffs against 1/1/1970 but log a better prettier message. Fixes bug 40182; bugfix on 0.2.4.4. - When we no longer have enough directory information to use the network, we would log a notice-level message -- but we would not reliably log a message when we recovered and resumed using the network. Now make sure there is always a corresponding message about recovering. Fixes bug 40496; bugfix on 0.3.5.1-alpha. o Minor bugfixes (logging, relay): - Add spaces between the "and" when logging the "Your server has not managed to confirm reachability for its" on dual-stack relays. Fixes bug 40453; bugfix on 0.4.5.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (metrics port, onion service): - Fix the metrics with a port label to be unique. Before this, all ports of an onion service would be on the same line which violates the Prometheus rules of unique labels. Fixes bug 40581; bugfix on 0.4.5.1-alpha. o Minor bugfixes (onion service congestion control): - Avoid a non-fatal assertion failure in the case where we fail to set up congestion control on a rendezvous circuit. This could happen naturally if a cache entry expired at an unexpected time. Fixes bug 40576; bugfix on 0.4.7.4-alpha. o Minor bugfixes (onion service): - Do not flag an HSDir as non-running in case the descriptor upload or fetch fails. An onion service closes pending directory connections before uploading a new descriptor which leads to wrongly flagging many relays and thus affecting circuit path selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha. - Fix a warning BUG that would occur often on heavily loaded onion service leading to filling the logs with useless warnings. Fixes bug 34083; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service, client): - Fix a rare but fatal assertion failure due to a guard subsystem recursion triggered by the onion service client. Fixes bug 40579; bugfix on 0.3.5.1-alpha. o Minor bugfixes (onion service, config): - Fix a memory leak for a small config line string that could occur if the onion service failed to be configured from file properly. Fixes bug 40484; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service, TROVE-2021-008): - Only log v2 access attempts once total, in order to not pollute the logs with warnings and to avoid recording the times on disk when v2 access was attempted. Note that the onion address was _never_ logged. This counts as a Low-severity security issue. Fixes bug 40474; bugfix on 0.4.5.8. - Note that due to #40476 which removes v2 support entirely, this log line is not emitted anymore. We still mention this in the changelog because it is a Low-severity TROVE. o Minor bugfixes (performance, DoS): - Fix one case of a not-especially viable denial-of-service attack found by OSS-Fuzz in our consensus-diff parsing code. This attack causes a lot small of memory allocations and then immediately frees them: this is only slow when running with all the sanitizers enabled. Fixes one case of bug 40472; bugfix on 0.3.1.1-alpha. o Minor bugfixes (relay): - Reject IPv6-only DirPorts. Our reachability self-test forces DirPorts to be IPv4, but our configuration parser allowed them to be IPv6-only, which led to an assertion failure. Fixes bug 40494; bugfix on 0.4.5.1-alpha. o Minor bugfixes (relay, overload): - Decide whether to signal overload based on a fraction and assessment period of ntor handshake drops. Previously, a single drop could trigger an overload state, which caused many false positives. Fixes bug 40560; bugfix on 0.4.7.1-alpha. o Minor bugfixes (sandbox): - Fix the sandbox on i386 by modifying it to allow the "clock_gettime64" and "statx" system calls and to filter the "chown32" and "stat64" system calls in place of "chown" and "stat", respectively. Fixes bug 40505; bugfix on 0.2.5.4-alpha. o Minor bugfixes (statistics): - Fix a fencepost issue when we check stability_last_downrated where we called rep_hist_downrate_old_runs() twice. Fixes bug 40394; bugfix on 0.2.0.5-alpha. Patch by Neel Chauhan. o Minor bugfixes (tests): - Fix a bug that prevented some tests from running with the correct names. Fixes bug 40365; bugfix on 0.4.3.1-alpha. o Minor bugfixes (usability): - Do not log "RENDEZVOUS1 cell with unrecognized rendezvous cookie" at LOG_PROTOCOL_WARN; instead log it at DEBUG. This warning can happen naturally if a client gives up on a rendezvous circuit after sending INTRODUCE1. Fixes part of bug 40400; bugfix on 0.1.1.13-alpha. - Do not log "circuit_receive_relay_cell failed" at LOG_PROTOCOL_WARN; instead log it at DEBUG. In every case where we would want to log this as a protocol warning, we are already logging another warning from inside circuit_receive_relay_cell. Fixes part of bug 40400; bugfix on 0.1.1.9-alpha. o Code simplification and refactoring: - Lower the official maximum for "guard-extreme-restriction-percent" to 100. This has no effect on when the guard code will generate a warning, but it makes the intent of the option clearer. Fixes bug 40486; bugfix on 0.3.0.1-alpha. o Documentation: - Add links to original tor design paper and anonbib to docs/HACKING/README.1st.md. Closes ticket 33742. Patch from Emily Bones. - Describe the "fingerprint-ed25519" file in the tor.1 man page. Fixes bug 40467; bugfix on 0.4.3.1-alpha. Patch by Neel Chauhan. - Provide an improved version of the tor-exit-notice.html file for exit relays to use as a landing page. The text is unchanged, but the page design and layout are significantly modernized, and several links are fixed. Patch from "n_user"; closes ticket 40529. o Testing: - Add unit tests for the Linux seccomp sandbox. Resolves issue 16803. o Code simplification and refactoring (rust): - Remove Rust support and its associated code. It is unsupported and Rust focus should be shifted to arti. Closes ticket 40469. o Documentation (man, relay): - Missing "OverloadStatistics" in tor.1 manpage. Fixes bug 40504; bugfix on 0.4.6.1-alpha. o Testing (CI, chutney): - Bump the data size that chutney transmits to 5MBytes in order to trigger the flow control and congestion window code. Closes ticket 40485. Changes in version 0.4.6.10 - 2022-02-04 This version contains minor bugfixes but one in particular is that relays don't advertise onion service v2 support at the protocol version level. o Minor features (fallbackdir): - Regenerate fallback directories generated on February 04, 2022. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2022/02/04. o Minor bugfix (logging): - Update a log notice dead URL to a working one. Fixes bug 40544; bugfix on 0.3.5.1-alpha. o Minor bugfix (relay): - Remove the HSDir and HSIntro onion service v2 protocol versions so relay stop advertising that they support them. Fixes bug 40509; bugfix on 0.3.5.17. o Minor bugfixes (MetricsPort, Prometheus): - Add double quotes to the label values of the onion service metrics. Fixes bug 40552; bugfix on 0.4.5.1-alpha. Changes in version 0.4.6.9 - 2021-12-15 This version fixes several bugs from earlier versions of Tor. One important piece is the removal of DNS timeout metric from the overload general signal. See below for more details. o Major bugfixes (relay, overload): - Don't make Tor DNS timeout trigger an overload general state. These timeouts are different from DNS server timeout. They have to be seen as timeout related to UX and not because of a network problem. Fixes bug 40527; bugfix on 0.4.6.1-alpha. o Minor feature (reproducible build): - The repository can now build reproducible tarballs which adds the build command "make dist-reprod" for that purpose. Closes ticket 26299. o Minor features (compilation): - Give an error message if trying to build with a version of LibreSSL known not to work with Tor. (There's an incompatibility with LibreSSL versions 3.2.1 through 3.4.0 inclusive because of their incompatibility with OpenSSL 1.1.1's TLSv1.3 APIs.) Closes ticket 40511. o Minor features (fallbackdir): - Regenerate fallback directories generated on December 15, 2021. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/12/15. o Minor bugfixes (compilation): - Fix our configuration logic to detect whether we had OpenSSL 3: previously, our logic was reversed. This has no other effect than to change whether we suppress deprecated API warnings. Fixes bug 40429; bugfix on 0.3.5.13. o Minor bugfixes (relay): - Reject IPv6-only DirPorts. Our reachability self-test forces DirPorts to be IPv4, but our configuration parser allowed them to be IPv6-only, which led to an assertion failure. Fixes bug 40494; bugfix on 0.4.5.1-alpha. o Documentation (man, relay): - Missing "OverloadStatistics" in tor.1 manpage. Fixes bug 40504; bugfix on 0.4.6.1-alpha. Changes in version 0.4.6.8 - 2021-10-26 This version fixes several bugs from earlier versions of Tor. One highlight is a fix on how we track DNS timeouts to report general relay overload. o Major bugfixes (relay, overload state): - Relays report the general overload state for DNS timeout errors only if X% of all DNS queries over Y seconds are errors. Before that, it only took 1 timeout to report the overload state which was just too low of a threshold. The X and Y values are 1% and 10 minutes respectively but they are also controlled by consensus parameters. Fixes bug 40491; bugfix on 0.4.6.1-alpha. o Minor features (fallbackdir): - Regenerate fallback directories for October 2021. Closes ticket 40493. o Minor features (testing): - On a testing network, relays can now use the TestingMinTimeToReportBandwidth option to change the smallest amount of time over which they're willing to report their observed maximum bandwidth. Previously, this was fixed at 1 day. For safety, values under 2 hours are only supported on testing networks. Part of a fix for ticket 40337. - Relays on testing networks no longer rate-limit how frequently they are willing to report new bandwidth measurements. Part of a fix for ticket 40337. - Relays on testing networks now report their observed bandwidths immediately from startup. Previously, they waited until they had been running for a full day. Closes ticket 40337. o Minor bugfix (onion service): - Do not flag an HSDir as non-running in case the descriptor upload or fetch fails. An onion service closes pending directory connections before uploading a new descriptor which can thus lead to wrongly flagging many relays and thus affecting circuit building path selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha. - Improve logging when a bad HS version is given. Fixes bug 40476; bugfix on 0.4.6.1-alpha. o Minor bugfix (CI, onion service): - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500; bugfix on 0.3.2.1-alpha. o Minor bugfixes (compatibility): - Fix compatibility with the most recent Libevent versions, which no longer have an evdns_set_random_bytes() function. Because this function has been a no-op since Libevent 2.0.4-alpha, it is safe for us to just stop calling it. Fixes bug 40371; bugfix on 0.2.1.7-alpha. o Minor bugfixes (onion service, TROVE-2021-008): - Only log v2 access attempts once total, in order to not pollute the logs with warnings and to avoid recording the times on disk when v2 access was attempted. Note that the onion address was _never_ logged. This counts as a Low-severity security issue. Fixes bug 40474; bugfix on 0.4.5.8. Changes in version 0.4.5.11 - 2021-10-26 The major change in this version is that v2 onion services are now disabled at the client, service, and relay: any Tor nodes running this version and onward will stop supporting v2 onion services. This is the last step in the long deprecation process of v2 onion services. Everyone running an earlier version, whether as a client, a relay, or an onion service, should upgrade to Tor 0.3.5.17, 0.4.5.11, or 0.4.6.8. o Major feature (onion service v2): - See https://blog.torproject.org/v2-deprecation-timeline for details on how to transition from v2 to v3. - The control port commands HSFETCH and HSPOST no longer allow version 2, and it is no longer possible to create a v2 service with ADD_ONION. - Tor no longer allows creating v2 services, or connecting as a client to a v2 service. Relays will decline to be a v2 HSDir or introduction point. This effectively disables onion service version 2 Tor-wide. Closes ticket 40476. o Minor features (bridge, backport from 0.4.6.8): - We now announce the URL to Tor's new bridge status at https://bridges.torproject.org/ when Tor is configured to run as a bridge relay. Closes ticket 30477. o Minor features (fallbackdir): - Regenerate fallback directories for October 2021. Closes ticket 40493. o Minor features (logging, diagnostic, backport from 0.4.6.5): - Log decompression failures at a higher severity level, since they can help provide missing context for other warning messages. We rate-limit these messages, to avoid flooding the logs if they begin to occur frequently. Closes ticket 40175. o Minor features (testing, backport from 0.4.6.8): - On a testing network, relays can now use the TestingMinTimeToReportBandwidth option to change the smallest amount of time over which they're willing to report their observed maximum bandwidth. Previously, this was fixed at 1 day. For safety, values under 2 hours are only supported on testing networks. Part of a fix for ticket 40337. - Relays on testing networks no longer rate-limit how frequently they are willing to report new bandwidth measurements. Part of a fix for ticket 40337. - Relays on testing networks now report their observed bandwidths immediately from startup. Previously, they waited until they had been running for a full day. Closes ticket 40337. o Minor bugfix (CI, onion service): - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500; bugfix on 0.3.2.1-alpha. o Minor bugfix (onion service, backport from 0.4.6.8): - Do not flag an HSDir as non-running in case the descriptor upload or fetch fails. An onion service closes pending directory connections before uploading a new descriptor which can thus lead to wrongly flagging many relays and thus affecting circuit building path selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha. o Minor bugfixes (compatibility, backport from 0.4.6.8): - Fix compatibility with the most recent Libevent versions, which no longer have an evdns_set_random_bytes() function. Because this function has been a no-op since Libevent 2.0.4-alpha, it is safe for us to just stop calling it. Fixes bug 40371; bugfix on 0.2.1.7-alpha. o Minor bugfixes (consensus handling, backport from 0.4.6.4-rc): - Avoid a set of bugs that could be caused by inconsistently preferring an out-of-date consensus stored in a stale directory cache over a more recent one stored on disk as the latest consensus. Fixes bug 40375; bugfix on 0.3.1.1-alpha. o Minor bugfixes (onion service, TROVE-2021-008, backport from 0.4.6.8): - Only log v2 access attempts once total, in order to not pollute the logs with warnings and to avoid recording the times on disk when v2 access was attempted. Note that the onion address was _never_ logged. This counts as a Low-severity security issue. Fixes bug 40474; bugfix on 0.4.5.8. Changes in version 0.3.5.17 - 2021-10-26 The major change in this version is that v2 onion services are now disabled at the client, service, and relay: any Tor nodes running this version and onward will stop supporting v2 onion services. This is the last step in the long deprecation process of v2 onion services. Everyone running an earlier version, whether as a client, a relay, or an onion service, should upgrade to Tor 0.3.5.17, 0.4.5.11, or 0.4.6.8. o Major feature (onion service v2, backport from 0.4.5.11): - See https://blog.torproject.org/v2-deprecation-timeline for details on how to transition from v2 to v3. - The control port commands HSFETCH and HSPOST no longer allow version 2, and it is no longer possible to create a v2 service with ADD_ONION. - Tor no longer allows creating v2 services, or connecting as a client to a v2 service. Relays will decline to be a v2 HSDir or introduction point. This effectively disables onion service version 2 Tor-wide. Closes ticket 40476. o Minor features (bridge, backport from 0.4.6.8): - We now announce the URL to Tor's new bridge status at https://bridges.torproject.org/ when Tor is configured to run as a bridge relay. Closes ticket 30477. o Minor features (fallbackdir): - Regenerate fallback directories for October 2021. Closes ticket 40493. o Minor bugfixes (compatibility, backport from 0.4.6.8): - Fix compatibility with the most recent Libevent versions, which no longer have an evdns_set_random_bytes() function. Because this function has been a no-op since Libevent 2.0.4-alpha, it is safe for us to just stop calling it. Fixes bug 40371; bugfix on 0.2.1.7-alpha. Changes in version 0.4.6.7 - 2021-08-16 This version fixes several bugs from earlier versions of Tor, including one that could lead to a denial-of-service attack. Everyone running an earlier version, whether as a client, a relay, or an onion service, should upgrade to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7. o Major bugfixes (cryptography, security): - Resolve an assertion failure caused by a behavior mismatch between our batch-signature verification code and our single-signature verification code. This assertion failure could be triggered remotely, leading to a denial of service attack. We fix this issue by disabling batch verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de Valence. o Minor feature (fallbackdir): - Regenerate fallback directories list. Close ticket 40447. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/08/12. o Minor bugfix (crypto): - Disable the unused batch verification feature of ed25519-donna. Fixes bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence. o Minor bugfixes (onion service): - Send back the extended SOCKS error 0xF6 (Onion Service Invalid Address) for a v2 onion address. Fixes bug 40421; bugfix on 0.4.6.2-alpha. o Minor bugfix (CI, onion service): - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500; bugfix on 0.3.2.1-alpha. o Minor bugfixes (relay): - Reduce the compression level for data streaming from HIGH to LOW in order to reduce CPU load on the directory relays. Fixes bug 40301; bugfix on 0.3.5.1-alpha. o Minor bugfixes (timekeeping): - Calculate the time of day correctly on systems where the time_t type includes leap seconds. (This is not the case on most operating systems, but on those where it occurs, our tor_timegm function did not correctly invert the system's gmtime function, which could result in assertion failures when calculating voting schedules.) Fixes bug 40383; bugfix on 0.2.0.3-alpha. Changes in version 0.4.5.10 - 2021-08-16 This version fixes several bugs from earlier versions of Tor, including one that could lead to a denial-of-service attack. Everyone running an earlier version, whether as a client, a relay, or an onion service, should upgrade to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7. o Major bugfixes (cryptography, security): - Resolve an assertion failure caused by a behavior mismatch between our batch-signature verification code and our single-signature verification code. This assertion failure could be triggered remotely, leading to a denial of service attack. We fix this issue by disabling batch verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de Valence. o Minor feature (fallbackdir): - Regenerate fallback directories list. Close ticket 40447. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/08/12. o Minor features (testing): - Enable the deterministic RNG for unit tests that covers the address set bloomfilter-based API's. Fixes bug 40419; bugfix on 0.3.3.2-alpha. o Minor bugfix (crypto): - Disable the unused batch verification feature of ed25519-donna. Fixes bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence. o Minor bugfixes (relay, backport from 0.4.6.x): - Reduce the compression level for data streaming from HIGH to LOW. Fixes bug 40301; bugfix on 0.3.5.1-alpha. o Minor bugfixes (timekeeping, backport from 0.4.6.x): - Calculate the time of day correctly on systems where the time_t type includes leap seconds. (This is not the case on most operating systems, but on those where it occurs, our tor_timegm function did not correctly invert the system's gmtime function, which could result in assertion failures when calculating voting schedules.) Fixes bug 40383; bugfix on 0.2.0.3-alpha. o Minor bugfixes (warnings, portability, backport from 0.4.6.x): - Suppress a strict-prototype warning when building with some versions of NSS. Fixes bug 40409; bugfix on 0.3.5.1-alpha. Changes in version 0.3.5.16 - 2021-08-16 This version fixes several bugs from earlier versions of Tor, including one that could lead to a denial-of-service attack. Everyone running an earlier version, whether as a client, a relay, or an onion service, should upgrade to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7. o Major bugfixes (cryptography, security): - Resolve an assertion failure caused by a behavior mismatch between our batch-signature verification code and our single-signature verification code. This assertion failure could be triggered remotely, leading to a denial of service attack. We fix this issue by disabling batch verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de Valence. o Minor feature (fallbackdir): - Regenerate fallback directories list. Close ticket 40447. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/08/12. o Minor bugfix (crypto): - Disable the unused batch verification feature of ed25519-donna. Fixes bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence. o Minor bugfixes (relay, backport from 0.4.6.x): - Reduce the compression level for data streaming from HIGH to LOW. Fixes bug 40301; bugfix on 0.3.5.1-alpha. Changes in version 0.4.6.6 - 2021-06-30 Tor 0.4.6.6 makes several small fixes on 0.4.6.5, including one that allows Tor to build correctly on older versions of GCC. You should upgrade to this version if you were having trouble building Tor 0.4.6.5; otherwise, there is probably no need. o Minor bugfixes (compilation): - Fix a compilation error when trying to build Tor with a compiler that does not support const variables in static initializers. Fixes bug 40410; bugfix on 0.4.6.5. - Suppress a strict-prototype warning when building with some versions of NSS. Fixes bug 40409; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing): - Enable the deterministic RNG for unit tests that covers the address set bloomfilter-based API's. Fixes bug 40419; bugfix on 0.3.3.2-alpha. Changes in version 0.4.6.5 - 2021-06-14 Tor 0.4.6.5 is the first stable release in its series. The 0.4.6.x series includes numerous features and bugfixes, including a significant improvement to our circuit timeout algorithm that should improve observed client performance, and a way for relays to report when they are overloaded. This release also includes security fixes for several security issues, including a denial-of-service attack against onion service clients, and another denial-of-service attack against relays. Everybody should upgrade to one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5. Below are the changes since 0.4.5.8. For a list of changes since 0.4.6.4-rc, see the ChangeLog file. o Major bugfixes (security): - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on half-closed streams. Previously, clients failed to validate which hop sent these cells: this would allow a relay on a circuit to end a stream that wasn't actually built with it. Fixes bug 40389; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021- 003 and CVE-2021-34548. o Major bugfixes (security, defense-in-depth): - Detect more failure conditions from the OpenSSL RNG code. Previously, we would detect errors from a missing RNG implementation, but not failures from the RNG code itself. Fortunately, it appears those failures do not happen in practice when Tor is using OpenSSL's default RNG implementation. Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. o Major bugfixes (security, denial of service): - Resist a hashtable-based CPU denial-of-service attack against relays. Previously we used a naive unkeyed hash function to look up circuits in a circuitmux object. An attacker could exploit this to construct circuits with chosen circuit IDs, to create collisions and make the hash table inefficient. Now we use a SipHash construction here instead. Fixes bug 40391; bugfix on 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and CVE-2021-34549. Reported by Jann Horn from Google's Project Zero. - Fix an out-of-bounds memory access in v3 onion service descriptor parsing. An attacker could exploit this bug by crafting an onion service descriptor that would crash any client that tried to visit it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei Glazunov from Google's Project Zero. o Major features (control port, onion services): - Add controller support for creating version 3 onion services with client authorization. Previously, only v2 onion services could be created with client authorization. Closes ticket 40084. Patch by Neel Chauhan. o Major features (directory authority): - When voting on a relay with a Sybil-like appearance, add the Sybil flag when clearing out the other flags. This lets a relay operator know why their relay hasn't been included in the consensus. Closes ticket 40255. Patch by Neel Chauhan. o Major features (metrics): - Relays now report how overloaded they are in their extrainfo documents. This information is controlled with the OverloadStatistics torrc option, and it will be used to improve decisions about the network's load balancing. Implements proposal 328; closes ticket 40222. o Major features (relay, denial of service): - Add a new DoS subsystem feature to control the rate of client connections for relays. Closes ticket 40253. o Major features (statistics): - Relays now publish statistics about the number of v3 onion services and volume of v3 onion service traffic, in the same manner they already do for v2 onions. Closes ticket 23126. o Major bugfixes (circuit build timeout): - Improve the accuracy of our circuit build timeout calculation for 60%, 70%, and 80% build rates for various guard choices. We now use a maximum likelihood estimator for Pareto parameters of the circuit build time distribution, instead of a "right-censored estimator". This causes clients to ignore circuits that never finish building in their timeout calculations. Previously, clients were counting such unfinished circuits as having the highest possible build time value, when in reality these circuits most likely just contain relays that are offline. We also now wait a bit longer to let circuits complete for measurement purposes, lower the minimum possible effective timeout from 1.5 seconds to 10ms, and increase the resolution of the circuit build time histogram from 50ms bin widths to 10ms bin widths. Additionally, we alter our estimate Xm by taking the maximum of the top 10 most common build time values of the 10ms histogram, and compute Xm as the average of these. Fixes bug 40168; bugfix on 0.2.2.14-alpha. - Remove max_time calculation and associated warning from circuit build timeout 'alpha' parameter estimation, as this is no longer needed by our new estimator from 40168. Fixes bug 34088; bugfix on 0.2.2.9-alpha. o Major bugfixes (signing key): - In the tor-gencert utility, give an informative error message if the passphrase given in `--create-identity-key` is too short. Fixes bug 40189; bugfix on 0.2.0.1-alpha. Patch by Neel Chauhan. o Minor features (bridge): - We now announce the URL to Tor's new bridge status at https://bridges.torproject.org/ when Tor is configured to run as a bridge relay. Closes ticket 30477. o Minor features (build system): - New "make lsp" command to auto generate the compile_commands.json file used by the ccls server. The "bear" program is needed for this. Closes ticket 40227. o Minor features (client): - Clients now check whether their streams are attempting to re-enter the Tor network (i.e. to send Tor traffic over Tor), and close them preemptively if they think exit relays will refuse them for this reason. See ticket 2667 for details. Closes ticket 40271. o Minor features (command line): - Add long format name "--torrc-file" equivalent to the existing command-line option "-f". Closes ticket 40324. Patch by Daniel Pinto. o Minor features (command-line interface): - Add build informations to `tor --version` in order to ease reproducible builds. Closes ticket 32102. - When parsing command-line flags that take an optional argument, treat the argument as absent if it would start with a '-' character. Arguments in that form are not intelligible for any of our optional-argument flags. Closes ticket 40223. - Allow a relay operator to list the ed25519 keys on the command line by adding the `rsa` and `ed25519` arguments to the --list-fingerprint flag to show the respective RSA and ed25519 relay fingerprint. Closes ticket 33632. Patch by Neel Chauhan. o Minor features (compatibility): - Remove an assertion function related to TLS renegotiation. It was used nowhere outside the unit tests, and it was breaking compilation with recent alpha releases of OpenSSL 3.0.0. Closes ticket 40399. o Minor features (control port, stream handling): - Add the stream ID to the event line in the ADDRMAP control event. Closes ticket 40249. Patch by Neel Chauhan. o Minor features (dormant mode): - Add a new 'DormantTimeoutEnabled' option to allow coarse-grained control over whether the client ever becomes dormant from inactivity. Most people won't need this. Closes ticket 40228. - Add a new 'DormantTimeoutEnabled' option for coarse-grained control over whether the client can become dormant from inactivity. Most people won't need this. Closes ticket 40228. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/06/10. o Minor features (logging): - Edit heartbeat log messages so that more of them begin with the string "Heartbeat: ". Closes ticket 40322; patch from 'cypherpunks'. - Change the DoS subsystem heartbeat line format to be more clear on what has been detected/rejected, and which option is disabled (if any). Closes ticket 40308. - In src/core/mainloop/mainloop.c and src/core/mainloop/connection.c, put brackets around IPv6 addresses in log messages. Closes ticket 40232. Patch by Neel Chauhan. o Minor features (logging, diagnostic): - Log decompression failures at a higher severity level, since they can help provide missing context for other warning messages. We rate-limit these messages, to avoid flooding the logs if they begin to occur frequently. Closes ticket 40175. o Minor features (onion services): - Add a warning message when trying to connect to (no longer supported) v2 onion services. Closes ticket 40373. o Minor features (performance, windows): - Use SRWLocks to implement locking on Windows. Replaces the "critical section" locking implementation with the faster SRWLocks, available since Windows Vista. Closes ticket 17927. Patch by Daniel Pinto. o Minor features (protocol, proxy support, defense in depth): - Close HAProxy connections if they somehow manage to send us data before we start reading. Closes another case of ticket 40017. o Minor features (tests, portability): - Port the hs_build_address.py test script to work with recent versions of python. Closes ticket 40213. Patch from Samanta Navarro. o Minor features (vote document): - Add a "stats" line to directory authority votes, to report various statistics that authorities compute about the relays. This will help us diagnose the network better. Closes ticket 40314. o Minor bugfixes (build): - The configure script now shows whether or not lzma and zstd have been used, not just if the enable flag was passed in. Fixes bug 40236; bugfix on 0.4.3.1-alpha. o Minor bugfixes (compatibility): - Fix a failure in the test cases when running on the "hppa" architecture, along with a related test that might fail on other architectures in the future. Fixes bug 40274; bugfix on 0.2.5.1-alpha. o Minor bugfixes (compilation): - Fix a compilation warning about unused functions when building with a libc that lacks the GLOB_ALTDIRFUNC constant. Fixes bug 40354; bugfix on 0.4.5.1-alpha. Patch by Daniel Pinto. o Minor bugfixes (consensus handling): - Avoid a set of bugs that could be caused by inconsistently preferring an out-of-date consensus stored in a stale directory cache over a more recent one stored on disk as the latest consensus. Fixes bug 40375; bugfix on 0.3.1.1-alpha. o Minor bugfixes (control, sandbox): - Allow the control command SAVECONF to succeed when the seccomp sandbox is enabled, and make SAVECONF keep only one backup file to simplify implementation. Previously SAVECONF allowed a large number of backup files, which made it incompatible with the sandbox. Fixes bug 40317; bugfix on 0.2.5.4-alpha. Patch by Daniel Pinto. o Minor bugfixes (directory authorities, voting): - Add a new consensus method (31) to support any future changes that authorities decide to make to the value of bwweightscale or maxunmeasuredbw. Previously, there was a bug that prevented the authorities from parsing these consensus parameters correctly under most circumstances. Fixes bug 19011; bugfix on 0.2.2.10-alpha. o Minor bugfixes (ipv6): - Allow non-SOCKSPorts to disable IPv4, IPv6, and PreferIPv4. Some rare configurations might break, but in this case you can disable NoIPv4Traffic and NoIPv6Traffic as needed. Fixes bug 33607; bugfix on 0.4.1.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (key generation): - Do not require a valid torrc when using the `--keygen` argument to generate a signing key. This allows us to generate keys on systems or users which may not run Tor. Fixes bug 40235; bugfix on 0.2.7.2-alpha. Patch by Neel Chauhan. o Minor bugfixes (logging, relay): - Emit a warning if an Address is found to be internal and tor can't use it. Fixes bug 40290; bugfix on 0.4.5.1-alpha. o Minor bugfixes (metrics port): - Fix a bug that made tor try to re-bind() on an already open MetricsPort every 60 seconds. Fixes bug 40370; bugfix on 0.4.5.1-alpha. o Minor bugfixes (onion services, logging): - Downgrade the severity of a few rendezvous circuit-related warnings from warning to info. Fixes bug 40207; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (relay): - Reduce the compression level for data streaming from HIGH to LOW. This should reduce the CPU and memory burden for directory caches. Fixes bug 40301; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, BSD): - Fix pattern-matching errors when patterns expand to invalid paths on BSD systems. Fixes bug 40318; bugfix on 0.4.5.1-alpha. Patch by Daniel Pinto. o Code simplification and refactoring: - Remove the orconn_ext_or_id_map structure and related functions. (Nothing outside of unit tests used them.) Closes ticket 33383. Patch by Neel Chauhan. o Removed features: - Remove unneeded code for parsing private keys in directory documents. This code was only used for client authentication in v2 onion services, which are now unsupported. Closes ticket 40374. - As of this release, Tor no longer supports the old v2 onion services. They were deprecated last July for security, and support will be removed entirely later this year. We strongly encourage everybody to migrate to v3 onion services. For more information, see https://blog.torproject.org/v2-deprecation-timeline . Closes ticket 40266. (NOTE: We accidentally released an earlier version of the 0.4.6.1-alpha changelog without this entry. Sorry for the confusion!) o Code simplification and refactoring (metrics, DoS): - Move the DoS subsystem into the subsys manager, including its configuration options. Closes ticket 40261. o Documentation (manual): - Move the ServerTransport* options to the "SERVER OPTIONS" section. Closes issue 40331. - Indicate that the HiddenServiceStatistics option also applies to bridges. Closes ticket 40346. - Move the description of BridgeRecordUsageByCountry to the section "STATISTICS OPTIONS". Closes ticket 40323. o Removed features (relay): - Because DirPorts are only used on authorities, relays no longer advertise them. Similarly, self-testing for DirPorts has been disabled, since an unreachable DirPort is no reason for a relay not to advertise itself. (Configuring a DirPort will still work, for now.) Closes ticket 40282. Changes in version 0.4.5.9 - 2021-06-14 Tor 0.4.5.9 fixes several security issues, including a denial-of-service attack against onion service clients, and another denial-of-service attack against relays. Everybody should upgrade to one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5. o Major bugfixes (security, backport from 0.4.6.5): - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on half-closed streams. Previously, clients failed to validate which hop sent these cells: this would allow a relay on a circuit to end a stream that wasn't actually built with it. Fixes bug 40389; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021- 003 and CVE-2021-34548. o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5): - Detect more failure conditions from the OpenSSL RNG code. Previously, we would detect errors from a missing RNG implementation, but not failures from the RNG code itself. Fortunately, it appears those failures do not happen in practice when Tor is using OpenSSL's default RNG implementation. Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. o Major bugfixes (security, denial of service, backport from 0.4.6.5): - Resist a hashtable-based CPU denial-of-service attack against relays. Previously we used a naive unkeyed hash function to look up circuits in a circuitmux object. An attacker could exploit this to construct circuits with chosen circuit IDs, to create collisions and make the hash table inefficient. Now we use a SipHash construction here instead. Fixes bug 40391; bugfix on 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and CVE-2021-34549. Reported by Jann Horn from Google's Project Zero. - Fix an out-of-bounds memory access in v3 onion service descriptor parsing. An attacker could exploit this bug by crafting an onion service descriptor that would crash any client that tried to visit it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei Glazunov from Google's Project Zero. o Minor features (compatibility, backport from 0.4.6.4-rc): - Remove an assertion function related to TLS renegotiation. It was used nowhere outside the unit tests, and it was breaking compilation with recent alpha releases of OpenSSL 3.0.0. Closes ticket 40399. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/06/10. o Minor bugfixes (control, sandbox, backport from 0.4.6.4-rc): - Allow the control command SAVECONF to succeed when the seccomp sandbox is enabled, and make SAVECONF keep only one backup file to simplify implementation. Previously SAVECONF allowed a large number of backup files, which made it incompatible with the sandbox. Fixes bug 40317; bugfix on 0.2.5.4-alpha. Patch by Daniel Pinto. o Minor bugfixes (metrics port, backport from 0.4.6.4-rc): - Fix a bug that made tor try to re-bind() on an already open MetricsPort every 60 seconds. Fixes bug 40370; bugfix on 0.4.5.1-alpha. Changes in version 0.4.4.9 - 2021-06-14 Tor 0.4.4.9 fixes several security issues, including a denial-of-service attack against onion service clients, and another denial-of-service attack against relays. Everybody should upgrade to one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5. Note that the scheduled end-of-life date for the Tor 0.4.4.x series is June 15. This is therefore the last release in its series. Everybody still running 0.4.4.x should plan to upgrade to 0.4.5.x or later. o Major bugfixes (security, backport from 0.4.6.5): - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on half-closed streams. Previously, clients failed to validate which hop sent these cells: this would allow a relay on a circuit to end a stream that wasn't actually built with it. Fixes bug 40389; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021- 003 and CVE-2021-34548. o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5): - Detect more failure conditions from the OpenSSL RNG code. Previously, we would detect errors from a missing RNG implementation, but not failures from the RNG code itself. Fortunately, it appears those failures do not happen in practice when Tor is using OpenSSL's default RNG implementation. Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. o Major bugfixes (security, denial of service, backport from 0.4.6.5): - Resist a hashtable-based CPU denial-of-service attack against relays. Previously we used a naive unkeyed hash function to look up circuits in a circuitmux object. An attacker could exploit this to construct circuits with chosen circuit IDs, to create collisions and make the hash table inefficient. Now we use a SipHash construction here instead. Fixes bug 40391; bugfix on 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and CVE-2021-34549. Reported by Jann Horn from Google's Project Zero. - Fix an out-of-bounds memory access in v3 onion service descriptor parsing. An attacker could exploit this bug by crafting an onion service descriptor that would crash any client that tried to visit it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei Glazunov from Google's Project Zero. o Minor features (compatibility, backport from 0.4.6.4-rc): - Remove an assertion function related to TLS renegotiation. It was used nowhere outside the unit tests, and it was breaking compilation with recent alpha releases of OpenSSL 3.0.0. Closes ticket 40399. o Minor features (fallback directory list, backport from 0.4.6.2-alpha): - Regenerate the list of fallback directories to contain a new set of 200 relays. Closes ticket 40265. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/06/10. o Minor bugfixes (channel, DoS, backport from 0.4.6.2-alpha): - Fix a non-fatal BUG() message due to a too-early free of a string, when listing a client connection from the DoS defenses subsystem. Fixes bug 40345; bugfix on 0.4.3.4-rc. o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc): - Fix an indentation problem that led to a warning from GCC 11.1.1. Fixes bug 40380; bugfix on 0.3.0.1-alpha. Changes in version 0.3.5.15 - 2021-06-14 Tor 0.3.5.15 fixes several security issues, including a denial-of-service attack against onion service clients, and another denial-of-service attack against relays. Everybody should upgrade to one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5. o Major bugfixes (security, backport from 0.4.6.5): - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on half-closed streams. Previously, clients failed to validate which hop sent these cells: this would allow a relay on a circuit to end a stream that wasn't actually built with it. Fixes bug 40389; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021- 003 and CVE-2021-34548. o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5): - Detect more failure conditions from the OpenSSL RNG code. Previously, we would detect errors from a missing RNG implementation, but not failures from the RNG code itself. Fortunately, it appears those failures do not happen in practice when Tor is using OpenSSL's default RNG implementation. Fixes bug 40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as TROVE-2021-004. Reported by Jann Horn at Google's Project Zero. o Major bugfixes (security, denial of service, backport from 0.4.6.5): - Resist a hashtable-based CPU denial-of-service attack against relays. Previously we used a naive unkeyed hash function to look up circuits in a circuitmux object. An attacker could exploit this to construct circuits with chosen circuit IDs, to create collisions and make the hash table inefficient. Now we use a SipHash construction here instead. Fixes bug 40391; bugfix on 0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and CVE-2021-34549. Reported by Jann Horn from Google's Project Zero. - Fix an out-of-bounds memory access in v3 onion service descriptor parsing. An attacker could exploit this bug by crafting an onion service descriptor that would crash any client that tried to visit it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei Glazunov from Google's Project Zero. o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc): - Fix an indentation problem that led to a warning from GCC 11.1.1. Fixes bug 40380; bugfix on 0.3.0.1-alpha. o Minor features (compatibility, backport from 0.4.6.4-rc): - Remove an assertion function related to TLS renegotiation. It was used nowhere outside the unit tests, and it was breaking compilation with recent alpha releases of OpenSSL 3.0.0. Closes ticket 40399. o Minor features (fallback directory list, backport from 0.4.6.2-alpha): - Regenerate the list of fallback directories to contain a new set of 200 relays. Closes ticket 40265. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/06/10. Changes in version 0.4.5.8 - 2021-05-10 Tor 0.4.5.8 fixes several bugs in earlier version, backporting fixes from the 0.4.6.x series. o Minor features (compatibility, Linux seccomp sandbox, backport from 0.4.6.3-rc): - Add a workaround to enable the Linux sandbox to work correctly with Glibc 2.33. This version of Glibc has started using the fstatat() system call, which previously our sandbox did not allow. Closes ticket 40382; see the ticket for a discussion of trade-offs. o Minor features (compilation, backport from 0.4.6.3-rc): - Make the autoconf script build correctly with autoconf versions 2.70 and later. Closes part of ticket 40335. o Minor features (fallback directory list, backport from 0.4.6.2-alpha): - Regenerate the list of fallback directories to contain a new set of 200 relays. Closes ticket 40265. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2021/05/07. o Minor features (onion services): - Add warning message when connecting to now deprecated v2 onion services. As announced, Tor 0.4.5.x is the last series that will support v2 onions. Closes ticket 40373. o Minor bugfixes (bridge, pluggable transport, backport from 0.4.6.2-alpha): - Fix a regression that made it impossible start Tor using a bridge line with a transport name and no fingerprint. Fixes bug 40360; bugfix on 0.4.5.4-rc. o Minor bugfixes (build, cross-compilation, backport from 0.4.6.3-rc): - Allow a custom "ar" for cross-compilation. Our previous build script had used the $AR environment variable in most places, but it missed one. Fixes bug 40369; bugfix on 0.4.5.1-alpha. o Minor bugfixes (channel, DoS, backport from 0.4.6.2-alpha): - Fix a non-fatal BUG() message due to a too-early free of a string, when listing a client connection from the DoS defenses subsystem. Fixes bug 40345; bugfix on 0.4.3.4-rc. o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc): - Fix an indentation problem that led to a warning from GCC 11.1.1. Fixes bug 40380; bugfix on 0.3.0.1-alpha. o Minor bugfixes (controller, backport from 0.4.6.1-alpha): - Fix a "BUG" warning that would appear when a controller chooses the first hop for a circuit, and that circuit completes. Fixes bug 40285; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service, client, memory leak, backport from 0.4.6.3-rc): - Fix a bug where an expired cached descriptor could get overwritten with a new one without freeing it, leading to a memory leak. Fixes bug 40356; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, BSD, backport from 0.4.6.2-alpha): - Fix pattern-matching errors when patterns expand to invalid paths on BSD systems. Fixes bug 40318; bugfix on 0.4.5.1-alpha. Patch by Daniel Pinto. Changes in version 0.3.5.14 - 2021-03-16 Tor 0.3.5.14 backports fixes for two important denial-of-service bugs in earlier versions of Tor. One of these vulnerabilities (TROVE-2021-001) would allow an attacker who can send directory data to a Tor instance to force that Tor instance to consume huge amounts of CPU. This is easiest to exploit against authorities, since anybody can upload to them, but directory caches could also exploit this vulnerability against relays or clients when they download. The other vulnerability (TROVE-2021-002) only affects directory authorities, and would allow an attacker to remotely crash the authority with an assertion failure. Patches have already been provided to the authority operators, to help ensure network stability. We recommend that everybody upgrade to one of the releases that fixes these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available to you. This release also updates our GeoIP data source, and fixes a compatibility issue. o Major bugfixes (security, denial of service, backport from 0.4.5.7): - Disable the dump_desc() function that we used to dump unparseable information to disk. It was called incorrectly in several places, in a way that could lead to excessive CPU usage. Fixes bug 40286; bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021- 001 and CVE-2021-28089. - Fix a bug in appending detached signatures to a pending consensus document that could be used to crash a directory authority. Fixes bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002 and CVE-2021-28090. o Minor features (geoip data, backport from 0.4.5.7): - We have switched geoip data sources. Previously we shipped IP-to- country mappings from Maxmind's GeoLite2, but in 2019 they changed their licensing terms, so we were unable to update them after that point. We now ship geoip files based on the IPFire Location Database instead. (See https://location.ipfire.org/ for more information). This release updates our geoip files to match the IPFire Location Database as retrieved on 2021/03/12. Closes ticket 40224. o Removed features (mallinfo deprecated, backport from 0.4.5.7): - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it. Closes ticket 40309. Changes in version 0.4.4.8 - 2021-03-16 Tor 0.4.4.8 backports fixes for two important denial-of-service bugs in earlier versions of Tor. One of these vulnerabilities (TROVE-2021-001) would allow an attacker who can send directory data to a Tor instance to force that Tor instance to consume huge amounts of CPU. This is easiest to exploit against authorities, since anybody can upload to them, but directory caches could also exploit this vulnerability against relays or clients when they download. The other vulnerability (TROVE-2021-002) only affects directory authorities, and would allow an attacker to remotely crash the authority with an assertion failure. Patches have already been provided to the authority operators, to help ensure network stability. We recommend that everybody upgrade to one of the releases that fixes these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available to you. This release also updates our GeoIP data source, and fixes a compatibility issue. o Major bugfixes (security, denial of service, backport from 0.4.5.7): - Disable the dump_desc() function that we used to dump unparseable information to disk. It was called incorrectly in several places, in a way that could lead to excessive CPU usage. Fixes bug 40286; bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021- 001 and CVE-2021-28089. - Fix a bug in appending detached signatures to a pending consensus document that could be used to crash a directory authority. Fixes bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002 and CVE-2021-28090. o Minor features (geoip data, backport from 0.4.5.7): - We have switched geoip data sources. Previously we shipped IP-to- country mappings from Maxmind's GeoLite2, but in 2019 they changed their licensing terms, so we were unable to update them after that point. We now ship geoip files based on the IPFire Location Database instead. (See https://location.ipfire.org/ for more information). This release updates our geoip files to match the IPFire Location Database as retrieved on 2021/03/12. Closes ticket 40224. o Removed features (mallinfo deprecated, backport from 0.4.5.7): - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it. Closes ticket 40309. Changes in version 0.4.5.7 - 2021-03-16 Tor 0.4.5.7 fixes two important denial-of-service bugs in earlier versions of Tor. One of these vulnerabilities (TROVE-2021-001) would allow an attacker who can send directory data to a Tor instance to force that Tor instance to consume huge amounts of CPU. This is easiest to exploit against authorities, since anybody can upload to them, but directory caches could also exploit this vulnerability against relays or clients when they download. The other vulnerability (TROVE-2021-002) only affects directory authorities, and would allow an attacker to remotely crash the authority with an assertion failure. Patches have already been provided to the authority operators, to help ensure network stability. We recommend that everybody upgrade to one of the releases that fixes these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available to you. This release also updates our GeoIP data source, and fixes a few smaller bugs in earlier releases. o Major bugfixes (security, denial of service): - Disable the dump_desc() function that we used to dump unparseable information to disk. It was called incorrectly in several places, in a way that could lead to excessive CPU usage. Fixes bug 40286; bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021- 001 and CVE-2021-28089. - Fix a bug in appending detached signatures to a pending consensus document that could be used to crash a directory authority. Fixes bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002 and CVE-2021-28090. o Minor features (geoip data): - We have switched geoip data sources. Previously we shipped IP-to- country mappings from Maxmind's GeoLite2, but in 2019 they changed their licensing terms, so we were unable to update them after that point. We now ship geoip files based on the IPFire Location Database instead. (See https://location.ipfire.org/ for more information). This release updates our geoip files to match the IPFire Location Database as retrieved on 2021/03/12. Closes ticket 40224. o Minor bugfixes (directory authority): - Now that exit relays don't allow exit connections to directory authority DirPorts (to prevent network reentry), disable authorities' reachability self test on the DirPort. Fixes bug 40287; bugfix on 0.4.5.5-rc. o Minor bugfixes (documentation): - Fix a formatting error in the documentation for VirtualAddrNetworkIPv6. Fixes bug 40256; bugfix on 0.2.9.4-alpha. o Minor bugfixes (Linux, relay): - Fix a bug in determining total available system memory that would have been triggered if the format of Linux's /proc/meminfo file had ever changed to include "MemTotal:" in the middle of a line. Fixes bug 40315; bugfix on 0.2.5.4-alpha. o Minor bugfixes (metrics port): - Fix a BUG() warning on the MetricsPort for an internal missing handler. Fixes bug 40295; bugfix on 0.4.5.1-alpha. o Minor bugfixes (onion service): - Remove a harmless BUG() warning when reloading tor configured with onion services. Fixes bug 40334; bugfix on 0.4.5.1-alpha. o Minor bugfixes (portability): - Fix a non-portable usage of "==" with "test" in the configure script. Fixes bug 40298; bugfix on 0.4.5.1-alpha. o Minor bugfixes (relay): - Remove a spammy log notice falsely claiming that the IPv4/v6 address was missing. Fixes bug 40300; bugfix on 0.4.5.1-alpha. - Do not query the address cache early in the boot process when deciding if a relay needs to fetch early directory information from an authority. This bug resulted in a relay falsely believing it didn't have an address and thus triggering an authority fetch at each boot. Related to our fix for 40300. o Removed features (mallinfo deprecated): - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it. Closes ticket 40309. Changes in version 0.4.5.6 - 2021-02-15 The Tor 0.4.5.x release series is dedicated to the memory of Karsten Loesing (1979-2020), Tor developer, cypherpunk, husband, and father. Karsten is best known for creating the Tor metrics portal and leading the metrics team, but he was involved in Tor from the early days. For example, while he was still a student he invented and implemented the v2 onion service directory design, and he also served as an ambassador to the many German researchers working in the anonymity field. We loved him and respected him for his patience, his consistency, and his welcoming approach to growing our community. This release series introduces significant improvements in relay IPv6 address discovery, a new "MetricsPort" mechanism for relay operators to measure performance, LTTng support, build system improvements to help when using Tor as a static library, and significant bugfixes related to Windows relay performance. It also includes numerous smaller features and bugfixes. Below are the changes since 0.4.4.7. For a list of changes since 0.4.5.5-rc, see the ChangeLog file. o Major features (build): - When building Tor, first link all object files into a single static library. This may help with embedding Tor in other programs. Note that most Tor functions do not constitute a part of a stable or supported API: only those functions in tor_api.h should be used if embedding Tor. Closes ticket 40127. o Major features (metrics): - Introduce a new MetricsPort which exposes, through an HTTP interface, a series of metrics that tor collects at runtime. At the moment, the only supported output format is Prometheus data model. Closes ticket 40063. See the manual page for more information and security considerations. o Major features (relay, IPv6): - The torrc option Address now supports IPv6. This unifies our address discovery interface to support IPv4, IPv6, and hostnames. Closes ticket 33233. - Launch IPv4 and IPv6 ORPort self-test circuits on relays and bridges. Closes ticket 33222. - Relays now automatically bind on IPv6 for their ORPort, unless specified otherwise with the IPv4Only flag. Closes ticket 33246. - When a relay with IPv6 support is told to open a connection to another relay, and the extend cell lists both IPv4 and IPv6 addresses, the first relay now picks randomly which address to use. Closes ticket 33220. - Relays now track their IPv6 ORPort reachability separately from the reachability of their IPv4 ORPort. They will not publish a descriptor unless _both_ ports appear to be externally reachable. Closes ticket 34067. o Major features (tracing): - Add event-tracing library support for USDT and LTTng-UST, and a few tracepoints in the circuit subsystem. More will come incrementally. This feature is compiled out by default: it needs to be enabled at configure time. See documentation in doc/HACKING/Tracing.md. Closes ticket 32910. o Major bugfixes (directory cache, performance, windows): - Limit the number of items in the consensus diff cache to 64 on Windows. We hope this will mitigate an issue where Windows relay operators reported Tor using 100% CPU, while we investigate better solutions. Fixes bug 24857; bugfix on 0.3.1.1-alpha. o Major bugfixes (relay, windows): - Fix a bug in our implementation of condition variables on Windows. Previously, a relay on Windows would use 100% CPU after running for some time. Because of this change, Tor now require Windows Vista or later to build and run. Fixes bug 30187; bugfix on 0.2.6.3-alpha. (This bug became more serious in 0.3.1.1-alpha with the introduction of consensus diffs.) Patch by Daniel Pinto. o Major bugfixes (TLS, buffer): - When attempting to read N bytes on a TLS connection, really try to read all N bytes. Previously, Tor would stop reading after the first TLS record, which can be smaller than the N bytes requested, and not check for more data until the next mainloop event. Fixes bug 40006; bugfix on 0.1.0.5-rc. o Minor features (address discovery): - If no Address statements are found, relays now prioritize guessing their address by looking at the local interface instead of the local hostname. If the interface address can't be found, the local hostname is used. Closes ticket 33238. o Minor features (admin tools): - Add a new --format argument to -key-expiration option to allow specifying the time format of the expiration date. Adds Unix timestamp format support. Patch by Daniel Pinto. Closes ticket 30045. o Minor features (authority, logging): - Log more information for directory authority operators during the consensus voting process, and while processing relay descriptors. Closes ticket 40245. o Minor features (bootstrap reporting): - When reporting bootstrapping status on a relay, do not consider connections that have never been the target of an origin circuit. Previously, all connection failures were treated as potential bootstrapping failures, including connections that had been opened because of client requests. Closes ticket 25061. o Minor features (build): - When running the configure script, try to detect version mismatches between the OpenSSL headers and libraries, and suggest that the user should try "--with-openssl-dir". Closes 40138. - If the configure script has given any warnings, remind the user about them at the end of the script. Related to 40138. o Minor features (configuration): - Allow using wildcards (* and ?) with the %include option on configuration files. Closes ticket 25140. Patch by Daniel Pinto. - Allow the configuration options EntryNodes, ExcludeNodes, ExcludeExitNodes, ExitNodes, MiddleNodes, HSLayer2Nodes and HSLayer3Nodes to be specified multiple times. Closes ticket 28361. Patch by Daniel Pinto. o Minor features (control port): - Add a DROPTIMEOUTS command to drop circuit build timeout history and reset the current timeout. Closes ticket 40002. - When a stream enters the AP_CONN_STATE_CONTROLLER_WAIT status, send a control port event. Closes ticket 32190. Patch by Neel Chauhan. - Introduce GETINFO "stats/ntor/{assigned/requested}" and "stats/tap/{assigned/requested}" to get the NTor and TAP circuit onion handshake counts respectively. Closes ticket 28279. Patch by Neel Chauhan. o Minor features (control port, IPv6): - Tor relays now try to report to the controller when they are launching an IPv6 self-test. Closes ticket 34068. - Introduce "GETINFO address/v4" and "GETINFO address/v6" in the control port to fetch the Tor host's respective IPv4 or IPv6 address. We keep "GETINFO address" for backwards-compatibility. Closes ticket 40039. Patch by Neel Chauhan. o Minor features (directory authorities): - Add a new consensus method 30 that removes the unnecessary "=" padding from ntor-onion-key. Closes ticket 7869. Patch by Daniel Pinto. - Directory authorities now reject descriptors from relays running Tor versions from the obsolete 0.4.1 series. Resolves ticket 34357. Patch by Neel Chauhan. - The AssumeReachable option no longer stops directory authorities from checking whether other relays are running. A new AuthDirTestReachability option can be used to disable these checks. Closes ticket 34445. - When looking for possible Sybil attacks, also consider IPv6 addresses. Two routers are considered to have "the same" address by this metric if they are in the same /64 network. Patch from Maurice Pibouin. Closes ticket 7193. o Minor features (directory authorities, IPv6): - Make authorities add their IPv6 ORPort (if any) to the trusted servers list. Authorities previously added only their IPv4 addresses. Closes ticket 32822. o Minor features (documentation): - Mention the "!badexit" directive that can appear in an authority's approved-routers file, and update the description of the "!invalid" directive. Closes ticket 40188. o Minor features (ed25519, relay): - Save a relay's base64-encoded ed25519 identity key to the data directory in a file named fingerprint-ed25519. Closes ticket 30642. Patch by Neel Chauhan. o Minor features (heartbeat): - Include the total number of inbound and outbound IPv4 and IPv6 connections in the heartbeat message. Closes ticket 29113. o Minor features (IPv6, ExcludeNodes): - Handle IPv6 addresses in ExcludeNodes; previously they were ignored. Closes ticket 34065. Patch by Neel Chauhan. o Minor features (logging): - Add the running glibc version to the log, and the compiled glibc version to the library list returned when using --library-versions. Patch from Daniel Pinto. Closes ticket 40047. - Consider an HTTP 301 response to be an error (like a 404) when processing a directory response. Closes ticket 40053. - Log directory fetch statistics as a single line. Closes ticket 40159. - Provide more complete descriptions of our connections when logging about them. Closes ticket 40041. - When describing a relay in the logs, we now include its ed25519 identity. Closes ticket 22668. o Minor features (onion services): - Only overwrite an onion service's existing hostname file if its contents are wrong. This enables read-only onion-service directories. Resolves ticket 40062. Patch by Neel Chauhan. o Minor features (pluggable transports): - Add an OutboundBindAddressPT option to allow users to specify which IPv4 and IPv6 address pluggable transports should use for outgoing IP packets. Tor does not have a way to enforce that the pluggable transport honors this option, so each pluggable transport needs to implement support on its own. Closes ticket 5304. o Minor features (protocol, proxy support, defense in depth): - Respond more deliberately to misbehaving proxies that leave leftover data on their connections, so as to make Tor even less likely to allow the proxies to pass their data off as having come from a relay. Closes ticket 40017. o Minor features (relay address tracking): - We now store relay addresses for OR connections in a more logical way. Previously we would sometimes overwrite the actual address of a connection with a "canonical address", and then store the "real address" elsewhere to remember it. We now track the "canonical address" elsewhere for the cases where we need it, and leave the connection's address alone. Closes ticket 33898. o Minor features (relay): - If a relay is unable to discover its address, attempt to learn it from the NETINFO cell. Closes ticket 40022. - Log immediately when launching a relay self-check. Previously we would try to log before launching checks, or approximately when we intended to launch checks, but this tended to be error-prone. Closes ticket 34137. o Minor features (relay, address discovery): - If Address option is not found in torrc, attempt to learn our address with the configured ORPort address if any. Closes ticket 33236. o Minor features (relay, IPv6): - Add an AssumeReachableIPv6 option to disable self-checking IPv6 reachability. Closes part of ticket 33224. - Add new "assume-reachable" and "assume-reachable-ipv6" consensus parameters to be used in an emergency to tell relays that they should publish even if they cannot complete their ORPort self- checks. Closes ticket 34064 and part of 33224. - Allow relays to send IPv6-only extend cells. Closes ticket 33222. - Declare support for the Relay=3 subprotocol version. Closes ticket 33226. - When launching IPv6 ORPort self-test circuits, make sure that the second-last hop can initiate an IPv6 extend. Closes ticket 33222. o Minor features (safety): - Log a warning at startup if Tor is built with compile-time options that are likely to make it less stable or reliable. Closes ticket 18888. o Minor features (specification update): - Several fields in microdescriptors, router descriptors, and consensus documents that were formerly optional are now required. Implements proposal 315; closes ticket 40132. o Minor features (state management): - When loading the state file, remove entries from the statefile that have been obsolete for a long time. Ordinarily Tor preserves unrecognized entries in order to keep forward-compatibility, but these entries have not actually been used in any release since before 0.3.5.x. Closes ticket 40137. o Minor features (statistics, ipv6): - Relays now publish IPv6-specific counts of single-direction versus bidirectional relay connections. Closes ticket 33264. - Relays now publish their IPv6 read and write statistics over time, if statistics are enabled. Closes ticket 33263. o Minor features (subprotocol versions): - Use the new limitations on subprotocol versions due to proposal 318 to simplify our implementation. Part of ticket 40133. o Minor features (testing configuration): - The TestingTorNetwork option no longer implicitly sets AssumeReachable to 1. This change allows us to test relays' self- testing mechanisms, and to test authorities' relay-testing functionality. Closes ticket 34446. o Minor features (testing): - Added unit tests for channel_matches_target_addr_for_extend(). Closes Ticket 33919. Patch by MrSquanchee. o Minor bugfixes (circuit padding): - When circpad_send_padding_cell_for_callback is called, `is_padding_timer_scheduled` flag was not reset. Now it is set to 0 at the top of that function. Fixes bug 32671; bugfix on 0.4.0.1-alpha. - Add a per-circuit padding machine instance counter, so we can differentiate between shutdown requests for old machines on a circuit. Fixes bug 30992; bugfix on 0.4.1.1-alpha. - Add the ability to keep circuit padding machines if they match a set of circuit states or purposes. This allows us to have machines that start up under some conditions but don't shut down under others. We now use this mask to avoid starting up introduction circuit padding again after the machines have already completed. Fixes bug 32040; bugfix on 0.4.1.1-alpha. o Minor bugfixes (circuit, handshake): - In the v3 handshaking code, use connection_or_change_state() to change the state. Previously, we changed the state directly, but this did not pass the state change to the pubsub or channel objects, potentially leading to bugs. Fixes bug 32880; bugfix on 0.2.3.6-alpha. Patch by Neel Chauhan. o Minor bugfixes (compilation): - Change the linker flag ordering in our library search code so that it works for compilers that need the libraries to be listed in the right order. Fixes bug 33624; bugfix on 0.1.1.0-alpha. - Fix the "--enable-static-tor" switch to properly set the "-static" compile option onto the tor binary only. Fixes bug 40111; bugfix on 0.2.3.1-alpha. o Minor bugfixes (configuration): - Exit Tor on a misconfiguration when the Bridge line is configured to use a transport but no corresponding ClientTransportPlugin can be found. Prior to this fix, Tor would attempt to connect to the bridge directly without using the transport, making it easier for adversaries to notice the bridge. Fixes bug 25528; bugfix on 0.2.6.1-alpha. o Minor bugfixes (control port): - Make sure we send the SOCKS request address in relay begin cells when a stream is attached with the purpose CIRCUIT_PURPOSE_CONTROLLER. Fixes bug 33124; bugfix on 0.0.5. Patch by Neel Chauhan. o Minor bugfixes (crash, relay, signing key): - Avoid assertion failures when we run Tor from the command line with `--key-expiration sign`, but an ORPort is not set. Fixes bug 40015; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (logging): - Avoid a spurious log message about missing subprotocol versions, when the consensus that we're reading from is older than the current release. Previously we had made this message nonfatal, but in practice, it is never relevant when the consensus is older than the current release. Fixes bug 40281; bugfix on 0.4.0.1-alpha. - Remove trailing whitespace from control event log messages. Fixes bug 32178; bugfix on 0.1.1.1-alpha. Based on a patch by Amadeusz Pawlik. - Turn warning-level log message about SENDME failure into a debug- level message. (This event can happen naturally, and is no reason for concern). Fixes bug 40142; bugfix on 0.4.1.1-alpha. - When logging a rate-limited message about how many messages have been suppressed in the last N seconds, give an accurate value for N, rounded up to the nearest minute. Previously we would report the size of the rate-limiting interval, regardless of when the messages started to occur. Fixes bug 19431; bugfix on 0.2.2.16-alpha. o Minor bugfixes (onion services): - Avoid a non-fatal assertion in certain edge-cases when establishing a circuit to an onion service. Fixes bug 32666; bugfix on 0.3.0.3-alpha. o Minor bugfixes (rust, protocol versions): - Declare support for the onion service introduction point denial of service extensions when building with Rust. Fixes bug 34248; bugfix on 0.4.2.1-alpha. - Make Rust protocol version support checks consistent with the undocumented error behavior of the corresponding C code. Fixes bug 34251; bugfix on 0.3.3.5-rc. o Minor bugfixes (self-testing): - When receiving an incoming circuit, only accept it as evidence that we are reachable if the declared address of its channel is the same address we think that we have. Otherwise, it could be evidence that we're reachable on some other address. Fixes bug 20165; bugfix on 0.1.0.1-rc. o Minor bugfixes (spec conformance): - Use the correct key type when generating signing->link certificates. Fixes bug 40124; bugfix on 0.2.7.2-alpha. o Minor bugfixes (subprotocol versions): - Consistently reject extra commas, instead of only rejecting leading commas. Fixes bug 27194; bugfix on 0.2.9.4-alpha. - In summarize_protover_flags(), treat empty strings the same as NULL. This prevents protocols_known from being set. Previously, we treated empty strings as normal strings, which led to protocols_known being set. Fixes bug 34232; bugfix on 0.3.3.2-alpha. Patch by Neel Chauhan. o Code simplification and refactoring: - Add and use a set of functions to perform down-casts on constant connection and channel pointers. Closes ticket 40046. - Refactor our code that logs descriptions of connections, channels, and the peers on them, to use a single call path. This change enables us to refactor the data types that they use, and eliminates many confusing usages of those types. Closes ticket 40041. - Refactor some common node selection code into a single function. Closes ticket 34200. - Remove the now-redundant 'outbuf_flushlen' field from our connection type. It was previously used for an older version of our rate-limiting logic. Closes ticket 33097. - Rename "fascist_firewall_*" identifiers to "reachable_addr_*" instead, for consistency with other code. Closes ticket 18106. - Rename functions about "advertised" ports which are not in fact guaranteed to return the ports that have been advertised. Closes ticket 40055. - Split implementation of several command line options from options_init_from_torrc into smaller isolated functions. Patch by Daniel Pinto. Closes ticket 40102. - When an extend cell is missing an IPv4 or IPv6 address, fill in the address from the extend info. This is similar to what was done in ticket 33633 for ed25519 keys. Closes ticket 33816. Patch by Neel Chauhan. o Deprecated features: - The "non-builtin" argument to the "--dump-config" command is now deprecated. When it works, it behaves the same as "short", which you should use instead. Closes ticket 33398. o Documentation: - Replace URLs from our old bugtracker so that they refer to the new bugtracker and wiki. Closes ticket 40101. o Removed features: - We no longer ship or build a "tor.service" file for use with systemd. No distribution included this script unmodified, and we don't have the expertise ourselves to maintain this in a way that all the various systemd-based distributions can use. Closes ticket 30797. - We no longer ship support for the Android logging API. Modern versions of Android can use the syslog API instead. Closes ticket 32181. - The "optimistic data" feature is now always on; there is no longer an option to disable it from the torrc file or from the consensus directory. Closes part of 40139. - The "usecreatefast" network parameter is now removed; there is no longer an option for authorities to turn it off. Closes part of 40139. o Testing: - Add unit tests for bandwidth statistics manipulation functions. Closes ticket 33812. Patch by MrSquanchee. o Code simplification and refactoring (autoconf): - Remove autoconf checks for unused funcs and headers. Closes ticket 31699; Patch by @bduszel o Code simplification and refactoring (maintainer scripts): - Disable by default the pre-commit hook. Use the environment variable TOR_EXTRA_PRE_COMMIT_CHECKS in order to run it. Furthermore, stop running practracker in the pre-commit hook and make check-local. Closes ticket 40019. o Code simplification and refactoring (relay address): - Most of IPv4 representation was using "uint32_t". It has now been moved to use the internal "tor_addr_t" interface instead. This is so we can properly integrate IPv6 along IPv4 with common interfaces. Closes ticket 40043. o Documentation (manual page): - Move them from doc/ to doc/man/. Closes ticket 40044. - Describe the status of the "Sandbox" option more accurately. It is no longer "experimental", but it _is_ dependent on kernel and libc versions. Closes ticket 23378. o Documentation (tracing): - Document in depth the circuit subsystem trace events in the new doc/tracing/EventsCircuit.md. Closes ticket 40036. o Removed features (controller): - Remove the "GETINFO network-status" controller command. It has been deprecated since 0.3.1.1-alpha. Closes ticket 22473. Changes in version 0.4.4.7 - 2021-02-03 Tor 0.4.4.7 backports numerous bugfixes from later releases, including one that made v3 onion services more susceptible to denial-of-service attacks, and a feature that makes some kinds of DoS attacks harder to perform. o Major bugfixes (onion service v3, backport from 0.4.5.3-rc): - Stop requiring a live consensus for v3 clients and services, and allow a "reasonably live" consensus instead. This allows v3 onion services to work even if the authorities fail to generate a consensus for more than 2 hours in a row. Fixes bug 40237; bugfix on 0.3.5.1-alpha. o Major feature (exit, backport from 0.4.5.5-rc): - Re-entry into the network is now denied at the Exit level to all relays' ORPorts and authorities' ORPorts and DirPorts. This change should help mitgate a set of denial-of-service attacks. Closes ticket 2667. o Minor feature (build system, backport from 0.4.5.4-rc): - New "make lsp" command to generate the compile_commands.json file used by the ccls language server. The "bear" program is needed for this. Closes ticket 40227. o Minor features (compilation, backport from 0.4.5.2-rc): - Disable deprecation warnings when building with OpenSSL 3.0.0 or later. There are a number of APIs newly deprecated in OpenSSL 3.0.0 that Tor still requires. (A later version of Tor will try to stop depending on these APIs.) Closes ticket 40165. o Minor features (crypto, backport from 0.4.5.3-rc): - Fix undefined behavior on our Keccak library. The bug only appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel) and would result in wrong digests. Fixes bug 40210; bugfix on 0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and weasel for diagnosing this. o Minor bugfixes (compatibility, backport from 0.4.5.1-rc): - Strip '\r' characters when reading text files on Unix platforms. This should resolve an issue where a relay operator migrates a relay from Windows to Unix, but does not change the line ending of Tor's various state files to match the platform, and the CRLF line endings from Windows end up leaking into other files such as the extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5. o Minor bugfixes (compilation, backport from 0.4.5.3-rc): - Fix a compilation warning about unreachable fallthrough annotations when building with "--enable-all-bugs-are-fatal" on some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha. o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc): - Handle partial SOCKS5 messages correctly. Previously, our code would send an incorrect error message if it got a SOCKS5 request that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, backport from 0.4.5.2-alpha): - Fix the `config/parse_tcp_proxy_line` test so that it works correctly on systems where the DNS provider hijacks invalid queries. Fixes part of bug 40179; bugfix on 0.4.3.1-alpha. - Fix our Python reference-implementation for the v3 onion service handshake so that it works correctly with the version of hashlib provided by Python 3.9. Fixes part of bug 40179; bugfix on 0.3.1.6-rc. - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL 3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha. Changes in version 0.4.3.8 - 2021-02-03 Tor 0.4.3.8 backports numerous bugfixes from later releases, including one that made v3 onion services more susceptible to denial-of-service attacks, and a feature that makes some kinds of DoS attacks harder to perform. Note that this is, in all likelihood, the last release of Tor 0.4.3.x, which will reach end-of-life on 15 Feb 2021. o Major bugfixes (onion service v3, backport from 0.4.5.3-rc): - Stop requiring a live consensus for v3 clients and services, and allow a "reasonably live" consensus instead. This allows v3 onion services to work even if the authorities fail to generate a consensus for more than 2 hours in a row. Fixes bug 40237; bugfix on 0.3.5.1-alpha. o Major bugfixes (stats, onion services, backport from 0.4.4.5): - Fix a bug where we were undercounting the Tor network's total onion service traffic, by ignoring any traffic originating from clients. Now we count traffic from both clients and services. Fixes bug 40117; bugfix on 0.2.6.2-alpha. o Major feature (exit, backport from 0.4.5.5-rc): - Re-entry into the network is now denied at the Exit level to all relays' ORPorts and authorities' ORPorts and DirPorts. This change should help mitgate a set of denial-of-service attacks. Closes ticket 2667. o Minor feature (build system, backport from 0.4.5.4-rc): - New "make lsp" command to generate the compile_commands.json file used by the ccls language server. The "bear" program is needed for this. Closes ticket 40227. o Minor features (compilation, backport from 0.4.5.2-rc): - Disable deprecation warnings when building with OpenSSL 3.0.0 or later. There are a number of APIs newly deprecated in OpenSSL 3.0.0 that Tor still requires. (A later version of Tor will try to stop depending on these APIs.) Closes ticket 40165. o Minor features (crypto, backport from 0.4.5.3-rc): - Fix undefined behavior on our Keccak library. The bug only appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel) and would result in wrong digests. Fixes bug 40210; bugfix on 0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and weasel for diagnosing this. o Minor bugfixes (compatibility, backport from 0.4.5.1-rc): - Strip '\r' characters when reading text files on Unix platforms. This should resolve an issue where a relay operator migrates a relay from Windows to Unix, but does not change the line ending of Tor's various state files to match the platform, and the CRLF line endings from Windows end up leaking into other files such as the extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5. o Minor bugfixes (compilation, backport from 0.4.5.1-rc): - Resolve a compilation warning that could occur in test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha. o Minor bugfixes (compilation, backport from 0.4.5.3-rc): - Fix a compilation warning about unreachable fallthrough annotations when building with "--enable-all-bugs-are-fatal" on some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha. o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc): - Handle partial SOCKS5 messages correctly. Previously, our code would send an incorrect error message if it got a SOCKS5 request that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, backport from 0.4.5.2-alpha): - Fix the `config/parse_tcp_proxy_line` test so that it works correctly on systems where the DNS provider hijacks invalid queries. Fixes part of bug 40179; bugfix on 0.4.3.1-alpha. - Fix our Python reference-implementation for the v3 onion service handshake so that it works correctly with the version of hashlib provided by Python 3.9. Fixes part of bug 40179; bugfix on 0.3.1.6-rc. - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL 3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha. Changes in version 0.3.5.13 - 2020-02-03 Tor 0.3.5.13 backports numerous bugfixes from later releases, including one that made v3 onion services more susceptible to denial-of-service attacks, and a feature that makes some kinds of DoS attacks harder to perform. o Major bugfixes (onion service v3, backport from 0.4.5.3-rc): - Stop requiring a live consensus for v3 clients and services, and allow a "reasonably live" consensus instead. This allows v3 onion services to work even if the authorities fail to generate a consensus for more than 2 hours in a row. Fixes bug 40237; bugfix on 0.3.5.1-alpha. o Major bugfixes (stats, onion services, backport from 0.4.4.5): - Fix a bug where we were undercounting the Tor network's total onion service traffic, by ignoring any traffic originating from clients. Now we count traffic from both clients and services. Fixes bug 40117; bugfix on 0.2.6.2-alpha. o Major feature (exit, backport from 0.4.5.5-rc): - Re-entry into the network is now denied at the Exit level to all relays' ORPorts and authorities' ORPorts and DirPorts. This change should help mitgate a set of denial-of-service attacks. Closes ticket 2667. o Minor feature (build system, backport from 0.4.5.4-rc): - New "make lsp" command to generate the compile_commands.json file used by the ccls language server. The "bear" program is needed for this. Closes ticket 40227. o Minor features (compilation, backport from 0.4.5.2-rc): - Disable deprecation warnings when building with OpenSSL 3.0.0 or later. There are a number of APIs newly deprecated in OpenSSL 3.0.0 that Tor still requires. (A later version of Tor will try to stop depending on these APIs.) Closes ticket 40165. o Minor features (crypto, backport from 0.4.5.3-rc): - Fix undefined behavior on our Keccak library. The bug only appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel) and would result in wrong digests. Fixes bug 40210; bugfix on 0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and weasel for diagnosing this. o Minor bugfixes (compatibility, backport from 0.4.5.1-rc): - Strip '\r' characters when reading text files on Unix platforms. This should resolve an issue where a relay operator migrates a relay from Windows to Unix, but does not change the line ending of Tor's various state files to match the platform, and the CRLF line endings from Windows end up leaking into other files such as the extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5. o Minor bugfixes (compilation, backport from 0.4.5.1-rc): - Resolve a compilation warning that could occur in test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha. o Minor bugfixes (compilation, backport from 0.4.5.3-rc): - Fix a compilation warning about unreachable fallthrough annotations when building with "--enable-all-bugs-are-fatal" on some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha. o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc): - Handle partial SOCKS5 messages correctly. Previously, our code would send an incorrect error message if it got a SOCKS5 request that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, backport from 0.4.5.2-alpha): - Fix our Python reference-implementation for the v3 onion service handshake so that it works correctly with the version of hashlib provided by Python 3.9. Fixes part of bug 40179; bugfix on 0.3.1.6-rc. - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL 3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha. Changes in version 0.4.4.6 - 2020-11-12 Tor 0.4.4.6 is the second stable release in the 0.4.4.x series. It backports fixes from later releases, including a fix for TROVE-2020- 005, a security issue that could be used, under certain cases, by an adversary to observe traffic patterns on a limited number of circuits intended for a different relay. o Major bugfixes (security, backport from 0.4.5.1-alpha): - When completing a channel, relays now check more thoroughly to make sure that it matches any pending circuits before attaching those circuits. Previously, address correctness and Ed25519 identities were not checked in this case, but only when extending circuits on an existing channel. Fixes bug 40080; bugfix on 0.2.7.2-alpha. Resolves TROVE-2020-005. o Minor features (directory authorities, backport from 0.4.5.1-alpha): - Authorities now list a different set of protocols as required and recommended. These lists have been chosen so that only truly recommended and/or required protocols are included, and so that clients using 0.2.9 or later will continue to work (even though they are not supported), whereas only relays running 0.3.5 or later will meet the requirements. Closes ticket 40162. - Make it possible to specify multiple ConsensusParams torrc lines. Now directory authority operators can for example put the main ConsensusParams config in one torrc file and then add to it from a different torrc file. Closes ticket 40164. o Minor features (subprotocol versions, backport from 0.4.5.1-alpha): - Tor no longer allows subprotocol versions larger than 63. Previously version numbers up to UINT32_MAX were allowed, which significantly complicated our code. Implements proposal 318; closes ticket 40133. o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha): - Fix a rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40125; bugfix on 0.2.8.1-alpha. - Fix another rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40126; bugfix on 0.2.8.1-alpha. o Minor bugfixes (compilation, backport from 0.4.5.1-alpha): - Fix compiler warnings that would occur when building with "--enable-all-bugs-are-fatal" and "--disable-module-relay" at the same time. Fixes bug 40129; bugfix on 0.4.4.1-alpha. - Resolve a compilation warning that could occur in test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha. o Minor bugfixes (logging, backport from 0.4.5.1-alpha): - Remove a debug logging statement that uselessly spammed the logs. Fixes bug 40135; bugfix on 0.3.5.0-alpha. o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha): - Avoid a fatal assert() when failing to create a listener connection for an address that was in use. Fixes bug 40073; bugfix on 0.3.5.1-alpha. o Minor bugfixes (v2 onion services, backport from 0.4.5.1-alpha): - For HSFETCH commands on v2 onion services addresses, check the length of bytes decoded, not the base32 length. Fixes bug 34400; bugfix on 0.4.1.1-alpha. Patch by Neel Chauhan. Changes in version 0.4.3.7 - 2020-11-12 Tor 0.4.3.7 backports several bugfixes from later releases. It includes a fix for TROVE-2020-005, a security issue that could be used, under certain cases, by an adversary to observe traffic patterns on a limited number of circuits intended for a different relay. Please be aware that support for the 0.4.3.x series will end on 15 February 2021. Please upgrade to 0.4.4.x or 0.4.5.x before then, or downgrade to 0.3.5.x, which will be supported until at least 1 February 2022. o Major features (fallback directory list, backport form 0.4.4.3-alpha): - Replace the 148 fallback directories originally included in Tor 0.4.1.4-rc (of which around 105 are still functional) with a list of 144 fallbacks generated in July 2020. Closes ticket 40061. o Major bugfixes (security, backport from 0.4.5.1-alpha): - When completing a channel, relays now check more thoroughly to make sure that it matches any pending circuits before attaching those circuits. Previously, address correctness and Ed25519 identities were not checked in this case, but only when extending circuits on an existing channel. Fixes bug 40080; bugfix on 0.2.7.2-alpha. Resolves TROVE-2020-005. o Major bugfixes (NSS, backport from 0.4.4.3-alpha): - When running with NSS enabled, make sure that NSS knows to expect nonblocking sockets. Previously, we set our TCP sockets as nonblocking, but did not tell NSS, which in turn could lead to unexpected blocking behavior. Fixes bug 40035; bugfix on 0.3.5.1-alpha. o Minor features (security, backport from 0.4.4.4-rc): - Channels using obsolete versions of the Tor link protocol are no longer allowed to circumvent address-canonicity checks. (This is only a minor issue, since such channels have no way to set ed25519 keys, and therefore should always be rejected for circuits that specify ed25519 identities.) Closes ticket 40081. o Minor features (subprotocol versions, backport from 0.4.5.1-alpha): - Tor no longer allows subprotocol versions larger than 63. Previously version numbers up to UINT32_MAX were allowed, which significantly complicated our code. Implements proposal 318; closes ticket 40133. o Minor features (tests, backport from 0.4.4.5): - Our "make check" target now runs the unit tests in 8 parallel chunks. Doing this speeds up hardened CI builds by more than a factor of two. Closes ticket 40098. o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha): - Fix a rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40125; bugfix on 0.2.8.1-alpha. - Fix another rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40126; bugfix on 0.2.8.1-alpha. o Minor bugfixes (correctness, buffers, backport from 0.4.4.4-rc): - Fix a correctness bug that could cause an assertion failure if we ever tried using the buf_move_all() function with an empty input buffer. As far as we know, no released versions of Tor do this. Fixes bug 40076; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.5.1-alpha): - Remove a debug logging statement that uselessly spammed the logs. Fixes bug 40135; bugfix on 0.3.5.0-alpha. o Minor bugfixes (rate limiting, bridges, pluggable transports, backport from 0.4.4.4-rc): - On a bridge, treat all connections from an ExtORPort as remote by default for the purposes of rate-limiting. Previously, bridges would treat the connection as local unless they explicitly received a "USERADDR" command. ExtORPort connections still count as local if there is a USERADDR command with an explicit local address. Fixes bug 33747; bugfix on 0.2.5.1-alpha. o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha): - Avoid a fatal assert() when failing to create a listener connection for an address that was in use. Fixes bug 40073; bugfix on 0.3.5.1-alpha. o Minor bugfixes (relay, usability, backport from 0.4.4.3-alpha): - Adjust the rules for when to warn about having too many connections to other relays. Previously we'd tolerate up to 1.5 connections per relay on average. Now we tolerate more connections for directory authorities, and raise the number of total connections we need to see before we warn. Fixes bug 33880; bugfix on 0.3.1.1-alpha. o Minor bugfixes (tests, 0.4.4.5): - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run on its own. Previously, it would exit with an error. Fixes bug 40099; bugfix on 0.2.8.1-alpha. o Minor bugfixes (v2 onion services, backport from 0.4.5.1-alpha): - For HSFETCH commands on v2 onion services addresses, check the length of bytes decoded, not the base32 length. Fixes bug 34400; bugfix on 0.4.1.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (windows, backport from 0.4.4.4-rc): - Fix a bug that prevented Tor from starting if its log file grew above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha. o Deprecated features (onion service v2, backport form 0.4.4.2-alpha): - Add a deprecation warning for version 2 onion services. Closes ticket 40003. o Removed features (backport from 0.4.4.3-alpha): - Our "check-local" test target no longer tries to use the Coccinelle semantic patching tool parse all the C files. While it is a good idea to try to make sure Coccinelle works on our C before we run a Coccinelle patch, doing so on every test run has proven to be disruptive. You can still run this tool manually with "make check-cocci". Closes ticket 40030. ticket 40030. Changes in version 0.3.5.12 - 2020-11-12 Tor 0.4.3.7 backports several bugfixes from later releases. It includes a fix for TROVE-2020-005, a security issue that could be used, under certain cases, by an adversary to observe traffic patterns on a limited number of circuits intended for a different relay. o Major features (fallback directory list, backport form 0.4.4.3-alpha): - Replace the 148 fallback directories originally included in Tor 0.4.1.4-rc (of which around 105 are still functional) with a list of 144 fallbacks generated in July 2020. Closes ticket 40061. o Major bugfixes (security, backport from 0.4.5.1-alpha): - When completing a channel, relays now check more thoroughly to make sure that it matches any pending circuits before attaching those circuits. Previously, address correctness and Ed25519 identities were not checked in this case, but only when extending circuits on an existing channel. Fixes bug 40080; bugfix on 0.2.7.2-alpha. Resolves TROVE-2020-005. o Major bugfixes (NSS, backport from 0.4.4.3-alpha): - When running with NSS enabled, make sure that NSS knows to expect nonblocking sockets. Previously, we set our TCP sockets as nonblocking, but did not tell NSS, which in turn could lead to unexpected blocking behavior. Fixes bug 40035; bugfix on 0.3.5.1-alpha. o Minor features (security, backport from 0.4.4.4-rc): - Channels using obsolete versions of the Tor link protocol are no longer allowed to circumvent address-canonicity checks. (This is only a minor issue, since such channels have no way to set ed25519 keys, and therefore should always be rejected for circuits that specify ed25519 identities.) Closes ticket 40081. o Minor features (debugging, directory system): - Don't crash when we find a non-guard with a guard-fraction value set. Instead, log a bug warning, in an attempt to figure out how this happened. Diagnostic for ticket 32868. o Minor features (subprotocol versions, backport from 0.4.5.1-alpha): - Tor no longer allows subprotocol versions larger than 63. Previously version numbers up to UINT32_MAX were allowed, which significantly complicated our code. Implements proposal 318; closes ticket 40133. o Minor features (tests, backport from 0.4.4.5): - Our "make check" target now runs the unit tests in 8 parallel chunks. Doing this speeds up hardened CI builds by more than a factor of two. Closes ticket 40098. o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha): - Fix a rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40125; bugfix on 0.2.8.1-alpha. - Fix another rendezvous cache unit test that was triggering an underflow on the global rend cache allocation. Fixes bug 40126; bugfix on 0.2.8.1-alpha. o Minor bugfixes (correctness, buffers, backport from 0.4.4.4-rc): - Fix a correctness bug that could cause an assertion failure if we ever tried using the buf_move_all() function with an empty input buffer. As far as we know, no released versions of Tor do this. Fixes bug 40076; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.5.1-alpha): - Remove a debug logging statement that uselessly spammed the logs. Fixes bug 40135; bugfix on 0.3.5.0-alpha. o Minor bugfixes (rate limiting, bridges, pluggable transports, backport from 0.4.4.4-rc): - On a bridge, treat all connections from an ExtORPort as remote by default for the purposes of rate-limiting. Previously, bridges would treat the connection as local unless they explicitly received a "USERADDR" command. ExtORPort connections still count as local if there is a USERADDR command with an explicit local address. Fixes bug 33747; bugfix on 0.2.5.1-alpha. o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha): - Avoid a fatal assert() when failing to create a listener connection for an address that was in use. Fixes bug 40073; bugfix on 0.3.5.1-alpha. o Minor bugfixes (relay, usability, backport from 0.4.4.3-alpha): - Adjust the rules for when to warn about having too many connections to other relays. Previously we'd tolerate up to 1.5 connections per relay on average. Now we tolerate more connections for directory authorities, and raise the number of total connections we need to see before we warn. Fixes bug 33880; bugfix on 0.3.1.1-alpha. o Minor bugfixes (relays, backport from 0.4.4.1-alpha): - Stop advertising incorrect IPv6 ORPorts in relay and bridge descriptors, when the IPv6 port was configured as "auto". Fixes bug 32588; bugfix on 0.2.3.9-alpha. o Minor bugfixes (tests, 0.4.4.5): - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run on its own. Previously, it would exit with an error. Fixes bug 40099; bugfix on 0.2.8.1-alpha. o Minor bugfixes (windows, backport from 0.4.4.4-rc): - Fix a bug that prevented Tor from starting if its log file grew above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha. o Deprecated features (onion service v2, backport form 0.4.4.2-alpha): - Add a deprecation warning for version 2 onion services. Closes ticket 40003. Changes in version 0.4.4.5 - 2020-09-15 Tor 0.4.4.5 is the first stable release in the 0.4.4.x series. This series improves our guard selection algorithms, adds v3 onion balance support, improves the amount of code that can be disabled when running without relay support, and includes numerous small bugfixes and enhancements. It also lays the ground for some IPv6 features that we'll be developing more in the next (0.4.5) series. Per our support policy, we support each stable release series for nine months after its first stable release, or three months after the first stable release of the next series: whichever is longer. This means that 0.4.4.x will be supported until around June 2021--or later, if 0.4.5.x is later than anticipated. Note also that support for 0.4.2.x has just ended; support for 0.4.3 will continue until Feb 15, 2021. We still plan to continue supporting 0.3.5.x, our long-term stable series, until Feb 2022. Below are the changes since 0.4.3.6-rc. For a complete list of changes since 0.4.4.4-rc, see the ChangeLog file. o Major features (Proposal 310, performance + security): - Implements Proposal 310, "Bandaid on guard selection". Proposal 310 solves load-balancing issues with older versions of the guard selection algorithm, and improves its security. Under this new algorithm, a newly selected guard never becomes Primary unless all previously sampled guards are unreachable. Implements recommendation from 32088. (Proposal 310 is linked to the CLAPS project researching optimal client location-aware path selections. This project is a collaboration between the UCLouvain Crypto Group, the U.S. Naval Research Laboratory, and Princeton University.) o Major features (fallback directory list): - Replace the 148 fallback directories originally included in Tor 0.4.1.4-rc (of which around 105 are still functional) with a list of 144 fallbacks generated in July 2020. Closes ticket 40061. o Major features (IPv6, relay): - Consider IPv6-only EXTEND2 cells valid on relays. Log a protocol warning if the IPv4 or IPv6 address is an internal address, and internal addresses are not allowed. But continue to use the other address, if it is valid. Closes ticket 33817. - If a relay can extend over IPv4 and IPv6, and both addresses are provided, it chooses between them uniformly at random. Closes ticket 33817. - Re-use existing IPv6 connections for circuit extends. Closes ticket 33817. - Relays may extend circuits over IPv6, if the relay has an IPv6 ORPort, and the client supplies the other relay's IPv6 ORPort in the EXTEND2 cell. IPv6 extends will be used by the relay IPv6 ORPort self-tests in 33222. Closes ticket 33817. o Major features (v3 onion services): - Allow v3 onion services to act as OnionBalance backend instances, by using the HiddenServiceOnionBalanceInstance torrc option. Closes ticket 32709. o Major bugfixes (NSS): - When running with NSS enabled, make sure that NSS knows to expect nonblocking sockets. Previously, we set our TCP sockets as nonblocking, but did not tell NSS, which in turn could lead to unexpected blocking behavior. Fixes bug 40035; bugfix on 0.3.5.1-alpha. o Major bugfixes (onion services, DoS): - Correct handling of parameters for the onion service DoS defense. Previously, the consensus parameters for the onion service DoS defenses were overwriting the parameters set by the service operator using HiddenServiceEnableIntroDoSDefense. Fixes bug 40109; bugfix on 0.4.2.1-alpha. o Major bugfixes (stats, onion services): - Fix a bug where we were undercounting the Tor network's total onion service traffic, by ignoring any traffic originating from clients. Now we count traffic from both clients and services. Fixes bug 40117; bugfix on 0.2.6.2-alpha. o Minor features (security): - Channels using obsolete versions of the Tor link protocol are no longer allowed to circumvent address-canonicity checks. (This is only a minor issue, since such channels have no way to set ed25519 keys, and therefore should always be rejected for circuits that specify ed25519 identities.) Closes ticket 40081. o Minor features (bootstrap reporting): - Report more detailed reasons for bootstrap failure when the failure happens due to a TLS error. Previously we would just call these errors "MISC" when they happened during read, and "DONE" when they happened during any other TLS operation. Closes ticket 32622. o Minor features (client-only compilation): - Disable more code related to the ext_orport protocol when compiling without support for relay mode. Closes ticket 33368. - Disable more of our self-testing code when support for relay mode is disabled. Closes ticket 33370. - Most server-side DNS code is now disabled when building without support for relay mode. Closes ticket 33366. o Minor features (code safety): - Check for failures of tor_inet_ntop() and tor_inet_ntoa() functions in DNS and IP address processing code, and adjust codepaths to make them less likely to crash entire Tor instances. Resolves issue 33788. o Minor features (continuous integration): - Run unit-test and integration test (Stem, Chutney) jobs with ALL_BUGS_ARE_FATAL macro being enabled on Travis and Appveyor. Resolves ticket 32143. o Minor features (control port): - If a ClientName was specified in ONION_CLIENT_AUTH_ADD for an onion service, display it when we use ONION_CLIENT_AUTH_VIEW. Closes ticket 40089. Patch by Neel Chauhan. - Return a descriptive error message from the 'GETINFO status/fresh- relay-descs' command on the control port. Previously, we returned a generic error of "Error generating descriptor". Closes ticket 32873. Patch by Neel Chauhan. o Minor features (defense in depth): - Wipe more data from connection address fields before returning them to the memory heap. Closes ticket 6198. o Minor features (denial-of-service memory limiter): - Allow the user to configure even lower values for the MaxMemInQueues parameter. Relays now enforce a minimum of 64 MB, when previously the minimum was 256 MB. On clients, there is no minimum. Relays and clients will both warn if the value is set so low that Tor is likely to stop working. Closes ticket 24308. o Minor features (developer tooling): - Add a script to help check the alphabetical ordering of option names in the manual page. Closes ticket 33339. - Refrain from listing all .a files that are generated by the Tor build in .gitignore. Add a single wildcard *.a entry that covers all of them for present and future. Closes ticket 33642. - Add a script ("git-install-tools.sh") to install git hooks and helper scripts. Closes ticket 33451. o Minor features (directory authority): - Authorities now recommend the protocol versions that are supported by Tor 0.3.5 and later. (Earlier versions of Tor have been deprecated since January of this year.) This recommendation will cause older clients and relays to give a warning on startup, or when they download a consensus directory. Closes ticket 32696. o Minor features (directory authority, shared random): - Refactor more authority-only parts of the shared-random scheduling code to reside in the dirauth module, and to be disabled when compiling with --disable-module-dirauth. Closes ticket 33436. o Minor features (directory): - Remember the number of bytes we have downloaded for each directory purpose while bootstrapping, and while fully bootstrapped. Log this information as part of the heartbeat message. Closes ticket 32720. o Minor features (entry guards): - Reinstate support for GUARD NEW/UP/DOWN control port events. Closes ticket 40001. o Minor features (IPv6 support): - Adds IPv6 support to tor_addr_is_valid(). Adds tests for the above changes and tor_addr_is_null(). Closes ticket 33679. Patch by MrSquanchee. - Allow clients and relays to send dual-stack and IPv6-only EXTEND2 cells. Parse dual-stack and IPv6-only EXTEND2 cells on relays. Closes ticket 33901. o Minor features (linux seccomp2 sandbox, portability): - Allow Tor to build on platforms where it doesn't know how to report which syscall caused the linux seccomp2 sandbox to fail. This change should make the sandbox code more portable to less common Linux architectures. Closes ticket 34382. - Permit the unlinkat() syscall, which some Libc implementations use to implement unlink(). Closes ticket 33346. o Minor features (logging): - When trying to find our own address, add debug-level logging to report the sources of candidate addresses. Closes ticket 32888. o Minor features (onion service client, SOCKS5): - Add 3 new SocksPort ExtendedErrors (F2, F3, F7) that reports back new type of onion service connection failures. The semantics of these error codes are documented in proposal 309. Closes ticket 32542. o Minor features (onion service v3): - If a service cannot upload its descriptor(s), log why at INFO level. Closes ticket 33400; bugfix on 0.3.2.1-alpha. o Minor features (python scripts): - Stop assuming that /usr/bin/python exists. Instead of using a hardcoded path in scripts that still use Python 2, use /usr/bin/env, similarly to the scripts that use Python 3. Fixes bug 33192; bugfix on 0.4.2. o Minor features (testing, architecture): - Our test scripts now double-check that subsystem initialization order is consistent with the inter-module dependencies established by our .may_include files. Implements ticket 31634. - Initialize all subsystems at the beginning of our unit test harness, to avoid crashes due to uninitialized subsystems. Follow- up from ticket 33316. - Our "make check" target now runs the unit tests in 8 parallel chunks. Doing this speeds up hardened CI builds by more than a factor of two. Closes ticket 40098. o Minor features (v3 onion services): - Add v3 onion service status to the dumpstats() call which is triggered by a SIGUSR1 signal. Previously, we only did v2 onion services. Closes ticket 24844. Patch by Neel Chauhan. o Minor features (windows): - Add support for console control signals like Ctrl+C in Windows. Closes ticket 34211. Patch from Damon Harris (TheDcoder). o Minor bugfixes (control port, onion service): - Consistently use 'address' in "Invalid v3 address" response to ONION_CLIENT_AUTH commands. Previously, we would sometimes say 'addr'. Fixes bug 40005; bugfix on 0.4.3.1-alpha. o Minor bugfixes (correctness, buffers): - Fix a correctness bug that could cause an assertion failure if we ever tried using the buf_move_all() function with an empty input buffer. As far as we know, no released versions of Tor do this. Fixes bug 40076; bugfix on 0.3.3.1-alpha. o Minor bugfixes (directory authorities): - Directory authorities now reject votes that arrive too late. In particular, once an authority has started fetching missing votes, it no longer accepts new votes posted by other authorities. This change helps prevent a consensus split, where only some authorities have the late vote. Fixes bug 4631; bugfix on 0.2.0.5-alpha. o Minor bugfixes (git scripts): - Stop executing the checked-out pre-commit hook from the pre-push hook. Instead, execute the copy in the user's git directory. Fixes bug 33284; bugfix on 0.4.1.1-alpha. o Minor bugfixes (initialization): - Initialize the subsystems in our code in an order more closely corresponding to their dependencies, so that every system is initialized before the ones that (theoretically) depend on it. Fixes bug 33316; bugfix on 0.4.0.1-alpha. o Minor bugfixes (IPv4, relay): - Check for invalid zero IPv4 addresses and ports when sending and receiving extend cells. Fixes bug 33900; bugfix on 0.2.4.8-alpha. o Minor bugfixes (IPv6, relay): - Consider IPv6 addresses when checking if a connection is canonical. In 17604, relays assumed that a remote relay could consider an IPv6 connection canonical, but did not set the canonical flag on their side of the connection. Fixes bug 33899; bugfix on 0.3.1.1-alpha. - Log IPv6 addresses on connections where this relay is the responder. Previously, responding relays would replace the remote IPv6 address with the IPv4 address from the consensus. Fixes bug 33899; bugfix on 0.3.1.1-alpha. o Minor bugfixes (linux seccomp2 sandbox): - Fix a regression on sandboxing rules for the openat() syscall. The fix for bug 25440 fixed the problem on systems with glibc >= 2.27 but broke with versions of glibc. We now choose a rule based on the glibc version. Patch from Daniel Pinto. Fixes bug 27315; bugfix on 0.3.5.11. - Makes the seccomp sandbox allow the correct syscall for opendir according to the running glibc version. This fixes crashes when reloading torrc with sandbox enabled when running on glibc 2.15 to 2.21 and 2.26. Patch from Daniel Pinto. Fixes bug 40020; bugfix on 0.3.5.11. o Minor bugfixes (logging, testing): - Make all of tor's assertion macros support the ALL_BUGS_ARE_FATAL and DISABLE_ASSERTS_IN_UNIT_TESTS debugging modes. (IF_BUG_ONCE() used to log a non-fatal warning, regardless of the debugging mode.) Fixes bug 33917; bugfix on 0.2.9.1-alpha. - Remove surprising empty line in the INFO-level log about circuit build timeout. Fixes bug 33531; bugfix on 0.3.3.1-alpha. o Minor bugfixes (mainloop): - Better guard against growing a buffer past its maximum 2GB in size. Fixes bug 33131; bugfix on 0.3.0.4-rc. o Minor bugfixes (onion service v3 client): - Remove a BUG() warning that could occur naturally. Fixes bug 34087; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service, logging): - Fix a typo in a log message PublishHidServDescriptors is set to 0. Fixes bug 33779; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services v3): - Avoid a non-fatal assertion failure in certain edge-cases when opening an intro circuit as a client. Fixes bug 34084; bugfix on 0.3.2.1-alpha. o Minor bugfixes (protocol versions): - Sort tor's supported protocol version lists, as recommended by the tor directory specification. Fixes bug 33285; bugfix on 0.4.0.1-alpha. o Minor bugfixes (rate limiting, bridges, pluggable transports): - On a bridge, treat all connections from an ExtORPort as remote by default for the purposes of rate-limiting. Previously, bridges would treat the connection as local unless they explicitly received a "USERADDR" command. ExtORPort connections still count as local if there is a USERADDR command with an explicit local address. Fixes bug 33747; bugfix on 0.2.5.1-alpha. o Minor bugfixes (refactoring): - Lift circuit_build_times_disabled() out of the circuit_expire_building() loop, to save CPU time when there are many circuits open. Fixes bug 33977; bugfix on 0.3.5.9. o Minor bugfixes (relay, self-testing): - When starting up as a relay, if we haven't been able to verify that we're reachable, only launch reachability tests at most once a minute. Previously, we had been launching tests up to once a second, which was needlessly noisy. Fixes bug 40083; bugfix on 0.2.8.1-alpha. o Minor bugfixes (relay, usability): - Adjust the rules for when to warn about having too many connections to other relays. Previously we'd tolerate up to 1.5 connections per relay on average. Now we tolerate more connections for directory authorities, and raise the number of total connections we need to see before we warn. Fixes bug 33880; bugfix on 0.3.1.1-alpha. o Minor bugfixes (SOCKS, onion service client): - Detect v3 onion service addresses of the wrong length when returning the F6 ExtendedErrors code. Fixes bug 33873; bugfix on 0.4.3.1-alpha. o Minor bugfixes (tests): - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run on its own. Previously, it would exit with an error. Fixes bug 40099; bugfix on 0.2.8.1-alpha. o Minor bugfixes (v3 onion services): - Remove a BUG() warning that could trigger in certain unlikely edge-cases. Fixes bug 34086; bugfix on 0.3.2.1-alpha. - Remove a BUG() that was causing a stacktrace when a descriptor changed at an unexpected time. Fixes bug 28992; bugfix on 0.3.2.1-alpha. o Minor bugfixes (windows): - Fix a bug that prevented Tor from starting if its log file grew above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha. o Code simplification and refactoring: - Define and use a new constant TOR_ADDRPORT_BUF_LEN which is like TOR_ADDR_BUF_LEN but includes enough space for an IP address, brackets, separating colon, and port number. Closes ticket 33956. Patch by Neel Chauhan. - Merge the orconn and ocirc events into the "core" subsystem, which manages or connections and origin circuits. Previously they were isolated in subsystems of their own. - Move LOG_PROTOCOL_WARN to app/config. Resolves a dependency inversion. Closes ticket 33633. - Move the circuit extend code to the relay module. Split the circuit extend function into smaller functions. Closes ticket 33633. - Rewrite port_parse_config() to use the default port flags from port_cfg_new(). Closes ticket 32994. Patch by MrSquanchee. - Updated comments in 'scheduler.c' to reflect old code changes, and simplified the scheduler channel state change code. Closes ticket 33349. - Refactor configuration parsing to use the new config subsystem code. Closes ticket 33014. - Move a series of functions related to address resolving into their own files. Closes ticket 33789. o Documentation: - Replace most http:// URLs in our code and documentation with https:// URLs. (We have left unchanged the code in src/ext/, and the text in LICENSE.) Closes ticket 31812. Patch from Jeremy Rand. - Document the limitations of using %include on config files with seccomp sandbox enabled. Fixes documentation bug 34133; bugfix on 0.3.1.1-alpha. Patch by Daniel Pinto. o Removed features: - Our "check-local" test target no longer tries to use the Coccinelle semantic patching tool parse all the C files. While it is a good idea to try to make sure Coccinelle works on our C before we run a Coccinelle patch, doing so on every test run has proven to be disruptive. You can still run this tool manually with "make check-cocci". Closes ticket 40030. - Remove the ClientAutoIPv6ORPort option. This option attempted to randomly choose between IPv4 and IPv6 for client connections, and wasn't a true implementation of Happy Eyeballs. Often, this option failed on IPv4-only or IPv6-only connections. Closes ticket 32905. Patch by Neel Chauhan. - Stop shipping contrib/dist/rc.subr file, as it is not being used on FreeBSD anymore. Closes issue 31576. o Testing: - Add a basic IPv6 test to "make test-network". This test only runs when the local machine has an IPv6 stack. Closes ticket 33300. - Add test-network-ipv4 and test-network-ipv6 jobs to the Makefile. These jobs run the IPv4-only and dual-stack chutney flavours from test-network-all. Closes ticket 33280. - Remove a redundant distcheck job. Closes ticket 33194. - Run the test-network-ipv6 Makefile target in the Travis CI IPv6 chutney job. This job runs on macOS, so it's a bit slow. Closes ticket 33303. - Sort the Travis jobs in order of speed. Putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194. - Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires allow_failure), to speed up the build. Closes ticket 33195. - Test v3 onion services to tor's mixed IPv4 chutney network. And add a mixed IPv6 chutney network. These networks are used in the test-network-all, test-network-ipv4, and test-network-ipv6 make targets. Closes ticket 33334. - Use the "bridges+hs-v23" chutney network flavour in "make test- network". This test requires a recent version of chutney (mid- February 2020). Closes ticket 28208. - When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792. o Deprecated features (onion service v2): - Add a deprecation warning for version 2 onion services. Closes ticket 40003. o Documentation (manual page): - Add cross reference links and a table of contents to the HTML tor manual page. Closes ticket 33369. Work by Swati Thacker as part of Google Season of Docs. - Alphabetize the Denial of Service Mitigation Options, Directory Authority Server Options, Hidden Service Options, and Testing Network Options sections of the tor(1) manual page. Closes ticket 33275. Work by Swati Thacker as part of Google Season of Docs. - Refrain from mentioning nicknames in manpage section for MyFamily torrc option. Resolves issue 33417. - Updated the options set by TestingTorNetwork in the manual page. Closes ticket 33778. Changes in version 0.3.5.11 - 2020-07-09 Tor 0.3.5.11 backports fixes from later tor releases, including several usability, portability, and reliability fixes. This release also fixes TROVE-2020-001, a medium-severity denial of service vulnerability affecting all versions of Tor when compiled with the NSS encryption library. (This is not the default configuration.) Using this vulnerability, an attacker could cause an affected Tor instance to crash remotely. This issue is also tracked as CVE-2020- 15572. Anybody running a version of Tor built with the NSS library should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha or later. o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha): - Fix a crash due to an out-of-bound memory access when Tor is compiled with NSS support. Fixes bug 33119; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001 and CVE-2020-15572. o Major bugfixes (DoS defenses, bridges, pluggable transport, backport from 0.4.3.4-rc): - Fix a bug that was preventing DoS defenses from running on bridges with a pluggable transport. Previously, the DoS subsystem was not given the transport name of the client connection, thus failed to find the GeoIP cache entry for that client address. Fixes bug 33491; bugfix on 0.3.3.2-alpha. o Minor features (testing, backport from 0.4.3.4-rc): - The unit tests now support a "TOR_SKIP_TESTCASES" environment variable to specify a list of space-separated test cases that should not be executed. We will use this to disable certain tests that are failing on Appveyor because of mismatched OpenSSL libraries. Part of ticket 33643. o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha): - Use the correct 64-bit printf format when compiling with MINGW on Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha. o Minor bugfix (relay, configuration, backport from 0.4.3.3-alpha): - Warn if the ContactInfo field is not set, and tell the relay operator that not having a ContactInfo field set might cause their relay to get rejected in the future. Fixes bug 33361; bugfix on 0.1.1.10-alpha. o Minor bugfixes (client performance, backport from 0.4.4.1-alpha): - Resume use of preemptively-built circuits when UseEntryGuards is set to 0. We accidentally disabled this feature with that config setting, leading to slower load times. Fixes bug 34303; bugfix on 0.3.3.2-alpha. o Minor bugfixes (compiler compatibility, backport from 0.4.3.5): - Avoid compiler warnings from Clang 10 related to the use of GCC- style "/* falls through */" comments. Both Clang and GCC allow __attribute__((fallthrough)) instead, so that's what we're using now. Fixes bug 34078; bugfix on 0.3.1.3-alpha. o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha): - Fix a compiler warning on platforms with 32-bit time_t values. Fixes bug 40028; bugfix on 0.3.2.8-rc. o Minor bugfixes (embedded Tor, backport from 0.4.3.1-alpha): - When starting Tor any time after the first time in a process, register the thread in which it is running as the main thread. Previously, we only did this on Windows, which could lead to bugs like 23081 on non-Windows platforms. Fixes bug 32884; bugfix on 0.3.3.1-alpha. o Minor bugfixes (key portability, backport from 0.4.3.4-rc): - When reading PEM-encoded key data, tolerate CRLF line-endings even if we are not running on Windows. Previously, non-Windows hosts would reject these line-endings in certain positions, making certain key files hard to move from one host to another. Fixes bug 33032; bugfix on 0.3.5.1-alpha. o Minor bugfixes (logging, backport from 0.4.4.2-alpha): - Downgrade a noisy log message that could occur naturally when receiving an extrainfo document that we no longer want. Fixes bug 16016; bugfix on 0.2.6.3-alpha. o Minor bugfixes (onion service v3, client, backport from 0.4.3.3-alpha): - Remove a BUG() warning that would cause a stack trace if an onion service descriptor was freed while we were waiting for a rendezvous circuit to complete. Fixes bug 28992; bugfix on 0.3.2.1-alpha. o Testing (CI, backport from 0.4.3.4-rc): - In our Appveyor Windows CI, copy required DLLs to test and app directories, before running tor's tests. This ensures that tor.exe and test*.exe use the correct version of each DLL. This fix is not required, but we hope it will avoid DLL search issues in future. Fixes bug 33673; bugfix on 0.3.4.2-alpha. - On Appveyor, skip the crypto/openssl_version test, which is failing because of a mismatched library installation. Fix for 33643. Changes in version 0.4.2.8 - 2020-07-09 Tor 0.4.2.8 backports various fixes from later releases, including several that affect usability and portability. This release also fixes TROVE-2020-001, a medium-severity denial of service vulnerability affecting all versions of Tor when compiled with the NSS encryption library. (This is not the default configuration.) Using this vulnerability, an attacker could cause an affected Tor instance to crash remotely. This issue is also tracked as CVE-2020- 15572. Anybody running a version of Tor built with the NSS library should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha or later. o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha): - Fix a crash due to an out-of-bound memory access when Tor is compiled with NSS support. Fixes bug 33119; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001 and CVE-2020-15572. o Major bugfixes (DoS defenses, bridges, pluggable transport, backport from 0.4.3.4-rc): - Fix a bug that was preventing DoS defenses from running on bridges with a pluggable transport. Previously, the DoS subsystem was not given the transport name of the client connection, thus failed to find the GeoIP cache entry for that client address. Fixes bug 33491; bugfix on 0.3.3.2-alpha. o Minor feature (sendme, flow control, backport form 0.4.3.4-rc): - Default to sending SENDME version 1 cells. (Clients are already sending these, because of a consensus parameter telling them to do so: this change only affects what clients would do if the consensus didn't contain a recommendation.) Closes ticket 33623. o Minor features (diagnostic, backport from 0.4.3.3-alpha): - Improve assertions and add some memory-poisoning code to try to track down possible causes of a rare crash (32564) in the EWMA code. Closes ticket 33290. o Minor features (testing, backport from 0.4.3.4-rc): - The unit tests now support a "TOR_SKIP_TESTCASES" environment variable to specify a list of space-separated test cases that should not be executed. We will use this to disable certain tests that are failing on Appveyor because of mismatched OpenSSL libraries. Part of ticket 33643. o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha): - Use the correct 64-bit printf format when compiling with MINGW on Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha. o Minor bugfix (relay, configuration, backport from 0.4.3.3-alpha): - Warn if the ContactInfo field is not set, and tell the relay operator that not having a ContactInfo field set might cause their relay to get rejected in the future. Fixes bug 33361; bugfix on 0.1.1.10-alpha. o Minor bugfixes (client performance, backport from 0.4.4.1-alpha): - Resume use of preemptively-built circuits when UseEntryGuards is set to 0. We accidentally disabled this feature with that config setting, leading to slower load times. Fixes bug 34303; bugfix on 0.3.3.2-alpha. o Minor bugfixes (compiler compatibility, backport from 0.4.3.5): - Avoid compiler warnings from Clang 10 related to the use of GCC- style "/* falls through */" comments. Both Clang and GCC allow __attribute__((fallthrough)) instead, so that's what we're using now. Fixes bug 34078; bugfix on 0.3.1.3-alpha. - Fix compilation warnings with GCC 10.0.1. Fixes bug 34077; bugfix on 0.4.0.3-alpha. o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha): - Fix a compiler warning on platforms with 32-bit time_t values. Fixes bug 40028; bugfix on 0.3.2.8-rc. o Minor bugfixes (controller protocol, backport from 0.4.3.2-alpha): - When receiving "ACTIVE" or "DORMANT" signals on the control port, report them as SIGNAL events. Previously we would log a bug warning. Fixes bug 33104; bugfix on 0.4.0.1-alpha. o Minor bugfixes (embedded Tor, backport from 0.4.3.1-alpha): - When starting Tor any time after the first time in a process, register the thread in which it is running as the main thread. Previously, we only did this on Windows, which could lead to bugs like 23081 on non-Windows platforms. Fixes bug 32884; bugfix on 0.3.3.1-alpha. o Minor bugfixes (key portability, backport from 0.4.3.4-rc): - When reading PEM-encoded key data, tolerate CRLF line-endings even if we are not running on Windows. Previously, non-Windows hosts would reject these line-endings in certain positions, making certain key files hard to move from one host to another. Fixes bug 33032; bugfix on 0.3.5.1-alpha. o Minor bugfixes (logging, backport from 0.4.3.2-rc): - When logging a bug, do not say "Future instances of this warning will be silenced" unless we are actually going to silence them. Previously we would say this whenever a BUG() check failed in the code. Fixes bug 33095; bugfix on 0.4.1.1-alpha. o Minor bugfixes (logging, backport from 0.4.3.4-rc): - Flush stderr, stdout, and file logs during shutdown, if supported by the OS. This change helps make sure that any final logs are recorded. Fixes bug 33087; bugfix on 0.4.1.6. o Minor bugfixes (logging, backport from 0.4.4.2-alpha): - Downgrade a noisy log message that could occur naturally when receiving an extrainfo document that we no longer want. Fixes bug 16016; bugfix on 0.2.6.3-alpha. o Minor bugfixes (onion service v3, client, backport from 0.4.3.3-alpha): - Remove a BUG() warning that would cause a stack trace if an onion service descriptor was freed while we were waiting for a rendezvous circuit to complete. Fixes bug 28992; bugfix on 0.3.2.1-alpha. o Testing (CI, backport from 0.4.3.4-rc): - In our Appveyor Windows CI, copy required DLLs to test and app directories, before running tor's tests. This ensures that tor.exe and test*.exe use the correct version of each DLL. This fix is not required, but we hope it will avoid DLL search issues in future. Fixes bug 33673; bugfix on 0.3.4.2-alpha. - On Appveyor, skip the crypto/openssl_version test, which is failing because of a mismatched library installation. Fix for 33643. Changes in version 0.4.3.6 - 2020-07-09 Tor 0.4.3.6 backports several bugfixes from later releases, including some affecting usability. This release also fixes TROVE-2020-001, a medium-severity denial of service vulnerability affecting all versions of Tor when compiled with the NSS encryption library. (This is not the default configuration.) Using this vulnerability, an attacker could cause an affected Tor instance to crash remotely. This issue is also tracked as CVE-2020- 15572. Anybody running a version of Tor built with the NSS library should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha or later. o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha): - Fix a crash due to an out-of-bound memory access when Tor is compiled with NSS support. Fixes bug 33119; bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001 and CVE-2020-15572. o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha): - Use the correct 64-bit printf format when compiling with MINGW on Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha. o Minor bugfixes (client performance, backport from 0.4.4.1-alpha): - Resume use of preemptively-built circuits when UseEntryGuards is set to 0. We accidentally disabled this feature with that config setting, leading to slower load times. Fixes bug 34303; bugfix on 0.3.3.2-alpha. o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha): - Fix a compiler warning on platforms with 32-bit time_t values. Fixes bug 40028; bugfix on 0.3.2.8-rc. o Minor bugfixes (linux seccomp sandbox, nss, backport from 0.4.4.1-alpha): - Fix a startup crash when tor is compiled with --enable-nss and sandbox support is enabled. Fixes bug 34130; bugfix on 0.3.5.1-alpha. Patch by Daniel Pinto. o Minor bugfixes (logging, backport from 0.4.4.2-alpha): - Downgrade a noisy log message that could occur naturally when receiving an extrainfo document that we no longer want. Fixes bug 16016; bugfix on 0.2.6.3-alpha. o Minor bugfixes (manual page, backport from 0.4.4.1-alpha): - Update the man page to reflect that MinUptimeHidServDirectoryV2 defaults to 96 hours. Fixes bug 34299; bugfix on 0.2.6.3-alpha. o Minor bugfixes (onion service v3, backport from 0.4.4.1-alpha): - Prevent an assert() that would occur when cleaning the client descriptor cache, and attempting to close circuits for a non- decrypted descriptor (lacking client authorization). Fixes bug 33458; bugfix on 0.4.2.1-alpha. o Minor bugfixes (portability, backport from 0.4.4.1-alpha): - Fix a portability error in the configure script, where we were using "==" instead of "=". Fixes bug 34233; bugfix on 0.4.3.5. o Minor bugfixes (relays, backport from 0.4.4.1-alpha): - Stop advertising incorrect IPv6 ORPorts in relay and bridge descriptors, when the IPv6 port was configured as "auto". Fixes bug 32588; bugfix on 0.2.3.9-alpha. o Documentation (backport from 0.4.4.1-alpha): - Fix several doxygen warnings related to imbalanced groups. Closes ticket 34255. Changes in version 0.4.3.5 - 2020-05-15 Tor 0.4.3.5 is the first stable release in the 0.4.3.x series. This series adds support for building without relay code enabled, and implements functionality needed for OnionBalance with v3 onion services. It includes significant refactoring of our configuration and controller functionality, and fixes numerous smaller bugs and performance issues. Per our support policy, we support each stable release series for nine months after its first stable release, or three months after the first stable release of the next series: whichever is longer. This means that 0.4.3.x will be supported until around February 2021--later, if 0.4.4.x is later than anticipated. Note also that support for 0.4.1.x is about to end on May 20 of this year; 0.4.2.x will be supported until September 15. We still plan to continue supporting 0.3.5.x, our long-term stable series, until Feb 2022. Below are the changes since 0.4.2.6. For a list of only the changes since 0.4.3.4-rc, see the ChangeLog file. o New system requirements: - When building Tor, you now need to have Python 3 in order to run the integration tests. (Python 2 is officially unsupported upstream, as of 1 Jan 2020.) Closes ticket 32608. o Major features (build system): - The relay code can now be disabled using the --disable-module-relay configure option. When this option is set, we also disable the dirauth module. Closes ticket 32123. - When Tor is compiled --disable-module-relay, we also omit the code used to act as a directory cache. Closes ticket 32487. o Major features (directory authority, ed25519): - Add support for banning a relay's ed25519 keys in the approved- routers file. This will help us migrate away from RSA keys in the future. Previously, only RSA keys could be banned in approved- routers. Resolves ticket 22029. Patch by Neel Chauhan. o Major features (onion services): - New control port commands to manage client-side onion service authorization credentials. The ONION_CLIENT_AUTH_ADD command adds a credential, ONION_CLIENT_AUTH_REMOVE deletes a credential, and ONION_CLIENT_AUTH_VIEW lists the credentials. Closes ticket 30381. - Introduce a new SocksPort flag, ExtendedErrors, to support more detailed error codes in information for applications that support them. Closes ticket 30382; implements proposal 304. o Major features (proxy): - In addition to its current supported proxy types (HTTP CONNECT, SOCKS4, and SOCKS5), Tor can now make its OR connections through a HAProxy server. A new torrc option was added to specify the address/port of the server: TCPProxy :. Currently the only supported protocol for the option is haproxy. Closes ticket 31518. Patch done by Suphanat Chunhapanya (haxxpop). o Major bugfixes (security, denial-of-service): - Fix a denial-of-service bug that could be used by anyone to consume a bunch of CPU on any Tor relay or authority, or by directories to consume a bunch of CPU on clients or hidden services. Because of the potential for CPU consumption to introduce observable timing patterns, we are treating this as a high-severity security issue. Fixes bug 33119; bugfix on 0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue as TROVE-2020-002 and CVE-2020-10592. o Major bugfixes (circuit padding, memory leak): - Avoid a remotely triggered memory leak in the case that a circuit padding machine is somehow negotiated twice on the same circuit. Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls. This is also tracked as TROVE-2020-004 and CVE-2020-10593. o Major bugfixes (directory authority): - Directory authorities will now send a 503 (not enough bandwidth) code to clients when under bandwidth pressure. Known relays and other authorities will always be answered regardless of the bandwidth situation. Fixes bug 33029; bugfix on 0.1.2.5-alpha. o Major bugfixes (DoS defenses, bridges, pluggable transport): - Fix a bug that was preventing DoS defenses from running on bridges with a pluggable transport. Previously, the DoS subsystem was not given the transport name of the client connection, thus failed to find the GeoIP cache entry for that client address. Fixes bug 33491; bugfix on 0.3.3.2-alpha. o Major bugfixes (networking): - Correctly handle IPv6 addresses in SOCKS5 RESOLVE_PTR requests, and accept strings as well as binary addresses. Fixes bug 32315; bugfix on 0.3.5.1-alpha. o Major bugfixes (onion service): - Report HS circuit failure back into the HS subsystem so we take appropriate action with regards to the client introduction point failure cache. This improves reachability of onion services, since now clients notice failing introduction circuits properly. Fixes bug 32020; bugfix on 0.3.2.1-alpha. o Minor feature (heartbeat, onion service): - Add the DoS INTRODUCE2 defenses counter to the heartbeat DoS message. Closes ticket 31371. o Minor feature (sendme, flow control): - Default to sending SENDME version 1 cells. (Clients are already sending these, because of a consensus parameter telling them to do so: this change only affects what clients would do if the consensus didn't contain a recommendation.) Closes ticket 33623. o Minor features (best practices tracker): - Practracker now supports a --regen-overbroad option to regenerate the exceptions file, but only to revise exceptions to be _less_ tolerant of best-practices violations. Closes ticket 32372. o Minor features (configuration validation): - Configuration validation can now be done by per-module callbacks, rather than a global validation function. This will let us reduce the size of config.c and some of its more cumbersome functions. Closes ticket 31241. o Minor features (configuration): - If a configured hardware crypto accelerator in AccelName is prefixed with "!", Tor now exits when it cannot be found. Closes ticket 32406. - We now use flag-driven logic to warn about obsolete configuration fields, so that we can include their names. In 0.4.2, we used a special type, which prevented us from generating good warnings. Implements ticket 32404. o Minor features (configure, build system): - Output a list of enabled/disabled features at the end of the configure process in a pleasing way. Closes ticket 31373. o Minor features (continuous integration): - Run Doxygen Makefile target on Travis, so we can learn about regressions in our internal documentation. Closes ticket 32455. - Stop allowing failures on the Travis CI stem tests job. It looks like all the stem hangs we were seeing before are now fixed. Closes ticket 33075. o Minor features (controller): - Add stream isolation data to STREAM event. Closes ticket 19859. - Implement a new GETINFO command to fetch microdescriptor consensus. Closes ticket 31684. o Minor features (debugging, directory system): - Don't crash when we find a non-guard with a guard-fraction value set. Instead, log a bug warning, in an attempt to figure out how this happened. Diagnostic for ticket 32868. o Minor features (defense in depth): - Add additional checks around tor_vasprintf() usage, in case the function returns an error. Patch by Tobias Stoeckmann. Fixes ticket 31147. o Minor features (developer tools): - Remove the 0.2.9.x series branches from git scripts (git-merge- forward.sh, git-pull-all.sh, git-push-all.sh, git-setup-dirs.sh). Closes ticket 32772. - Add a check_cocci_parse.sh script that checks that new code is parseable by Coccinelle. Add an exceptions file for unparseable files, and run the script from travis CI. Closes ticket 31919. - Call the check_cocci_parse.sh script from a 'check-cocci' Makefile target. Closes ticket 31919. - Add a rename_c_identifiers.py tool to rename a bunch of C identifiers at once, and generate a well-formed commit message describing the change. This should help with refactoring. Closes ticket 32237. - Add some scripts in "scripts/coccinelle" to invoke the Coccinelle semantic patching tool with the correct flags. These flags are fairly easy to forget, and these scripts should help us use Coccinelle more effectively in the future. Closes ticket 31705. o Minor features (diagnostic): - Improve assertions and add some memory-poisoning code to try to track down possible causes of a rare crash (32564) in the EWMA code. Closes ticket 33290. o Minor features (directory authorities): - Directory authorities now reject descriptors from relays running Tor versions from the 0.2.9 and 0.4.0 series. The 0.3.5 series is still allowed. Resolves ticket 32672. Patch by Neel Chauhan. o Minor features (Doxygen): - Update Doxygen configuration file to a more recent template (from 1.8.15). Closes ticket 32110. - "make doxygen" now works with out-of-tree builds. Closes ticket 32113. - Make sure that doxygen outputs documentation for all of our C files. Previously, some were missing @file declarations, causing them to be ignored. Closes ticket 32307. - Our "make doxygen" target now respects --enable-fatal-warnings by default, and does not warn about items that are missing documentation. To warn about missing documentation, run configure with the "--enable-missing-doc-warnings" flag: doing so suspends fatal warnings for doxygen. Closes ticket 32385. o Minor features (git scripts): - Add TOR_EXTRA_CLONE_ARGS to git-setup-dirs.sh for git clone customisation. Closes ticket 32347. - Add git-setup-dirs.sh, which sets up an upstream git repository and worktrees for tor maintainers. Closes ticket 29603. - Add TOR_EXTRA_REMOTE_* to git-setup-dirs.sh for a custom extra remote. Closes ticket 32347. - Call the check_cocci_parse.sh script from the git commit and push hooks. Closes ticket 31919. - Make git-push-all.sh skip unchanged branches when pushing to upstream. The script already skipped unchanged test branches. Closes ticket 32216. - Make git-setup-dirs.sh create a master symlink in the worktree directory. Closes ticket 32347. - Skip unmodified source files when doing some existing git hook checks. Related to ticket 31919. o Minor features (IPv6, client): - Make Tor clients tell dual-stack exits that they prefer IPv6 connections. This change is equivalent to setting the PreferIPv6 flag on SOCKSPorts (and most other listener ports). Tor Browser has been setting this flag for some time, and we want to remove a client distinguisher at exits. Closes ticket 32637. o Minor features (portability, android): - When building for Android, disable some tests that depend on $HOME and/or pwdb, which Android doesn't have. Closes ticket 32825. Patch from Hans-Christoph Steiner. o Minor features (relay modularity): - Split the relay and server pluggable transport config code into separate files in the relay module. Disable this code when the relay module is disabled. Closes part of ticket 32213. - When the relay module is disabled, reject attempts to set the ORPort, DirPort, DirCache, BridgeRelay, ExtORPort, or ServerTransport* options, rather than ignoring the values of these options. Closes part of ticket 32213. - When the relay module is disabled, change the default config so that DirCache is 0, and ClientOnly is 1. Closes ticket 32410. o Minor features (release tools): - Port our ChangeLog formatting and sorting tools to Python 3. Closes ticket 32704. o Minor features (testing): - The unit tests now support a "TOR_SKIP_TESTCASES" environment variable to specify a list of space-separated test cases that should not be executed. We will use this to disable certain tests that are failing on Appveyor because of mismatched OpenSSL libraries. Part of ticket 33643. - Detect some common failure cases for test_parseconf.sh in src/test/conf_failures. Closes ticket 32451. - Allow test_parseconf.sh to test expected log outputs for successful configs, as well as failed configs. Closes ticket 32451. - The test_parseconf.sh script now supports result variants for any combination of the optional libraries lzma, nss, and zstd. Closes ticket 32397. - When running the unit tests on Android, create temporary files in a subdirectory of /data/local/tmp. Closes ticket 32172. Based on a patch from Hans-Christoph Steiner. o Minor features (usability): - Include more information when failing to parse a configuration value. This should make it easier to tell what's going wrong when a configuration file doesn't parse. Closes ticket 33460. o Minor bugfix (relay, configuration): - Warn if the ContactInfo field is not set, and tell the relay operator that not having a ContactInfo field set might cause their relay to get rejected in the future. Fixes bug 33361; bugfix on 0.1.1.10-alpha. o Minor bugfixes (bridges): - Lowercase the configured value of BridgeDistribution before adding it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha. o Minor bugfixes (build system): - Fix "make autostyle" for out-of-tree builds. Fixes bug 32370; bugfix on 0.4.1.2-alpha. o Minor bugfixes (compiler compatibility): - Avoid compiler warnings from Clang 10 related to the use of GCC- style "/* falls through */" comments. Both Clang and GCC allow __attribute__((fallthrough)) instead, so that's what we're using now. Fixes bug 34078; bugfix on 0.3.1.3-alpha. - Fix compilation warnings with GCC 10.0.1. Fixes bug 34077; bugfix on 0.4.0.3-alpha. o Minor bugfixes (configuration handling): - Make control_event_conf_changed() take in a config_line_t instead of a smartlist of alternating key/value entries. Fixes bug 31531; bugfix on 0.2.3.3-alpha. Patch by Neel Chauhan. - Check for multiplication overflow when parsing memory units inside configuration. Fixes bug 30920; bugfix on 0.0.9rc1. - When dumping the configuration, stop adding a trailing space after the option name when there is no option value. This issue only affects options that accept an empty value or list. (Most options reject empty values, or delete the entire line from the dumped options.) Fixes bug 32352; bugfix on 0.0.9pre6. - Avoid changing the user's value of HardwareAccel as stored by SAVECONF, when AccelName is set but HardwareAccel is not. Fixes bug 32382; bugfix on 0.2.2.1-alpha. - When creating a KeyDirectory with the same location as the DataDirectory (not recommended), respect the DataDirectory's group-readable setting if one has not been set for the KeyDirectory. Fixes bug 27992; bugfix on 0.3.3.1-alpha. o Minor bugfixes (continuous integration): - Remove the buggy and unused mirroring job. Fixes bug 33213; bugfix on 0.3.2.2-alpha. o Minor bugfixes (controller protocol): - When receiving "ACTIVE" or "DORMANT" signals on the control port, report them as SIGNAL events. Previously we would log a bug warning. Fixes bug 33104; bugfix on 0.4.0.1-alpha. o Minor bugfixes (controller): - In routerstatus_has_changed(), check all the fields that are output over the control port. Fixes bug 20218; bugfix on 0.1.1.11-alpha. o Minor bugfixes (developer tools): - Allow paths starting with ./ in scripts/add_c_file.py. Fixes bug 31336; bugfix on 0.4.1.2-alpha. o Minor bugfixes (dirauth module): - Split the dirauth config code into a separate file in the dirauth module. Disable this code when the dirauth module is disabled. Closes ticket 32213. - When the dirauth module is disabled, reject attempts to set the AuthoritativeDir option, rather than ignoring the value of the option. Fixes bug 32213; bugfix on 0.3.4.1-alpha. o Minor bugfixes (embedded Tor): - When starting Tor any time after the first time in a process, register the thread in which it is running as the main thread. Previously, we only did this on Windows, which could lead to bugs like 23081 on non-Windows platforms. Fixes bug 32884; bugfix on 0.3.3.1-alpha. o Minor bugfixes (git scripts): - Avoid sleeping before the last push in git-push-all.sh. Closes ticket 32216. - Forward all unrecognised arguments in git-push-all.sh to git push. Closes ticket 32216. o Minor bugfixes (key portability): - When reading PEM-encoded key data, tolerate CRLF line-endings even if we are not running on Windows. Previously, non-Windows hosts would reject these line-endings in certain positions, making certain key files hard to move from one host to another. Fixes bug 33032; bugfix on 0.3.5.1-alpha. o Minor bugfixes (logging): - Stop truncating IPv6 addresses and ports in channel and connection logs. Fixes bug 33918; bugfix on 0.2.4.4-alpha. - Flush stderr, stdout, and file logs during shutdown, if supported by the OS. This change helps make sure that any final logs are recorded. Fixes bug 33087; bugfix on 0.4.1.6. - Stop closing stderr and stdout during shutdown. Closing these file descriptors can hide sanitiser logs. Fixes bug 33087; bugfix on 0.4.1.6. - If we encounter a bug when flushing a buffer to a TLS connection, only log the bug once per invocation of the Tor process. Previously we would log with every occurrence, which could cause us to run out of disk space. Fixes bug 33093; bugfix on 0.3.2.2-alpha. - When logging a bug, do not say "Future instances of this warning will be silenced" unless we are actually going to silence them. Previously we would say this whenever a BUG() check failed in the code. Fixes bug 33095; bugfix on 0.4.1.1-alpha. o Minor bugfixes (onion services v2): - Move a series of v2 onion service warnings to protocol-warning level because they can all be triggered remotely by a malformed request. Fixes bug 32706; bugfix on 0.1.1.14-alpha. - When sending the INTRO cell for a v2 Onion Service, look at the failure cache alongside timeout values to check if the intro point is marked as failed. Previously, we only looked at the relay timeout values. Fixes bug 25568; bugfix on 0.2.7.3-rc. Patch by Neel Chauhan. o Minor bugfixes (onion services v3): - Remove a BUG() warning that would cause a stack trace if an onion service descriptor was freed while we were waiting for a rendezvous circuit to complete. Fixes bug 28992; bugfix on 0.3.2.1-alpha. - Relax severity of a log message that can appear naturally when decoding onion service descriptors as a relay. Also add some diagnostics to debug any future bugs in that area. Fixes bug 31669; bugfix on 0.3.0.1-alpha. - Fix an assertion failure that could result from a corrupted ADD_ONION control port command. Found by Saibato. Fixes bug 33137; bugfix on 0.3.3.1-alpha. This issue is also tracked as TROVE-2020-003. - Properly handle the client rendezvous circuit timeout. Previously Tor would sometimes timeout a rendezvous circuit awaiting the introduction ACK, and find itself unable to re-establish all circuits because the rendezvous circuit timed out too early. Fixes bug 32021; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services): - Do not rely on a "circuit established" flag for intro circuits but instead always query the HS circuit map. This is to avoid sync issue with that flag and the map. Fixes bug 32094; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services, all): - In cancel_descriptor_fetches(), use connection_list_by_type_purpose() instead of connection_list_by_type_state(). Fixes bug 32639; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (pluggable transports): - When receiving a message on standard error from a pluggable transport, log it at info level, rather than as a warning. Fixes bug 33005; bugfix on 0.4.0.1-alpha. o Minor bugfixes (rust, build): - Fix a syntax warning given by newer versions of Rust that was creating problems for our continuous integration. Fixes bug 33212; bugfix on 0.3.5.1-alpha. o Minor bugfixes (scripts): - Fix update_versions.py for out-of-tree builds. Fixes bug 32371; bugfix on 0.4.0.1-alpha. o Minor bugfixes (testing): - Use the same code to find the tor binary in all of our test scripts. This change makes sure we are always using the coverage binary when coverage is enabled. Fixes bug 32368; bugfix on 0.2.7.3-rc. - Stop ignoring "tor --dump-config" errors in test_parseconf.sh. Fixes bug 32468; bugfix on 0.4.2.1-alpha. - Our option-validation tests no longer depend on specially configured non-default, non-passing sets of options. Previously, the tests had been written to assume that options would _not_ be set to their defaults, which led to needless complexity and verbosity. Fixes bug 32175; bugfix on 0.2.8.1-alpha. o Minor bugfixes (TLS bug handling): - When encountering a bug in buf_read_from_tls(), return a "MISC" error code rather than "WANTWRITE". This change might help avoid some CPU-wasting loops if the bug is ever triggered. Bug reported by opara. Fixes bug 32673; bugfix on 0.3.0.4-alpha. o Deprecated features: - Deprecate the ClientAutoIPv6ORPort option. This option was not true "Happy Eyeballs", and often failed on connections that weren't reliably dual-stack. Closes ticket 32942. Patch by Neel Chauhan. o Documentation: - Provide a quickstart guide for a Circuit Padding Framework, and documentation for researchers to implement and study circuit padding machines. Closes ticket 28804. - Add documentation in 'HelpfulTools.md' to describe how to build a tag file. Closes ticket 32779. - Create a high-level description of the long-term software architecture goals. Closes ticket 32206. - Describe the --dump-config command in the manual page. Closes ticket 32467. - Unite coding advice from this_not_that.md in torguts repo into our coding standards document. Resolves ticket 31853. o Removed features: - Our Doxygen configuration no longer generates LaTeX output. The reference manual produced by doing this was over 4000 pages long, and generally unusable. Closes ticket 32099. - The option "TestingEstimatedDescriptorPropagationTime" is now marked as obsolete. It has had no effect since 0.3.0.7, when clients stopped rejecting consensuses "from the future". Closes ticket 32807. - We no longer support consensus methods before method 28; these methods were only used by authorities running versions of Tor that are now at end-of-life. In effect, this means that clients, relays, and authorities now assume that authorities will be running version 0.3.5.x or later. Closes ticket 32695. o Testing: - Avoid conflicts between the fake sockets in tor's unit tests, and real file descriptors. Resolves issues running unit tests with GitHub Actions, where the process that embeds or launches the tests has already opened a large number of file descriptors. Fixes bug 33782; bugfix on 0.2.8.1-alpha. Found and fixed by Putta Khunchalee. - Add more test cases for tor's UTF-8 validation function. Also, check the arguments passed to the function for consistency. Closes ticket 32845. - Improve test coverage for relay and dirauth config code, focusing on option validation and normalization. Closes ticket 32213. - Improve the consistency of test_parseconf.sh output, and run all the tests, even if one fails. Closes ticket 32213. - Run the practracker unit tests in the pre-commit git hook. Closes ticket 32609. o Code simplification and refactoring (channel): - Channel layer had a variable length cell handler that was not used and thus removed. Closes ticket 32892. o Code simplification and refactoring (configuration): - Immutability is now implemented as a flag on individual configuration options rather than as part of the option-transition checking code. Closes ticket 32344. - Instead of keeping a list of configuration options to check for relative paths, check all the options whose type is "FILENAME". Solves part of ticket 32339. - Our default log (which ordinarily sends NOTICE-level messages to standard output) is now handled in a more logical manner. Previously, we replaced the configured log options if they were empty. Now, we interpret an empty set of log options as meaning "use the default log". Closes ticket 31999. - Remove some unused arguments from the options_validate() function, to simplify our code and tests. Closes ticket 32187. - Simplify the options_validate() code so that it looks at the default options directly, rather than taking default options as an argument. This change lets us simplify its interface. Closes ticket 32185. - Use our new configuration architecture to move most authority- related options to the directory authority module. Closes ticket 32806. - When parsing the command line, handle options that determine our "quiet level" and our mode of operation (e.g., --dump-config and so on) all in one table. Closes ticket 32003. o Code simplification and refactoring (controller): - Create a new abstraction for formatting control protocol reply lines based on key-value pairs. Refactor some existing control protocol code to take advantage of this. Closes ticket 30984. - Create a helper function that can fetch network status or microdesc consensuses. Closes ticket 31684. o Code simplification and refactoring (dirauth modularization): - Remove the last remaining HAVE_MODULE_DIRAUTH inside a function. Closes ticket 32163. - Replace some confusing identifiers in process_descs.c. Closes ticket 29826. - Simplify some relay and dirauth config code. Closes ticket 32213. o Code simplification and refactoring (mainloop): - Simplify the ip_address_changed() function by removing redundant checks. Closes ticket 33091. o Code simplification and refactoring (misc): - Make all the structs we declare follow the same naming convention of ending with "_t". Closes ticket 32415. - Move and rename some configuration-related code for clarity. Closes ticket 32304. - Our include.am files are now broken up by subdirectory. Previously, src/core/include.am covered all of the subdirectories in "core", "feature", and "app". Closes ticket 32137. - Remove underused NS*() macros from test code: they make our tests more confusing, especially for code-formatting tools. Closes ticket 32887. o Code simplification and refactoring (relay modularization): - Disable relay_periodic when the relay module is disabled. Closes ticket 32244. - Disable relay_sys when the relay module is disabled. Closes ticket 32245. o Code simplification and refactoring (tool support): - Add numerous missing dependencies to our include files, so that they can be included in different reasonable orders and still compile. Addresses part of ticket 32764. - Fix some parts of our code that were difficult for Coccinelle to parse. Related to ticket 31705. - Fix some small issues in our code that prevented automatic formatting tools from working. Addresses part of ticket 32764. o Documentation (manpage): - Alphabetize the Server and Directory server sections of the tor manpage. Also split Statistics options into their own section of the manpage. Closes ticket 33188. Work by Swati Thacker as part of Google Season of Docs. - Document the __OwningControllerProcess torrc option and specify its polling interval. Resolves issue 32971. - Split "Circuit Timeout" options and "Node Selection" options into their own sections of the tor manpage. Closes tickets 32928 and 32929. Work by Swati Thacker as part of Google Season of Docs. - Alphabetize the Client Options section of the tor manpage. Closes ticket 32846. - Alphabetize the General Options section of the tor manpage. Closes ticket 32708. - In the tor(1) manpage, reword and improve formatting of the COMMAND-LINE OPTIONS and DESCRIPTION sections. Closes ticket 32277. Based on work by Swati Thacker as part of Google Season of Docs. - In the tor(1) manpage, reword and improve formatting of the FILES, SEE ALSO, and BUGS sections. Closes ticket 32176. Based on work by Swati Thacker as part of Google Season of Docs. o Testing (Appveyor CI): - In our Appveyor Windows CI, copy required DLLs to test and app directories, before running tor's tests. This ensures that tor.exe and test*.exe use the correct version of each DLL. This fix is not required, but we hope it will avoid DLL search issues in future. Fixes bug 33673; bugfix on 0.3.4.2-alpha. - On Appveyor, skip the crypto/openssl_version test, which is failing because of a mismatched library installation. Fix for 33643. o Testing (circuit, EWMA): - Add unit tests for circuitmux and EWMA subsystems. Closes ticket 32196. o Testing (Travis CI): - Remove a redundant distcheck job. Closes ticket 33194. - Sort the Travis jobs in order of speed: putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194. - Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires allow_failure), to speed up the build. Closes ticket 33195. - When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792. Changes in version 0.4.2.7 - 2020-03-18 This is the third stable release in the 0.4.2.x series. It backports numerous fixes from later releases, including a fix for TROVE-2020- 002, a major denial-of-service vulnerability that affected all released Tor instances since 0.2.1.5-alpha. Using this vulnerability, an attacker could cause Tor instances to consume a huge amount of CPU, disrupting their operations for several seconds or minutes. This attack could be launched by anybody against a relay, or by a directory cache against any client that had connected to it. The attacker could launch this attack as much as they wanted, thereby disrupting service or creating patterns that could aid in traffic analysis. This issue was found by OSS-Fuzz, and is also tracked as CVE-2020-10592. We do not have reason to believe that this attack is currently being exploited in the wild, but nonetheless we advise everyone to upgrade as soon as packages are available. o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha): - Fix a denial-of-service bug that could be used by anyone to consume a bunch of CPU on any Tor relay or authority, or by directories to consume a bunch of CPU on clients or hidden services. Because of the potential for CPU consumption to introduce observable timing patterns, we are treating this as a high-severity security issue. Fixes bug 33119; bugfix on 0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue as TROVE-2020-002 and CVE-2020-10592. o Major bugfixes (circuit padding, memory leak, backport from 0.4.3.3-alpha): - Avoid a remotely triggered memory leak in the case that a circuit padding machine is somehow negotiated twice on the same circuit. Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls. This is also tracked as TROVE-2020-004 and CVE-2020-10593. o Major bugfixes (directory authority, backport from 0.4.3.3-alpha): - Directory authorities will now send a 503 (not enough bandwidth) code to clients when under bandwidth pressure. Known relays and other authorities will always be answered regardless of the bandwidth situation. Fixes bug 33029; bugfix on 0.1.2.5-alpha. o Minor features (continuous integration, backport from 0.4.3.2-alpha): - Stop allowing failures on the Travis CI stem tests job. It looks like all the stem hangs we were seeing before are now fixed. Closes ticket 33075. o Minor bugfixes (bridges, backport from 0.4.3.1-alpha): - Lowercase the configured value of BridgeDistribution before adding it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha. o Minor bugfixes (logging, backport from 0.4.3.2-alpha): - If we encounter a bug when flushing a buffer to a TLS connection, only log the bug once per invocation of the Tor process. Previously we would log with every occurrence, which could cause us to run out of disk space. Fixes bug 33093; bugfix on 0.3.2.2-alpha. o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha): - Fix an assertion failure that could result from a corrupted ADD_ONION control port command. Found by Saibato. Fixes bug 33137; bugfix on 0.3.3.1-alpha. This issue is also tracked as TROVE-2020-003. o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha): - Fix a syntax warning given by newer versions of Rust that was creating problems for our continuous integration. Fixes bug 33212; bugfix on 0.3.5.1-alpha. o Testing (Travis CI, backport from 0.4.3.3-alpha): - Remove a redundant distcheck job. Closes ticket 33194. - Sort the Travis jobs in order of speed: putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194. - Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires allow_failure), to speed up the build. Closes ticket 33195. - When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792. Changes in version 0.4.1.9 - 2020-03-18 Tor 0.4.1.9 backports important fixes from later Tor releases, including a fix for TROVE-2020-002, a major denial-of-service vulnerability that affected all released Tor instances since 0.2.1.5-alpha. Using this vulnerability, an attacker could cause Tor instances to consume a huge amount of CPU, disrupting their operations for several seconds or minutes. This attack could be launched by anybody against a relay, or by a directory cache against any client that had connected to it. The attacker could launch this attack as much as they wanted, thereby disrupting service or creating patterns that could aid in traffic analysis. This issue was found by OSS-Fuzz, and is also tracked as CVE-2020-10592. We do not have reason to believe that this attack is currently being exploited in the wild, but nonetheless we advise everyone to upgrade as soon as packages are available. o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha): - Fix a denial-of-service bug that could be used by anyone to consume a bunch of CPU on any Tor relay or authority, or by directories to consume a bunch of CPU on clients or hidden services. Because of the potential for CPU consumption to introduce observable timing patterns, we are treating this as a high-severity security issue. Fixes bug 33119; bugfix on 0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue as TROVE-2020-002 and CVE-2020-10592. o Major bugfixes (circuit padding, memory leak, backport from 0.4.3.3-alpha): - Avoid a remotely triggered memory leak in the case that a circuit padding machine is somehow negotiated twice on the same circuit. Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls. This is also tracked as TROVE-2020-004 and CVE-2020-10593. o Minor bugfixes (bridges, backport from 0.4.3.1-alpha): - Lowercase the configured value of BridgeDistribution before adding it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha. o Minor bugfixes (logging, backport from 0.4.3.2-alpha): - If we encounter a bug when flushing a buffer to a TLS connection, only log the bug once per invocation of the Tor process. Previously we would log with every occurrence, which could cause us to run out of disk space. Fixes bug 33093; bugfix on 0.3.2.2-alpha. o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha): - Fix an assertion failure that could result from a corrupted ADD_ONION control port command. Found by Saibato. Fixes bug 33137; bugfix on 0.3.3.1-alpha. This issue is also tracked as TROVE-2020-003. o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha): - Fix a syntax warning given by newer versions of Rust that was creating problems for our continuous integration. Fixes bug 33212; bugfix on 0.3.5.1-alpha. o Testing (Travis CI, backport from 0.4.3.3-alpha): - Remove a redundant distcheck job. Closes ticket 33194. - Sort the Travis jobs in order of speed: putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194. - Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires allow_failure), to speed up the build. Closes ticket 33195. - When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792. Changes in version 0.3.5.10 - 2020-03-18 Tor 0.3.5.10 backports many fixes from later Tor releases, including a fix for TROVE-2020-002, a major denial-of-service vulnerability that affected all released Tor instances since 0.2.1.5-alpha. Using this vulnerability, an attacker could cause Tor instances to consume a huge amount of CPU, disrupting their operations for several seconds or minutes. This attack could be launched by anybody against a relay, or by a directory cache against any client that had connected to it. The attacker could launch this attack as much as they wanted, thereby disrupting service or creating patterns that could aid in traffic analysis. This issue was found by OSS-Fuzz, and is also tracked as CVE-2020-10592. We do not have reason to believe that this attack is currently being exploited in the wild, but nonetheless we advise everyone to upgrade as soon as packages are available. o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha): - Fix a denial-of-service bug that could be used by anyone to consume a bunch of CPU on any Tor relay or authority, or by directories to consume a bunch of CPU on clients or hidden services. Because of the potential for CPU consumption to introduce observable timing patterns, we are treating this as a high-severity security issue. Fixes bug 33119; bugfix on 0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue as TROVE-2020-002 and CVE-2020-10592. o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha): - Correct how we use libseccomp. Particularly, stop assuming that rules are applied in a particular order or that more rules are processed after the first match. Neither is the case! In libseccomp <2.4.0 this lead to some rules having no effect. libseccomp 2.4.0 changed how rules are generated, leading to a different ordering, which in turn led to a fatal crash during startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by Peter Gerber. o Minor features (continuous integration, backport from 0.4.3.2-alpha): - Stop allowing failures on the Travis CI stem tests job. It looks like all the stem hangs we were seeing before are now fixed. Closes ticket 33075. o Minor bugfixes (bridges, backport from 0.4.3.1-alpha): - Lowercase the configured value of BridgeDistribution before adding it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha. o Minor bugfixes (crash, backport from 0.4.2.4-rc): - When running Tor with an option like --verify-config or --dump-config that does not start the event loop, avoid crashing if we try to exit early because of an error. Fixes bug 32407; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.3.2-alpha): - If we encounter a bug when flushing a buffer to a TLS connection, only log the bug once per invocation of the Tor process. Previously we would log with every occurrence, which could cause us to run out of disk space. Fixes bug 33093; bugfix on 0.3.2.2-alpha. o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha): - Fix an assertion failure that could result from a corrupted ADD_ONION control port command. Found by Saibato. Fixes bug 33137; bugfix on 0.3.3.1-alpha. This issue is also tracked as TROVE-2020-003. o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha): - Fix a syntax warning given by newer versions of Rust that was creating problems for our continuous integration. Fixes bug 33212; bugfix on 0.3.5.1-alpha. o Testing (backport from 0.4.3.1-alpha): - Re-enable the Travis CI macOS Chutney build, but don't let it prevent the Travis job from finishing. (The Travis macOS jobs are slow, so we don't want to have it delay the whole CI process.) Closes ticket 32629. - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on Ubuntu Bionic. Turning off the Sandbox is a work-around, until we fix the sandbox errors in 32722. Closes ticket 32240. o Testing (continuous integration, backport from 0.4.3.1-alpha): - Use zstd in our Travis Linux builds. Closes ticket 32242. o Testing (Travis CI, backport from 0.4.3.3-alpha): - Remove a redundant distcheck job. Closes ticket 33194. - Sort the Travis jobs in order of speed: putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194. - Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires - When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792. Changes in version 0.4.2.6 - 2020-01-30 This is the second stable release in the 0.4.2.x series. It backports several bugfixes from 0.4.3.1-alpha, including some that had affected the Linux seccomp2 sandbox or Windows services. If you're running with one of those configurations, you'll probably want to upgrade; otherwise, you should be fine with 0.4.2.5. o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha): - Correct how we use libseccomp. Particularly, stop assuming that rules are applied in a particular order or that more rules are processed after the first match. Neither is the case! In libseccomp <2.4.0 this led to some rules having no effect. libseccomp 2.4.0 changed how rules are generated, leading to a different ordering, which in turn led to a fatal crash during startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by Peter Gerber. - Fix crash when reloading logging configuration while the experimental sandbox is enabled. Fixes bug 32841; bugfix on 0.4.1.7. Patch by Peter Gerber. o Minor bugfixes (correctness checks, backport from 0.4.3.1-alpha): - Use GCC/Clang's printf-checking feature to make sure that tor_assertf() arguments are correctly typed. Fixes bug 32765; bugfix on 0.4.1.1-alpha. o Minor bugfixes (logging, crash, backport from 0.4.3.1-alpha): - Avoid a possible crash when trying to log a (fatal) assertion failure about mismatched magic numbers in configuration objects. Fixes bug 32771; bugfix on 0.4.2.1-alpha. o Minor bugfixes (testing, backport from 0.4.3.1-alpha): - When TOR_DISABLE_PRACTRACKER is set, do not apply it to the test_practracker.sh script. Doing so caused a test failure. Fixes bug 32705; bugfix on 0.4.2.1-alpha. - When TOR_DISABLE_PRACTRACKER is set, log a notice to stderr when skipping practracker checks. Fixes bug 32705; bugfix on 0.4.2.1-alpha. o Minor bugfixes (windows service, backport from 0.4.3.1-alpha): - Initialize the publish/subscribe system when running as a windows service. Fixes bug 32778; bugfix on 0.4.1.1-alpha. o Testing (backport from 0.4.3.1-alpha): - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on Ubuntu Bionic. Turning off the Sandbox is a work-around, until we fix the sandbox errors in 32722. Closes ticket 32240. - Re-enable the Travis CI macOS Chutney build, but don't let it prevent the Travis job from finishing. (The Travis macOS jobs are slow, so we don't want to have it delay the whole CI process.) Closes ticket 32629. o Testing (continuous integration, backport from 0.4.3.1-alpha): - Use zstd in our Travis Linux builds. Closes ticket 32242. Changes in version 0.4.1.8 - 2020-01-30 This release backports several bugfixes from later release series, including some that had affected the Linux seccomp2 sandbox or Windows services. If you're running with one of those configurations, you'll probably want to upgrade; otherwise, you should be fine with your current version of 0.4.1.x. o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha): - Correct how we use libseccomp. Particularly, stop assuming that rules are applied in a particular order or that more rules are processed after the first match. Neither is the case! In libseccomp <2.4.0 this led to some rules having no effect. libseccomp 2.4.0 changed how rules are generated, leading to a different ordering, which in turn led to a fatal crash during startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by Peter Gerber. - Fix crash when reloading logging configuration while the experimental sandbox is enabled. Fixes bug 32841; bugfix on 0.4.1.7. Patch by Peter Gerber. o Minor bugfixes (crash, backport form 0.4.2.4-rc): - When running Tor with an option like --verify-config or --dump-config that does not start the event loop, avoid crashing if we try to exit early because of an error. Fixes bug 32407; bugfix on 0.3.3.1-alpha. o Minor bugfixes (windows service, backport from 0.4.3.1-alpha): - Initialize the publish/subscribe system when running as a windows service. Fixes bug 32778; bugfix on 0.4.1.1-alpha. o Testing (backport from 0.4.3.1-alpha): - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on Ubuntu Bionic. Turning off the Sandbox is a work-around, until we fix the sandbox errors in 32722. Closes ticket 32240. - Re-enable the Travis CI macOS Chutney build, but don't let it prevent the Travis job from finishing. (The Travis macOS jobs are slow, so we don't want to have it delay the whole CI process.) Closes ticket 32629. o Testing (continuous integration, backport from 0.4.3.1-alpha): - Use zstd in our Travis Linux builds. Closes ticket 32242. Changes in version 0.4.2.5 - 2019-12-09 This is the first stable release in the 0.4.2.x series. This series improves reliability and stability, and includes several stability and correctness improvements for onion services. It also fixes many smaller bugs present in previous series. Per our support policy, we will support the 0.4.2.x series for nine months, or until three months after the release of a stable 0.4.3.x: whichever is longer. If you need longer-term support, please stick with 0.3.5.x, which will we plan to support until Feb 2022. Below are the changes since 0.4.1.4-rc. For a complete list of only the changes since 0.4.2.4-rc, see the ChangeLog file. o Major features (directory authorities): - Directory authorities now reject relays running all currently deprecated release series. The currently supported release series are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549. o Major features (onion service v3, denial of service): - Add onion service introduction denial of service defenses. Intro points can now rate-limit client introduction requests, using parameters that can be sent by the service within the ESTABLISH_INTRO cell. If the cell extension for this is not used, the intro point will honor the consensus parameters. Closes ticket 30924. o Major bugfixes (circuit build, guard): - When considering upgrading circuits from "waiting for guard" to "open", always ignore circuits that are marked for close. Previously we could end up in the situation where a subsystem is notified of a circuit opening, but the circuit is still marked for close, leading to undesirable behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha. o Major bugfixes (crash, Linux, Android): - Tolerate systems (including some Android installations) where madvise and MADV_DONTDUMP are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31570; bugfix on 0.4.1.1-alpha. - Tolerate systems (including some Linux installations) where madvise and/or MADV_DONTFORK are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31696; bugfix on 0.4.1.1-alpha. o Major bugfixes (embedded Tor): - Avoid a possible crash when restarting Tor in embedded mode and enabling a different set of publish/subscribe messages. Fixes bug 31898; bugfix on 0.4.1.1-alpha. o Major bugfixes (relay): - Relays now respect their AccountingMax bandwidth again. When relays entered "soft" hibernation (which typically starts when we've hit 90% of our AccountingMax), we had stopped checking whether we should enter hard hibernation. Soft hibernation refuses new connections and new circuits, but the existing circuits can continue, meaning that relays could have exceeded their configured AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha. o Major bugfixes (torrc parsing): - Stop ignoring torrc options after an %include directive, when the included directory ends with a file that does not contain any config options (but does contain comments or whitespace). Fixes bug 31408; bugfix on 0.3.1.1-alpha. o Major bugfixes (v3 onion services): - Onion services now always use the exact number of intro points configured with the HiddenServiceNumIntroductionPoints option (or fewer if nodes are excluded). Before, a service could sometimes pick more intro points than configured. Fixes bug 31548; bugfix on 0.3.2.1-alpha. o Minor feature (onion services, control port): - The ADD_ONION command's keyword "BEST" now defaults to ED25519-V3 (v3) onion services. Previously it defaulted to RSA1024 (v2). Closes ticket 29669. o Minor features (auto-formatting scripts): - When annotating C macros, never generate a line that our check- spaces script would reject. Closes ticket 31759. - When annotating C macros, try to remove cases of double-negation. Closes ticket 31779. o Minor features (best practices tracker): - Our best-practices tracker now integrates with our include-checker tool to keep track of how many layering violations we have not yet fixed. We hope to reduce this number over time to improve Tor's modularity. Closes ticket 31176. - Add a TOR_PRACTRACKER_OPTIONS variable for passing arguments to practracker from the environment. We may want this for continuous integration. Closes ticket 31309. - Give a warning rather than an error when a practracker exception is violated by a small amount, add a --list-overbroad option to practracker that lists exceptions that are stricter than they need to be, and provide an environment variable for disabling practracker. Closes ticket 30752. - Our best-practices tracker now looks at headers as well as C files. Closes ticket 31175. o Minor features (build system): - Make pkg-config use --prefix when cross-compiling, if PKG_CONFIG_PATH is not set. Closes ticket 32191. - Add --disable-manpage and --disable-html-manual options to configure script. This will enable shortening build times by not building documentation. Resolves issue 19381. o Minor features (compilation): - Log a more useful error message when we are compiling and one of the compile-time hardening options we have selected can be linked but not executed. Closes ticket 27530. o Minor features (configuration): - The configuration code has been extended to allow splitting configuration data across multiple objects. Previously, all configuration data needed to be kept in a single object, which tended to become bloated. Closes ticket 31240. o Minor features (continuous integration): - When building on Appveyor and Travis, pass the "-k" flag to make, so that we are informed of all compilation failures, not just the first one or two. Closes ticket 31372. - When running CI builds on Travis, put some random data in ~/.torrc, to make sure no tests are reading the Tor configuration file from its default location. Resolves issue 30102. o Minor features (debugging): - Log a nonfatal assertion failure if we encounter a configuration line whose command is "CLEAR" but which has a nonempty value. This should be impossible, according to the rules of our configuration line parsing. Closes ticket 31529. o Minor features (geoip): - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2 Country database. Closes ticket 32685. o Minor features (git hooks): - Our pre-commit git hook now checks for a special file before running practracker, so that practracker only runs on branches that are based on master. Since the pre-push hook calls the pre- commit hook, practracker will also only run before pushes of branches based on master. Closes ticket 30979. o Minor features (git scripts): - Add a "--" command-line argument, to separate git-push-all.sh script arguments from arguments that are passed through to git push. Closes ticket 31314. - Add a -r argument to git-push-all.sh, so the script can push test branches to a personal remote. Closes ticket 31314. - Add a -t argument to git-merge-forward.sh and git-push-all.sh, which makes these scripts create, merge forward, and push test branches. Closes ticket 31314. - Add a -u argument to git-merge-forward.sh, so that the script can re-use existing test branches after a merge failure and fix. Closes ticket 31314. - Add a TOR_GIT_PUSH env var, which sets the default git push command and arguments for git-push-all.sh. Closes ticket 31314. - Add a TOR_PUSH_DELAY variable to git-push-all.sh, which makes the script push master and maint branches with a delay between each branch. These delays trigger the CI jobs in a set order, which should show the most likely failures first. Also make pushes atomic by default, and make the script pass any command-line arguments to git push. Closes ticket 29879. - Call the shellcheck script from the pre-commit hook. Closes ticket 30967. - Skip pushing test branches that are the same as a remote maint/release/master branch in git-push-all.sh by default. Add a -s argument, so git-push-all.sh can push all test branches. Closes ticket 31314. o Minor features (IPv6, logging): - Log IPv6 addresses as well as IPv4 addresses when describing routerinfos, routerstatuses, and nodes. Closes ticket 21003. o Minor features (maintenance scripts): - Add a Coccinelle script to detect bugs caused by incrementing or decrementing a variable inside a call to log_debug(). Since log_debug() is a macro whose arguments are conditionally evaluated, it is usually an error to do this. One such bug was 30628, in which SENDME cells were miscounted by a decrement operator inside a log_debug() call. Closes ticket 30743. o Minor features (onion service v3): - Do not allow single hop clients to fetch or post an HS descriptor from an HSDir. Closes ticket 24964. o Minor features (onion service): - Disallow single-hop clients at the introduction point. We've removed Tor2web support a while back and single-hop rendezvous attempts are blocked at the relays. This change should remove load off the network from spammy clients. Close ticket 24963. o Minor features (onion services v3): - Assist users who try to setup v2 client authorization in v3 onion services by pointing them to the right documentation. Closes ticket 28966. o Minor features (stem tests): - Change "make test-stem" so it only runs the stem tests that use tor. This change makes test-stem faster and more reliable. Closes ticket 31554. o Minor features (testing): - When running tests that attempt to look up hostnames, replace the libc name lookup functions with ones that do not actually touch the network. This way, the tests complete more quickly in the presence of a slow or missing DNS resolver. Closes ticket 31841. - Add a script to invoke "tor --dump-config" and "tor --verify-config" with various configuration options, and see whether tor's resulting configuration or error messages are what we expect. Use it for integration testing of our +Option and /Option flags. Closes ticket 31637. - Improve test coverage for our existing configuration parsing and management API. Closes ticket 30893. - Add integration tests to make sure that practracker gives the outputs we expect. Closes ticket 31477. - The practracker self-tests are now run as part of the Tor test suite. Closes ticket 31304. o Minor features (testing, continuous integration): - Disable all but one Travis CI macOS build, to mitigate slow scheduling of Travis macOS jobs. Closes ticket 32177. - Run the chutney IPv6 networks as part of Travis CI. Closes ticket 30860. - Simplify the Travis CI build matrix, and optimise for build time. Closes ticket 31859. - Use Windows Server 2019 instead of Windows Server 2016 in our Appveyor builds. Closes ticket 32086. o Minor features (token bucket): - Implement a generic token bucket that uses a single counter, for use in anti-DoS onion service work. Closes ticket 30687. o Minor bugfixes (Appveyor continuous integration): - Avoid spurious errors when Appveyor CI fails before the install step. Fixes bug 31884; bugfix on 0.3.4.2-alpha. o Minor bugfixes (best practices tracker): - Fix a few issues in the best-practices script, including tests, tab tolerance, error reporting, and directory-exclusion logic. Fixes bug 29746; bugfix on 0.4.1.1-alpha. - When running check-best-practices, only consider files in the src subdirectory. Previously we had recursively considered all subdirectories, which made us get confused by the temporary directories made by "make distcheck". Fixes bug 31578; bugfix on 0.4.1.1-alpha. o Minor bugfixes (build system): - Interpret "--disable-module-dirauth=no" correctly. Fixes bug 32124; bugfix on 0.3.4.1-alpha. - Interpret "--with-tcmalloc=no" correctly. Fixes bug 32124; bugfix on 0.2.0.20-rc. - Stop failing when jemalloc is requested, but tcmalloc is not found. Fixes bug 32124; bugfix on 0.3.5.1-alpha. - When pkg-config is not installed, or a library that depends on pkg-config is not found, tell the user what to do to fix the problem. Fixes bug 31922; bugfix on 0.3.1.1-alpha. - Do not include the deprecated on Linux or Windows systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha. o Minor bugfixes (chutney, makefiles, documentation): - "make test-network-all" now shows the warnings from each test- network.sh run on the console, so developers see new warnings early. We've also improved the documentation for this feature, and renamed a Makefile variable so the code is self-documenting. Fixes bug 30455; bugfix on 0.3.0.4-rc. o Minor bugfixes (client, onion service v3): - Fix a BUG() assertion that occurs within a very small race window between when a client intro circuit opens and when its descriptor gets cleaned up from the cache. The circuit is now closed early, which will trigger a re-fetch of the descriptor and continue the connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha. o Minor bugfixes (code quality): - Fix "make check-includes" so it runs correctly on out-of-tree builds. Fixes bug 31335; bugfix on 0.3.5.1-alpha. o Minor bugfixes (compilation): - Add more stub functions to fix compilation on Android with link- time optimization when --disable-module-dirauth is used. Previously, these compilation settings would make the compiler look for functions that didn't exist. Fixes bug 31552; bugfix on 0.4.1.1-alpha. - Suppress spurious float-conversion warnings from GCC when calling floating-point classifier functions on FreeBSD. Fixes part of bug 31687; bugfix on 0.3.1.5-alpha. o Minor bugfixes (configuration): - Invalid floating-point values in the configuration file are now treated as errors in the configuration. Previously, they were ignored and treated as zero. Fixes bug 31475; bugfix on 0.0.1. o Minor bugfixes (connections): - Avoid trying to read data from closed connections, which can cause needless loops in Libevent and infinite loops in Shadow. Fixes bug 30344; bugfix on 0.1.1.1-alpha. o Minor bugfixes (controller protocol): - Fix the MAPADDRESS controller command to accept one or more arguments. Previously, it required two or more arguments, and ignored the first. Fixes bug 31772; bugfix on 0.4.1.1-alpha. o Minor bugfixes (coverity): - Add an assertion when parsing a BEGIN cell so that coverity can be sure that we are not about to dereference a NULL address. Fixes bug 31026; bugfix on 0.2.4.7-alpha. This is CID 1447296. - In our siphash implementation, when building for coverity, use memcpy in place of a switch statement, so that coverity can tell we are not accessing out-of-bounds memory. Fixes bug 31025; bugfix on 0.2.8.1-alpha. This is tracked as CID 1447293 and 1447295. - Fix several coverity warnings from our unit tests. Fixes bug 31030; bugfix on 0.2.4.1-alpha, 0.3.2.1-alpha, and 0.4.0.1-alpha. o Minor bugfixes (crash): - When running Tor with an option like --verify-config or --dump-config that does not start the event loop, avoid crashing if we try to exit early because of an error. Fixes bug 32407; bugfix on 0.3.3.1-alpha. o Minor bugfixes (developer tooling): - Only log git script changes in the post-merge script when the merge was to the master branch. Fixes bug 31040; bugfix on 0.4.1.1-alpha. o Minor bugfixes (directory authorities): - Return a distinct status when formatting annotations fails. Fixes bug 30780; bugfix on 0.2.0.8-alpha. o Minor bugfixes (error handling): - Always lock the backtrace buffer before it is used. Fixes bug 31734; bugfix on 0.2.5.3-alpha. - On abort, try harder to flush the output buffers of log messages. On some platforms (macOS), log messages could be discarded when the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - Report the tor version whenever an assertion fails. Previously, we only reported the Tor version on some crashes, and some non-fatal assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - When tor aborts due to an error, close log file descriptors before aborting. Closing the logs makes some OSes flush log file buffers, rather than deleting buffered log lines. Fixes bug 31594; bugfix on 0.2.5.2-alpha. o Minor bugfixes (FreeBSD, PF-based proxy, IPv6): - When extracting an IPv6 address from a PF-based proxy, verify that we are actually configured to receive an IPv6 address, and log an internal error if not. Fixes part of bug 31687; bugfix on 0.2.3.4-alpha. o Minor bugfixes (git hooks): - Remove a duplicate call to practracker from the pre-push hook. The pre-push hook already calls the pre-commit hook, which calls practracker. Fixes bug 31462; bugfix on 0.4.1.1-alpha. o Minor bugfixes (git scripts): - Stop hard-coding the bash path in the git scripts. Some OSes don't have bash in /usr/bin, others have an ancient bash at this path. Fixes bug 30840; bugfix on 0.4.0.1-alpha. - Stop hard-coding the tor master branch name and worktree path in the git scripts. Fixes bug 30841; bugfix on 0.4.0.1-alpha. - Allow git-push-all.sh to be run from any directory. Previously, the script only worked if run from an upstream worktree directory. Closes ticket 31678. o Minor bugfixes (guards): - When tor is missing descriptors for some primary entry guards, make the log message less alarming. It's normal for descriptors to expire, as long as tor fetches new ones soon after. Fixes bug 31657; bugfix on 0.3.3.1-alpha. o Minor bugfixes (ipv6): - Check for private IPv6 addresses alongside their IPv4 equivalents when authorities check descriptors. Previously, we only checked for private IPv4 addresses. Fixes bug 31088; bugfix on 0.2.3.21-rc. Patch by Neel Chauhan. - When parsing microdescriptors, we should check the IPv6 exit policy alongside IPv4. Previously, we checked both exit policies for only router info structures, while microdescriptors were IPv4-only. Fixes bug 27284; bugfix on 0.2.3.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (logging): - Add a missing check for HAVE_PTHREAD_H, because the backtrace code uses mutexes. Fixes bug 31614; bugfix on 0.2.5.2-alpha. - Disable backtrace signal handlers when shutting down tor. Fixes bug 31614; bugfix on 0.2.5.2-alpha. - Rate-limit the logging message about the obsolete .exit notation. Previously, there was no limit on this warning, which could potentially be triggered many times by a hostile website. Fixes bug 31466; bugfix on 0.2.2.1-alpha. - When initialising log domain masks, only set known log domains. Fixes bug 31854; bugfix on 0.2.1.1-alpha. - Change log level of message "Hash of session info was not as expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix on 0.1.1.10-alpha. - Fix a code issue that would have broken our parsing of log domains as soon as we had 33 of them. Fortunately, we still only have 29. Fixes bug 31451; bugfix on 0.4.1.4-rc. o Minor bugfixes (logging, protocol violations): - Do not log a nonfatal assertion failure when receiving a VERSIONS cell on a connection using the obsolete v1 link protocol. Log a protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha. o Minor bugfixes (mainloop, periodic events, in-process API): - Reset the periodic events' "enabled" flag when Tor is shut down cleanly. Previously, this flag was left on, which caused periodic events not to be re-enabled when Tor was relaunched in-process with tor_api.h after a shutdown. Fixes bug 32058; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory management): - Stop leaking a small amount of memory in nt_service_install(), in unreachable code. Fixes bug 30799; bugfix on 0.2.0.7-alpha. Patch by Xiaoyin Liu. o Minor bugfixes (modules): - Explain what the optional Directory Authority module is, and what happens when it is disabled. Fixes bug 31825; bugfix on 0.3.4.1-alpha. o Minor bugfixes (multithreading): - Avoid some undefined behaviour when freeing mutexes. Fixes bug 31736; bugfix on 0.0.7. o Minor bugfixes (networking, IP addresses): - When parsing addresses via Tor's internal DNS lookup API, reject IPv4 addresses in square brackets, and accept IPv6 addresses in square brackets. This change completes the work started in 23082, making address parsing consistent between tor's internal DNS lookup and address parsing APIs. Fixes bug 30721; bugfix on 0.2.1.5-alpha. - When parsing addresses via Tor's internal address:port parsing and DNS lookup APIs, require IPv6 addresses with ports to have square brackets. But allow IPv6 addresses without ports, whether or not they have square brackets. Fixes bug 30721; bugfix on 0.2.1.5-alpha. o Minor bugfixes (onion service v3): - When purging the client descriptor cache, close any introduction point circuits associated with purged cache entries. This avoids picking those circuits later when connecting to the same introduction points. Fixes bug 30921; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services): - In the hs_ident_circuit_t data structure, remove the unused field circuit_type and the respective argument in hs_ident_circuit_new(). This field was set by clients (for introduction) and services (for introduction and rendezvous) but was never used afterwards. Fixes bug 31490; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (operator tools): - Make tor-print-ed-signing-cert(1) print certificate expiration date in RFC 1123 and UNIX timestamp formats, to make output machine readable. Fixes bug 31012; bugfix on 0.3.5.1-alpha. o Minor bugfixes (process management): - Remove overly strict assertions that triggered when a pluggable transport failed to launch. Fixes bug 31091; bugfix on 0.4.0.1-alpha. - Remove an assertion in the Unix process backend. This assertion would trigger when we failed to find the executable for a child process. Fixes bug 31810; bugfix on 0.4.0.1-alpha. o Minor bugfixes (relay): - Avoid crashing when starting with a corrupt keys directory where the old ntor key and the new ntor key are identical. Fixes bug 30916; bugfix on 0.2.4.8-alpha. o Minor bugfixes (rust): - Correctly exclude a redundant rust build job in Travis. Fixes bug 31463; bugfix on 0.3.5.4-alpha. - Raise the minimum rustc version to 1.31.0, as checked by configure and CI. Fixes bug 31442; bugfix on 0.3.5.4-alpha. o Minor bugfixes (sendme, code structure): - Rename the trunnel SENDME file definition from sendme.trunnel to sendme_cell.trunnel to avoid having twice sendme.{c|h} in the repository. Fixes bug 30769; bugfix on 0.4.1.1-alpha. o Minor bugfixes (statistics): - Stop removing the ed25519 signature if the extra info file is too big. If the signature data was removed, but the keyword was kept, this could result in an unparseable extra info file. Fixes bug 30958; bugfix on 0.2.7.2-alpha. o Minor bugfixes (subsystems): - Make the subsystem init order match the subsystem module dependencies. Call windows process security APIs as early as possible. Initialize logging before network and time, so that network and time can use logging. Fixes bug 31615; bugfix on 0.4.0.1-alpha. o Minor bugfixes (testing): - Avoid intermittent test failures due to a test that had relied on inconsistent timing sources. Fixes bug 31995; bugfix on 0.3.1.3-alpha. - When testing port rebinding, don't busy-wait for tor to log. Instead, actually sleep for a short time before polling again. Also improve the formatting of control commands and log messages. Fixes bug 31837; bugfix on 0.3.5.1-alpha. - Teach the util/socketpair_ersatz test to work correctly when we have no network stack configured. Fixes bug 30804; bugfix on 0.2.5.1-alpha. o Minor bugfixes (tests, SunOS): - Avoid a map_anon_nofork test failure due to a signed/unsigned integer comparison. Fixes bug 31897; bugfix on 0.4.1.1-alpha. o Minor bugfixes (tls, logging): - Log bugs about the TLS read buffer's length only once, rather than filling the logs with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc. o Minor bugfixes (v2 single onion services): - Always retry v2 single onion service intro and rend circuits with a 3-hop path. Previously, v2 single onion services used a 3-hop path when rendezvous circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.2.9.3-alpha. o Minor bugfixes (v3 onion services): - When cleaning up intro circuits for a v3 onion service, don't remove circuits that have an established or pending circuit, even if they ran out of retries. This way, we don't remove a circuit on its last retry. Fixes bug 31652; bugfix on 0.3.2.1-alpha. o Minor bugfixes (v3 single onion services): - Always retry v3 single onion service intro and rend circuits with a 3-hop path. Previously, v3 single onion services used a 3-hop path when rend circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.3.2.1-alpha. - Make v3 single onion services fall back to a 3-hop intro, when all intro points are unreachable via a 1-hop path. Previously, v3 single onion services failed when all intro nodes were unreachable via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha. o Code simplification and refactoring: - Refactor connection_control_process_inbuf() to reduce the size of a practracker exception. Closes ticket 31840. - Refactor the microdescs_parse_from_string() function into smaller pieces, for better comprehensibility. Closes ticket 31675. - Use SEVERITY_MASK_IDX() to find the LOG_* mask indexes in the unit tests and fuzzers, rather than using hard-coded values. Closes ticket 31334. - Interface for function `decrypt_desc_layer` cleaned up. Closes ticket 31589. o Documentation: - Correct the description of "GuardLifetime". Fixes bug 31189; bugfix on 0.3.0.1-alpha. - Make clear in the man page, in both the bandwidth section and the AccountingMax section, that Tor counts in powers of two, not powers of ten: 1 GByte is 1024*1024*1024 bytes, not one billion bytes. Resolves ticket 32106. - Document the signal-safe logging behaviour in the tor man page. Also add some comments to the relevant functions. Closes ticket 31839. - Explain why we can't destroy the backtrace buffer mutex. Explain why we don't need to destroy the log mutex. Closes ticket 31736. - The Tor source code repository now includes a (somewhat dated) description of Tor's modular architecture, in doc/HACKING/design. This is based on the old "tor-guts.git" repository, which we are adopting and superseding. Closes ticket 31849. - Improve documentation in circuit padding subsystem. Patch by Tobias Pulls. Closes ticket 31113. - Include an example usage for IPv6 ORPort in our sample torrc. Closes ticket 31320; patch from Ali Raheem. - Use RFC 2397 data URL scheme to embed an image into tor-exit- notice.html so that operators no longer have to host it themselves. Closes ticket 31089. o Removed features: - No longer include recommended package digests in votes as detailed in proposal 301. The RecommendedPackages torrc option is deprecated and will no longer have any effect. "package" lines will still be considered when computing consensuses for consensus methods that include them. (This change has no effect on the list of recommended Tor versions, which is still in use.) Closes ticket 29738. - Remove torctl.in from contrib/dist directory. Resolves ticket 30550. o Testing: - Require C99 standards-conforming code in Travis CI, but allow GNU gcc extensions. Also activates clang's -Wtypedef-redefinition warnings. Build some jobs with -std=gnu99, and some jobs without. Closes ticket 32500. - Run shellcheck for all non-third-party shell scripts that are shipped with Tor. Closes ticket 29533. - When checking shell scripts, ignore any user-created directories. Closes ticket 30967. o Code simplification and refactoring (config handling): - Extract our variable manipulation code from confparse.c to a new lower-level typedvar.h module. Closes ticket 30864. - Lower another layer of object management from confparse.c to a more general tool. Now typed structure members are accessible via an abstract type. Implements ticket 30914. - Move our backend logic for working with configuration and state files into a lower-level library, since it no longer depends on any tor-specific functionality. Closes ticket 31626. - Numerous simplifications in configuration-handling logic: remove duplicated macro definitions, replace magical names with flags, and refactor "TestingTorNetwork" to use the same default-option logic as the rest of Tor. Closes ticket 30935. - Replace our ad-hoc set of flags for configuration variables and configuration variable types with fine-grained orthogonal flags corresponding to the actual behavior we want. Closes ticket 31625. o Code simplification and refactoring (misc): - Eliminate some uses of lower-level control reply abstractions, primarily in the onion_helper functions. Closes ticket 30889. - Rework bootstrap tracking to use the new publish-subscribe subsystem. Closes ticket 29976. - Rewrite format_node_description() and router_get_verbose_nickname() to use strlcpy() and strlcat(). The previous implementation used memcpy() and pointer arithmetic, which was error-prone. Closes ticket 31545. This is CID 1452819. - Split extrainfo_dump_to_string() into smaller functions. Closes ticket 30956. - Use the ptrdiff_t type consistently for expressing variable offsets and pointer differences. Previously we incorrectly (but harmlessly) used int and sometimes off_t for these cases. Closes ticket 31532. - Use the subsystems mechanism to manage the main event loop code. Closes ticket 30806. - Various simplifications and minor improvements to the circuit padding machines. Patch by Tobias Pulls. Closes tickets 31112 and 31098. o Documentation (hard-coded directories): - Improve the documentation for the DirAuthority and FallbackDir torrc options. Closes ticket 30955. o Documentation (tor.1 man page): - Fix typo in tor.1 man page: the option is "--help", not "-help". Fixes bug 31008; bugfix on 0.2.2.9-alpha. o Testing (continuous integration): - Use Ubuntu Bionic images for our Travis CI builds, so we can get a recent version of coccinelle. But leave chutney on Ubuntu Trusty, until we can fix some Bionic permissions issues (see ticket 32240). Related to ticket 31919. - Install the mingw OpenSSL package in Appveyor. This makes sure that the OpenSSL headers and libraries match in Tor's Appveyor builds. (This bug was triggered by an Appveyor image update.) Fixes bug 32449; bugfix on 0.3.5.6-rc. - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241. Changes in version 0.4.1.7 - 2019-12-09 This release backports several bugfixes to improve stability and correctness. Anyone experiencing build problems or crashes with 0.4.1.6, including all relays relying on AccountingMax, should upgrade. o Major features (directory authorities, backport from 0.4.2.2-alpha): - Directory authorities now reject relays running all currently deprecated release series. The currently supported release series are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549. o Major bugfixes (embedded Tor, backport from 0.4.2.2-alpha): - Avoid a possible crash when restarting Tor in embedded mode and enabling a different set of publish/subscribe messages. Fixes bug 31898; bugfix on 0.4.1.1-alpha. o Major bugfixes (relay, backport from 0.4.2.3-alpha): - Relays now respect their AccountingMax bandwidth again. When relays entered "soft" hibernation (which typically starts when we've hit 90% of our AccountingMax), we had stopped checking whether we should enter hard hibernation. Soft hibernation refuses new connections and new circuits, but the existing circuits can continue, meaning that relays could have exceeded their configured AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha. o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha): - Stop ignoring torrc options after an %include directive, when the included directory ends with a file that does not contain any config options (but does contain comments or whitespace). Fixes bug 31408; bugfix on 0.3.1.1-alpha. o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha): - Onion services now always use the exact number of intro points configured with the HiddenServiceNumIntroductionPoints option (or fewer if nodes are excluded). Before, a service could sometimes pick more intro points than configured. Fixes bug 31548; bugfix on 0.3.2.1-alpha. o Minor features (continuous integration, backport from 0.4.2.2-alpha): - When building on Appveyor and Travis, pass the "-k" flag to make, so that we are informed of all compilation failures, not just the first one or two. Closes ticket 31372. o Minor features (geoip, backport from 0.4.2.5): - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2 Country database. Closes ticket 32685. o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha): - Avoid spurious errors when Appveyor CI fails before the install step. Fixes bug 31884; bugfix on 0.3.4.2-alpha. o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc): - Fix a BUG() assertion that occurs within a very small race window between when a client intro circuit opens and when its descriptor gets cleaned up from the cache. The circuit is now closed early, which will trigger a re-fetch of the descriptor and continue the connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha. o Minor bugfixes (connections, backport from 0.4.2.3-rc): - Avoid trying to read data from closed connections, which can cause needless loops in Libevent and infinite loops in Shadow. Fixes bug 30344; bugfix on 0.1.1.1-alpha. o Minor bugfixes (error handling, backport from 0.4.2.1-alpha): - On abort, try harder to flush the output buffers of log messages. On some platforms (macOS), log messages could be discarded when the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - Report the tor version whenever an assertion fails. Previously, we only reported the Tor version on some crashes, and some non-fatal assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - When tor aborts due to an error, close log file descriptors before aborting. Closing the logs makes some OSes flush log file buffers, rather than deleting buffered log lines. Fixes bug 31594; bugfix on 0.2.5.2-alpha. o Minor bugfixes (logging, backport from 0.4.2.2-alpha): - Add a missing check for HAVE_PTHREAD_H, because the backtrace code uses mutexes. Fixes bug 31614; bugfix on 0.2.5.2-alpha. - Disable backtrace signal handlers when shutting down tor. Fixes bug 31614; bugfix on 0.2.5.2-alpha. - Rate-limit the logging message about the obsolete .exit notation. Previously, there was no limit on this warning, which could potentially be triggered many times by a hostile website. Fixes bug 31466; bugfix on 0.2.2.1-alpha. o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha): - Do not log a nonfatal assertion failure when receiving a VERSIONS cell on a connection using the obsolete v1 link protocol. Log a protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha. o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha): - Reset the periodic events' "enabled" flag when Tor is shut down cleanly. Previously, this flag was left on, which caused periodic events not to be re-enabled when Tor was relaunched in-process with tor_api.h after a shutdown. Fixes bug 32058; bugfix on 0.3.3.1-alpha. o Minor bugfixes (multithreading, backport from 0.4.2.2-alpha): - Avoid some undefined behaviour when freeing mutexes. Fixes bug 31736; bugfix on 0.0.7. o Minor bugfixes (process management, backport from 0.4.2.3-alpha): - Remove overly strict assertions that triggered when a pluggable transport failed to launch. Fixes bug 31091; bugfix on 0.4.0.1-alpha. - Remove an assertion in the Unix process backend. This assertion would trigger when we failed to find the executable for a child process. Fixes bug 31810; bugfix on 0.4.0.1-alpha. o Minor bugfixes (relay, backport from 0.4.2.2-alpha): - Avoid crashing when starting with a corrupt keys directory where the old ntor key and the new ntor key are identical. Fixes bug 30916; bugfix on 0.2.4.8-alpha. o Minor bugfixes (testing, backport from 0.4.2.3-alpha): - When testing port rebinding, don't busy-wait for tor to log. Instead, actually sleep for a short time before polling again. Also improve the formatting of control commands and log messages. Fixes bug 31837; bugfix on 0.3.5.1-alpha. o Minor bugfixes (tests, SunOS, backport from 0.4.2.2-alpha): - Avoid a map_anon_nofork test failure due to a signed/unsigned integer comparison. Fixes bug 31897; bugfix on 0.4.1.1-alpha. o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha): - Log bugs about the TLS read buffer's length only once, rather than filling the logs with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc. o Documentation (backport from 0.4.2.2-alpha): - Explain why we can't destroy the backtrace buffer mutex. Explain why we don't need to destroy the log mutex. Closes ticket 31736. o Testing (continuous integration, backport from 0.4.2.3-alpha): - Disable all but one Travis CI macOS build, to mitigate slow scheduling of Travis macOS jobs. Closes ticket 32177. - Run the chutney IPv6 networks as part of Travis CI. Closes ticket 30860. - Simplify the Travis CI build matrix, and optimise for build time. Closes ticket 31859. - Use Windows Server 2019 instead of Windows Server 2016 in our Appveyor builds. Closes ticket 32086. o Testing (continuous integration, backport from 0.4.2.4-rc): - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241. - Use Ubuntu Bionic images for our Travis CI builds, so we can get a recent version of coccinelle. But leave chutney on Ubuntu Trusty, until we can fix some Bionic permissions issues (see ticket 32240). Related to ticket 31919. - Install the mingw OpenSSL package in Appveyor. This makes sure that the OpenSSL headers and libraries match in Tor's Appveyor builds. (This bug was triggered by an Appveyor image update.) Fixes bug 32449; bugfix on 0.3.5.6-rc. o Testing (continuous integration, backport from 0.4.2.5): - Require C99 standards-conforming code in Travis CI, but allow GNU gcc extensions. Also activates clang's -Wtypedef-redefinition warnings. Build some jobs with -std=gnu99, and some jobs without. Closes ticket 32500. Changes in version 0.4.0.6 - 2019-12-09 This is the second stable release in the 0.4.0.x series. This release backports several bugfixes to improve stability and correctness. Anyone experiencing build problems or crashes with 0.4.0.5, including all relays relying on AccountingMax, should upgrade. Note that, per our support policy, support for the 0.4.0.x series will end on 2 Feb 2020. Anyone still running 0.4.0.x should plan to upgrade to the latest stable release, or downgrade to 0.3.5.x, which will get long-term support until 1 Feb 2022. o Directory authority changes (backport from 0.4.1.5): - The directory authority "dizum" has a new IP address. Closes ticket 31406. o Major bugfixes (bridges, backport from 0.4.1.2-alpha): - Consider our directory information to have changed when our list of bridges changes. Previously, Tor would not re-compute the status of its directory information when bridges changed, and therefore would not realize that it was no longer able to build circuits. Fixes part of bug 29875. - Do not count previously configured working bridges towards our total of working bridges. Previously, when Tor's list of bridges changed, it would think that the old bridges were still usable, and delay fetching router descriptors for the new ones. Fixes part of bug 29875; bugfix on 0.3.0.1-alpha. o Major bugfixes (circuit build, guard, backport from 0.4.1.4-rc): - When considering upgrading circuits from "waiting for guard" to "open", always ignore circuits that are marked for close. Otherwise, we can end up in the situation where a subsystem is notified that a closing circuit has just opened, leading to undesirable behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha. o Major bugfixes (Onion service reachability, backport from 0.4.1.3-alpha): - Properly clean up the introduction point map when circuits change purpose from onion service circuits to pathbias, measurement, or other circuit types. This should fix some service-side instances of introduction point failure. Fixes bug 29034; bugfix on 0.3.2.1-alpha. o Major bugfixes (onion service v3, backport from 0.4.1.1-alpha): - Fix an unreachable bug in which an introduction point could try to send an INTRODUCE_ACK with a status code that Trunnel would refuse to encode, leading the relay to assert(). We've consolidated the ABI values into Trunnel now. Fixes bug 30454; bugfix on 0.3.0.1-alpha. - Clients can now handle unknown status codes from INTRODUCE_ACK cells. (The NACK behavior will stay the same.) This will allow us to extend status codes in the future without breaking the normal client behavior. Fixes another part of bug 30454; bugfix on 0.3.0.1-alpha. o Major bugfixes (relay, backport from 0.4.2.3-alpha): - Relays now respect their AccountingMax bandwidth again. When relays entered "soft" hibernation (which typically starts when we've hit 90% of our AccountingMax), we had stopped checking whether we should enter hard hibernation. Soft hibernation refuses new connections and new circuits, but the existing circuits can continue, meaning that relays could have exceeded their configured AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha. o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha): - Stop ignoring torrc options after an %include directive, when the included directory ends with a file that does not contain any config options (but does contain comments or whitespace). Fixes bug 31408; bugfix on 0.3.1.1-alpha. o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha): - Onion services now always use the exact number of intro points configured with the HiddenServiceNumIntroductionPoints option (or fewer if nodes are excluded). Before, a service could sometimes pick more intro points than configured. Fixes bug 31548; bugfix on 0.3.2.1-alpha. o Minor features (compile-time modules, backport from version 0.4.1.1-alpha): - Add a "--list-modules" command to print a list of which compile- time modules are enabled. Closes ticket 30452. o Minor features (continuous integration, backport from 0.4.1.1-alpha): - Remove sudo configuration lines from .travis.yml as they are no longer needed with current Travis build environment. Resolves issue 30213. o Minor features (continuous integration, backport from 0.4.1.4-rc): - Our Travis configuration now uses Chutney to run some network integration tests automatically. Closes ticket 29280. o Minor features (continuous integration, backport from 0.4.2.2-alpha): - When building on Appveyor and Travis, pass the "-k" flag to make, so that we are informed of all compilation failures, not just the first one or two. Closes ticket 31372. o Minor features (fallback directory list, backport from 0.4.1.4-rc): - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc in December 2018 (of which ~122 were still functional), with a list of 148 fallbacks (70 new, 78 existing, 79 removed) generated in June 2019. Closes ticket 28795. o Minor features (geoip, backport from 0.4.2.5): - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2 Country database. Closes ticket 32685. o Minor features (stem tests, backport from 0.4.2.1-alpha): - Change "make test-stem" so it only runs the stem tests that use tor. This change makes test-stem faster and more reliable. Closes ticket 31554. o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha): - Avoid spurious errors when Appveyor CI fails before the install step. Fixes bug 31884; bugfix on 0.3.4.2-alpha. o Minor bugfixes (build system, backport form 0.4.2.1-alpha): - Do not include the deprecated on Linux or Windows systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha. o Minor bugfixes (circuit isolation, backport from 0.4.1.3-alpha): - Fix a logic error that prevented the SessionGroup sub-option from being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha. o Minor bugfixes (circuit padding, backport from 0.4.1.4-rc): - On relays, properly check that a padding machine is absent before logging a warning about it being absent. Fixes bug 30649; bugfix on 0.4.0.1-alpha. o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc): - Fix a BUG() assertion that occurs within a very small race window between when a client intro circuit opens and when its descriptor gets cleaned up from the cache. The circuit is now closed early, which will trigger a re-fetch of the descriptor and continue the connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha. o Minor bugfixes (clock skew detection, backport from 0.4.1.5): - Don't believe clock skew results from NETINFO cells that appear to arrive before we sent the VERSIONS cells they are responding to. Previously, we would accept them up to 3 minutes "in the past". Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compilation warning, backport from 0.4.1.5): - Fix a compilation warning on Windows about casting a function pointer for GetTickCount64(). Fixes bug 31374; bugfix on 0.2.9.1-alpha. o Minor bugfixes (compilation, backport from 0.4.1.5): - Avoid using labs() on time_t, which can cause compilation warnings on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compilation, backport from 0.4.2.1-alpha): - Suppress spurious float-conversion warnings from GCC when calling floating-point classifier functions on FreeBSD. Fixes part of bug 31687; bugfix on 0.3.1.5-alpha. o Minor bugfixes (compilation, unusual configurations, backport from 0.4.1.1-alpha): - Avoid failures when building with the ALL_BUGS_ARE_FATAL option due to missing declarations of abort(), and prevent other such failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha. o Minor bugfixes (configuration, proxies, backport from 0.4.1.2-alpha): - Fix a bug that prevented us from supporting SOCKS5 proxies that want authentication along with configured (but unused!) ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha. o Minor bugfixes (connections, backport from 0.4.2.3-rc): - Avoid trying to read data from closed connections, which can cause needless loops in Libevent and infinite loops in Shadow. Fixes bug 30344; bugfix on 0.1.1.1-alpha. o Minor bugfixes (continuous integration, backport from 0.4.1.3-alpha): - Allow the test-stem job to fail in Travis, because it sometimes hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha. - Skip test_rebind on macOS in Travis, because it is unreliable on macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha. - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha. o Minor bugfixes (crash on exit, backport from 0.4.1.4-rc): - Avoid a set of possible code paths that could try to use freed memory in routerlist_free() while Tor was exiting. Fixes bug 31003; bugfix on 0.1.2.2-alpha. o Minor bugfixes (directory authorities, backport from 0.4.1.3-alpha): - Stop crashing after parsing an unknown descriptor purpose annotation. We think this bug can only be triggered by modifying a local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha. o Minor bugfixes (directory authority, backport from 0.4.1.2-alpha): - Move the "bandwidth-file-headers" line in directory authority votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix on 0.3.5.1-alpha. o Minor bugfixes (error handling, backport from 0.4.2.1-alpha): - On abort, try harder to flush the output buffers of log messages. On some platforms (macOS), log messages could be discarded when the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - Report the tor version whenever an assertion fails. Previously, we only reported the Tor version on some crashes, and some non-fatal assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha. o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha): - When extracting an IPv6 address from a PF-based proxy, verify that we are actually configured to receive an IPv6 address, and log an internal error if not. Fixes part of bug 31687; bugfix on 0.2.3.4-alpha. o Minor bugfixes (guards, backport from 0.4.2.1-alpha): - When tor is missing descriptors for some primary entry guards, make the log message less alarming. It's normal for descriptors to expire, as long as tor fetches new ones soon after. Fixes bug 31657; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.1.1-alpha): - Do not log a warning when running with an OpenSSL version other than the one Tor was compiled with, if the two versions should be compatible. Previously, we would warn whenever the version was different. Fixes bug 30190; bugfix on 0.2.4.2-alpha. o Minor bugfixes (logging, backport from 0.4.2.1-alpha): - Change log level of message "Hash of session info was not as expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix on 0.1.1.10-alpha. o Minor bugfixes (logging, backport from 0.4.2.2-alpha): - Rate-limit the logging message about the obsolete .exit notation. Previously, there was no limit on this warning, which could potentially be triggered many times by a hostile website. Fixes bug 31466; bugfix on 0.2.2.1-alpha. o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha): - Do not log a nonfatal assertion failure when receiving a VERSIONS cell on a connection using the obsolete v1 link protocol. Log a protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha. o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha): - Reset the periodic events' "enabled" flag when Tor is shut down cleanly. Previously, this flag was left on, which caused periodic events not to be re-enabled when Tor was relaunched in-process with tor_api.h after a shutdown. Fixes bug 32058; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leak, backport from 0.4.1.1-alpha): - Avoid a minor memory leak that could occur on relays when failing to create a "keys" directory. Fixes bug 30148; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leak, backport from 0.4.1.4-rc): - Fix a trivial memory leak when parsing an invalid value from a download schedule in the configuration. Fixes bug 30894; bugfix on 0.3.4.1-alpha. o Minor bugfixes (NetBSD, backport from 0.4.1.2-alpha): - Fix usage of minherit() on NetBSD and other platforms that define MAP_INHERIT_{ZERO,NONE} instead of INHERIT_{ZERO,NONE}. Fixes bug 30614; bugfix on 0.4.0.2-alpha. Patch from Taylor Campbell. o Minor bugfixes (onion services, backport from 0.4.1.1-alpha): - Avoid a GCC 9.1.1 warning (and possible crash depending on libc implementation) when failing to load an onion service client authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha. o Minor bugfixes (out-of-memory handler, backport from 0.4.1.2-alpha): - When purging the DNS cache because of an out-of-memory condition, try purging just the older entries at first. Previously, we would always purge the whole thing. Fixes bug 29617; bugfix on 0.3.5.1-alpha. o Minor bugfixes (portability, backport from 0.4.1.2-alpha): - Avoid crashing in our tor_vasprintf() implementation on systems that define neither vasprintf() nor _vscprintf(). (This bug has been here long enough that we question whether people are running Tor on such systems, but we're applying the fix out of caution.) Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by Tobias Stoeckmann. o Minor bugfixes (process management, backport from 0.4.2.3-alpha): - Remove overly strict assertions that triggered when a pluggable transport failed to launch. Fixes bug 31091; bugfix on 0.4.0.1-alpha. - Remove an assertion in the Unix process backend. This assertion would trigger when we failed to find the executable for a child process. Fixes bug 31810; bugfix on 0.4.0.1-alpha. o Minor bugfixes (relay, backport from 0.4.2.2-alpha): - Avoid crashing when starting with a corrupt keys directory where the old ntor key and the new ntor key are identical. Fixes bug 30916; bugfix on 0.2.4.8-alpha. o Minor bugfixes (rust, backport from 0.4.2.1-alpha): - Correctly exclude a redundant rust build job in Travis. Fixes bug 31463; bugfix on 0.3.5.4-alpha. o Minor bugfixes (testing, backport from 0.4.2.3-alpha): - When testing port rebinding, don't busy-wait for tor to log. Instead, actually sleep for a short time before polling again. Also improve the formatting of control commands and log messages. Fixes bug 31837; bugfix on 0.3.5.1-alpha. o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha): - Log bugs about the TLS read buffer's length only once, rather than filling the logs with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc. o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha): - Always retry v2 single onion service intro and rend circuits with a 3-hop path. Previously, v2 single onion services used a 3-hop path when rendezvous circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.2.9.3-alpha. - Make v3 single onion services fall back to a 3-hop intro, when all intro points are unreachable via a 1-hop path. Previously, v3 single onion services failed when all intro nodes were unreachable via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha. o Documentation (backport from 0.4.2.1-alpha): - Use RFC 2397 data URL scheme to embed an image into tor-exit- notice.html so that operators no longer have to host it themselves. Closes ticket 31089. o Testing (backport from 0.4.1.2-alpha): - Specify torrc paths (with empty files) when launching tor in integration tests; refrain from reading user and system torrcs. Resolves issue 29702. o Testing (continuous integration, backport from 0.4.1.1-alpha): - In Travis, show stem's tor log after failure. Closes ticket 30234. o Testing (continuous integration, backport from 0.4.1.5): - In Travis, make stem log a controller trace to the console, and tail stem's tor log after failure. Closes ticket 30591. - In Travis, only run the stem tests that use a tor binary. Closes ticket 30694. o Testing (continuous integration, backport from 0.4.2.3-alpha): - Disable all but one Travis CI macOS build, to mitigate slow scheduling of Travis macOS jobs. Closes ticket 32177. - Run the chutney IPv6 networks as part of Travis CI. Closes ticket 30860. - Simplify the Travis CI build matrix, and optimise for build time. Closes ticket 31859. - Use Windows Server 2019 instead of Windows Server 2016 in our Appveyor builds. Closes ticket 32086. o Testing (continuous integration, backport from 0.4.2.4-rc): - Use Ubuntu Bionic images for our Travis CI builds, so we can get a recent version of coccinelle. But leave chutney on Ubuntu Trusty, until we can fix some Bionic permissions issues (see ticket 32240). Related to ticket 31919. - Install the mingw OpenSSL package in Appveyor. This makes sure that the OpenSSL headers and libraries match in Tor's Appveyor builds. (This bug was triggered by an Appveyor image update.) Fixes bug 32449; bugfix on 0.3.5.6-rc. - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241. o Testing (continuous integration, backport from 0.4.2.5): - Require C99 standards-conforming code in Travis CI, but allow GNU gcc extensions. Also activates clang's -Wtypedef-redefinition warnings. Build some jobs with -std=gnu99, and some jobs without. Closes ticket 32500. Changes in version 0.3.5.9 - 2019-12-09 Tor 0.3.5.9 backports serveral fixes from later releases, including several that affect bridge users, relay stability, onion services, and much more. o Directory authority changes (backport from 0.4.1.5): - The directory authority "dizum" has a new IP address. Closes ticket 31406. o Major bugfixes (bridges, backport from 0.4.1.2-alpha): - Consider our directory information to have changed when our list of bridges changes. Previously, Tor would not re-compute the status of its directory information when bridges changed, and therefore would not realize that it was no longer able to build circuits. Fixes part of bug 29875. - Do not count previously configured working bridges towards our total of working bridges. Previously, when Tor's list of bridges changed, it would think that the old bridges were still usable, and delay fetching router descriptors for the new ones. Fixes part of bug 29875; bugfix on 0.3.0.1-alpha. o Major bugfixes (circuit build, guard, backport from 0.4.1.4-rc): - When considering upgrading circuits from "waiting for guard" to "open", always ignore circuits that are marked for close. Otherwise, we can end up in the situation where a subsystem is notified that a closing circuit has just opened, leading to undesirable behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha. o Major bugfixes (NSS, relay, backport from 0.4.0.4-rc): - When running with NSS, disable TLS 1.2 ciphersuites that use SHA384 for their PRF. Due to an NSS bug, the TLS key exporters for these ciphersuites don't work -- which caused relays to fail to handshake with one another when these ciphersuites were enabled. Fixes bug 29241; bugfix on 0.3.5.1-alpha. o Major bugfixes (Onion service reachability, backport from 0.4.1.3-alpha): - Properly clean up the introduction point map when circuits change purpose from onion service circuits to pathbias, measurement, or other circuit types. This should fix some service-side instances of introduction point failure. Fixes bug 29034; bugfix on 0.3.2.1-alpha. o Major bugfixes (onion service v3, backport from 0.4.1.1-alpha): - Fix an unreachable bug in which an introduction point could try to send an INTRODUCE_ACK with a status code that Trunnel would refuse to encode, leading the relay to assert(). We've consolidated the ABI values into Trunnel now. Fixes bug 30454; bugfix on 0.3.0.1-alpha. - Clients can now handle unknown status codes from INTRODUCE_ACK cells. (The NACK behavior will stay the same.) This will allow us to extend status codes in the future without breaking the normal client behavior. Fixes another part of bug 30454; bugfix on 0.3.0.1-alpha. o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha): - Stop ignoring torrc options after an %include directive, when the included directory ends with a file that does not contain any config options (but does contain comments or whitespace). Fixes bug 31408; bugfix on 0.3.1.1-alpha. o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha): - Onion services now always use the exact number of intro points configured with the HiddenServiceNumIntroductionPoints option (or fewer if nodes are excluded). Before, a service could sometimes pick more intro points than configured. Fixes bug 31548; bugfix on 0.3.2.1-alpha. o Minor features (address selection, backport from 0.4.0.3-alpha): - Treat the subnet 100.64.0.0/10 as public for some purposes; private for others. This subnet is the RFC 6598 (Carrier Grade NAT) IP range, and is deployed by many ISPs as an alternative to RFC 1918 that does not break existing internal networks. Tor now blocks SOCKS and control ports on these addresses and warns users if client ports or ExtORPorts are listening on a RFC 6598 address. Closes ticket 28525. Patch by Neel Chauhan. o Minor features (bandwidth authority, backport from 0.4.0.4-rc): - Make bandwidth authorities ignore relays that are reported in the bandwidth file with the flag "vote=0". This change allows us to report unmeasured relays for diagnostic reasons without including their bandwidth in the bandwidth authorities' vote. Closes ticket 29806. o Minor features (compile-time modules, backport from version 0.4.1.1-alpha): - Add a "--list-modules" command to print a list of which compile- time modules are enabled. Closes ticket 30452. o Minor features (continuous integration, backport from 0.4.0.4-rc): - On Travis Rust builds, cleanup Rust registry and refrain from caching the "target/" directory to speed up builds. Resolves issue 29962. o Minor features (continuous integration, backport from 0.4.0.5): - In Travis, tell timelimit to use stem's backtrace signals, and launch python directly from timelimit, so python receives the signals from timelimit, rather than make. Closes ticket 30117. o Minor features (continuous integration, backport from 0.4.1.1-alpha): - Remove sudo configuration lines from .travis.yml as they are no longer needed with current Travis build environment. Resolves issue 30213. o Minor features (continuous integration, backport from 0.4.1.4-rc): - Our Travis configuration now uses Chutney to run some network integration tests automatically. Closes ticket 29280. o Minor features (continuous integration, backport from 0.4.2.2-alpha): - When building on Appveyor and Travis, pass the "-k" flag to make, so that we are informed of all compilation failures, not just the first one or two. Closes ticket 31372. o Minor features (fallback directory list, backport from 0.4.1.4-rc): - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc in December 2018 (of which ~122 were still functional), with a list of 148 fallbacks (70 new, 78 existing, 79 removed) generated in June 2019. Closes ticket 28795. o Minor features (geoip, backport from 0.4.2.5): - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2 Country database. Closes ticket 32685. o Minor features (NSS, diagnostic, backport from 0.4.0.4-rc): - Try to log an error from NSS (if there is any) and a more useful description of our situation if we are using NSS and a call to SSL_ExportKeyingMaterial() fails. Diagnostic for ticket 29241. o Minor features (stem tests, backport from 0.4.2.1-alpha): - Change "make test-stem" so it only runs the stem tests that use tor. This change makes test-stem faster and more reliable. Closes ticket 31554. o Minor bugfixes (security, backport from 0.4.0.4-rc): - Verify in more places that we are not about to create a buffer with more than INT_MAX bytes, to avoid possible OOB access in the event of bugs. Fixes bug 30041; bugfix on 0.2.0.16. Found and fixed by Tobias Stoeckmann. - Fix a potential double free bug when reading huge bandwidth files. The issue is not exploitable in the current Tor network because the vulnerable code is only reached when directory authorities read bandwidth files, but bandwidth files come from a trusted source (usually the authorities themselves). Furthermore, the issue is only exploitable in rare (non-POSIX) 32-bit architectures, which are not used by any of the current authorities. Fixes bug 30040; bugfix on 0.3.5.1-alpha. Bug found and fixed by Tobias Stoeckmann. o Minor bugfix (continuous integration, backport from 0.4.0.4-rc): - Reset coverage state on disk after Travis CI has finished. This should prevent future coverage merge errors from causing the test suite for the "process" subsystem to fail. The process subsystem was introduced in 0.4.0.1-alpha. Fixes bug 29036; bugfix on 0.2.9.15. - Terminate test-stem if it takes more than 9.5 minutes to run. (Travis terminates the job after 10 minutes of no output.) Diagnostic for 29437. Fixes bug 30011; bugfix on 0.3.5.4-alpha. o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha): - Avoid spurious errors when Appveyor CI fails before the install step. Fixes bug 31884; bugfix on 0.3.4.2-alpha. o Minor bugfixes (build system, backport form 0.4.2.1-alpha): - Do not include the deprecated on Linux or Windows systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha. o Minor bugfixes (C correctness, backport from 0.4.0.4-rc): - Fix an unlikely memory leak in consensus_diff_apply(). Fixes bug 29824; bugfix on 0.3.1.1-alpha. This is Coverity warning CID 1444119. o Minor bugfixes (circuit isolation, backport from 0.4.1.3-alpha): - Fix a logic error that prevented the SessionGroup sub-option from being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha. o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc): - Fix a BUG() assertion that occurs within a very small race window between when a client intro circuit opens and when its descriptor gets cleaned up from the cache. The circuit is now closed early, which will trigger a re-fetch of the descriptor and continue the connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha. o Minor bugfixes (clock skew detection, backport from 0.4.1.5): - Don't believe clock skew results from NETINFO cells that appear to arrive before we sent the VERSIONS cells they are responding to. Previously, we would accept them up to 3 minutes "in the past". Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compilation warning, backport from 0.4.1.5): - Fix a compilation warning on Windows about casting a function pointer for GetTickCount64(). Fixes bug 31374; bugfix on 0.2.9.1-alpha. o Minor bugfixes (compilation, backport from 0.4.0.2-alpha): - Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug 29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn. o Minor bugfixes (compilation, backport from 0.4.1.5): - Avoid using labs() on time_t, which can cause compilation warnings on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compilation, backport from 0.4.2.1-alpha): - Suppress spurious float-conversion warnings from GCC when calling floating-point classifier functions on FreeBSD. Fixes part of bug 31687; bugfix on 0.3.1.5-alpha. o Minor bugfixes (compilation, unusual configurations, backport from 0.4.1.1-alpha): - Avoid failures when building with the ALL_BUGS_ARE_FATAL option due to missing declarations of abort(), and prevent other such failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha. o Minor bugfixes (configuration, proxies, backport from 0.4.1.2-alpha): - Fix a bug that prevented us from supporting SOCKS5 proxies that want authentication along with configured (but unused!) ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha. o Minor bugfixes (connections, backport from 0.4.2.3-rc): - Avoid trying to read data from closed connections, which can cause needless loops in Libevent and infinite loops in Shadow. Fixes bug 30344; bugfix on 0.1.1.1-alpha. o Minor bugfixes (continuous integration, backport from 0.4.1.3-alpha): - Allow the test-stem job to fail in Travis, because it sometimes hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha. - Skip test_rebind on macOS in Travis, because it is unreliable on macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha. - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha. o Minor bugfixes (crash on exit, backport from 0.4.1.4-rc): - Avoid a set of possible code paths that could try to use freed memory in routerlist_free() while Tor was exiting. Fixes bug 31003; bugfix on 0.1.2.2-alpha. o Minor bugfixes (directory authorities, backport from 0.4.1.3-alpha): - Stop crashing after parsing an unknown descriptor purpose annotation. We think this bug can only be triggered by modifying a local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha. o Minor bugfixes (directory authority, backport from 0.4.1.2-alpha): - Move the "bandwidth-file-headers" line in directory authority votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix on 0.3.5.1-alpha. o Minor bugfixes (error handling, backport from 0.4.2.1-alpha): - On abort, try harder to flush the output buffers of log messages. On some platforms (macOS), log messages could be discarded when the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha. - Report the tor version whenever an assertion fails. Previously, we only reported the Tor version on some crashes, and some non-fatal assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha. o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha): - When extracting an IPv6 address from a PF-based proxy, verify that we are actually configured to receive an IPv6 address, and log an internal error if not. Fixes part of bug 31687; bugfix on 0.2.3.4-alpha. o Minor bugfixes (guards, backport from 0.4.2.1-alpha): - When tor is missing descriptors for some primary entry guards, make the log message less alarming. It's normal for descriptors to expire, as long as tor fetches new ones soon after. Fixes bug 31657; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.0.2-alpha): - Avoid logging that we are relaxing a circuit timeout when that timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha. o Minor bugfixes (logging, backport from 0.4.0.3-alpha): - Correct a misleading error message when IPv4Only or IPv6Only is used but the resolved address can not be interpreted as an address of the specified IP version. Fixes bug 13221; bugfix on 0.2.3.9-alpha. Patch from Kris Katterjohn. - Log the correct port number for listening sockets when "auto" is used to let Tor pick the port number. Previously, port 0 was logged instead of the actual port number. Fixes bug 29144; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. - Stop logging a BUG() warning when Tor is waiting for exit descriptors. Fixes bug 28656; bugfix on 0.3.5.1-alpha. o Minor bugfixes (logging, backport from 0.4.1.1-alpha): - Do not log a warning when running with an OpenSSL version other than the one Tor was compiled with, if the two versions should be compatible. Previously, we would warn whenever the version was different. Fixes bug 30190; bugfix on 0.2.4.2-alpha. o Minor bugfixes (logging, backport from 0.4.2.1-alpha): - Change log level of message "Hash of session info was not as expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix on 0.1.1.10-alpha. o Minor bugfixes (logging, backport from 0.4.2.2-alpha): - Rate-limit the logging message about the obsolete .exit notation. Previously, there was no limit on this warning, which could potentially be triggered many times by a hostile website. Fixes bug 31466; bugfix on 0.2.2.1-alpha. o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha): - Do not log a nonfatal assertion failure when receiving a VERSIONS cell on a connection using the obsolete v1 link protocol. Log a protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha. o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha): - Reset the periodic events' "enabled" flag when Tor is shut down cleanly. Previously, this flag was left on, which caused periodic events not to be re-enabled when Tor was relaunched in-process with tor_api.h after a shutdown. Fixes bug 32058; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leak, backport from 0.4.1.1-alpha): - Avoid a minor memory leak that could occur on relays when failing to create a "keys" directory. Fixes bug 30148; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leak, backport from 0.4.1.4-rc): - Fix a trivial memory leak when parsing an invalid value from a download schedule in the configuration. Fixes bug 30894; bugfix on 0.3.4.1-alpha. o Minor bugfixes (memory management, backport from 0.4.0.3-alpha): - Refactor the shared random state's memory management so that it actually takes ownership of the shared random value pointers. Fixes bug 29706; bugfix on 0.2.9.1-alpha. o Minor bugfixes (memory management, testing, backport from 0.4.0.3-alpha): - Stop leaking parts of the shared random state in the shared-random unit tests. Fixes bug 29599; bugfix on 0.2.9.1-alpha. o Minor bugfixes (onion services, backport from 0.4.1.1-alpha): - Avoid a GCC 9.1.1 warning (and possible crash depending on libc implementation) when failing to load an onion service client authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha. o Minor bugfixes (out-of-memory handler, backport from 0.4.1.2-alpha): - When purging the DNS cache because of an out-of-memory condition, try purging just the older entries at first. Previously, we would always purge the whole thing. Fixes bug 29617; bugfix on 0.3.5.1-alpha. o Minor bugfixes (portability, backport from 0.4.1.2-alpha): - Avoid crashing in our tor_vasprintf() implementation on systems that define neither vasprintf() nor _vscprintf(). (This bug has been here long enough that we question whether people are running Tor on such systems, but we're applying the fix out of caution.) Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by Tobias Stoeckmann. o Minor bugfixes (relay, backport from 0.4.2.2-alpha): - Avoid crashing when starting with a corrupt keys directory where the old ntor key and the new ntor key are identical. Fixes bug 30916; bugfix on 0.2.4.8-alpha. o Minor bugfixes (rust, backport from 0.4.0.5): - Abort on panic in all build profiles, instead of potentially unwinding into C code. Fixes bug 27199; bugfix on 0.3.3.1-alpha. o Minor bugfixes (rust, backport from 0.4.2.1-alpha): - Correctly exclude a redundant rust build job in Travis. Fixes bug 31463; bugfix on 0.3.5.4-alpha. o Minor bugfixes (single onion services, backport from 0.4.0.3-alpha): - Allow connections to single onion services to remain idle without being disconnected. Previously, relays acting as rendezvous points for single onion services were mistakenly closing idle rendezvous circuits after 60 seconds, thinking that they were unused directory-fetching circuits that had served their purpose. Fixes bug 29665; bugfix on 0.2.1.26. o Minor bugfixes (stats, backport from 0.4.0.3-alpha): - When ExtraInfoStatistics is 0, stop including PaddingStatistics in relay and bridge extra-info documents. Fixes bug 29017; bugfix on 0.3.1.1-alpha. o Minor bugfixes (testing, backport from 0.4.0.3-alpha): - Downgrade some LOG_ERR messages in the address/* tests to warnings. The LOG_ERR messages were occurring when we had no configured network. We were failing the unit tests, because we backported 28668 to 0.3.5.8, but did not backport 29530. Fixes bug 29530; bugfix on 0.3.5.8. - Fix our gcov wrapper script to look for object files at the correct locations. Fixes bug 29435; bugfix on 0.3.5.1-alpha. o Minor bugfixes (testing, backport from 0.4.0.4-rc): - Backport the 0.3.4 src/test/test-network.sh to 0.2.9. We need a recent test-network.sh to use new chutney features in CI. Fixes bug 29703; bugfix on 0.2.9.1-alpha. - Fix a test failure on Windows caused by an unexpected "BUG" warning in our tests for tor_gmtime_r(-1). Fixes bug 29922; bugfix on 0.2.9.3-alpha. o Minor bugfixes (testing, backport from 0.4.2.3-alpha): - When testing port rebinding, don't busy-wait for tor to log. Instead, actually sleep for a short time before polling again. Also improve the formatting of control commands and log messages. Fixes bug 31837; bugfix on 0.3.5.1-alpha. o Minor bugfixes (TLS protocol, backport form 0.4.0.4-rc): - When classifying a client's selection of TLS ciphers, if the client ciphers are not yet available, do not cache the result. Previously, we had cached the unavailability of the cipher list and never looked again, which in turn led us to assume that the client only supported the ancient V1 link protocol. This, in turn, was causing Stem integration tests to stall in some cases. Fixes bug 30021; bugfix on 0.2.4.8-alpha. o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha): - Log bugs about the TLS read buffer's length only once, rather than filling the logs with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc. o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha): - Always retry v2 single onion service intro and rend circuits with a 3-hop path. Previously, v2 single onion services used a 3-hop path when rendezvous circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.2.9.3-alpha. - Make v3 single onion services fall back to a 3-hop intro, when all intro points are unreachable via a 1-hop path. Previously, v3 single onion services failed when all intro nodes were unreachable via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha. o Minor bugfixes (Windows, CI, backport from 0.4.0.3-alpha): - Skip the Appveyor 32-bit Windows Server 2016 job, and 64-bit Windows Server 2012 R2 job. The remaining 2 jobs still provide coverage of 64/32-bit, and Windows Server 2016/2012 R2. Also set fast_finish, so failed jobs terminate the build immediately. Fixes bug 29601; bugfix on 0.3.5.4-alpha. o Documentation (backport from 0.4.2.1-alpha): - Use RFC 2397 data URL scheme to embed an image into tor-exit- notice.html so that operators no longer have to host it themselves. Closes ticket 31089. o Testing (backport from 0.4.1.2-alpha): - Specify torrc paths (with empty files) when launching tor in integration tests; refrain from reading user and system torrcs. Resolves issue 29702. o Testing (continuous integration, backport from 0.4.1.1-alpha): - In Travis, show stem's tor log after failure. Closes ticket 30234. o Testing (continuous integration, backport from 0.4.1.5): - In Travis, make stem log a controller trace to the console, and tail stem's tor log after failure. Closes ticket 30591. - In Travis, only run the stem tests that use a tor binary. Closes ticket 30694. o Testing (continuous integration, backport from 0.4.2.3-alpha): - Disable all but one Travis CI macOS build, to mitigate slow scheduling of Travis macOS jobs. Closes ticket 32177. - Run the chutney IPv6 networks as part of Travis CI. Closes ticket 30860. - Simplify the Travis CI build matrix, and optimise for build time. Closes ticket 31859. - Use Windows Server 2019 instead of Windows Server 2016 in our Appveyor builds. Closes ticket 32086. o Testing (continuous integration, backport from 0.4.2.4-rc): - Use Ubuntu Bionic images for our Travis CI builds, so we can get a recent version of coccinelle. But leave chutney on Ubuntu Trusty, until we can fix some Bionic permissions issues (see ticket 32240). Related to ticket 31919. - Install the mingw OpenSSL package in Appveyor. This makes sure that the OpenSSL headers and libraries match in Tor's Appveyor builds. (This bug was triggered by an Appveyor image update.) Fixes bug 32449; bugfix on 0.3.5.6-rc. - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241. o Testing (continuous integration, backport from 0.4.2.5): - Require C99 standards-conforming code in Travis CI, but allow GNU gcc extensions. Also activates clang's -Wtypedef-redefinition warnings. Build some jobs with -std=gnu99, and some jobs without. Closes ticket 32500. Changes in version 0.4.1.6 - 2019-09-19 This release backports several bugfixes to improve stability and correctness. Anyone experiencing build problems or crashes with 0.4.1.5, or experiencing reliability issues with single onion services, should upgrade. o Major bugfixes (crash, Linux, Android, backport from 0.4.2.1-alpha): - Tolerate systems (including some Android installations) where madvise and MADV_DONTDUMP are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31570; bugfix on 0.4.1.1-alpha. - Tolerate systems (including some Linux installations) where madvise and/or MADV_DONTFORK are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31696; bugfix on 0.4.1.1-alpha. o Minor features (stem tests, backport from 0.4.2.1-alpha): - Change "make test-stem" so it only runs the stem tests that use tor. This change makes test-stem faster and more reliable. Closes ticket 31554. o Minor bugfixes (build system, backport form 0.4.2.1-alpha): - Do not include the deprecated on Linux or Windows systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha. o Minor bugfixes (compilation, backport from 0.4.2.1-alpha): - Add more stub functions to fix compilation on Android with link- time optimization when --disable-module-dirauth is used. Previously, these compilation settings would make the compiler look for functions that didn't exist. Fixes bug 31552; bugfix on 0.4.1.1-alpha. - Suppress spurious float-conversion warnings from GCC when calling floating-point classifier functions on FreeBSD. Fixes part of bug 31687; bugfix on 0.3.1.5-alpha. o Minor bugfixes (controller protocol): - Fix the MAPADDRESS controller command to accept one or more arguments. Previously, it required two or more arguments, and ignored the first. Fixes bug 31772; bugfix on 0.4.1.1-alpha. o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha): - When extracting an IPv6 address from a PF-based proxy, verify that we are actually configured to receive an IPv6 address, and log an internal error if not. Fixes part of bug 31687; bugfix on 0.2.3.4-alpha. o Minor bugfixes (guards, backport from 0.4.2.1-alpha): - When tor is missing descriptors for some primary entry guards, make the log message less alarming. It's normal for descriptors to expire, as long as tor fetches new ones soon after. Fixes bug 31657; bugfix on 0.3.3.1-alpha. o Minor bugfixes (logging, backport from 0.4.2.1-alpha): - Change log level of message "Hash of session info was not as expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix on 0.1.1.10-alpha. o Minor bugfixes (rust, backport from 0.4.2.1-alpha): - Correctly exclude a redundant rust build job in Travis. Fixes bug 31463; bugfix on 0.3.5.4-alpha. o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha): - Always retry v2 single onion service intro and rend circuits with a 3-hop path. Previously, v2 single onion services used a 3-hop path when rendezvous circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.2.9.3-alpha. o Minor bugfixes (v3 single onion services, backport from 0.4.2.1-alpha): - Always retry v3 single onion service intro and rend circuits with a 3-hop path. Previously, v3 single onion services used a 3-hop path when rend circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.3.2.1-alpha. - Make v3 single onion services fall back to a 3-hop intro, when all intro points are unreachable via a 1-hop path. Previously, v3 single onion services failed when all intro nodes were unreachable via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha. o Documentation (backport from 0.4.2.1-alpha): - Use RFC 2397 data URL scheme to embed an image into tor-exit- notice.html so that operators no longer have to host it themselves. Closes ticket 31089. Changes in version 0.4.1.5 - 2019-08-20 This is the first stable release in the 0.4.1.x series. This series adds experimental circuit-level padding, authenticated SENDME cells to defend against certain attacks, and several performance improvements to save on CPU consumption. It fixes bugs in bootstrapping and v3 onion services. It also includes numerous smaller features and bugfixes on earlier versions. Per our support policy, we will support the 0.4.1.x series for nine months, or until three months after the release of a stable 0.4.2.x: whichever is longer. If you need longer-term support, please stick with 0.3.5.x, which will we plan to support until Feb 2022. Below are the changes since 0.4.0.5. For a list of only the changes since 0.4.1.4-rc, see the ChangeLog file. o Directory authority changes: - The directory authority "dizum" has a new IP address. Closes ticket 31406. o Major features (circuit padding): - Onion service clients now add padding cells at the start of their INTRODUCE and RENDEZVOUS circuits, to make those circuits' traffic look more like general purpose Exit traffic. The overhead for this is 2 extra cells in each direction for RENDEZVOUS circuits, and 1 extra upstream cell and 10 downstream cells for INTRODUCE circuits. This feature is only enabled when also supported by the circuit's middle node. (Clients may specify fixed middle nodes with the MiddleNodes option, and may force-disable this feature with the CircuitPadding option.) Closes ticket 28634. o Major features (code organization): - Tor now includes a generic publish-subscribe message-passing subsystem that we can use to organize intermodule dependencies. We hope to use this to reduce dependencies between modules that don't need to be related, and to generally simplify our codebase. Closes ticket 28226. o Major features (controller protocol): - Controller commands are now parsed using a generalized parsing subsystem. Previously, each controller command was responsible for parsing its own input, which led to strange inconsistencies. Closes ticket 30091. o Major features (flow control): - Implement authenticated SENDMEs as detailed in proposal 289. A SENDME cell now includes the digest of the traffic that it acknowledges, so that once an end point receives the SENDME, it can confirm the other side's knowledge of the previous cells that were sent, and prevent certain types of denial-of-service attacks. This behavior is controlled by two new consensus parameters: see the proposal for more details. Fixes ticket 26288. o Major features (performance): - Our node selection algorithm now excludes nodes in linear time. Previously, the algorithm was quadratic, which could slow down heavily used onion services. Closes ticket 30307. o Major features (performance, RNG): - Tor now constructs a fast secure pseudorandom number generator for each thread, to use when performance is critical. This PRNG is based on AES-CTR, using a buffering construction similar to libottery and the (newer) OpenBSD arc4random() code. It outperforms OpenSSL 1.1.1a's CSPRNG by roughly a factor of 100 for small outputs. Although we believe it to be cryptographically strong, we are only using it when necessary for performance. Implements tickets 29023 and 29536. o Major bugfixes (bridges): - Consider our directory information to have changed when our list of bridges changes. Previously, Tor would not re-compute the status of its directory information when bridges changed, and therefore would not realize that it was no longer able to build circuits. Fixes part of bug 29875. - Do not count previously configured working bridges towards our total of working bridges. Previously, when Tor's list of bridges changed, it would think that the old bridges were still usable, and delay fetching router descriptors for the new ones. Fixes part of bug 29875; bugfix on 0.3.0.1-alpha. o Major bugfixes (circuit build, guard): - On relays, properly check that a padding machine is absent before logging a warning about it being absent. Fixes bug 30649; bugfix on 0.4.0.1-alpha. - When considering upgrading circuits from "waiting for guard" to "open", always ignore circuits that are marked for close. Otherwise, we can end up in the situation where a subsystem is notified that a closing circuit has just opened, leading to undesirable behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha. o Major bugfixes (onion service reachability): - Properly clean up the introduction point map when circuits change purpose from onion service circuits to pathbias, measurement, or other circuit types. This should fix some service-side instances of introduction point failure. Fixes bug 29034; bugfix on 0.3.2.1-alpha. o Major bugfixes (onion service v3): - Fix an unreachable bug in which an introduction point could try to send an INTRODUCE_ACK with a status code that Trunnel would refuse to encode, leading the relay to assert(). We've consolidated the ABI values into Trunnel now. Fixes bug 30454; bugfix on 0.3.0.1-alpha. - Clients can now handle unknown status codes from INTRODUCE_ACK cells. (The NACK behavior will stay the same.) This will allow us to extend status codes in the future without breaking the normal client behavior. Fixes another part of bug 30454; bugfix on 0.3.0.1-alpha. o Minor features (authenticated SENDME): - Ensure that there is enough randomness on every circuit to prevent an attacker from successfully predicting the hashes they will need to include in authenticated SENDME cells. At a random interval, if we have not sent randomness already, we now leave some extra space at the end of a cell that we can fill with random bytes. Closes ticket 26846. o Minor features (circuit padding logging): - Demote noisy client-side warn logs about circuit padding to protocol warnings. Add additional log messages and circuit ID fields to help with bug 30992 and any other future issues. o Minor features (circuit padding): - We now use a fast PRNG when scheduling circuit padding. Part of ticket 28636. - Allow the padding machine designer to pick the edges of their histogram instead of trying to compute them automatically using an exponential formula. Resolves some undefined behavior in the case of small histograms and allows greater flexibility on machine design. Closes ticket 29298; bugfix on 0.4.0.1-alpha. - Allow circuit padding machines to hold a circuit open until they are done padding it. Closes ticket 28780. o Minor features (compile-time modules): - Add a "--list-modules" command to print a list of which compile- time modules are enabled. Closes ticket 30452. o Minor features (continuous integration): - Our Travis configuration now uses Chutney to run some network integration tests automatically. Closes ticket 29280. - When running coverage builds on Travis, we now set TOR_TEST_RNG_SEED, to avoid RNG-based coverage differences. Part of ticket 28878. - Remove sudo configuration lines from .travis.yml as they are no longer needed with current Travis build environment. Resolves issue 30213. - In Travis, show stem's tor log after failure. Closes ticket 30234. o Minor features (controller): - Add onion service version 3 support to the HSFETCH command. Previously, only version 2 onion services were supported. Closes ticket 25417. Patch by Neel Chauhan. o Minor features (debugging): - Introduce tor_assertf() and tor_assertf_nonfatal() to enable logging of additional information during assert failure. Now we can use format strings to include information for trouble shooting. Resolves ticket 29662. o Minor features (defense in depth): - In smartlist_remove_keeporder(), set unused pointers to NULL, in case a bug causes them to be used later. Closes ticket 30176. Patch from Tobias Stoeckmann. - Tor now uses a cryptographically strong PRNG even for decisions that we do not believe are security-sensitive. Previously, for performance reasons, we had used a trivially predictable linear congruential generator algorithm for certain load-balancing and statistical sampling decisions. Now we use our fast RNG in those cases. Closes ticket 29542. o Minor features (developer tools): - Tor's "practracker" test script now checks for files and functions that seem too long and complicated. Existing overlong functions and files are accepted for now, but should eventually be refactored. Closes ticket 29221. - Add some scripts used for git maintenance to scripts/git. Closes ticket 29391. - Call practracker from pre-push and pre-commit git hooks to let developers know if they made any code style violations. Closes ticket 30051. - Add a script to check that each header has a well-formed and unique guard macro. Closes ticket 29756. o Minor features (fallback directory list): - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc in December 2018 (of which ~122 were still functional), with a list of 148 fallbacks (70 new, 78 existing, 79 removed) generated in June 2019. Closes ticket 28795. o Minor features (geoip): - Update geoip and geoip6 to the June 10 2019 Maxmind GeoLite2 Country database. Closes ticket 30852. - Update geoip and geoip6 to the May 13 2019 Maxmind GeoLite2 Country database. Closes ticket 30522. o Minor features (HTTP tunnel): - Return an informative web page when the HTTPTunnelPort is used as an HTTP proxy. Closes ticket 27821, patch by "eighthave". o Minor features (IPv6, v3 onion services): - Make v3 onion services put IPv6 addresses in service descriptors. Before this change, service descriptors only contained IPv4 addresses. Implements 26992. o Minor features (logging): - Give a more useful assertion failure message if we think we have minherit() but we fail to make a region non-inheritable. Give a compile-time warning if our support for minherit() is incomplete. Closes ticket 30686. o Minor features (maintenance): - Add a new "make autostyle" target that developers can use to apply all automatic Tor style and consistency conversions to the codebase. Closes ticket 30539. o Minor features (modularity): - The "--disable-module-dirauth" compile-time option now disables even more dirauth-only code. Closes ticket 30345. o Minor features (performance): - Use OpenSSL's implementations of SHA3 when available (in OpenSSL 1.1.1 and later), since they tend to be faster than tiny-keccak. Closes ticket 28837. o Minor features (testing): - The circuitpadding tests now use a reproducible RNG implementation, so that if a test fails, we can learn why. Part of ticket 28878. - Tor's tests now support an environment variable, TOR_TEST_RNG_SEED, to set the RNG seed for tests that use a reproducible RNG. Part of ticket 28878. - When running tests in coverage mode, take additional care to make our coverage deterministic, so that we can accurately track changes in code coverage. Closes ticket 30519. - Tor's unit test code now contains helper functions to replace the PRNG with a deterministic or reproducible version for testing. Previously, various tests implemented this in various ways. Implements ticket 29732. - We now have a script, cov-test-determinism.sh, to identify places where our unit test coverage has become nondeterministic. Closes ticket 29436. - Check that representative subsets of values of `int` and `unsigned int` can be represented by `void *`. Resolves issue 29537. o Minor bugfixes (bridge authority): - Bridge authorities now set bridges as running or non-running when about to dump their status to a file. Previously, they set bridges as running in response to a GETINFO command, but those shouldn't modify data structures. Fixes bug 24490; bugfix on 0.2.0.13-alpha. Patch by Neel Chauhan. o Minor bugfixes (channel padding statistics): - Channel padding write totals and padding-enabled totals are now counted properly in relay extrainfo descriptors. Fixes bug 29231; bugfix on 0.3.1.1-alpha. o Minor bugfixes (circuit isolation): - Fix a logic error that prevented the SessionGroup sub-option from being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha. o Minor bugfixes (circuit padding): - Add a "CircuitPadding" torrc option to disable circuit padding. Fixes bug 28693; bugfix on 0.4.0.1-alpha. - Allow circuit padding machines to specify that they do not contribute much overhead, and provide consensus flags and torrc options to force clients to only use these low overhead machines. Fixes bug 29203; bugfix on 0.4.0.1-alpha. - Provide a consensus parameter to fully disable circuit padding, to be used in emergency network overload situations. Fixes bug 30173; bugfix on 0.4.0.1-alpha. - The circuit padding subsystem will no longer schedule padding if dormant mode is enabled. Fixes bug 28636; bugfix on 0.4.0.1-alpha. - Inspect a circuit-level cell queue before sending padding, to avoid sending padding while too much data is already queued. Fixes bug 29204; bugfix on 0.4.0.1-alpha. - Avoid calling monotime_absolute_usec() in circuit padding machines that do not use token removal or circuit RTT estimation. Fixes bug 29085; bugfix on 0.4.0.1-alpha. o Minor bugfixes (clock skew detection): - Don't believe clock skew results from NETINFO cells that appear to arrive before we sent the VERSIONS cells they are responding to. Previously, we would accept them up to 3 minutes "in the past". Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compatibility, standards compliance): - Fix a bug that would invoke undefined behavior on certain operating systems when trying to asprintf() a string exactly INT_MAX bytes long. We don't believe this is exploitable, but it's better to fix it anyway. Fixes bug 31001; bugfix on 0.2.2.11-alpha. Found and fixed by Tobias Stoeckmann. o Minor bugfixes (compilation warning): - Fix a compilation warning on Windows about casting a function pointer for GetTickCount64(). Fixes bug 31374; bugfix on 0.2.9.1-alpha. o Minor bugfixes (compilation): - Avoid using labs() on time_t, which can cause compilation warnings on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha. o Minor bugfixes (compilation, unusual configurations): - Avoid failures when building with the ALL_BUGS_ARE_FATAL option due to missing declarations of abort(), and prevent other such failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha. o Minor bugfixes (configuration, proxies): - Fix a bug that prevented us from supporting SOCKS5 proxies that want authentication along with configured (but unused!) ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha. o Minor bugfixes (continuous integration): - Allow the test-stem job to fail in Travis, because it sometimes hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha. - Skip test_rebind on macOS in Travis, because it is unreliable on macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha. - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha. o Minor bugfixes (controller protocol): - Teach the controller parser to distinguish an object preceded by an argument list from one without. Previously, it couldn't distinguish an argument list from the first line of a multiline object. Fixes bug 29984; bugfix on 0.2.3.8-alpha. o Minor bugfixes (crash on exit): - Avoid a set of possible code paths that could try to use freed memory in routerlist_free() while Tor was exiting. Fixes bug 31003; bugfix on 0.1.2.2-alpha. o Minor bugfixes (developer tooling): - Fix pre-push hook to allow fixup and squash commits when pushing to non-upstream git remote. Fixes bug 30286; bugfix on 0.4.0.1-alpha. o Minor bugfixes (directory authorities): - Stop crashing after parsing an unknown descriptor purpose annotation. We think this bug can only be triggered by modifying a local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha. - Move the "bandwidth-file-headers" line in directory authority votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix on 0.3.5.1-alpha. - Directory authorities with IPv6 support now always mark themselves as reachable via IPv6. Fixes bug 24338; bugfix on 0.2.4.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (documentation): - Improve the documentation for using MapAddress with ".exit". Fixes bug 30109; bugfix on 0.1.0.1-rc. - Improve the monotonic time module and function documentation to explain what "monotonic" actually means, and document some results that have surprised people. Fixes bug 29640; bugfix on 0.2.9.1-alpha. - Use proper formatting when providing an example on quoting options that contain whitespace. Fixes bug 29635; bugfix on 0.2.3.18-rc. o Minor bugfixes (logging): - Do not log a warning when running with an OpenSSL version other than the one Tor was compiled with, if the two versions should be compatible. Previously, we would warn whenever the version was different. Fixes bug 30190; bugfix on 0.2.4.2-alpha. - Warn operators when the MyFamily option is set but ContactInfo is missing, as the latter should be set too. Fixes bug 25110; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leaks): - Avoid a minor memory leak that could occur on relays when failing to create a "keys" directory. Fixes bug 30148; bugfix on 0.3.3.1-alpha. - Fix a trivial memory leak when parsing an invalid value from a download schedule in the configuration. Fixes bug 30894; bugfix on 0.3.4.1-alpha. o Minor bugfixes (NetBSD): - Fix usage of minherit() on NetBSD and other platforms that define MAP_INHERIT_{ZERO,NONE} instead of INHERIT_{ZERO,NONE}. Fixes bug 30614; bugfix on 0.4.0.2-alpha. Patch from Taylor Campbell. o Minor bugfixes (onion services): - Avoid a GCC 9.1.1 warning (and possible crash depending on libc implementation) when failing to load an onion service client authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha. - When refusing to launch a controller's HSFETCH request because of rate-limiting, respond to the controller with a new response, "QUERY_RATE_LIMITED". Previously, we would log QUERY_NO_HSDIR for this case. Fixes bug 28269; bugfix on 0.3.1.1-alpha. Patch by Neel Chauhan. - When relaunching a circuit to a rendezvous service, mark the circuit as needing high-uptime routers as appropriate. Fixes bug 17357; bugfix on 0.1.0.1-rc. Patch by Neel Chauhan. - Stop ignoring IPv6 link specifiers sent to v3 onion services. (IPv6 support for v3 onion services is still incomplete: see ticket 23493 for details.) Fixes bug 23588; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (onion services, performance): - When building circuits to onion services, call tor_addr_parse() less often. Previously, we called tor_addr_parse() in circuit_is_acceptable() even if its output wasn't used. This change should improve performance when building circuits. Fixes bug 22210; bugfix on 0.2.8.12. Patch by Neel Chauhan. o Minor bugfixes (out-of-memory handler): - When purging the DNS cache because of an out-of-memory condition, try purging just the older entries at first. Previously, we would always purge the whole thing. Fixes bug 29617; bugfix on 0.3.5.1-alpha. o Minor bugfixes (performance): - When checking whether a node is a bridge, use a fast check to make sure that its identity is set. Previously, we used a constant-time check, which is not necessary in this case. Fixes bug 30308; bugfix on 0.3.5.1-alpha. o Minor bugfixes (pluggable transports): - Tor now sets TOR_PT_EXIT_ON_STDIN_CLOSE=1 for client transports as well as servers. Fixes bug 25614; bugfix on 0.2.7.1-alpha. o Minor bugfixes (portability): - Avoid crashing in our tor_vasprintf() implementation on systems that define neither vasprintf() nor _vscprintf(). (This bug has been here long enough that we question whether people are running Tor on such systems, but we're applying the fix out of caution.) Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by Tobias Stoeckmann. o Minor bugfixes (probability distributions): - Refactor and improve parts of the probability distribution code that made Coverity complain. Fixes bug 29805; bugfix on 0.4.0.1-alpha. o Minor bugfixes (python): - Stop assuming that /usr/bin/python3 exists. For scripts that work with python2, use /usr/bin/python. Otherwise, use /usr/bin/env python3. Fixes bug 29913; bugfix on 0.2.5.3-alpha. o Minor bugfixes (relay): - When running as a relay, if IPv6Exit is set to 1 while ExitRelay is auto, act as if ExitRelay is 1. Previously, we would ignore IPv6Exit if ExitRelay was 0 or auto. Fixes bug 29613; bugfix on 0.3.5.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (static analysis): - Fix several spurious Coverity warnings about the unit tests, to lower our chances of missing real warnings in the future. Fixes bug 30150; bugfix on 0.3.5.1-alpha and various other Tor versions. o Minor bugfixes (stats): - When ExtraInfoStatistics is 0, stop including bandwidth usage statistics, GeoIPFile hashes, ServerTransportPlugin lines, and bridge statistics by country in extra-info documents. Fixes bug 29018; bugfix on 0.2.4.1-alpha. o Minor bugfixes (testing): - Call setrlimit() to disable core dumps in test_bt_cl.c. Previously we used `ulimit -c` in test_bt.sh, which violates POSIX shell compatibility. Fixes bug 29061; bugfix on 0.3.5.1-alpha. - Fix some incorrect code in the v3 onion service unit tests. Fixes bug 29243; bugfix on 0.3.2.1-alpha. - In the "routerkeys/*" tests, check the return values of mkdir() for possible failures. Fixes bug 29939; bugfix on 0.2.7.2-alpha. Found by Coverity as CID 1444254. - Split test_utils_general() into several smaller test functions. This makes it easier to perform resource deallocation on assert failure, and fixes Coverity warnings CID 1444117 and CID 1444118. Fixes bug 29823; bugfix on 0.2.9.1-alpha. o Minor bugfixes (tor-resolve): - Fix a memory leak in tor-resolve that could happen if Tor gave it a malformed SOCKS response. (Memory leaks in tor-resolve don't actually matter, but it's good to fix them anyway.) Fixes bug 30151; bugfix on 0.4.0.1-alpha. o Code simplification and refactoring: - Abstract out the low-level formatting of replies on the control port. Implements ticket 30007. - Add several assertions in an attempt to fix some Coverity warnings. Closes ticket 30149. - Introduce a connection_dir_buf_add() helper function that checks for compress_state of dir_connection_t and automatically writes a string to directory connection with or without compression. Resolves issue 28816. - Make the base32_decode() API return the number of bytes written, for consistency with base64_decode(). Closes ticket 28913. - Move most relay-only periodic events out of mainloop.c into the relay subsystem. Closes ticket 30414. - Refactor and encapsulate parts of the codebase that manipulate crypt_path_t objects. Resolves issue 30236. - Refactor several places in our code that Coverity incorrectly believed might have memory leaks. Closes ticket 30147. - Remove redundant return values in crypto_format, and the associated return value checks elsewhere in the code. Make the implementations in crypto_format consistent, and remove redundant code. Resolves ticket 29660. - Rename tor_mem_is_zero() to fast_mem_is_zero(), to emphasize that it is not a constant-time function. Closes ticket 30309. - Replace hs_desc_link_specifier_t with link_specifier_t, and remove all hs_desc_link_specifier_t-specific code. Fixes bug 22781; bugfix on 0.3.2.1-alpha. - Simplify v3 onion service link specifier handling code. Fixes bug 23576; bugfix on 0.3.2.1-alpha. - Split crypto_digest.c into NSS code, OpenSSL code, and shared code. Resolves ticket 29108. - Split control.c into several submodules, in preparation for distributing its current responsibilities throughout the codebase. Closes ticket 29894. - Start to move responsibility for knowing about periodic events to the appropriate subsystems, so that the mainloop doesn't need to know all the periodic events in the rest of the codebase. Implements tickets 30293 and 30294. o Documentation: - Mention URLs for Travis/Appveyor/Jenkins in ReleasingTor.md. Closes ticket 30630. - Document how to find git commits and tags for bug fixes in CodingStandards.md. Update some file documentation. Closes ticket 30261. o Removed features: - Remove the linux-tor-prio.sh script from contrib/operator-tools directory. Resolves issue 29434. - Remove the obsolete OpenSUSE initscript. Resolves issue 30076. - Remove the obsolete script at contrib/dist/tor.sh.in. Resolves issue 30075. o Testing: - Specify torrc paths (with empty files) when launching tor in integration tests; refrain from reading user and system torrcs. Resolves issue 29702. o Code simplification and refactoring (shell scripts): - Clean up many of our shell scripts to fix shellcheck warnings. These include autogen.sh (ticket 26069), test_keygen.sh (ticket 29062), test_switch_id.sh (ticket 29065), test_rebind.sh (ticket 29063), src/test/fuzz/minimize.sh (ticket 30079), test_rust.sh (ticket 29064), torify (ticket 29070), asciidoc-helper.sh (29926), fuzz_multi.sh (30077), fuzz_static_testcases.sh (ticket 29059), nagios-check-tor-authority-cert (ticket 29071), src/test/fuzz/fixup_filenames.sh (ticket 30078), test-network.sh (ticket 29060), test_key_expiration.sh (ticket 30002), zero_length_keys.sh (ticket 29068), and test_workqueue_*.sh (ticket 29067). o Testing (chutney): - In "make test-network-all", test IPv6-only v3 single onion services, using the chutney network single-onion-v23-ipv6-md. Closes ticket 27251. o Testing (continuous integration): - In Travis, make stem log a controller trace to the console, and tail stem's tor log after failure. Closes ticket 30591. - In Travis, only run the stem tests that use a tor binary. Closes ticket 30694. Changes in version 0.4.0.5 - 2019-05-02 This is the first stable release in the 0.4.0.x series. It contains improvements for power management and bootstrap reporting, as well as preliminary backend support for circuit padding to prevent some kinds of traffic analysis. It also continues our work in refactoring Tor for long-term maintainability. Per our support policy, we will support the 0.4.0.x series for nine months, or until three months after the release of a stable 0.4.1.x: whichever is longer. If you need longer-term support, please stick with 0.3.5.x, which will we plan to support until Feb 2022. Below are the changes since 0.3.5.7. For a complete list of changes since 0.4.0.4-rc, see the ChangeLog file. o Major features (battery management, client, dormant mode): - When Tor is running as a client, and it is unused for a long time, it can now enter a "dormant" state. When Tor is dormant, it avoids network and CPU activity until it is reawoken either by a user request or by a controller command. For more information, see the configuration options starting with "Dormant". Implements tickets 2149 and 28335. - The client's memory of whether it is "dormant", and how long it has spent idle, persists across invocations. Implements ticket 28624. - There is a DormantOnFirstStartup option that integrators can use if they expect that in many cases, Tor will be installed but not used. o Major features (bootstrap reporting): - When reporting bootstrap progress, report the first connection uniformly, regardless of whether it's a connection for building application circuits. This allows finer-grained reporting of early progress than previously possible, with the improvements of ticket 27169. Closes tickets 27167 and 27103. Addresses ticket 27308. - When reporting bootstrap progress, treat connecting to a proxy or pluggable transport as separate from having successfully used that proxy or pluggable transport to connect to a relay. Closes tickets 27100 and 28884. o Major features (circuit padding): - Implement preliminary support for the circuit padding portion of Proposal 254. The implementation supports Adaptive Padding (aka WTF-PAD) state machines for use between experimental clients and relays. Support is also provided for APE-style state machines that use probability distributions instead of histograms to specify inter-packet delay. At the moment, Tor does not provide any padding state machines that are used in normal operation: for now, this feature exists solely for experimentation. Closes ticket 28142. o Major features (refactoring): - Tor now uses an explicit list of its own subsystems when initializing and shutting down. Previously, these systems were managed implicitly in various places throughout the codebase. (There may still be some subsystems using the old system.) Closes ticket 28330. o Major bugfixes (cell scheduler, KIST, security): - Make KIST consider the outbuf length when computing what it can put in the outbuf. Previously, KIST acted as though the outbuf were empty, which could lead to the outbuf becoming too full. It is possible that an attacker could exploit this bug to cause a Tor client or relay to run out of memory and crash. Fixes bug 29168; bugfix on 0.3.2.1-alpha. This issue is also being tracked as TROVE-2019-001 and CVE-2019-8955. o Major bugfixes (networking): - Gracefully handle empty username/password fields in SOCKS5 username/password auth message and allow SOCKS5 handshake to continue. Previously, we had rejected these handshakes, breaking certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha. o Major bugfixes (NSS, relay): - When running with NSS, disable TLS 1.2 ciphersuites that use SHA384 for their PRF. Due to an NSS bug, the TLS key exporters for these ciphersuites don't work -- which caused relays to fail to handshake with one another when these ciphersuites were enabled. Fixes bug 29241; bugfix on 0.3.5.1-alpha. o Minor features (address selection): - Treat the subnet 100.64.0.0/10 as public for some purposes; private for others. This subnet is the RFC 6598 (Carrier Grade NAT) IP range, and is deployed by many ISPs as an alternative to RFC 1918 that does not break existing internal networks. Tor now blocks SOCKS and control ports on these addresses and warns users if client ports or ExtORPorts are listening on a RFC 6598 address. Closes ticket 28525. Patch by Neel Chauhan. o Minor features (bandwidth authority): - Make bandwidth authorities ignore relays that are reported in the bandwidth file with the flag "vote=0". This change allows us to report unmeasured relays for diagnostic reasons without including their bandwidth in the bandwidth authorities' vote. Closes ticket 29806. - When a directory authority is using a bandwidth file to obtain the bandwidth values that will be included in the next vote, serve this bandwidth file at /tor/status-vote/next/bandwidth. Closes ticket 21377. o Minor features (bootstrap reporting): - When reporting bootstrap progress, stop distinguishing between situations where only internal paths are available and situations where external paths are available. Previously, Tor would often erroneously report that it had only internal paths. Closes ticket 27402. o Minor features (compilation): - Compile correctly when OpenSSL is built with engine support disabled, or with deprecated APIs disabled. Closes ticket 29026. Patches from "Mangix". o Minor features (continuous integration): - On Travis Rust builds, cleanup Rust registry and refrain from caching the "target/" directory to speed up builds. Resolves issue 29962. - Log Python version during each Travis CI job. Resolves issue 28551. - In Travis, tell timelimit to use stem's backtrace signals, and launch python directly from timelimit, so python receives the signals from timelimit, rather than make. Closes ticket 30117. o Minor features (controller): - Add a DROPOWNERSHIP command to undo the effects of TAKEOWNERSHIP. Implements ticket 28843. o Minor features (developer tooling): - Check that bugfix versions in changes files look like Tor versions from the versions spec. Warn when bugfixes claim to be on a future release. Closes ticket 27761. - Provide a git pre-commit hook that disallows committing if we have any failures in our code and changelog formatting checks. It is now available in scripts/maint/pre-commit.git-hook. Implements feature 28976. - Provide a git hook script to prevent "fixup!" and "squash!" commits from ending up in the master branch, as scripts/main/pre- push.git-hook. Closes ticket 27993. o Minor features (diagnostic): - Add more diagnostic log messages in an attempt to solve the issue of NUL bytes appearing in a microdescriptor cache. Related to ticket 28223. o Minor features (directory authority): - When a directory authority is using a bandwidth file to obtain bandwidth values, include the digest of that file in the vote. Closes ticket 26698. - Directory authorities support a new consensus algorithm, under which the family lines in microdescriptors are encoded in a canonical form. This change makes family lines more compressible in transit, and on the client. Closes ticket 28266; implements proposal 298. o Minor features (directory authority, relay): - Authorities now vote on a "StaleDesc" flag to indicate that a relay's descriptor is so old that the relay should upload again soon. Relays treat this flag as a signal to upload a new descriptor. This flag will eventually let us remove the 'published' date from routerstatus entries, and make our consensus diffs much smaller. Closes ticket 26770; implements proposal 293. o Minor features (dormant mode): - Add a DormantCanceledByStartup option to tell Tor that it should treat a startup event as cancelling any previous dormant state. Integrators should use this option with caution: it should only be used if Tor is being started because of something that the user did, and not if Tor is being automatically started in the background. Closes ticket 29357. o Minor features (fallback directory mirrors): - Update the fallback whitelist based on operator opt-ins and opt- outs. Closes ticket 24805, patch by Phoul. o Minor features (FreeBSD): - On FreeBSD-based systems, warn relay operators if the "net.inet.ip.random_id" sysctl (IP ID randomization) is disabled. Closes ticket 28518. o Minor features (geoip): - Update geoip and geoip6 to the April 2 2019 Maxmind GeoLite2 Country database. Closes ticket 29992. o Minor features (HTTP standards compliance): - Stop sending the header "Content-type: application/octet-stream" along with transparently compressed documents: this confused browsers. Closes ticket 28100. o Minor features (IPv6): - We add an option ClientAutoIPv6ORPort, to make clients randomly prefer a node's IPv4 or IPv6 ORPort. The random preference is set every time a node is loaded from a new consensus or bridge config. We expect that this option will enable clients to bootstrap more quickly without having to determine whether they support IPv4, IPv6, or both. Closes ticket 27490. Patch by Neel Chauhan. - When using addrs_in_same_network_family(), avoid choosing circuit paths that pass through the same IPv6 subnet more than once. Previously, we only checked IPv4 subnets. Closes ticket 24393. Patch by Neel Chauhan. o Minor features (log messages): - Improve log message in v3 onion services that could print out negative revision counters. Closes ticket 27707. Patch by "ffmancera". o Minor features (memory usage): - Save memory by storing microdescriptor family lists with a more compact representation. Closes ticket 27359. - Tor clients now use mmap() to read consensus files from disk, so that they no longer need keep the full text of a consensus in memory when parsing it or applying a diff. Closes ticket 27244. o Minor features (NSS, diagnostic): - Try to log an error from NSS (if there is any) and a more useful description of our situation if we are using NSS and a call to SSL_ExportKeyingMaterial() fails. Diagnostic for ticket 29241. o Minor features (parsing): - Directory authorities now validate that router descriptors and ExtraInfo documents are in a valid subset of UTF-8, and reject them if they are not. Closes ticket 27367. o Minor features (performance): - Cache the results of summarize_protocol_flags(), so that we don't have to parse the same protocol-versions string over and over. This should save us a huge number of malloc calls on startup, and may reduce memory fragmentation with some allocators. Closes ticket 27225. - Remove a needless memset() call from get_token_arguments, thereby speeding up the tokenization of directory objects by about 20%. Closes ticket 28852. - Replace parse_short_policy() with a faster implementation, to improve microdescriptor parsing time. Closes ticket 28853. - Speed up directory parsing a little by avoiding use of the non- inlined strcmp_len() function. Closes ticket 28856. - Speed up microdescriptor parsing by about 30%, to help improve startup time. Closes ticket 28839. o Minor features (pluggable transports): - Add support for emitting STATUS updates to Tor's control port from a pluggable transport process. Closes ticket 28846. - Add support for logging to Tor's logging subsystem from a pluggable transport process. Closes ticket 28180. o Minor features (process management): - Add a new process API for handling child processes. This new API allows Tor to have bi-directional communication with child processes on both Unix and Windows. Closes ticket 28179. - Use the subsystem manager to initialize and shut down the process module. Closes ticket 28847. o Minor features (relay): - When listing relay families, list them in canonical form including the relay's own identity, and try to give a more useful set of warnings. Part of ticket 28266 and proposal 298. o Minor features (required protocols): - Before exiting because of a missing required protocol, Tor will now check the publication time of the consensus, and not exit unless the consensus is newer than the Tor program's own release date. Previously, Tor would not check the consensus publication time, and so might exit because of a missing protocol that might no longer be required in a current consensus. Implements proposal 297; closes ticket 27735. o Minor features (testing): - Treat all unexpected ERR and BUG messages as test failures. Closes ticket 28668. - Allow a HeartbeatPeriod of less than 30 minutes in testing Tor networks. Closes ticket 28840. Patch by Rob Jansen. - Use the approx_time() function when setting the "Expires" header in directory replies, to make them more testable. Needed for ticket 30001. o Minor bugfixes (security): - Fix a potential double free bug when reading huge bandwidth files. The issue is not exploitable in the current Tor network because the vulnerable code is only reached when directory authorities read bandwidth files, but bandwidth files come from a trusted source (usually the authorities themselves). Furthermore, the issue is only exploitable in rare (non-POSIX) 32-bit architectures, which are not used by any of the current authorities. Fixes bug 30040; bugfix on 0.3.5.1-alpha. Bug found and fixed by Tobias Stoeckmann. - Verify in more places that we are not about to create a buffer with more than INT_MAX bytes, to avoid possible OOB access in the event of bugs. Fixes bug 30041; bugfix on 0.2.0.16. Found and fixed by Tobias Stoeckmann. o Minor bugfix (continuous integration): - Reset coverage state on disk after Travis CI has finished. This should prevent future coverage merge errors from causing the test suite for the "process" subsystem to fail. The process subsystem was introduced in 0.4.0.1-alpha. Fixes bug 29036; bugfix on 0.2.9.15. - Terminate test-stem if it takes more than 9.5 minutes to run. (Travis terminates the job after 10 minutes of no output.) Diagnostic for 29437. Fixes bug 30011; bugfix on 0.3.5.4-alpha. o Minor bugfixes (build, compatibility, rust): - Update Cargo.lock file to match the version made by the latest version of Rust, so that "make distcheck" will pass again. Fixes bug 29244; bugfix on 0.3.3.4-alpha. o Minor bugfixes (C correctness): - Fix an unlikely memory leak in consensus_diff_apply(). Fixes bug 29824; bugfix on 0.3.1.1-alpha. This is Coverity warning CID 1444119. o Minor bugfixes (client, clock skew): - Bootstrap successfully even when Tor's clock is behind the clocks on the authorities. Fixes bug 28591; bugfix on 0.2.0.9-alpha. - Select guards even if the consensus has expired, as long as the consensus is still reasonably live. Fixes bug 24661; bugfix on 0.3.0.1-alpha. o Minor bugfixes (compilation): - Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug 29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn. - Compile correctly on OpenBSD; previously, we were missing some headers required in order to detect it properly. Fixes bug 28938; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. o Minor bugfixes (directory clients): - Mark outdated dirservers when Tor only has a reasonably live consensus. Fixes bug 28569; bugfix on 0.3.2.5-alpha. o Minor bugfixes (directory mirrors): - Even when a directory mirror's clock is behind the clocks on the authorities, we now allow the mirror to serve "future" consensuses. Fixes bug 28654; bugfix on 0.3.0.1-alpha. o Minor bugfixes (DNS): - Gracefully handle an empty or absent resolve.conf file by falling back to using "localhost" as a DNS server (and hoping it works). Previously, we would just stop running as an exit. Fixes bug 21900; bugfix on 0.2.1.10-alpha. o Minor bugfixes (documentation): - Describe the contents of the v3 onion service client authorization files correctly: They hold public keys, not private keys. Fixes bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix". o Minor bugfixes (guards): - In count_acceptable_nodes(), the minimum number is now one bridge or guard node, and two non-guard nodes for a circuit. Previously, we had added up the sum of all nodes with a descriptor, but that could cause us to build failing circuits when we had either too many bridges or not enough guard nodes. Fixes bug 25885; bugfix on 0.2.3.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (IPv6): - Fix tor_ersatz_socketpair on IPv6-only systems. Previously, the IPv6 socket was bound using an address family of AF_INET instead of AF_INET6. Fixes bug 28995; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. o Minor bugfixes (logging): - Correct a misleading error message when IPv4Only or IPv6Only is used but the resolved address can not be interpreted as an address of the specified IP version. Fixes bug 13221; bugfix on 0.2.3.9-alpha. Patch from Kris Katterjohn. - Log the correct port number for listening sockets when "auto" is used to let Tor pick the port number. Previously, port 0 was logged instead of the actual port number. Fixes bug 29144; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. - Stop logging a BUG() warning when Tor is waiting for exit descriptors. Fixes bug 28656; bugfix on 0.3.5.1-alpha. - Avoid logging that we are relaxing a circuit timeout when that timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha. - Log more information at "warning" level when unable to read a private key; log more information at "info" level when unable to read a public key. We had warnings here before, but they were lost during our NSS work. Fixes bug 29042; bugfix on 0.3.5.1-alpha. - Rework rep_hist_log_link_protocol_counts() to iterate through all link protocol versions when logging incoming/outgoing connection counts. Tor no longer skips version 5, and we won't have to remember to update this function when new link protocol version is developed. Fixes bug 28920; bugfix on 0.2.6.10. o Minor bugfixes (memory management): - Refactor the shared random state's memory management so that it actually takes ownership of the shared random value pointers. Fixes bug 29706; bugfix on 0.2.9.1-alpha. - Stop leaking parts of the shared random state in the shared-random unit tests. Fixes bug 29599; bugfix on 0.2.9.1-alpha. o Minor bugfixes (misc): - The amount of total available physical memory is now determined using the sysctl identifier HW_PHYSMEM (rather than HW_USERMEM) when it is defined and a 64-bit variant is not available. Fixes bug 28981; bugfix on 0.2.5.4-alpha. Patch from Kris Katterjohn. o Minor bugfixes (networking): - Introduce additional checks into tor_addr_parse() to reject certain incorrect inputs that previously were not detected. Fixes bug 23082; bugfix on 0.2.0.10-alpha. o Minor bugfixes (onion service v3, client): - Stop logging a "BUG()" warning and stacktrace when we find a SOCKS connection waiting for a descriptor that we actually have in the cache. It turns out that this can actually happen, though it is rare. Now, tor will recover and retry the descriptor. Fixes bug 28669; bugfix on 0.3.2.4-alpha. o Minor bugfixes (onion services): - Avoid crashing if ClientOnionAuthDir (incorrectly) contains more than one private key for a hidden service. Fixes bug 29040; bugfix on 0.3.5.1-alpha. - In hs_cache_store_as_client() log an HSDesc we failed to parse at "debug" level. Tor used to log it as a warning, which caused very long log lines to appear for some users. Fixes bug 29135; bugfix on 0.3.2.1-alpha. - Stop logging "Tried to establish rendezvous on non-OR circuit..." as a warning. Instead, log it as a protocol warning, because there is nothing that relay operators can do to fix it. Fixes bug 29029; bugfix on 0.2.5.7-rc. o Minor bugfixes (periodic events): - Refrain from calling routerlist_remove_old_routers() from check_descriptor_callback(). Instead, create a new hourly periodic event. Fixes bug 27929; bugfix on 0.2.8.1-alpha. o Minor bugfixes (pluggable transports): - Make sure that data is continously read from standard output and standard error pipes of a pluggable transport child-process, to avoid deadlocking when a pipe's buffer is full. Fixes bug 26360; bugfix on 0.2.3.6-alpha. o Minor bugfixes (rust): - Abort on panic in all build profiles, instead of potentially unwinding into C code. Fixes bug 27199; bugfix on 0.3.3.1-alpha. o Minor bugfixes (scheduler): - When re-adding channels to the pending list, check the correct channel's sched_heap_idx. This issue has had no effect in mainline Tor, but could have led to bugs down the road in improved versions of our circuit scheduling code. Fixes bug 29508; bugfix on 0.3.2.10. o Minor bugfixes (single onion services): - Allow connections to single onion services to remain idle without being disconnected. Previously, relays acting as rendezvous points for single onion services were mistakenly closing idle rendezvous circuits after 60 seconds, thinking that they were unused directory-fetching circuits that had served their purpose. Fixes bug 29665; bugfix on 0.2.1.26. o Minor bugfixes (stats): - When ExtraInfoStatistics is 0, stop including PaddingStatistics in relay and bridge extra-info documents. Fixes bug 29017; bugfix on 0.3.1.1-alpha. o Minor bugfixes (testing): - Backport the 0.3.4 src/test/test-network.sh to 0.2.9. We need a recent test-network.sh to use new chutney features in CI. Fixes bug 29703; bugfix on 0.2.9.1-alpha. - Fix a test failure on Windows caused by an unexpected "BUG" warning in our tests for tor_gmtime_r(-1). Fixes bug 29922; bugfix on 0.2.9.3-alpha. - Downgrade some LOG_ERR messages in the address/* tests to warnings. The LOG_ERR messages were occurring when we had no configured network. We were failing the unit tests, because we backported 28668 to 0.3.5.8, but did not backport 29530. Fixes bug 29530; bugfix on 0.3.5.8. - Fix our gcov wrapper script to look for object files at the correct locations. Fixes bug 29435; bugfix on 0.3.5.1-alpha. - Detect and suppress "bug" warnings from the util/time test on Windows. Fixes bug 29161; bugfix on 0.2.9.3-alpha. - Do not log an error-level message if we fail to find an IPv6 network interface from the unit tests. Fixes bug 29160; bugfix on 0.2.7.3-rc. - Instead of relying on hs_free_all() to clean up all onion service objects in test_build_descriptors(), we now deallocate them one by one. This lets Coverity know that we are not leaking memory there and fixes CID 1442277. Fixes bug 28989; bugfix on 0.3.5.1-alpha. o Minor bugfixes (TLS protocol): - When classifying a client's selection of TLS ciphers, if the client ciphers are not yet available, do not cache the result. Previously, we had cached the unavailability of the cipher list and never looked again, which in turn led us to assume that the client only supported the ancient V1 link protocol. This, in turn, was causing Stem integration tests to stall in some cases. Fixes bug 30021; bugfix on 0.2.4.8-alpha. o Minor bugfixes (usability): - Stop saying "Your Guard ..." in pathbias_measure_{use,close}_rate(). Some users took this phrasing to mean that the mentioned guard was under their control or responsibility, which it is not. Fixes bug 28895; bugfix on Tor 0.3.0.1-alpha. o Minor bugfixes (Windows, CI): - Skip the Appveyor 32-bit Windows Server 2016 job, and 64-bit Windows Server 2012 R2 job. The remaining 2 jobs still provide coverage of 64/32-bit, and Windows Server 2016/2012 R2. Also set fast_finish, so failed jobs terminate the build immediately. Fixes bug 29601; bugfix on 0.3.5.4-alpha. o Code simplification and refactoring: - Introduce a connection_dir_buf_add() helper function that detects whether compression is in use, and adds a string accordingly. Resolves issue 28816. - Refactor handle_get_next_bandwidth() to use connection_dir_buf_add(). Implements ticket 29897. - Reimplement NETINFO cell parsing and generation to rely on trunnel-generated wire format handling code. Closes ticket 27325. - Remove unnecessary unsafe code from the Rust macro "cstr!". Closes ticket 28077. - Rework SOCKS wire format handling to rely on trunnel-generated parsing/generation code. Resolves ticket 27620. - Split out bootstrap progress reporting from control.c into a separate file. Part of ticket 27402. - The .may_include files that we use to describe our directory-by- directory dependency structure now describe a noncircular dependency graph over the directories that they cover. Our checkIncludes.py tool now enforces this noncircularity. Closes ticket 28362. o Documentation: - Clarify that Tor performs stream isolation among *Port listeners by default. Resolves issue 29121. - In the manpage entry describing MapAddress torrc setting, use example IP addresses from ranges specified for use in documentation by RFC 5737. Resolves issue 28623. - Mention that you cannot add a new onion service if Tor is already running with Sandbox enabled. Closes ticket 28560. - Improve ControlPort documentation. Mention that it accepts address:port pairs, and can be used multiple times. Closes ticket 28805. - Document the exact output of "tor --version". Closes ticket 28889. o Removed features: - Remove the old check-tor script. Resolves issue 29072. - Stop responding to the 'GETINFO status/version/num-concurring' and 'GETINFO status/version/num-versioning' control port commands, as those were deprecated back in 0.2.0.30. Also stop listing them in output of 'GETINFO info/names'. Resolves ticket 28757. - The scripts used to generate and maintain the list of fallback directories have been extracted into a new "fallback-scripts" repository. Closes ticket 27914. o Testing: - Run shellcheck for scripts in the in scripts/ directory. Closes ticket 28058. - Add unit tests for tokenize_string() and get_next_token() functions. Resolves ticket 27625. o Code simplification and refactoring (onion service v3): - Consolidate the authorized client descriptor cookie computation code from client and service into one function. Closes ticket 27549. o Code simplification and refactoring (shell scripts): - Cleanup scan-build.sh to silence shellcheck warnings. Closes ticket 28007. - Fix issues that shellcheck found in chutney-git-bisect.sh. Resolves ticket 28006. - Fix issues that shellcheck found in updateRustDependencies.sh. Resolves ticket 28012. - Fix shellcheck warnings in cov-diff script. Resolves issue 28009. - Fix shellcheck warnings in run_calltool.sh. Resolves ticket 28011. - Fix shellcheck warnings in run_trunnel.sh. Resolves issue 28010. - Fix shellcheck warnings in scripts/test/coverage. Resolves issue 28008. Changes in version 0.3.5.8 - 2019-02-21 Tor 0.3.5.8 backports several fixes from later releases, including fixes for an annoying SOCKS-parsing bug that affected users in earlier 0.3.5.x releases. It also includes a fix for a medium-severity security bug affecting Tor 0.3.2.1-alpha and later. All Tor instances running an affected release should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha. o Major bugfixes (cell scheduler, KIST, security): - Make KIST consider the outbuf length when computing what it can put in the outbuf. Previously, KIST acted as though the outbuf were empty, which could lead to the outbuf becoming too full. It is possible that an attacker could exploit this bug to cause a Tor client or relay to run out of memory and crash. Fixes bug 29168; bugfix on 0.3.2.1-alpha. This issue is also being tracked as TROVE-2019-001 and CVE-2019-8955. o Major bugfixes (networking, backport from 0.4.0.2-alpha): - Gracefully handle empty username/password fields in SOCKS5 username/password auth messsage and allow SOCKS5 handshake to continue. Previously, we had rejected these handshakes, breaking certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha. o Minor features (compilation, backport from 0.4.0.2-alpha): - Compile correctly when OpenSSL is built with engine support disabled, or with deprecated APIs disabled. Closes ticket 29026. Patches from "Mangix". o Minor features (geoip): - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2 Country database. Closes ticket 29478. o Minor features (testing, backport from 0.4.0.2-alpha): - Treat all unexpected ERR and BUG messages as test failures. Closes ticket 28668. o Minor bugfixes (onion service v3, client, backport from 0.4.0.1-alpha): - Stop logging a "BUG()" warning and stacktrace when we find a SOCKS connection waiting for a descriptor that we actually have in the cache. It turns out that this can actually happen, though it is rare. Now, tor will recover and retry the descriptor. Fixes bug 28669; bugfix on 0.3.2.4-alpha. o Minor bugfixes (IPv6, backport from 0.4.0.1-alpha): - Fix tor_ersatz_socketpair on IPv6-only systems. Previously, the IPv6 socket was bound using an address family of AF_INET instead of AF_INET6. Fixes bug 28995; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha): - Update Cargo.lock file to match the version made by the latest version of Rust, so that "make distcheck" will pass again. Fixes bug 29244; bugfix on 0.3.3.4-alpha. o Minor bugfixes (client, clock skew, backport from 0.4.0.1-alpha): - Select guards even if the consensus has expired, as long as the consensus is still reasonably live. Fixes bug 24661; bugfix on 0.3.0.1-alpha. o Minor bugfixes (compilation, backport from 0.4.0.1-alpha): - Compile correctly on OpenBSD; previously, we were missing some headers required in order to detect it properly. Fixes bug 28938; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn. o Minor bugfixes (documentation, backport from 0.4.0.2-alpha): - Describe the contents of the v3 onion service client authorization files correctly: They hold public keys, not private keys. Fixes bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix". o Minor bugfixes (logging, backport from 0.4.0.1-alpha): - Rework rep_hist_log_link_protocol_counts() to iterate through all link protocol versions when logging incoming/outgoing connection counts. Tor no longer skips version 5, and we won't have to remember to update this function when new link protocol version is developed. Fixes bug 28920; bugfix on 0.2.6.10. o Minor bugfixes (logging, backport from 0.4.0.2-alpha): - Log more information at "warning" level when unable to read a private key; log more information at "info" level when unable to read a public key. We had warnings here before, but they were lost during our NSS work. Fixes bug 29042; bugfix on 0.3.5.1-alpha. o Minor bugfixes (misc, backport from 0.4.0.2-alpha): - The amount of total available physical memory is now determined using the sysctl identifier HW_PHYSMEM (rather than HW_USERMEM) when it is defined and a 64-bit variant is not available. Fixes bug 28981; bugfix on 0.2.5.4-alpha. Patch from Kris Katterjohn. o Minor bugfixes (onion services, backport from 0.4.0.2-alpha): - Avoid crashing if ClientOnionAuthDir (incorrectly) contains more than one private key for a hidden service. Fixes bug 29040; bugfix on 0.3.5.1-alpha. - In hs_cache_store_as_client() log an HSDesc we failed to parse at "debug" level. Tor used to log it as a warning, which caused very long log lines to appear for some users. Fixes bug 29135; bugfix on 0.3.2.1-alpha. - Stop logging "Tried to establish rendezvous on non-OR circuit..." as a warning. Instead, log it as a protocol warning, because there is nothing that relay operators can do to fix it. Fixes bug 29029; bugfix on 0.2.5.7-rc. o Minor bugfixes (tests, directory clients, backport from 0.4.0.1-alpha): - Mark outdated dirservers when Tor only has a reasonably live consensus. Fixes bug 28569; bugfix on 0.3.2.5-alpha. o Minor bugfixes (tests, backport from 0.4.0.2-alpha): - Detect and suppress "bug" warnings from the util/time test on Windows. Fixes bug 29161; bugfix on 0.2.9.3-alpha. - Do not log an error-level message if we fail to find an IPv6 network interface from the unit tests. Fixes bug 29160; bugfix on 0.2.7.3-rc. o Minor bugfixes (usability, backport from 0.4.0.1-alpha): - Stop saying "Your Guard ..." in pathbias_measure_{use,close}_rate(). Some users took this phrasing to mean that the mentioned guard was under their control or responsibility, which it is not. Fixes bug 28895; bugfix on Tor 0.3.0.1-alpha. Changes in version 0.3.4.11 - 2019-02-21 Tor 0.3.4.11 is the third stable release in its series. It includes a fix for a medium-severity security bug affecting Tor 0.3.2.1-alpha and later. All Tor instances running an affected release should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha. o Major bugfixes (cell scheduler, KIST, security): - Make KIST consider the outbuf length when computing what it can put in the outbuf. Previously, KIST acted as though the outbuf were empty, which could lead to the outbuf becoming too full. It is possible that an attacker could exploit this bug to cause a Tor client or relay to run out of memory and crash. Fixes bug 29168; bugfix on 0.3.2.1-alpha. This issue is also being tracked as TROVE-2019-001 and CVE-2019-8955. o Minor features (geoip): - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2 Country database. Closes ticket 29478. o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha): - Update Cargo.lock file to match the version made by the latest version of Rust, so that "make distcheck" will pass again. Fixes bug 29244; bugfix on 0.3.3.4-alpha. o Minor bugfixes (onion services, backport from 0.4.0.2-alpha): - Stop logging "Tried to establish rendezvous on non-OR circuit..." as a warning. Instead, log it as a protocol warning, because there is nothing that relay operators can do to fix it. Fixes bug 29029; bugfix on 0.2.5.7-rc. Changes in version 0.3.3.12 - 2019-02-21 Tor 0.3.3.12 fixes a medium-severity security bug affecting Tor 0.3.2.1-alpha and later. All Tor instances running an affected release should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha. This release marks the end of support for the Tor 0.3.3.x series. We recommend that users switch to either the Tor 0.3.4 series (supported until at least 10 June 2019), or the Tor 0.3.5 series, which will receive long-term support until at least 1 Feb 2022. o Major bugfixes (cell scheduler, KIST, security): - Make KIST consider the outbuf length when computing what it can put in the outbuf. Previously, KIST acted as though the outbuf were empty, which could lead to the outbuf becoming too full. It is possible that an attacker could exploit this bug to cause a Tor client or relay to run out of memory and crash. Fixes bug 29168; bugfix on 0.3.2.1-alpha. This issue is also being tracked as TROVE-2019-001 and CVE-2019-8955. o Minor features (geoip): - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2 Country database. Closes ticket 29478. o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha): - Update Cargo.lock file to match the version made by the latest version of Rust, so that "make distcheck" will pass again. Fixes bug 29244; bugfix on 0.3.3.4-alpha. o Minor bugfixes (onion services, backport from 0.4.0.2-alpha): - Stop logging "Tried to establish rendezvous on non-OR circuit..." as a warning. Instead, log it as a protocol warning, because there is nothing that relay operators can do to fix it. Fixes bug 29029; bugfix on 0.2.5.7-rc. Changes in version 0.3.3.11 - 2019-01-07 Tor 0.3.3.11 backports numerous fixes from later versions of Tor. numerous fixes, including an important fix for anyone using OpenSSL 1.1.1. Anyone running an earlier version of Tor 0.3.3 should upgrade to this version, or to a later series. As a reminder, support the Tor 0.3.3 series will end on 22 Feb 2019. We anticipate that this will be the last release of Tor 0.3.3, unless some major bug is before then. Some time between now and then, users should switch to either the Tor 0.3.4 series (supported until at least 10 June 2019), or the Tor 0.3.5 series, which will receive long-term support until at least 1 Feb 2022. o Major bugfixes (OpenSSL, portability, backport from 0.3.5.5-alpha): - Fix our usage of named groups when running as a TLS 1.3 client in OpenSSL 1.1.1. Previously, we only initialized EC groups when running as a relay, which caused clients to fail to negotiate TLS 1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3 support was added). o Major bugfixes (restart-in-process, backport from 0.3.5.1-alpha): - Fix a use-after-free error that could be caused by passing Tor an impossible set of options that would fail during options_act(). Fixes bug 27708; bugfix on 0.3.3.1-alpha. o Minor features (continuous integration, backport from 0.3.5.1-alpha): - Only run one online rust build in Travis, to reduce network errors. Skip offline rust builds on Travis for Linux gcc, because they're redundant. Implements ticket 27252. - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on Linux with default settings, because all the non-default builds use gcc on Linux. Implements ticket 27252. o Minor features (continuous integration, backport from 0.3.5.3-alpha): - Use the Travis Homebrew addon to install packages on macOS during Travis CI. The package list is the same, but the Homebrew addon does not do a `brew update` by default. Implements ticket 27738. o Minor features (fallback directory list, backport from 0.3.5.6-rc): - Replace the 150 fallbacks originally introduced in Tor 0.3.3.1-alpha in January 2018 (of which ~115 were still functional), with a list of 157 fallbacks (92 new, 65 existing, 85 removed) generated in December 2018. Closes ticket 24803. o Minor features (geoip): - Update geoip and geoip6 to the January 3 2019 Maxmind GeoLite2 Country database. Closes ticket 29012. o Minor features (OpenSSL bug workaround, backport from 0.3.5.7): - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3 key export function from handling long labels. When this bug is detected, Tor will disable TLS 1.3. We recommend upgrading to a version of OpenSSL without this bug when it becomes available. Closes ticket 28973. o Minor bugfixes (relay statistics, backport from 0.3.5.7): - Update relay descriptor on bandwidth changes only when the uptime is smaller than 24h, in order to reduce the efficiency of guard discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha. o Minor bugfixes (C correctness, backport from 0.3.5.4-alpha): - Avoid undefined behavior in an end-of-string check when parsing the BEGIN line in a directory object. Fixes bug 28202; bugfix on 0.2.0.3-alpha. o Minor bugfixes (code safety, backport from 0.3.5.3-alpha): - Rewrite our assertion macros so that they no longer suppress the compiler's -Wparentheses warnings. Fixes bug 27709; bugfix o Minor bugfixes (compilation, backport from 0.3.5.5-alpha): - Initialize a variable unconditionally in aes_new_cipher(), since some compilers cannot tell that we always initialize it before use. Fixes bug 28413; bugfix on 0.2.9.3-alpha. o Minor bugfixes (directory authority, backport from 0.3.5.4-alpha): - Log additional info when we get a relay that shares an ed25519 ID with a different relay, instead making a BUG() warning. Fixes bug 27800; bugfix on 0.3.2.1-alpha. o Minor bugfixes (directory permissions, backport form 0.3.5.3-alpha): - When a user requests a group-readable DataDirectory, give it to them. Previously, when the DataDirectory and the CacheDirectory were the same, the default setting (0) for CacheDirectoryGroupReadable would override the setting for DataDirectoryGroupReadable. Fixes bug 26913; bugfix on 0.3.3.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.1-alpha): - When the onion service directory can't be created or has the wrong permissions, do not log a stack trace. Fixes bug 27335; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.2-alpha): - Close all SOCKS request (for the same .onion) if the newly fetched descriptor is unusable. Before that, we would close only the first one leaving the other hanging and let to time out by themselves. Fixes bug 27410; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha): - Don't warn so loudly when Tor is unable to decode an onion descriptor. This can now happen as a normal use case if a client gets a descriptor with client authorization but the client is not authorized. Fixes bug 27550; bugfix on 0.3.5.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.6-rc): - When deleting an ephemeral onion service (DEL_ONION), do not close any rendezvous circuits in order to let the existing client connections finish by themselves or closed by the application. The HS v2 is doing that already so now we have the same behavior for all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha. o Minor bugfixes (HTTP tunnel): - Fix a bug warning when closing an HTTP tunnel connection due to an HTTP request we couldn't handle. Fixes bug 26470; bugfix on 0.3.2.1-alpha. o Minor bugfixes (memory leaks, backport from 0.3.5.5-alpha): - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419; bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger. o Minor bugfixes (netflow padding, backport from 0.3.5.1-alpha): - Ensure circuitmux queues are empty before scheduling or sending padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha. o Minor bugfixes (protover, backport from 0.3.5.3-alpha): - Reject protocol names containing bytes other than alphanumeric characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix on 0.2.9.4-alpha. o Minor bugfixes (rust, backport from 0.3.5.1-alpha): - Compute protover votes correctly in the rust version of the protover code. Previously, the protover rewrite in 24031 allowed repeated votes from the same voter for the same protocol version to be counted multiple times in protover_compute_vote(). Fixes bug 27649; bugfix on 0.3.3.5-rc. - Reject protover names that contain invalid characters. Fixes bug 27687; bugfix on 0.3.3.1-alpha. o Minor bugfixes (rust, backport from 0.3.5.2-alpha): - protover_all_supported() would attempt to allocate up to 16GB on some inputs, leading to a potential memory DoS. Fixes bug 27206; bugfix on 0.3.3.5-rc. o Minor bugfixes (rust, backport from 0.3.5.4-alpha): - Fix a potential null dereference in protover_all_supported(). Add a test for it. Fixes bug 27804; bugfix on 0.3.3.1-alpha. - Return a string that can be safely freed by C code, not one created by the rust allocator, in protover_all_supported(). Fixes bug 27740; bugfix on 0.3.3.1-alpha. - Fix an API mismatch in the rust implementation of protover_compute_vote(). This bug could have caused crashes on any directory authorities running Tor with Rust (which we do not yet recommend). Fixes bug 27741; bugfix on 0.3.3.6. o Minor bugfixes (testing, backport from 0.3.5.1-alpha): - If a unit test running in a subprocess exits abnormally or with a nonzero status code, treat the test as having failed, even if the test reported success. Without this fix, memory leaks don't cause the tests to fail, even with LeakSanitizer. Fixes bug 27658; bugfix on 0.2.2.4-alpha. o Minor bugfixes (testing, backport from 0.3.5.4-alpha): - Treat backtrace test failures as expected on BSD-derived systems (NetBSD, OpenBSD, and macOS/Darwin) until we solve bug 17808. (FreeBSD failures have been treated as expected since 18204 in 0.2.8.) Fixes bug 27948; bugfix on 0.2.5.2-alpha. o Minor bugfixes (unit tests, guard selection, backport from 0.3.5.6-rc): - Stop leaking memory in an entry guard unit test. Fixes bug 28554; bugfix on 0.3.0.1-alpha. Changes in version 0.3.4.10 - 2019-01-07 Tor 0.3.4.9 is the second stable release in its series; it backports numerous fixes, including an important fix for relays, and for anyone using OpenSSL 1.1.1. Anyone running an earlier version of Tor 0.3.4 should upgrade. As a reminder, the Tor 0.3.4 series will be supported until 10 June 2019. Some time between now and then, users should switch to the Tor 0.3.5 series, which will receive long-term support until at least 1 Feb 2022. o Major bugfixes (OpenSSL, portability, backport from 0.3.5.5-alpha): - Fix our usage of named groups when running as a TLS 1.3 client in OpenSSL 1.1.1. Previously, we only initialized EC groups when running as a relay, which caused clients to fail to negotiate TLS 1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3 support was added). o Major bugfixes (relay, directory, backport from 0.3.5.7): - Always reactivate linked connections in the main loop so long as any linked connection has been active. Previously, connections serving directory information wouldn't get reactivated after the first chunk of data was sent (usually 32KB), which would prevent clients from bootstrapping. Fixes bug 28912; bugfix on 0.3.4.1-alpha. Patch by "cypherpunks3". o Minor features (continuous integration, Windows, backport from 0.3.5.6-rc): - Always show the configure and test logs, and upload them as build artifacts, when building for Windows using Appveyor CI. Implements 28459. o Minor features (controller, backport from 0.3.5.1-alpha): - For purposes of CIRC_BW-based dropped cell detection, track half- closed stream ids, and allow their ENDs, SENDMEs, DATA and path bias check cells to arrive without counting it as dropped until either the END arrives, or the windows are empty. Closes ticket 25573. o Minor features (fallback directory list, backport from 0.3.5.6-rc): - Replace the 150 fallbacks originally introduced in Tor 0.3.3.1-alpha in January 2018 (of which ~115 were still functional), with a list of 157 fallbacks (92 new, 65 existing, 85 removed) generated in December 2018. Closes ticket 24803. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2018 Maxmind GeoLite2 Country database. Closes ticket 28395. o Minor features (OpenSSL bug workaround, backport from 0.3.5.7): - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3 key export function from handling long labels. When this bug is detected, Tor will disable TLS 1.3. We recommend upgrading to a version of OpenSSL without this bug when it becomes available. Closes ticket 28973. o Minor bugfixes (compilation, backport from 0.3.5.5-alpha): - Initialize a variable unconditionally in aes_new_cipher(), since some compilers cannot tell that we always initialize it before use. Fixes bug 28413; bugfix on 0.2.9.3-alpha. o Minor bugfixes (connection, relay, backport from 0.3.5.5-alpha): - Avoid a logging a BUG() stacktrace when closing connection held open because the write side is rate limited but not the read side. Now, the connection read side is simply shut down until Tor is able to flush the connection and close it. Fixes bug 27750; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, Windows, backport from 0.3.5.5-alpha): - Manually configure the zstd compiler options, when building using mingw on Appveyor Windows CI. The MSYS2 mingw zstd package does not come with a pkg-config file. Fixes bug 28454; bugfix on 0.3.4.1-alpha. - Stop using an external OpenSSL install, and stop installing MSYS2 packages, when building using mingw on Appveyor Windows CI. Fixes bug 28399; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, Windows, backport from 0.3.5.6-rc): - Explicitly specify the path to the OpenSSL library and do not download OpenSSL from Pacman, but instead use the library that is already provided by AppVeyor. Fixes bug 28574; bugfix on master. o Minor bugfixes (directory permissions, backport form 0.3.5.3-alpha): - When a user requests a group-readable DataDirectory, give it to them. Previously, when the DataDirectory and the CacheDirectory were the same, the default setting (0) for CacheDirectoryGroupReadable would override the setting for DataDirectoryGroupReadable. Fixes bug 26913; bugfix on 0.3.3.1-alpha. o Minor bugfixes (memory leaks, backport from 0.3.5.5-alpha): - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419; bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger. o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha): - Don't warn so loudly when Tor is unable to decode an onion descriptor. This can now happen as a normal use case if a client gets a descriptor with client authorization but the client is not authorized. Fixes bug 27550; bugfix on 0.3.5.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.6-rc): - When deleting an ephemeral onion service (DEL_ONION), do not close any rendezvous circuits in order to let the existing client connections finish by themselves or closed by the application. The HS v2 is doing that already so now we have the same behavior for all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha. o Minor bugfixes (relay statistics, backport from 0.3.5.7): - Update relay descriptor on bandwidth changes only when the uptime is smaller than 24h, in order to reduce the efficiency of guard discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha. o Minor bugfixes (unit tests, guard selection, backport from 0.3.5.6-rc): - Stop leaking memory in an entry guard unit test. Fixes bug 28554; bugfix on 0.3.0.1-alpha. Changes in version 0.3.5.7 - 2019-01-07 Tor 0.3.5.7 is the first stable release in its series; it includes compilation and portability fixes, and a fix for a severe problem affecting directory caches. The Tor 0.3.5 series includes several new features and performance improvements, including client authorization for v3 onion services, cleanups to bootstrap reporting, support for improved bandwidth- measurement tools, experimental support for NSS in place of OpenSSL, and much more. It also begins a full reorganization of Tor's code layout, for improved modularity and maintainability in the future. Finally, there is the usual set of performance improvements and bugfixes that we try to do in every release series. There are a couple of changes in the 0.3.5 that may affect compatibility. First, the default version for newly created onion services is now v3. Use the HiddenServiceVersion option if you want to override this. Second, some log messages related to bootstrapping have changed; if you use stem, you may need to update to the latest version so it will recognize them. We have designated 0.3.5 as a "long-term support" (LTS) series: we will continue to patch major bugs in typical configurations of 0.3.5 until at least 1 Feb 2022. (We do not plan to provide long-term support for embedding, Rust support, NSS support, running a directory authority, or unsupported platforms. For these, you will need to stick with the latest stable release.) Below are the changes since 0.3.4.9. For a complete list of changes since 0.3.5.6-rc, see the ChangeLog file. o Major features (bootstrap): - Don't report directory progress until after a connection to a relay or bridge has succeeded. Previously, we'd report 80% progress based on cached directory information when we couldn't even connect to the network. Closes ticket 27169. o Major features (new code layout): - Nearly all of Tor's source code has been moved around into more logical places. The "common" directory is now divided into a set of libraries in "lib", and files in the "or" directory have been split into "core" (logic absolutely needed for onion routing), "feature" (independent modules in Tor), and "app" (to configure and invoke the rest of Tor). See doc/HACKING/CodeStructure.md for more information. Closes ticket 26481. This refactoring is not complete: although the libraries have been refactored to be acyclic, the main body of Tor is still too interconnected. We will attempt to improve this in the future. o Major features (onion services v3): - Implement onion service client authorization at the descriptor level: only authorized clients can decrypt a service's descriptor to find out how to contact it. A new torrc option was added to control this client side: ClientOnionAuthDir . On the service side, if the "authorized_clients/" directory exists in the onion service directory path, client configurations are read from the files within. See the manpage for more details. Closes ticket 27547. Patch done by Suphanat Chunhapanya (haxxpop). - Improve revision counter generation in next-gen onion services. Onion services can now scale by hosting multiple instances on different hosts without synchronization between them, which was previously impossible because descriptors would get rejected by HSDirs. Addresses ticket 25552. - Version 3 onion services can now use the per-service HiddenServiceExportCircuitID option to differentiate client circuits. It communicates with the service by using the HAProxy protocol to assign virtual IP addresses to inbound client circuits. Closes ticket 4700. Patch by Mahrud Sayrafi. o Major features (onion services, UI change): - For a newly created onion service, the default version is now 3. Tor still supports existing version 2 services, but the operator now needs to set "HiddenServiceVersion 2" in order to create a new version 2 service. For existing services, Tor now learns the version by reading the key file. Closes ticket 27215. o Major features (portability, cryptography, experimental, TLS): - Tor now has the option to compile with the NSS library instead of OpenSSL. This feature is experimental, and we expect that bugs may remain. It is mainly intended for environments where Tor's performance is not CPU-bound, and where NSS is already known to be installed. To try it out, configure Tor with the --enable-nss flag. Closes tickets 26631, 26815, and 26816. If you are experimenting with this option and using an old cached consensus, Tor may fail to start. To solve this, delete your "cached-consensus" and "cached-microdesc-consensus" files, (if present), and restart Tor. o Major features (relay, UI change): - Relays no longer run as exits by default. If the "ExitRelay" option is auto (or unset), and no exit policy is specified with ExitPolicy or ReducedExitPolicy, we now treat ExitRelay as 0. Previously in this case, we allowed exit traffic and logged a warning message. Closes ticket 21530. Patch by Neel Chauhan. - Tor now validates that the ContactInfo config option is valid UTF- 8 when parsing torrc. Closes ticket 27428. o Major bugfixes (compilation): - Fix compilation on ARM (and other less-used CPUs) when compiling with OpenSSL before 1.1. Fixes bug 27781; bugfix on 0.3.4.1-alpha. o Major bugfixes (compilation, rust): - Rust tests can now build and run successfully with the --enable-fragile-hardening option enabled. Doing this currently requires the rust beta channel; it will be possible with stable rust once Rust version 1.31 is released. Patch from Alex Crichton. Fixes bugs 27272, 27273, and 27274. Bugfix on 0.3.1.1-alpha. o Major bugfixes (directory authority): - Actually check that the address we get from DirAuthority configuration line is valid IPv4. Explicitly disallow DirAuthority address to be a DNS hostname. Fixes bug 26488; bugfix on 0.1.2.10-rc. o Major bugfixes (embedding, main loop): - When DisableNetwork becomes set, actually disable periodic events that are already enabled. (Previously, we would refrain from enabling new ones, but we would leave the old ones turned on.) Fixes bug 28348; bugfix on 0.3.4.1-alpha. o Major bugfixes (main loop, bootstrap): - Make sure Tor bootstraps and works properly if only the ControlPort is set. Prior to this fix, Tor would only bootstrap when a client port was set (Socks, Trans, NATD, DNS or HTTPTunnel port). Fixes bug 27849; bugfix on 0.3.4.1-alpha. o Major bugfixes (onion service v3): - On an intro point for a version 3 onion service, stop closing introduction circuits on a NACK. This lets the client decide whether to reuse the circuit or discard it. Previously, we closed intro circuits when sending NACKs. Fixes bug 27841; bugfix on 0.3.2.1-alpha. Patch by Neel Chaunan. o Major bugfixes (OpenSSL, portability): - Fix our usage of named groups when running as a TLS 1.3 client in OpenSSL 1.1.1. Previously, we only initialized EC groups when running as a relay, which caused clients to fail to negotiate TLS 1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3 support was added). o Major bugfixes (relay bandwidth statistics): - When we close relayed circuits, report the data in the circuit queues as being written in our relay bandwidth stats. This mitigates guard discovery and other attacks that close circuits for the explicit purpose of noticing this discrepancy in statistics. Fixes bug 23512; bugfix on 0.0.8pre3. o Major bugfixes (relay): - When our write bandwidth limit is exhausted, stop writing on the connection. Previously, we had a typo in the code that would make us stop reading instead, leading to relay connections being stuck indefinitely and consuming kernel RAM. Fixes bug 28089; bugfix on 0.3.4.1-alpha. - Always reactivate linked connections in the main loop so long as any linked connection has been active. Previously, connections serving directory information wouldn't get reactivated after the first chunk of data was sent (usually 32KB), which would prevent clients from bootstrapping. Fixes bug 28912; bugfix on 0.3.4.1-alpha. Patch by "cypherpunks3". o Major bugfixes (restart-in-process): - Fix a use-after-free error that could be caused by passing Tor an impossible set of options that would fail during options_act(). Fixes bug 27708; bugfix on 0.3.3.1-alpha. o Minor features (admin tools): - Add a new --key-expiration option to print the expiration date of the signing cert in an ed25519_signing_cert file. Resolves issue 19506. o Minor features (build): - If you pass the "--enable-pic" option to configure, Tor will try to tell the compiler to build position-independent code suitable to link into a dynamic library. (The default remains -fPIE, for code suitable for a relocatable executable.) Closes ticket 23846. o Minor features (code correctness, testing): - Tor's build process now includes a "check-includes" make target to verify that no module of Tor relies on any headers from a higher- level module. We hope to use this feature over time to help refactor our codebase. Closes ticket 26447. o Minor features (code layout): - We have a new "lowest-level" error-handling API for use by code invoked from within the logging module. With this interface, the logging code is no longer at risk of calling into itself if a failure occurs while it is trying to log something. Closes ticket 26427. o Minor features (compilation): - When possible, place our warning flags in a separate file, to avoid flooding verbose build logs. Closes ticket 28924. - Tor's configure script now supports a --with-malloc= option to select your malloc implementation. Supported options are "tcmalloc", "jemalloc", "openbsd" (deprecated), and "system" (the default). Addresses part of ticket 20424. Based on a patch from Alex Xu. o Minor features (config): - The "auto" keyword in torrc is now case-insensitive. Closes ticket 26663. o Minor features (continuous integration): - Add a Travis CI build for --enable-nss on Linux gcc. Closes ticket 27751. - Add new CI job to Travis configuration to run stem-based integration tests. Closes ticket 27913. - Use the Travis Homebrew addon to install packages on macOS during Travis CI. The package list is the same, but the Homebrew addon does not do a `brew update` by default. Implements ticket 27738. - Report what program produced the mysterious core file that we occasionally see on Travis CI during make distcheck. Closes ticket 28024. - Don't do a distcheck with --disable-module-dirauth in Travis. Implements ticket 27252. - Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560. - Only run one online rust build in Travis, to reduce network errors. Skip offline rust builds on Travis for Linux gcc, because they're redundant. Implements ticket 27252. - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on Linux with default settings, because all the non-default builds use gcc on Linux. Implements ticket 27252. o Minor features (continuous integration, Windows): - Always show the configure and test logs, and upload them as build artifacts, when building for Windows using Appveyor CI. Implements 28459. - Build tor on Windows Server 2012 R2 and Windows Server 2016 using Appveyor's CI. Closes ticket 28318. o Minor features (controller): - Emit CIRC_BW events as soon as we detect that we processed an invalid or otherwise dropped cell on a circuit. This allows vanguards and other controllers to react more quickly to dropped cells. Closes ticket 27678. - For purposes of CIRC_BW-based dropped cell detection, track half- closed stream ids, and allow their ENDs, SENDMEs, DATA and path bias check cells to arrive without counting it as dropped until either the END arrives, or the windows are empty. Closes ticket 25573. - Implement a 'GETINFO md/all' controller command to enable getting all known microdescriptors. Closes ticket 8323. - The GETINFO command now support an "uptime" argument, to return Tor's uptime in seconds. Closes ticket 25132. o Minor features (denial-of-service avoidance): - Make our OOM handler aware of the DNS cache so that it doesn't fill up the memory. This check is important for our DoS mitigation subsystem. Closes ticket 18642. Patch by Neel Chauhan. o Minor features (development): - Tor's makefile now supports running the "clippy" Rust style tool on our Rust code. Closes ticket 22156. o Minor features (directory authority): - There is no longer an artificial upper limit on the length of bandwidth lines. Closes ticket 26223. - When a bandwidth file is used to obtain the bandwidth measurements, include this bandwidth file headers in the votes. Closes ticket 3723. - Improved support for networks with only a single authority or a single fallback directory. Patch from Gabriel Somlo. Closes ticket 25928. o Minor features (embedding API): - The Tor controller API now supports a function to launch Tor with a preconstructed owning controller FD, so that embedding applications don't need to manage controller ports and authentication. Closes ticket 24204. - The Tor controller API now has a function that returns the name and version of the backend implementing the API. Closes ticket 26947. o Minor features (fallback directory list): - Replace the 150 fallbacks originally introduced in Tor 0.3.3.1-alpha in January 2018 (of which ~115 were still functional), with a list of 157 fallbacks (92 new, 65 existing, 85 removed) generated in December 2018. Closes ticket 24803. o Minor features (geoip): - Update geoip and geoip6 to the January 3 2019 Maxmind GeoLite2 Country database. Closes ticket 29012. o Minor features (memory management): - Get Libevent to use the same memory allocator as Tor, by calling event_set_mem_functions() during initialization. Resolves ticket 8415. o Minor features (memory usage): - When not using them, store legacy TAP public onion keys in DER- encoded format, rather than as expanded public keys. This should save several megabytes on typical clients. Closes ticket 27246. o Minor features (OpenSSL bug workaround): - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3 key export function from handling long labels. When this bug is detected, Tor will disable TLS 1.3. We recommend upgrading to a version of OpenSSL without this bug when it becomes available. Closes ticket 28973. o Minor features (OpenSSL): - When possible, use RFC5869 HKDF implementation from OpenSSL rather than our own. Resolves ticket 19979. o Minor features (performance): - Remove about 96% of the work from the function that we run at startup to test our curve25519_basepoint implementation. Since this function has yet to find an actual failure, we now only run it for 8 iterations instead of 200. Based on our profile information, this change should save around 8% of our startup time on typical desktops, and may have a similar effect on other platforms. Closes ticket 28838. - Stop re-validating our hardcoded Diffie-Hellman parameters on every startup. Doing this wasted time and cycles, especially on low-powered devices. Closes ticket 28851. o Minor features (Rust, code quality): - Improve rust code quality in the rust protover implementation by making it more idiomatic. Includes changing an internal API to take &str instead of &String. Closes ticket 26492. o Minor features (testing): - Add scripts/test/chutney-git-bisect.sh, for bisecting using chutney. Implements ticket 27211. o Minor features (tor-resolve): - The tor-resolve utility can now be used with IPv6 SOCKS proxies. Side-effect of the refactoring for ticket 26526. o Minor features (UI): - Log each included configuration file or directory as we read it, to provide more visibility about where Tor is reading from. Patch from Unto Sten; closes ticket 27186. - Lower log level of "Scheduler type KIST has been enabled" to INFO. Closes ticket 26703. o Minor bugfixes (32-bit OSX and iOS, timing): - Fix an integer overflow bug in our optimized 32-bit millisecond- difference algorithm for 32-bit Apple platforms. Previously, it would overflow when calculating the difference between two times more than 47 days apart. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. - Improve the precision of our 32-bit millisecond difference algorithm for 32-bit Apple platforms. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. - Relax the tolerance on the mainloop/update_time_jumps test when running on 32-bit Apple platforms. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. o Minor bugfixes (bootstrap): - Try harder to get descriptors in non-exit test networks, by using the mid weight for the third hop when there are no exits. Fixes bug 27237; bugfix on 0.2.6.2-alpha. o Minor bugfixes (C correctness): - Avoid casting smartlist index to int implicitly, as it may trigger a warning (-Wshorten-64-to-32). Fixes bug 26282; bugfix on 0.2.3.13-alpha, 0.2.7.1-alpha and 0.2.1.1-alpha. - Use time_t for all values in predicted_ports_prediction_time_remaining(). Rework the code that computes difference between durations/timestamps. Fixes bug 27165; bugfix on 0.3.1.1-alpha. o Minor bugfixes (client, memory usage): - When not running as a directory cache, there is no need to store the text of the current consensus networkstatus in RAM. Previously, however, clients would store it anyway, at a cost of over 5 MB. Now, they do not. Fixes bug 27247; bugfix on 0.3.0.1-alpha. o Minor bugfixes (client, ReachableAddresses): - Instead of adding a "reject *:*" line to ReachableAddresses when loading the configuration, add one to the policy after parsing it in parse_reachable_addresses(). This prevents extra "reject *.*" lines from accumulating on reloads. Fixes bug 20874; bugfix on 0.1.1.5-alpha. Patch by Neel Chauhan. o Minor bugfixes (code quality): - Rename sandbox_getaddrinfo() and other functions to no longer misleadingly suggest that they are sandbox-only. Fixes bug 26525; bugfix on 0.2.7.1-alpha. o Minor bugfixes (code safety): - Rewrite our assertion macros so that they no longer suppress the compiler's -Wparentheses warnings. Fixes bug 27709; bugfix on 0.0.6. o Minor bugfixes (compilation): - Initialize a variable unconditionally in aes_new_cipher(), since some compilers cannot tell that we always initialize it before use. Fixes bug 28413; bugfix on 0.2.9.3-alpha. o Minor bugfixes (configuration): - Refuse to start with relative file paths and RunAsDaemon set (regression from the fix for bug 22731). Fixes bug 28298; bugfix on 0.3.3.1-alpha. o Minor bugfixes (configuration, Onion Services): - In rend_service_parse_port_config(), disallow any input to remain after address-port pair was parsed. This will catch address and port being whitespace-separated by mistake of the user. Fixes bug 27044; bugfix on 0.2.9.10. o Minor bugfixes (connection, relay): - Avoid a logging a BUG() stacktrace when closing connection held open because the write side is rate limited but not the read side. Now, the connection read side is simply shut down until Tor is able to flush the connection and close it. Fixes bug 27750; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, Windows): - Stop reinstalling identical packages in our Windows CI. Fixes bug 27464; bugfix on 0.3.4.1-alpha. - Install only the necessary mingw packages during our appveyor builds. This change makes the build a little faster, and prevents a conflict with a preinstalled mingw openssl that appveyor now ships. Fixes bugs 27765 and 27943; bugfix on 0.3.4.2-alpha. - Explicitly specify the path to the OpenSSL library and do not download OpenSSL from Pacman, but instead use the library that is already provided by AppVeyor. Fixes bug 28574; bugfix on master. - Manually configure the zstd compiler options, when building using mingw on Appveyor Windows CI. The MSYS2 mingw zstd package does not come with a pkg-config file. Fixes bug 28454; bugfix on 0.3.4.1-alpha. - Stop using an external OpenSSL install, and stop installing MSYS2 packages, when building using mingw on Appveyor Windows CI. Fixes bug 28399; bugfix on 0.3.4.1-alpha. o Minor bugfixes (controller): - Consider all routerinfo errors other than "not a server" to be transient for the purpose of "GETINFO exit-policy/*" controller request. Print stacktrace in the unlikely case of failing to recompute routerinfo digest. Fixes bug 27034; bugfix on 0.3.4.1-alpha. o Minor bugfixes (correctness): - Fix an unreached code path where we checked the value of "hostname" inside send_resolved_hostname_cell(). Previously, we used it before checking it; now we check it first. Fixes bug 28879; bugfix on 0.1.2.7-alpha. o Minor bugfixes (directory connection shutdown): - Avoid a double-close when shutting down a stalled directory connection. Fixes bug 26896; bugfix on 0.3.4.1-alpha. o Minor bugfixes (directory permissions): - When a user requests a group-readable DataDirectory, give it to them. Previously, when the DataDirectory and the CacheDirectory were the same, the default setting (0) for CacheDirectoryGroupReadable would override the setting for DataDirectoryGroupReadable. Fixes bug 26913; bugfix on 0.3.3.1-alpha. o Minor bugfixes (HTTP tunnel): - Fix a bug warning when closing an HTTP tunnel connection due to an HTTP request we couldn't handle. Fixes bug 26470; bugfix on 0.3.2.1-alpha. o Minor bugfixes (ipv6): - In addrs_in_same_network_family(), we choose the subnet size based on the IP version (IPv4 or IPv6). Previously, we chose a fixed subnet size of /16 for both IPv4 and IPv6 addresses. Fixes bug 15518; bugfix on 0.2.3.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (Linux seccomp2 sandbox): - Permit the "shutdown()" system call, which is apparently used by OpenSSL under some circumstances. Fixes bug 28183; bugfix on 0.2.5.1-alpha. o Minor bugfixes (logging): - Stop talking about the Named flag in log messages. Clients have ignored the Named flag since 0.3.2. Fixes bug 28441; bugfix on 0.3.2.1-alpha. - As a precaution, do an early return from log_addr_has_changed() if Tor is running as client. Also, log a stack trace for debugging as this function should only be called when Tor runs as server. Fixes bug 26892; bugfix on 0.1.1.9-alpha. - Refrain from mentioning bug 21018 in the logs, as it is already fixed. Fixes bug 25477; bugfix on 0.2.9.8. o Minor bugfixes (logging, documentation): - When SafeLogging is enabled, scrub IP address in channel_tls_process_netinfo_cell(). Also, add a note to manpage that scrubbing is not guaranteed on loglevels below Notice. Fixes bug 26882; bugfix on 0.2.4.10-alpha. o Minor bugfixes (memory leaks): - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419; bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger. - Fix a small memory leak when calling Tor with --dump-config. Fixes bug 27893; bugfix on 0.3.2.1-alpha. o Minor bugfixes (netflow padding): - Ensure circuitmux queues are empty before scheduling or sending padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha. o Minor bugfixes (onion service v2): - Log at level "info", not "warning", in the case that we do not have a consensus when a .onion request comes in. This can happen normally while bootstrapping. Fixes bug 27040; bugfix on 0.2.8.2-alpha. o Minor bugfixes (onion service v3): - When deleting an ephemeral onion service (DEL_ONION), do not close any rendezvous circuits in order to let the existing client connections finish by themselves or closed by the application. The HS v2 is doing that already so now we have the same behavior for all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha. - Build the service descriptor's signing key certificate before uploading, so we always have a fresh one: leaving no chances for it to expire service side. Fixes bug 27838; bugfix on 0.3.2.1-alpha. - Stop dumping a stack trace when trying to connect to an intro point without having a descriptor for it. Fixes bug 27774; bugfix on 0.3.2.1-alpha. - When selecting a v3 rendezvous point, don't only look at the protover, but also check whether the curve25519 onion key is present. This way we avoid picking a relay that supports the v3 rendezvous but for which we don't have the microdescriptor. Fixes bug 27797; bugfix on 0.3.2.1-alpha. - Close all SOCKS request (for the same .onion) if the newly fetched descriptor is unusable. Before that, we would close only the first one leaving the other hanging and let to time out by themselves. Fixes bug 27410; bugfix on 0.3.2.1-alpha. - When the onion service directory can't be created or has the wrong permissions, do not log a stack trace. Fixes bug 27335; bugfix on 0.3.2.1-alpha. - When replacing a descriptor in the client cache, make sure to close all client introduction circuits for the old descriptor, so we don't end up with unusable leftover circuits. Fixes bug 27471; bugfix on 0.3.2.1-alpha. o Minor bugfixes (OS compatibility): - Properly handle configuration changes that move a listener to/from wildcard IP address. If the first attempt to bind a socket fails, close the old listener and try binding the socket again. Fixes bug 17873; bugfix on 0.0.8pre-1. o Minor bugfixes (performance):: - Rework node_is_a_configured_bridge() to no longer call node_get_all_orports(), which was performing too many memory allocations. Fixes bug 27224; bugfix on 0.2.3.9. o Minor bugfixes (protover): - Reject protocol names containing bytes other than alphanumeric characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix on 0.2.9.4-alpha. o Minor bugfixes (protover, rust): - Reject extra commas in version strings. Fixes bug 27197; bugfix on 0.3.3.3-alpha. - protover_all_supported() would attempt to allocate up to 16GB on some inputs, leading to a potential memory DoS. Fixes bug 27206; bugfix on 0.3.3.5-rc. - Compute protover votes correctly in the rust version of the protover code. Previously, the protover rewrite in 24031 allowed repeated votes from the same voter for the same protocol version to be counted multiple times in protover_compute_vote(). Fixes bug 27649; bugfix on 0.3.3.5-rc. - Reject protover names that contain invalid characters. Fixes bug 27687; bugfix on 0.3.3.1-alpha. o Minor bugfixes (relay shutdown, systemd): - Notify systemd of ShutdownWaitLength so it can be set to longer than systemd's TimeoutStopSec. In Tor's systemd service file, set TimeoutSec to 60 seconds to allow Tor some time to shut down. Fixes bug 28113; bugfix on 0.2.6.2-alpha. o Minor bugfixes (relay statistics): - Update relay descriptor on bandwidth changes only when the uptime is smaller than 24h, in order to reduce the efficiency of guard discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha. o Minor bugfixes (relay): - Consider the fact that we'll be making direct connections to our entry and guard nodes when computing the fraction of nodes that have their descriptors. Also, if we are using bridges and there is at least one bridge with a full descriptor, treat the fraction of guards available as 100%. Fixes bug 25886; bugfix on 0.2.4.10-alpha. Patch by Neel Chauhan. - Update the message logged on relays when DirCache is disabled. Since 0.3.3.5-rc, authorities require DirCache (V2Dir) for the Guard flag. Fixes bug 24312; bugfix on 0.3.3.5-rc. o Minor bugfixes (testing): - Stop running stem's unit tests as part of "make test-stem", but continue to run stem's unit and online tests during "make test- stem-full". Fixes bug 28568; bugfix on 0.2.6.3-alpha. - Stop leaking memory in an entry guard unit test. Fixes bug 28554; bugfix on 0.3.0.1-alpha. - Make the hs_service tests use the same time source when creating the introduction point and when testing it. Now tests work better on very slow systems like ARM or Travis. Fixes bug 27810; bugfix on 0.3.2.1-alpha. - Revise the "conditionvar_timeout" test so that it succeeds even on heavily loaded systems where the test threads are not scheduled within 200 msec. Fixes bug 27073; bugfix on 0.2.6.3-alpha. - Fix two unit tests to work when HOME environment variable is not set. Fixes bug 27096; bugfix on 0.2.8.1-alpha. - If a unit test running in a subprocess exits abnormally or with a nonzero status code, treat the test as having failed, even if the test reported success. Without this fix, memory leaks don't cause the tests to fail, even with LeakSanitizer. Fixes bug 27658; bugfix on 0.2.2.4-alpha. - When logging a version mismatch in our openssl_version tests, report the actual offending version strings. Fixes bug 26152; bugfix on 0.2.9.1-alpha. - Fix forking tests on Windows when there is a space somewhere in the path. Fixes bug 26437; bugfix on 0.2.2.4-alpha. o Minor bugfixes (Windows): - Correctly identify Windows 8.1, Windows 10, and Windows Server 2008 and later from their NT versions. Fixes bug 28096; bugfix on 0.2.2.34; reported by Keifer Bly. - On recent Windows versions, the GetVersionEx() function may report an earlier Windows version than the running OS. To avoid user confusion, add "[or later]" to Tor's version string on affected versions of Windows. Fixes bug 28096; bugfix on 0.2.2.34; reported by Keifer Bly. - Remove Windows versions that were never supported by the GetVersionEx() function. Stop duplicating the latest Windows version in get_uname(). Fixes bug 28096; bugfix on 0.2.2.34; reported by Keifer Bly. o Code simplification and refactoring: - When parsing a port configuration, make it more obvious to static analyzer tools that we always initialize the address. Closes ticket 28881. - Divide more large Tor source files -- especially ones that span multiple areas of functionality -- into smaller parts, including onion.c and main.c. Closes ticket 26747. - Divide the "routerparse.c" module into separate modules for each group of parsed objects. Closes ticket 27924. - Move protover_rust.c to the same place protover.c was moved to. Closes ticket 27814. - Split directory.c into separate pieces for client, server, and common functionality. Closes ticket 26744. - Split the non-statistics-related parts from the rephist.c and geoip.c modules. Closes ticket 27892. - Split the router.c file into relay-only and shared components, to help with future modularization. Closes ticket 27864. - Divide the routerlist.c and dirserv.c modules into smaller parts. Closes ticket 27799. - 'updateFallbackDirs.py' now ignores the blacklist file, as it's not longer needed. Closes ticket 26502. - Include paths to header files within Tor are now qualified by directory within the top-level src directory. - Many structures have been removed from the centralized "or.h" header, and moved into their own headers. This will allow us to reduce the number of places in the code that rely on each structure's contents and layout. Closes ticket 26383. - Remove ATTR_NONNULL macro from codebase. Resolves ticket 26527. - Remove GetAdaptersAddresses_fn_t. The code that used it was removed as part of the 26481 refactor. Closes ticket 27467. - Rework Tor SOCKS server code to use Trunnel and benefit from autogenerated functions for parsing and generating SOCKS wire format. New implementation is cleaner, more maintainable and should be less prone to heartbleed-style vulnerabilities. Implements a significant fraction of ticket 3569. - Split sampled_guards_update_from_consensus() and select_entry_guard_for_circuit() into subfunctions. In entry_guards_update_primary() unite three smartlist enumerations into one and move smartlist comparison code out of the function. Closes ticket 21349. - Tor now assumes that you have standards-conformant stdint.h and inttypes.h headers when compiling. Closes ticket 26626. - Unify our bloom filter logic. Previously we had two copies of this code: one for routerlist filtering, and one for address set calculations. Closes ticket 26510. - Use the simpler strcmpstart() helper in rend_parse_v2_service_descriptor instead of strncmp(). Closes ticket 27630. - Utility functions that can perform a DNS lookup are now wholly separated from those that can't, in separate headers and C modules. Closes ticket 26526. o Documentation: - In the tor-resolve(1) manpage, fix the reference to socks- extensions.txt by adding a web URL. Resolves ticket 27853. - Mention that we require Python to be 2.7 or newer for some integration tests that we ship with Tor. Resolves ticket 27677. - Copy paragraph and URL to Tor's code of conduct document from CONTRIBUTING to new CODE_OF_CONDUCT file. Resolves ticket 26638. - Remove old instructions from INSTALL document. Closes ticket 26588. - Warn users that they should not include MyFamily line(s) in their torrc when running Tor bridge. Closes ticket 26908. o Removed features: - Tor no longer supports building with the dmalloc library. For debugging memory issues, we suggest using gperftools or msan instead. Closes ticket 26426. - Tor no longer attempts to run on Windows environments without the GetAdaptersAddresses() function. This function has existed since Windows XP, which is itself already older than we support. - Remove Tor2web functionality for version 2 onion services. The Tor2webMode and Tor2webRendezvousPoints options are now obsolete. (This feature was never shipped in vanilla Tor and it was only possible to use this feature by building the support at compile time. Tor2webMode is not implemented for version 3 onion services.) Closes ticket 26367. o Testing: - Increase logging and tag all log entries with timestamps in test_rebind.py. Provides diagnostics for issue 28229. o Code simplification and refactoring (shared random, dirauth): - Change many tor_assert() to use BUG() instead. The idea is to not crash a dirauth but rather scream loudly with a stacktrace and let it continue run. The shared random subsystem is very resilient and if anything wrong happens with it, at worst a non coherent value will be put in the vote and discarded by the other authorities. Closes ticket 19566. o Documentation (onion services): - Improve HSv3 client authorization by making some options more explicit and detailed. Closes ticket 28026. Patch by Mike Tigas. - Document in the man page that changing ClientOnionAuthDir value or adding a new file in the directory will not work at runtime upon sending a HUP if Sandbox 1. Closes ticket 28128. - Note in the man page that the only real way to fully revoke an onion service v3 client authorization is by restarting the tor process. Closes ticket 28275. Changes in version 0.3.4.9 - 2018-11-02 Tor 0.3.4.9 is the second stable release in its series; it backports numerous fixes, including a fix for a bandwidth management bug that was causing memory exhaustion on relays. Anyone running an earlier version of Tor 0.3.4.9 should upgrade. o Major bugfixes (compilation, backport from 0.3.5.3-alpha): - Fix compilation on ARM (and other less-used CPUs) when compiling with OpenSSL before 1.1. Fixes bug 27781; bugfix on 0.3.4.1-alpha. o Major bugfixes (mainloop, bootstrap, backport from 0.3.5.3-alpha): - Make sure Tor bootstraps and works properly if only the ControlPort is set. Prior to this fix, Tor would only bootstrap when a client port was set (Socks, Trans, NATD, DNS or HTTPTunnel port). Fixes bug 27849; bugfix on 0.3.4.1-alpha. o Major bugfixes (relay, backport from 0.3.5.3-alpha): - When our write bandwidth limit is exhausted, stop writing on the connection. Previously, we had a typo in the code that would make us stop reading instead, leading to relay connections being stuck indefinitely and consuming kernel RAM. Fixes bug 28089; bugfix on 0.3.4.1-alpha. o Major bugfixes (restart-in-process, backport from 0.3.5.1-alpha): - Fix a use-after-free error that could be caused by passing Tor an impossible set of options that would fail during options_act(). Fixes bug 27708; bugfix on 0.3.3.1-alpha. o Minor features (continuous integration, backport from 0.3.5.1-alpha): - Don't do a distcheck with --disable-module-dirauth in Travis. Implements ticket 27252. - Only run one online rust build in Travis, to reduce network errors. Skip offline rust builds on Travis for Linux gcc, because they're redundant. Implements ticket 27252. - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on Linux with default settings, because all the non-default builds use gcc on Linux. Implements ticket 27252. o Minor features (continuous integration, backport from 0.3.5.3-alpha): - Use the Travis Homebrew addon to install packages on macOS during Travis CI. The package list is the same, but the Homebrew addon does not do a `brew update` by default. Implements ticket 27738. o Minor features (geoip): - Update geoip and geoip6 to the October 9 2018 Maxmind GeoLite2 Country database. Closes ticket 27991. o Minor bugfixes (32-bit OSX and iOS, timing, backport from 0.3.5.2-alpha): - Fix an integer overflow bug in our optimized 32-bit millisecond- difference algorithm for 32-bit Apple platforms. Previously, it would overflow when calculating the difference between two times more than 47 days apart. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. - Improve the precision of our 32-bit millisecond difference algorithm for 32-bit Apple platforms. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. - Relax the tolerance on the mainloop/update_time_jumps test when running on 32-bit Apple platforms. Fixes part of bug 27139; bugfix on 0.3.4.1-alpha. o Minor bugfixes (C correctness, to appear in 0.3.5.4-alpha): - Avoid undefined behavior in an end-of-string check when parsing the BEGIN line in a directory object. Fixes bug 28202; bugfix on 0.2.0.3-alpha. o Minor bugfixes (CI, appveyor, to appear in 0.3.5.4-alpha): - Only install the necessary mingw packages during our appveyor builds. This change makes the build a little faster, and prevents a conflict with a preinstalled mingw openssl that appveyor now ships. Fixes bugs 27943 and 27765; bugfix on 0.3.4.2-alpha. o Minor bugfixes (code safety, backport from 0.3.5.3-alpha): - Rewrite our assertion macros so that they no longer suppress the compiler's -Wparentheses warnings. Fixes bug 27709; bugfix o Minor bugfixes (continuous integration, backport from 0.3.5.1-alpha): - Stop reinstalling identical packages in our Windows CI. Fixes bug 27464; bugfix on 0.3.4.1-alpha. o Minor bugfixes (directory authority, to appear in 0.3.5.4-alpha): - Log additional info when we get a relay that shares an ed25519 ID with a different relay, instead making a BUG() warning. Fixes bug 27800; bugfix on 0.3.2.1-alpha. o Minor bugfixes (directory connection shutdown, backport from 0.3.5.1-alpha): - Avoid a double-close when shutting down a stalled directory connection. Fixes bug 26896; bugfix on 0.3.4.1-alpha. o Minor bugfixes (HTTP tunnel, backport from 0.3.5.1-alpha): - Fix a bug warning when closing an HTTP tunnel connection due to an HTTP request we couldn't handle. Fixes bug 26470; bugfix on 0.3.2.1-alpha. o Minor bugfixes (netflow padding, backport from 0.3.5.1-alpha): - Ensure circuitmux queues are empty before scheduling or sending padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.1-alpha): - When the onion service directory can't be created or has the wrong permissions, do not log a stack trace. Fixes bug 27335; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.2-alpha): - Close all SOCKS request (for the same .onion) if the newly fetched descriptor is unusable. Before that, we would close only the first one leaving the other hanging and let to time out by themselves. Fixes bug 27410; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha): - When selecting a v3 rendezvous point, don't only look at the protover, but also check whether the curve25519 onion key is present. This way we avoid picking a relay that supports the v3 rendezvous but for which we don't have the microdescriptor. Fixes bug 27797; bugfix on 0.3.2.1-alpha. o Minor bugfixes (protover, backport from 0.3.5.3-alpha): - Reject protocol names containing bytes other than alphanumeric characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix on 0.2.9.4-alpha. o Minor bugfixes (rust, backport from 0.3.5.1-alpha): - Compute protover votes correctly in the rust version of the protover code. Previously, the protover rewrite in 24031 allowed repeated votes from the same voter for the same protocol version to be counted multiple times in protover_compute_vote(). Fixes bug 27649; bugfix on 0.3.3.5-rc. - Reject protover names that contain invalid characters. Fixes bug 27687; bugfix on 0.3.3.1-alpha. o Minor bugfixes (rust, backport from 0.3.5.2-alpha): - protover_all_supported() would attempt to allocate up to 16GB on some inputs, leading to a potential memory DoS. Fixes bug 27206; bugfix on 0.3.3.5-rc. o Minor bugfixes (rust, directory authority, to appear in 0.3.5.4-alpha): - Fix an API mismatch in the rust implementation of protover_compute_vote(). This bug could have caused crashes on any directory authorities running Tor with Rust (which we do not yet recommend). Fixes bug 27741; bugfix on 0.3.3.6. o Minor bugfixes (rust, to appear in 0.3.5.4-alpha): - Fix a potential null dereference in protover_all_supported(). Add a test for it. Fixes bug 27804; bugfix on 0.3.3.1-alpha. - Return a string that can be safely freed by C code, not one created by the rust allocator, in protover_all_supported(). Fixes bug 27740; bugfix on 0.3.3.1-alpha. o Minor bugfixes (testing, backport from 0.3.5.1-alpha): - If a unit test running in a subprocess exits abnormally or with a nonzero status code, treat the test as having failed, even if the test reported success. Without this fix, memory leaks don't cause the tests to fail, even with LeakSanitizer. Fixes bug 27658; bugfix on 0.2.2.4-alpha. o Minor bugfixes (testing, backport from 0.3.5.3-alpha): - Make the hs_service tests use the same time source when creating the introduction point and when testing it. Now tests work better on very slow systems like ARM or Travis. Fixes bug 27810; bugfix on 0.3.2.1-alpha. o Minor bugfixes (testing, to appear in 0.3.5.4-alpha): - Treat backtrace test failures as expected on BSD-derived systems (NetBSD, OpenBSD, and macOS/Darwin) until we solve bug 17808. (FreeBSD failures have been treated as expected since 18204 in 0.2.8.) Fixes bug 27948; bugfix on 0.2.5.2-alpha. Changes in version 0.2.9.17 - 2018-09-10 Tor 0.2.9.17 backports numerous bugfixes from later versions of Tor. o Minor features (compatibility, backport from 0.3.4.8): - Tell OpenSSL to maintain backward compatibility with previous RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these ciphers are disabled by default. Closes ticket 27344. o Minor features (continuous integration, backport from 0.3.4.7-rc): - Enable macOS builds in our Travis CI configuration. Closes ticket 24629. - Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560. - Run asciidoc during Travis CI. Implements ticket 27087. - Use ccache in our Travis CI configuration. Closes ticket 26952. o Minor features (geoip): - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2 Country database. Closes ticket 27089. o Minor bugfixes (compilation, backport from 0.3.4.6-rc): - When compiling with --enable-openbsd-malloc or --enable-tcmalloc, tell the compiler not to include the system malloc implementation. Fixes bug 20424; bugfix on 0.2.0.20-rc. o Minor bugfixes (compilation, backport from 0.3.4.7-rc): - Silence a spurious compiler warning on the GetAdaptersAddresses function pointer cast. This issue is already fixed by 26481 in 0.3.5 and later, by removing the lookup and cast. Fixes bug 27465; bugfix on 0.2.3.11-alpha. - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not supported, and always fails. Some compilers warn about the function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix on 0.2.2.23-alpha. o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc): - Don't link or search for pthreads when building for Windows, even if we are using build environment (like mingw) that provides a pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc. o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc): - Skip a pair of unreliable key generation tests on Windows, until the underlying issue in bug 26076 is resolved. Fixes bug 26830 and bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively. o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc): - Pass the module flags to distcheck configure, and log the flags before running configure. (Backported to 0.2.9 and later as a precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, backport from 0.3.4.8): - When a Travis build fails, and showing a log fails, keep trying to show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc. - When we use echo in Travis, don't pass a --flag as the first argument. Fixes bug 27418; bugfix on 0.3.4.7-rc. o Minor bugfixes (directory authority, backport from 0.3.4.6-rc): - When voting for recommended versions, make sure that all of the versions are well-formed and parsable. Fixes bug 26485; bugfix on 0.1.1.6-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc): - Fix a bug in out sandboxing rules for the openat() syscall. Previously, no openat() call would be permitted, which would break filesystem operations on recent glibc versions. Fixes bug 25440; bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto. o Minor bugfixes (onion services, backport from 0.3.4.8): - Silence a spurious compiler warning in rend_client_send_introduction(). Fixes bug 27463; bugfix on 0.1.1.2-alpha. o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc): - Log a protocol warning when single onion services or Tor2web clients fail to authenticate direct connections to relays. Fixes bug 26924; bugfix on 0.2.9.1-alpha. o Minor bugfixes (testing, backport from 0.3.4.6-rc): - Disable core dumps in test_bt.sh, to avoid failures in "make distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha. o Minor bugfixes (testing, chutney, backport from 0.3.4.8): - Before running make test-network-all, delete old logs and test result files, to avoid spurious failures. Fixes bug 27295; bugfix on 0.2.7.3-rc. o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc): - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha. o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc): - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug 27185; bugfix on 0.2.2.2-alpha. Changes in version 0.3.2.12 - 2018-09-10 Tor 0.3.2.12 backport numerous fixes from later versions of Tor. o Minor features (compatibility, backport from 0.3.4.8): - Tell OpenSSL to maintain backward compatibility with previous RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these ciphers are disabled by default. Closes ticket 27344. o Minor features (continuous integration, backport from 0.3.4.7-rc): - Enable macOS builds in our Travis CI configuration. Closes ticket 24629. - Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560. - Run asciidoc during Travis CI. Implements ticket 27087. - Use ccache in our Travis CI configuration. Closes ticket 26952. o Minor features (continuous integration, rust, backport from 0.3.4.7-rc): - Use cargo cache in our Travis CI configuration. Closes ticket 26952. o Minor features (controller, backport from 0.3.4.6-rc): - The control port now exposes the list of HTTPTunnelPorts and ExtOrPorts via GETINFO net/listeners/httptunnel and net/listeners/extor respectively. Closes ticket 26647. o Minor features (directory authorities, backport from 0.3.4.7-rc): - Authorities no longer vote to make the subprotocol version "LinkAuth=1" a requirement: it is unsupportable with NSS, and hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286. o Minor features (geoip): - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2 Country database. Closes ticket 27089. o Minor bugfixes (compilation, backport from 0.3.4.6-rc): - When compiling with --enable-openbsd-malloc or --enable-tcmalloc, tell the compiler not to include the system malloc implementation. Fixes bug 20424; bugfix on 0.2.0.20-rc. - Don't try to use a pragma to temporarily disable the -Wunused-const-variable warning if the compiler doesn't support it. Fixes bug 26785; bugfix on 0.3.2.11. o Minor bugfixes (compilation, backport from 0.3.4.7-rc): - Silence a spurious compiler warning on the GetAdaptersAddresses function pointer cast. This issue is already fixed by 26481 in 0.3.5 and later, by removing the lookup and cast. Fixes bug 27465; bugfix on 0.2.3.11-alpha. - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not supported, and always fails. Some compilers warn about the function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix on 0.2.2.23-alpha. o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc): - Don't link or search for pthreads when building for Windows, even if we are using build environment (like mingw) that provides a pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc. o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc): - Skip a pair of unreliable key generation tests on Windows, until the underlying issue in bug 26076 is resolved. Fixes bug 26830 and bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively. o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc): - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha. - Pass the module flags to distcheck configure, and log the flags before running configure. (Backported to 0.2.9 and later as a precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, backport from 0.3.4.8): - When a Travis build fails, and showing a log fails, keep trying to show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc. - When we use echo in Travis, don't pass a --flag as the first argument. Fixes bug 27418; bugfix on 0.3.4.7-rc. o Minor bugfixes (directory authority, backport from 0.3.4.6-rc): - When voting for recommended versions, make sure that all of the versions are well-formed and parsable. Fixes bug 26485; bugfix on 0.1.1.6-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc): - Fix a bug in out sandboxing rules for the openat() syscall. Previously, no openat() call would be permitted, which would break filesystem operations on recent glibc versions. Fixes bug 25440; bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto. o Minor bugfixes (logging, backport from 0.3.4.6-rc): - Improve the log message when connection initiators fail to authenticate direct connections to relays. Fixes bug 26927; bugfix on 0.3.0.1-alpha. o Minor bugfixes (onion services, backport from 0.3.4.7-rc): - Fix bug that causes services to not ever rotate their descriptors if they were getting SIGHUPed often. Fixes bug 26932; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services, backport from 0.3.4.8): - Silence a spurious compiler warning in rend_client_send_introduction(). Fixes bug 27463; bugfix on 0.1.1.2-alpha. o Minor bugfixes (rust, backport from 0.3.4.7-rc): - Backport test_rust.sh from master. Fixes bug 26497; bugfix on 0.3.1.5-alpha. - Consistently use ../../.. as a fallback for $abs_top_srcdir in test_rust.sh. Fixes bug 27093; bugfix on 0.3.4.3-alpha. - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha. o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc): - Log a protocol warning when single onion services or Tor2web clients fail to authenticate direct connections to relays. Fixes bug 26924; bugfix on 0.2.9.1-alpha. o Minor bugfixes (testing, backport from 0.3.4.6-rc): - Disable core dumps in test_bt.sh, to avoid failures in "make distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha. o Minor bugfixes (testing, chutney, backport from 0.3.4.8): - When running make test-network-all, use the mixed+hs-v2 network. (A previous fix to chutney removed v3 onion services from the mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha. - Before running make test-network-all, delete old logs and test result files, to avoid spurious failures. Fixes bug 27295; bugfix on 0.2.7.3-rc. o Minor bugfixes (testing, openssl compatibility): - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha. o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc): - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha. o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc): - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug 27185; bugfix on 0.2.2.2-alpha. Changes in version 0.3.3.10 - 2018-09-10 Tor 0.3.3.10 backports numerous fixes from later versions of Tor. o Minor features (bug workaround, backport from 0.3.4.7-rc): - Compile correctly on systems that provide the C11 stdatomic.h header, but where C11 atomic functions don't actually compile. Closes ticket 26779; workaround for Debian issue 903709. o Minor features (compatibility, backport from 0.3.4.8): - Tell OpenSSL to maintain backward compatibility with previous RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these ciphers are disabled by default. Closes ticket 27344. o Minor features (continuous integration, backport from 0.3.4.7-rc): - Backport Travis rust distcheck to 0.3.3. Closes ticket 24629. - Enable macOS builds in our Travis CI configuration. Closes ticket 24629. - Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560. - Run asciidoc during Travis CI. Implements ticket 27087. - Use ccache in our Travis CI configuration. Closes ticket 26952. o Minor features (continuous integration, rust, backport from 0.3.4.7-rc): - Use cargo cache in our Travis CI configuration. Closes ticket 26952. o Minor features (controller, backport from 0.3.4.6-rc): - The control port now exposes the list of HTTPTunnelPorts and ExtOrPorts via GETINFO net/listeners/httptunnel and net/listeners/extor respectively. Closes ticket 26647. o Minor features (directory authorities, backport from 0.3.4.7-rc): - Authorities no longer vote to make the subprotocol version "LinkAuth=1" a requirement: it is unsupportable with NSS, and hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286. o Minor features (geoip): - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2 Country database. Closes ticket 27089. o Minor bugfixes (compilation, backport from 0.3.4.6-rc): - When compiling with --enable-openbsd-malloc or --enable-tcmalloc, tell the compiler not to include the system malloc implementation. Fixes bug 20424; bugfix on 0.2.0.20-rc. - Don't try to use a pragma to temporarily disable the -Wunused-const-variable warning if the compiler doesn't support it. Fixes bug 26785; bugfix on 0.3.2.11. o Minor bugfixes (compilation, backport from 0.3.4.7-rc): - Silence a spurious compiler warning on the GetAdaptersAddresses function pointer cast. This issue is already fixed by 26481 in 0.3.5 and later, by removing the lookup and cast. Fixes bug 27465; bugfix on 0.2.3.11-alpha. - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not supported, and always fails. Some compilers warn about the function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix on 0.2.2.23-alpha. o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc): - Don't link or search for pthreads when building for Windows, even if we are using build environment (like mingw) that provides a pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc. o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc): - Skip a pair of unreliable key generation tests on Windows, until the underlying issue in bug 26076 is resolved. Fixes bug 26830 and bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively. o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc): - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha. - Pass the module flags to distcheck configure, and log the flags before running configure. (Backported to 0.2.9 and later as a precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha. o Minor bugfixes (continuous integration, backport from 0.3.4.8): - When a Travis build fails, and showing a log fails, keep trying to show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc. - When we use echo in Travis, don't pass a --flag as the first argument. Fixes bug 27418; bugfix on 0.3.4.7-rc. o Minor bugfixes (directory authority, backport from 0.3.4.6-rc): - When voting for recommended versions, make sure that all of the versions are well-formed and parsable. Fixes bug 26485; bugfix on 0.1.1.6-alpha. o Minor bugfixes (in-process restart, backport from 0.3.4.7-rc): - Always call tor_free_all() when leaving tor_run_main(). When we did not, restarting tor in-process would cause an assertion failure. Fixes bug 26948; bugfix on 0.3.3.1-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc): - Fix a bug in our sandboxing rules for the openat() syscall. Previously, no openat() call would be permitted, which would break filesystem operations on recent glibc versions. Fixes bug 25440; bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto. o Minor bugfixes (logging, backport from 0.3.4.6-rc): - Improve the log message when connection initiators fail to authenticate direct connections to relays. Fixes bug 26927; bugfix on 0.3.0.1-alpha. o Minor bugfixes (onion services, backport from 0.3.4.7-rc): - Fix bug that causes services to not ever rotate their descriptors if they were getting SIGHUPed often. Fixes bug 26932; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion services, backport from 0.3.4.8): - Silence a spurious compiler warning in rend_client_send_introduction(). Fixes bug 27463; bugfix on 0.1.1.2-alpha. o Minor bugfixes (portability, backport from 0.3.4.6-rc): - Work around two different bugs in the OS X 10.10 and later SDKs that would prevent us from successfully targeting earlier versions of OS X. Fixes bug 26876; bugfix on 0.3.3.1-alpha. o Minor bugfixes (portability, backport from 0.3.4.7-rc): - Fix compilation of the unit tests on GNU/Hurd, which does not define PATH_MAX. Fixes bug 26873; bugfix on 0.3.3.1-alpha. Patch from "paulusASol". o Minor bugfixes (rust, backport from 0.3.4.7-rc): - Backport test_rust.sh from master. Fixes bug 26497; bugfix on 0.3.1.5-alpha. - Consistently use ../../.. as a fallback for $abs_top_srcdir in test_rust.sh. Fixes bug 27093; bugfix on 0.3.4.3-alpha. - Protover parsing was accepting the presence of whitespace in version strings, which the C implementation would choke on, e.g. "Desc=1\t,2". Fixes bug 27177; bugfix on 0.3.3.5-rc. - Protover parsing was ignoring a 2nd hyphen and everything after it, accepting entries like "Link=1-5-foo". Fixes bug 27164; bugfix on 0.3.3.1-alpha. - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha. - cd to ${abs_top_builddir}/src/rust before running cargo in src/test/test_rust.sh. This makes the working directory consistent between builds and tests. Fixes bug 26497; bugfix on 0.3.3.2-alpha. o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc): - Log a protocol warning when single onion services or Tor2web clients fail to authenticate direct connections to relays. Fixes bug 26924; bugfix on 0.2.9.1-alpha. o Minor bugfixes (testing, backport from 0.3.4.6-rc): - Disable core dumps in test_bt.sh, to avoid failures in "make distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha. o Minor bugfixes (testing, chutney, backport from 0.3.4.8): - When running make test-network-all, use the mixed+hs-v2 network. (A previous fix to chutney removed v3 onion services from the mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha. - Before running make test-network-all, delete old logs and test result files, to avoid spurious failures. Fixes bug 27295; bugfix on 0.2.7.3-rc. o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc): - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha. o Minor bugfixes (v3 onion services, backport from 0.3.4.6-rc): - Stop sending ed25519 link specifiers in v3 onion service introduce cells and descriptors, when the rendezvous or introduction point doesn't support ed25519 link authentication. Fixes bug 26627; bugfix on 0.3.2.4-alpha. o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc): - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug 27185; bugfix on 0.2.2.2-alpha. Changes in version 0.3.4.8 - 2018-09-10 Tor 0.3.4.8 is the first stable release in its series; it includes compilation and portability fixes. The Tor 0.3.4 series includes improvements for running Tor in low-power and embedded environments, which should help performance in general. We've begun work on better modularity, and included preliminary changes on the directory authority side to accommodate a new bandwidth measurement system. We've also integrated more continuous-integration systems into our development process, and made corresponding changes to Tor's testing infrastructure. Finally, we've continued to refine our anti-denial-of-service code. Below are the changes since 0.3.3.9. For a list of only the changes since 0.3.4.7-rc, see the ChangeLog file. o New system requirements: - Tor no longer tries to support old operating systems without mmap() or some local equivalent. Apparently, compilation on such systems has been broken for some time, without anybody noticing or complaining. Closes ticket 25398. o Major features (directory authority, modularization): - The directory authority subsystem has been modularized. The code is now located in src/or/dirauth/, and is compiled in by default. To disable the module, the configure option --disable-module-dirauth has been added. This module may be disabled by default in some future release. Closes ticket 25610. o Major features (main loop, CPU usage): - When Tor is disabled (via DisableNetwork or via hibernation), it no longer needs to run any per-second events. This change should make it easier for mobile applications to disable Tor while the device is sleeping, or Tor is not running. Closes ticket 26063. - Tor no longer enables all of its periodic events by default. Previously, Tor would enable all possible main loop events, regardless of whether it needed them. Furthermore, many of these events are now disabled when Tor is hibernating or DisableNetwork is set. This is a big step towards reducing client CPU usage by reducing the amount of wake-ups the daemon does. Closes tickets 25376 and 25762. - The bandwidth-limitation logic has been refactored so that bandwidth calculations are performed on-demand, rather than every TokenBucketRefillInterval milliseconds. This change should improve the granularity of our bandwidth calculations, and limit the number of times that the Tor process needs to wake up when it is idle. Closes ticket 25373. - Move responsibility for many operations from a once-per-second callback to a callback that is only scheduled as needed. Moving this functionality has allowed us to disable the callback when Tor's network is disabled. Once enough items are removed from our once-per-second callback, we can eliminate it entirely to conserve CPU when idle. The functionality removed includes: closing connections, circuits, and channels (ticket 25932); consensus voting (25937); flushing log callbacks (25951); honoring delayed SIGNEWNYM requests (25949); rescanning the consensus cache (25931); saving the state file to disk (25948); warning relay operators about unreachable ports (25952); and keeping track of Tor's uptime (26009). o Minor features (accounting): - When Tor becomes dormant, it now uses a scheduled event to wake up at the right time. Previously, we would use the per-second timer to check whether to wake up, but we no longer have any per-second timers enabled when the network is disabled. Closes ticket 26064. o Minor features (bug workaround): - Compile correctly on systems that provide the C11 stdatomic.h header, but where C11 atomic functions don't actually compile. Closes ticket 26779; workaround for Debian issue 903709. o Minor features (code quality): - Add optional spell-checking for the Tor codebase, using the "misspell" program. To use this feature, run "make check-typos". Closes ticket 25024. o Minor features (compatibility): - Tell OpenSSL to maintain backward compatibility with previous RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these ciphers are disabled by default. Closes ticket 27344. - Tor now detects versions of OpenSSL 1.1.0 and later compiled with the no-deprecated option, and builds correctly with them. Closes tickets 19429, 19981, and 25353. o Minor features (compilation): - When compiling with --enable-openbsd-malloc or --enable-tcmalloc, tell the compiler not to include the system malloc implementation. Fixes bug 20424; bugfix on 0.2.0.20-rc. - Don't try to use a pragma to temporarily disable the -Wunused-const-variable warning if the compiler doesn't support it. Fixes bug 26785; bugfix on 0.3.2.11. - When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372. o Minor features (compression, zstd): - When running with zstd, Tor now considers using advanced functions that the zstd maintainers have labeled as potentially unstable. To prevent breakage, Tor will only use this functionality when the runtime version of the zstd library matches the version with which Tor was compiled. Closes ticket 25162. o Minor features (configuration): - The "DownloadSchedule" options have been renamed to end with "DownloadInitialDelay". The old names are still allowed, but will produce a warning. Comma-separated lists are still permitted for these options, but all values after the first are ignored (as they have been since 0.2.9). Closes ticket 23354. o Minor features (continuous integration): - Log the compiler path and version during Appveyor builds. Implements ticket 27449. - Show config.log and test-suite.log after failed Appveyor builds. Also upload the zipped full logs as a build artifact. Implements ticket 27430. - Backport Travis rust distcheck to 0.3.3. Closes ticket 24629. - Enable macOS builds in our Travis CI configuration. Closes ticket 24629. - Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560. - Only post Appveyor IRC notifications when the build fails. Implements ticket 27275. - Run asciidoc during Travis CI. Implements ticket 27087. - Use ccache in our Travis CI configuration. Closes ticket 26952. - Add the necessary configuration files for continuous integration testing on Windows, via the Appveyor platform. Closes ticket 25549. Patches from Marcin Cieślak and Isis Lovecruft. o Minor features (continuous integration, rust): - Use cargo cache in our Travis CI configuration. Closes ticket 26952. o Minor features (control port): - Introduce GETINFO "current-time/{local,utc}" to return the local and UTC times respectively in ISO format. This helps a controller like Tor Browser detect a time-related error. Closes ticket 25511. Patch by Neel Chauhan. - Introduce new fields to the CIRC_BW event. There are two new fields in each of the read and written directions. The DELIVERED fields report the total valid data on the circuit, as measured by the payload sizes of verified and error-checked relay command cells. The OVERHEAD fields report the total unused bytes in each of these cells. Closes ticket 25903. o Minor features (controller): - The control port now exposes the list of HTTPTunnelPorts and ExtOrPorts via GETINFO net/listeners/httptunnel and net/listeners/extor respectively. Closes ticket 26647. o Minor features (directory authorities): - Stop warning about incomplete bw lines before the first complete bw line has been found, so that additional header lines can be ignored. Fixes bug 25960; bugfix on 0.2.2.1-alpha - Authorities no longer vote to make the subprotocol version "LinkAuth=1" a requirement: it is unsupportable with NSS, and hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286. o Minor features (directory authority): - Directory authorities now open their key-pinning files as O_SYNC, to limit their chances of accidentally writing partial lines. Closes ticket 23909. o Minor features (directory authority, forward compatibility): - Make the lines of the measured bandwidth file able to contain their entries in any order. Previously, the node_id entry needed to come first. Closes ticket 26004. o Minor features (entry guards): - Introduce a new torrc option NumPrimaryGuards for controlling the number of primary guards. Closes ticket 25843. o Minor features (geoip): - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2 Country database. Closes ticket 27089. o Minor features (performance): - Avoid a needless call to malloc() when processing an incoming relay cell. Closes ticket 24914. - Make our timing-wheel code run a tiny bit faster on 32-bit platforms, by preferring 32-bit math to 64-bit. Closes ticket 24688. - Avoid a needless malloc()/free() pair every time we handle an ntor handshake. Closes ticket 25150. o Minor features (Rust, portability): - Rust cross-compilation is now supported. Closes ticket 25895. o Minor features (testing): - Add a unit test for voting_schedule_get_start_of_next_interval(). Closes ticket 26014, and helps make unit test coverage more deterministic. - A new unittests module specifically for testing the functions in the (new-ish) bridges.c module has been created with new unittests, raising the code coverage percentages. Closes 25425. - We now have improved testing for addressmap_get_virtual_address() function. This should improve our test coverage, and make our test coverage more deterministic. Closes ticket 25993. o Minor features (timekeeping, circuit scheduling): - When keeping track of how busy each circuit have been recently on a given connection, use coarse-grained monotonic timers rather than gettimeofday(). This change should marginally increase accuracy and performance. Implements part of ticket 25927. o Minor features (unit tests): - Test complete bandwidth measurements files, and test that incomplete bandwidth lines only give warnings when the end of the header has not been detected. Fixes bug 25947; bugfix on 0.2.2.1-alpha o Minor bugfixes (bandwidth management): - Consider ourselves "low on write bandwidth" if we have exhausted our write bandwidth some time in the last second. This was the documented behavior before, but the actual behavior was to change this value every TokenBucketRefillInterval. Fixes bug 25828; bugfix on 0.2.3.5-alpha. o Minor bugfixes (C correctness): - Add a missing lock acquisition in the shutdown code of the control subsystem. Fixes bug 25675; bugfix on 0.2.7.3-rc. Found by Coverity; this is CID 1433643. o Minor bugfixes (code style): - Fixed multiple includes of transports.h in src/or/connection.c Fixes bug 25261; bugfix on 0.2.5.1-alpha. - Remove the unused variable n_possible from the function channel_get_for_extend(). Fixes bug 25645; bugfix on 0.2.4.4-alpha o Minor bugfixes (compilation): - Silence a spurious compiler warning on the GetAdaptersAddresses function pointer cast. This issue is already fixed by 26481 in 0.3.5 and later, by removing the lookup and cast. Fixes bug 27465; bugfix on 0.2.3.11-alpha. - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not supported, and always fails. Some compilers warn about the function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix on 0.2.2.23-alpha. - Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha. - Refrain from compiling unit testing related object files when --disable-unittests is set to configure script. Fixes bug 24891; bugfix on 0.2.5.1-alpha. - The --enable-fatal-warnings flag now affects Rust code as well. Closes ticket 26245. - Avoid a compiler warning when casting the return value of smartlist_len() to double with DEBUG_SMARTLIST enabled. Fixes bug 26283; bugfix on 0.2.4.10-alpha. o Minor bugfixes (compilation, windows): - Don't link or search for pthreads when building for Windows, even if we are using build environment (like mingw) that provides a pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc. o Minor bugfixes (continuous integration): - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha. - Skip a pair of unreliable key generation tests on Windows, until the underlying issue in bug 26076 is resolved. Fixes bug 26830 and bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively. o Minor bugfixes (control port): - Respond with more human-readable error messages to GETINFO exit- policy/* requests. Also, let controller know if an error is transient (response code 551) or not (response code 552). Fixes bug 25852; bugfix on 0.2.8.1-alpha. - Parse the "HSADDRESS=" parameter in HSPOST commands properly. Previously, it was misparsed and ignored. Fixes bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran". - Make CIRC_BW event reflect the total of all data sent on a circuit, including padding and dropped cells. Also fix a mis- counting bug when STREAM_BW events were enabled. Fixes bug 25400; bugfix on 0.2.5.2-alpha. o Minor bugfixes (correctness, flow control): - Upon receiving a stream-level SENDME cell, verify that our window has not grown too large. Fixes bug 26214; bugfix on svn r54 (pre-0.0.1). o Minor bugfixes (directory authority): - When voting for recommended versions, make sure that all of the versions are well-formed and parsable. Fixes bug 26485; bugfix on 0.1.1.6-alpha. o Minor bugfixes (directory client): - When unverified-consensus is verified, rename it to cached- consenus. Fixes bug 4187; bugfix on 0.2.0.3-alpha. - Fixed launching a certificate fetch always during the scheduled periodic consensus fetch by fetching only in those cases when consensus are waiting for certs. Fixes bug 24740; bugfix on 0.2.9.1-alpha. o Minor bugfixes (error reporting): - Improve tolerance for directory authorities with skewed clocks. Previously, an authority with a clock more than 60 seconds ahead could cause a client with a correct clock to warn that the client's clock was behind. Now the clocks of a majority of directory authorities have to be ahead of the client before this warning will occur. Fixes bug 25756; bugfix on 0.2.2.25-alpha. o Minor bugfixes (in-process restart): - Always call tor_free_all() when leaving tor_run_main(). When we did not, restarting tor in-process would cause an assertion failure. Fixes bug 26948; bugfix on 0.3.3.1-alpha. o Minor bugfixes (Linux seccomp2 sandbox): - Fix a bug in our sandboxing rules for the openat() syscall. Previously, no openat() call would be permitted, which would break filesystem operations on recent glibc versions. Fixes bug 25440; bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto. o Minor bugfixes (logging): - Improve the log message when connection initiators fail to authenticate direct connections to relays. Fixes bug 26927; bugfix on 0.3.0.1-alpha. o Minor bugfixes (onion services): - Silence a spurious compiler warning in rend_client_send_introduction(). Fixes bug 27463; bugfix on 0.1.1.2-alpha. - Fix bug that causes services to not ever rotate their descriptors if they were getting SIGHUPed often. Fixes bug 26932; bugfix on 0.3.2.1-alpha. - Recompute some consensus information after detecting a clock jump, or after transitioning from a non-live consensus to a live consensus. We do this to avoid having an outdated state, and miscalculating the index for next-generation onion services. Fixes bug 24977; bugfix on 0.3.2.1-alpha. o Minor bugfixes (portability): - Fix compilation of the unit tests on GNU/Hurd, which does not define PATH_MAX. Fixes bug 26873; bugfix on 0.3.3.1-alpha. Patch from "paulusASol". - Work around two different bugs in the OS X 10.10 and later SDKs that would prevent us from successfully targeting earlier versions of OS X. Fixes bug 26876; bugfix on 0.3.3.1-alpha. - Do not align mmap length, as it is not required by POSIX, and the getpagesize function is deprecated. Fixes bug 25399; bugfix on 0.1.1.23. o Minor bugfixes (portability, FreeBSD): - In have_enough_mem_for_dircache(), the variable DIRCACHE_MIN_MEM_MB does not stringify on FreeBSD, so we switch to tor_asprintf(). Fixes bug 20887; bugfix on 0.2.8.1-alpha. Patch by Neel Chauhan. o Minor bugfixes (relay statistics): - When a relay is collecting internal statistics about how many create cell requests it has seen of each type, accurately count the requests from relays that temporarily fall out of the consensus. (To be extra conservative, we were already ignoring requests from clients in our counts, and we continue ignoring them here.) Fixes bug 24910; bugfix on 0.2.4.17-rc. o Minor bugfixes (rust): - Backport test_rust.sh from master. Fixes bug 26497; bugfix on 0.3.1.5-alpha. - Protover parsing was accepting the presence of whitespace in version strings, which the C implementation would choke on, e.g. "Desc=1\t,2". Fixes bug 27177; bugfix on 0.3.3.5-rc. - Protover parsing was ignoring a 2nd hyphen and everything after it, accepting entries like "Link=1-5-foo". Fixes bug 27164; bugfix on 0.3.3.1-alpha. - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha. - cd to ${abs_top_builddir}/src/rust before running cargo in src/test/test_rust.sh. This makes the working directory consistent between builds and tests. Fixes bug 26497; bugfix on 0.3.3.2-alpha. o Minor bugfixes (single onion services, Tor2web): - Log a protocol warning when single onion services or Tor2web clients fail to authenticate direct connections to relays. Fixes bug 26924; bugfix on 0.2.9.1-alpha. o Minor bugfixes (test coverage tools): - Update our "cov-diff" script to handle output from the latest version of gcov, and to remove extraneous timestamp information from its output. Fixes bugs 26101 and 26102; bugfix on 0.2.5.1-alpha. o Minor bugfixes (testing): - Disable core dumps in test_bt.sh, to avoid failures in "make distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha. - When testing workqueue event-cancellation, make sure that we actually cancel an event, and that cancel each event with equal probability. (It was previously possible, though extremely unlikely, for our event-canceling test not to cancel any events.) Fixes bug 26008; bugfix on 0.2.6.3-alpha. - Repeat part of the test in test_client_pick_intro() a number of times, to give it consistent coverage. Fixes bug 25996; bugfix on 0.3.2.1-alpha. - Remove randomness from the hs_common/responsible_hsdirs test, so that it always takes the same path through the function it tests. Fixes bug 25997; bugfix on 0.3.2.1-alpha. - Change the behavior of the "channel/outbound" test so that it never causes a 10-second rollover for the EWMA circuitmux code. Previously, this behavior would happen randomly, and result in fluctuating test coverage. Fixes bug 25994; bugfix on 0.3.3.1-alpha. - Use X509_new() to allocate certificates that will be freed later with X509_free(). Previously, some parts of the unit tests had used tor_malloc_zero(), which is incorrect, and which caused test failures on Windows when they were built with extra hardening. Fixes bugs 25943 and 25944; bugfix on 0.2.8.1-alpha. Patch by Marcin Cieślak. - While running the circuit_timeout test, fix the PRNG to a deterministic AES stream, so that the test coverage from this test will itself be deterministic. Fixes bug 25995; bugfix on 0.2.2.2-alpha. o Minor bugfixes (testing, bootstrap): - When calculating bootstrap progress, check exit policies and the exit flag. Previously, Tor would only check the exit flag, which caused race conditions in small and fast networks like chutney. Fixes bug 27236; bugfix on 0.2.6.3-alpha. o Minor bugfixes (testing, chutney): - When running make test-network-all, use the mixed+hs-v2 network. (A previous fix to chutney removed v3 onion services from the mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha. - Before running make test-network-all, delete old logs and test result files, to avoid spurious failures. Fixes bug 27295; bugfix on 0.2.7.3-rc. o Minor bugfixes (testing, openssl compatibility): - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha. o Minor bugfixes (v3 onion services): - Stop sending ed25519 link specifiers in v3 onion service introduce cells and descriptors, when the rendezvous or introduction point doesn't support ed25519 link authentication. Fixes bug 26627; bugfix on 0.3.2.4-alpha. o Minor bugfixes (vanguards): - Allow the last hop in a vanguard circuit to be the same as our first, to prevent the adversary from influencing guard node choice by choice of last hop. Also prevent the creation of A - B - A paths, or A - A paths, which are forbidden by relays. Fixes bug 25870; bugfix on 0.3.3.1-alpha. o Minor bugfixes (Windows, compilation): - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug 27185; bugfix on 0.2.2.2-alpha. o Code simplification and refactoring: - Remove duplicate code in parse_{c,s}method_line and bootstrap their functionalities into a single function. Fixes bug 6236; bugfix on 0.2.3.6-alpha. - We remove the PortForwarding and PortForwardingHelper options, related functions, and the port_forwarding tests. These options were used by the now-deprecated Vidalia to help ordinary users become Tor relays or bridges. Closes ticket 25409. Patch by Neel Chauhan. - In order to make the OR and dir checking function in router.c less confusing we renamed some functions and consider_testing_reachability() has been split into router_should_check_reachability() and router_do_reachability_checks(). Also we improved the documentation in some functions. Closes ticket 18918. - Initial work to isolate Libevent usage to a handful of modules in our codebase, to simplify our call structure, and so that we can more easily change event loops in the future if needed. Closes ticket 23750. - Introduce a function to call getsockname() and return tor_addr_t, to save a little complexity throughout the codebase. Closes ticket 18105. - Make hsdir_index in node_t a hsdir_index_t rather than a pointer as hsdir_index is always present. Also, we move hsdir_index_t into or.h. Closes ticket 23094. Patch by Neel Chauhan. - Merge functions used for describing nodes and suppress the functions that do not allocate memory for the output buffer string. NODE_DESC_BUF_LEN constant and format_node_description() function cannot be used externally from router.c module anymore. Closes ticket 25432. Patch by valentecaio. - Our main loop has been simplified so that all important operations happen inside events. Previously, some operations had to happen outside the event loop, to prevent infinite sequences of event activations. Closes ticket 25374. - Put a SHA1 public key digest in hs_service_intro_point_t, and use it in register_intro_circ() and service_intro_point_new(). This prevents the digest from being re-calculated each time. Closes ticket 23107. Patch by Neel Chauhan. - Refactor token-bucket implementations to use a common backend. Closes ticket 25766. - Remove extern declaration of stats_n_seconds_working variable from main, protecting its accesses with get_uptime() and reset_uptime() functions. Closes ticket 25081, patch by “valentecaio”. - Remove our previous logic for "cached gettimeofday()" -- our coarse monotonic timers are fast enough for this purpose, and far less error-prone. Implements part of ticket 25927. - Remove the return value for fascist_firewall_choose_address_base(), and sister functions such as fascist_firewall_choose_address_node() and fascist_firewall_choose_address_rs(). Also, while we're here, initialize the ap argument as leaving it uninitialized can pose a security hazard. Closes ticket 24734. Patch by Neel Chauhan. - Rename two fields of connection_t struct. timestamp_lastwritten is renamed to timestamp_last_write_allowed and timestamp_lastread is renamed to timestamp_last_read_allowed. Closes ticket 24714, patch by "valentecaio". - Since Tor requires C99, remove our old workaround code for libc implementations where free(NULL) doesn't work. Closes ticket 24484. - Use our standard rate-limiting code to deal with excessive libevent failures, rather than the hand-rolled logic we had before. Closes ticket 26016. - We remove the return value of node_get_prim_orport() and node_get_prim_dirport(), and introduce node_get_prim_orport() in node_ipv6_or_preferred() and node_ipv6_dir_preferred() in order to check for a null address. Closes ticket 23873. Patch by Neel Chauhan. - We switch to should_record_bridge_info() in geoip_note_client_seen() and options_need_geoip_info() instead of accessing the configuration values directly. Fixes bug 25290; bugfix on 0.2.1.6-alpha. Patch by Neel Chauhan. o Deprecated features: - As we are not recommending 0.2.5 anymore, we require relays that once had an ed25519 key associated with their RSA key to always have that key, instead of allowing them to drop back to a version that didn't support ed25519. This means they need to use a new RSA key if they want to downgrade to an older version of tor without ed25519. Closes ticket 20522. o Removed features: - Directory authorities will no longer support voting according to any consensus method before consensus method 25. This keeps authorities compatible with all authorities running 0.2.9.8 and later, and does not break any clients or relays. Implements ticket 24378 and proposal 290. - The PortForwarding and PortForwardingHelper features have been removed. The reasoning is, given that implementations of NAT traversal protocols within common consumer grade routers are frequently buggy, and that the target audience for a NAT punching feature is a perhaps less-technically-inclined relay operator, when the helper fails to setup traversal the problems are usually deep, ugly, and very router specific, making them horrendously impossible for technical support to reliable assist with, and thus resulting in frustration all around. Unfortunately, relay operators who would like to run relays behind NATs will need to become more familiar with the port forwarding configurations on their local router. Closes 25409. - The TestingEnableTbEmptyEvent option has been removed. It was used in testing simulations to measure how often connection buckets were emptied, in order to improve our scheduling, but it has not been actively used in years. Closes ticket 25760. - The old "round-robin" circuit multiplexer (circuitmux) implementation has been removed, along with a fairly large set of code that existed to support it. It has not been the default circuitmux since we introduced the "EWMA" circuitmux in 0.2.4.x, but it still required an unreasonable amount of memory and CPU. Closes ticket 25268. Changes in version 0.3.3.9 - 2018-07-13 Tor 0.3.3.9 moves to a new bridge authority, meaning people running bridge relays should upgrade. o Directory authority changes: - The "Bifroest" bridge authority has been retired; the new bridge authority is "Serge", and it is operated by George from the TorBSD project. Closes ticket 26771. Changes in version 0.3.2.11 - 2018-07-13 Tor 0.3.2.11 moves to a new bridge authority, meaning people running bridge relays should upgrade. We also take this opportunity to backport other minor fixes. o Directory authority changes: - The "Bifroest" bridge authority has been retired; the new bridge authority is "Serge", and it is operated by George from the TorBSD project. Closes ticket 26771. o Directory authority changes (backport from 0.3.3.7): - Add an IPv6 address for the "dannenberg" directory authority. Closes ticket 26343. o Major bugfixes (directory authorities, backport from 0.3.4.1-alpha): - When directory authorities read a zero-byte bandwidth file, they would previously log a warning with the contents of an uninitialised buffer. They now log a warning about the empty file instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha. o Major bugfixes (onion service, backport from 0.3.4.1-alpha): - Correctly detect when onion services get disabled after HUP. Fixes bug 25761; bugfix on 0.3.2.1. o Minor features (sandbox, backport from 0.3.3.4-alpha): - Explicitly permit the poll() system call when the Linux seccomp2-based sandbox is enabled: apparently, some versions of libc use poll() when calling getpwnam(). Closes ticket 25313. o Minor feature (continuous integration, backport from 0.3.3.5-rc): - Update the Travis CI configuration to use the stable Rust channel, now that we have decided to require that. Closes ticket 25714. o Minor features (continuous integration, backport from 0.3.4.1-alpha): - Our .travis.yml configuration now includes support for testing the results of "make distcheck". (It's not uncommon for "make check" to pass but "make distcheck" to fail.) Closes ticket 25814. - Our Travis CI configuration now integrates with the Coveralls coverage analysis tool. Closes ticket 25818. o Minor features (relay, diagnostic, backport from 0.3.4.3-alpha): - Add several checks to detect whether Tor relays are uploading their descriptors without specifying why they regenerated them. Diagnostic for ticket 25686. o Minor features (compilation, backport from 0.3.4.4-rc): - When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372. o Minor features (geoip): - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674. o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha): - Upon receiving a malformed connected cell, stop processing the cell immediately. Previously we would mark the connection for close, but continue processing the cell as if the connection were open. Fixes bug 26072; bugfix on 0.2.4.7-alpha. o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha): - Allow the nanosleep() system call, which glibc uses to implement sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha. o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc): - When running the hs_ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.3.1.1-alpha. - When running the ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.2.5.5-alpha. o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha): - Work around a change in OpenSSL 1.1.1 where return values that would previously indicate "no password" now indicate an empty password. Without this workaround, Tor instances running with OpenSSL 1.1.1 would accept descriptors that other Tor instances would reject. Fixes bug 26116; bugfix on 0.2.5.16. o Minor bugfixes (documentation, backport from 0.3.3.5-rc): - Document that the PerConnBW{Rate,Burst} options will fall back to their corresponding consensus parameters only if those parameters are set. Previously we had claimed that these values would always be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha. o Minor bugfixes (compilation, backport from 0.3.4.4-rc): - Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha. o Minor bugfixes (client, backport from 0.3.4.1-alpha): - Don't consider Tor running as a client if the ControlPort is open, but no actual client ports are open. Fixes bug 26062; bugfix on 0.2.9.4-alpha. o Minor bugfixes (hardening, backport from 0.3.4.2-alpha): - Prevent a possible out-of-bounds smartlist read in protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha. o Minor bugfixes (C correctness, backport from 0.3.3.4-alpha): - Fix a very unlikely (impossible, we believe) null pointer dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by Coverity; this is CID 1430932. o Minor bugfixes (onion service, backport from 0.3.4.1-alpha): - Fix a memory leak when a v3 onion service is configured and gets a SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha. - When parsing the descriptor signature, look for the token plus an extra white-space at the end. This is more correct but also will allow us to support new fields that might start with "signature". Fixes bug 26069; bugfix on 0.3.0.1-alpha. o Minor bugfixes (relay, backport from 0.3.4.3-alpha): - Relays now correctly block attempts to re-extend to the previous relay by Ed25519 identity. Previously they would warn in this case, but not actually reject the attempt. Fixes bug 26158; bugfix on 0.3.0.1-alpha. o Minor bugfixes (relay, crash, backport from 0.3.4.1-alpha): - Avoid a crash when running with DirPort set but ORPort turned off. Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha. o Minor bugfixes (compilation, backport from 0.3.4.2-alpha): - Silence unused-const-variable warnings in zstd.h with some GCC versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha. o Minor bugfixes (testing, backport from 0.3.3.4-alpha): - Avoid intermittent test failures due to a test that had relied on onion service introduction point creation finishing within 5 seconds of real clock time. Fixes bug 25450; bugfix on 0.3.1.3-alpha. o Minor bugfixes (compilation, backport from 0.3.3.4-alpha): - Fix a C99 compliance issue in our configuration script that caused compilation issues when compiling Tor with certain versions of xtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha. o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc): - Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions. o Code simplification and refactoring (backport from 0.3.3.5-rc): - Move the list of default directory authorities to its own file. Closes ticket 24854. Patch by "beastr0". Changes in version 0.2.9.16 - 2018-07-13 Tor 0.2.9.16 moves to a new bridge authority, meaning people running bridge relays should upgrade. We also take this opportunity to backport other minor fixes. o Directory authority changes: - The "Bifroest" bridge authority has been retired; the new bridge authority is "Serge", and it is operated by George from the TorBSD project. Closes ticket 26771. o Directory authority changes (backport from 0.3.3.7): - Add an IPv6 address for the "dannenberg" directory authority. Closes ticket 26343. o Major bugfixes (directory authorities, backport from 0.3.4.1-alpha): - When directory authorities read a zero-byte bandwidth file, they would previously log a warning with the contents of an uninitialised buffer. They now log a warning about the empty file instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha. o Minor features (sandbox, backport from 0.3.3.4-alpha): - Explicitly permit the poll() system call when the Linux seccomp2-based sandbox is enabled: apparently, some versions of libc use poll() when calling getpwnam(). Closes ticket 25313. o Minor features (continuous integration, backport from 0.3.4.1-alpha): - Our .travis.yml configuration now includes support for testing the results of "make distcheck". (It's not uncommon for "make check" to pass but "make distcheck" to fail.) Closes ticket 25814. - Our Travis CI configuration now integrates with the Coveralls coverage analysis tool. Closes ticket 25818. o Minor features (compilation, backport from 0.3.4.4-rc): - When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372. o Minor features (geoip): - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674. o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha): - Upon receiving a malformed connected cell, stop processing the cell immediately. Previously we would mark the connection for close, but continue processing the cell as if the connection were open. Fixes bug 26072; bugfix on 0.2.4.7-alpha. o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha): - Allow the nanosleep() system call, which glibc uses to implement sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha. o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc): - When running the ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.2.5.5-alpha. o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha): - Work around a change in OpenSSL 1.1.1 where return values that would previously indicate "no password" now indicate an empty password. Without this workaround, Tor instances running with OpenSSL 1.1.1 would accept descriptors that other Tor instances would reject. Fixes bug 26116; bugfix on 0.2.5.16. o Minor bugfixes (compilation, backport from 0.3.4.4-rc): - Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha. o Minor bugfixes (client, backport from 0.3.4.1-alpha): - Don't consider Tor running as a client if the ControlPort is open, but no actual client ports are open. Fixes bug 26062; bugfix on 0.2.9.4-alpha. o Minor bugfixes (hardening, backport from 0.3.4.2-alpha): - Prevent a possible out-of-bounds smartlist read in protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha. o Minor bugfixes (C correctness, backport from 0.3.3.4-alpha): - Fix a very unlikely (impossible, we believe) null pointer dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by Coverity; this is CID 1430932. o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc): - Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions. o Code simplification and refactoring (backport from 0.3.3.5-rc): - Move the list of default directory authorities to its own file. Closes ticket 24854. Patch by "beastr0". Changes in version 0.3.3.8 - 2018-07-09 Tor 0.3.3.8 backports several changes from the 0.3.4.x series, including fixes for a memory leak affecting directory authorities. o Major bugfixes (directory authority, backport from 0.3.4.3-alpha): - Stop leaking memory on directory authorities when planning to vote. This bug was crashing authorities by exhausting their memory. Fixes bug 26435; bugfix on 0.3.3.6. o Major bugfixes (rust, testing, backport from 0.3.4.3-alpha): - Make sure that failing tests in Rust will actually cause the build to fail: previously, they were ignored. Fixes bug 26258; bugfix on 0.3.3.4-alpha. o Minor features (compilation, backport from 0.3.4.4-rc): - When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372. o Minor features (geoip): - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674. o Minor features (relay, diagnostic, backport from 0.3.4.3-alpha): - Add several checks to detect whether Tor relays are uploading their descriptors without specifying why they regenerated them. Diagnostic for ticket 25686. o Minor bugfixes (circuit path selection, backport from 0.3.4.1-alpha): - Don't count path selection failures as circuit build failures. This change should eliminate cases where Tor blames its guard or the network for situations like insufficient microdescriptors and/or overly restrictive torrc settings. Fixes bug 25705; bugfix on 0.3.3.1-alpha. o Minor bugfixes (compilation, backport from 0.3.4.4-rc): - Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha. o Minor bugfixes (control port, backport from 0.3.4.4-rc): - Handle the HSADDRESS= argument to the HSPOST command properly. (Previously, this argument was misparsed and thus ignored.) Fixes bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran". o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc): - Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions. o Minor bugfixes (relay, backport from 0.3.4.3-alpha): - Relays now correctly block attempts to re-extend to the previous relay by Ed25519 identity. Previously they would warn in this case, but not actually reject the attempt. Fixes bug 26158; bugfix on 0.3.0.1-alpha. o Minor bugfixes (restart-in-process, backport from 0.3.4.1-alpha): - When shutting down, Tor now clears all the flags in the control.c module. This should prevent a bug where authentication cookies are not generated on restart. Fixes bug 25512; bugfix on 0.3.3.1-alpha. o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc): - When running the hs_ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.3.1.1-alpha. - When running the ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.2.5.5-alpha. Changes in version 0.3.3.7 - 2018-06-12 Tor 0.3.3.7 backports several changes from the 0.3.4.x series, including fixes for bugs affecting compatibility and stability. o Directory authority changes: - Add an IPv6 address for the "dannenberg" directory authority. Closes ticket 26343. o Minor features (geoip): - Update geoip and geoip6 to the June 7 2018 Maxmind GeoLite2 Country database. Closes ticket 26351. o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha): - Work around a change in OpenSSL 1.1.1 where return values that would previously indicate "no password" now indicate an empty password. Without this workaround, Tor instances running with OpenSSL 1.1.1 would accept descriptors that other Tor instances would reject. Fixes bug 26116; bugfix on 0.2.5.16. o Minor bugfixes (compilation, backport from 0.3.4.2-alpha): - Silence unused-const-variable warnings in zstd.h with some GCC versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha. o Minor bugfixes (controller, backport from 0.3.4.2-alpha): - Improve accuracy of the BUILDTIMEOUT_SET control port event's TIMEOUT_RATE and CLOSE_RATE fields. (We were previously miscounting the total number of circuits for these field values.) Fixes bug 26121; bugfix on 0.3.3.1-alpha. o Minor bugfixes (hardening, backport from 0.3.4.2-alpha): - Prevent a possible out-of-bounds smartlist read in protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha. o Minor bugfixes (path selection, backport from 0.3.4.1-alpha): - Only select relays when they have the descriptors we prefer to use for them. This change fixes a bug where we could select a relay because it had _some_ descriptor, but reject it later with a nonfatal assertion error because it didn't have the exact one we wanted. Fixes bugs 25691 and 25692; bugfix on 0.3.3.4-alpha. Changes in version 0.3.3.6 - 2018-05-22 Tor 0.3.3.6 is the first stable release in the 0.3.3 series. It backports several important fixes from the 0.3.4.1-alpha. The Tor 0.3.3 series includes controller support and other improvements for v3 onion services, official support for embedding Tor within other applications, and our first non-trivial module written in the Rust programming language. (Rust is still not enabled by default when building Tor.) And as usual, there are numerous other smaller bugfixes, features, and improvements. Below are the changes since 0.3.2.10. For a list of only the changes since 0.3.3.5-rc, see the ChangeLog file. o New system requirements: - When built with Rust, Tor now depends on version 0.2.39 of the libc crate. Closes tickets 25310 and 25664. o Major features (embedding): - There is now a documented stable API for programs that need to embed Tor. See tor_api.h for full documentation and known bugs. Closes ticket 23684. - Tor now has support for restarting in the same process. Controllers that run Tor using the "tor_api.h" interface can now restart Tor after Tor has exited. This support is incomplete, however: we fixed crash bugs that prevented it from working at all, but many bugs probably remain, including a possibility of security issues. Implements ticket 24581. o Major features (IPv6, directory documents): - Add consensus method 27, which adds IPv6 ORPorts to the microdesc consensus. This information makes it easier for IPv6 clients to bootstrap and choose reachable entry guards. Implements ticket 23826. - Add consensus method 28, which removes IPv6 ORPorts from microdescriptors. Now that the consensus contains IPv6 ORPorts, they are redundant in microdescs. This change will be used by Tor clients on 0.2.8.x and later. (That is to say, with all Tor clients that have IPv6 bootstrap and guard support.) Implements ticket 23828. - Expand the documentation for AuthDirHasIPv6Connectivity when it is set by different numbers of authorities. Fixes 23870 on 0.2.4.1-alpha. o Major features (onion service v3, control port): - The control port now supports commands and events for v3 onion services. It is now possible to create ephemeral v3 services using ADD_ONION. Additionally, several events (HS_DESC, HS_DESC_CONTENT, CIRC and CIRC_MINOR) and commands (GETINFO, HSPOST, ADD_ONION and DEL_ONION) have been extended to support v3 onion services. Closes ticket 20699; implements proposal 284. o Major features (onion services): - Provide torrc options to pin the second and third hops of onion service circuits to a list of nodes. The option HSLayer2Guards pins the second hop, and the option HSLayer3Guards pins the third hop. These options are for use in conjunction with experiments with "vanguards" for preventing guard enumeration attacks. Closes ticket 13837. - When v3 onion service clients send introduce cells, they now include the IPv6 address of the rendezvous point, if it has one. Current v3 onion services running 0.3.2 ignore IPv6 addresses, but in future Tor versions, IPv6-only v3 single onion services will be able to use IPv6 addresses to connect directly to the rendezvous point. Closes ticket 23577. Patch by Neel Chauhan. o Major features (relay): - Implement an option, ReducedExitPolicy, to allow an Tor exit relay operator to use a more reasonable ("reduced") exit policy, rather than the default one. If you want to run an exit node without thinking too hard about which ports to allow, this one is for you. Closes ticket 13605. Patch from Neel Chauhan. o Major features (rust, portability, experimental): - Tor now ships with an optional implementation of one of its smaller modules (protover.c) in the Rust programming language. To try it out, install a Rust build environment, and configure Tor with "--enable-rust --enable-cargo-online-mode". This should not cause any user-visible changes, but should help us gain more experience with Rust, and plan future Rust integration work. Implementation by Chelsea Komlo. Closes ticket 22840. o Major bugfixes (directory authorities, security, backport from 0.3.4.1-alpha): - When directory authorities read a zero-byte bandwidth file, they would previously log a warning with the contents of an uninitialised buffer. They now log a warning about the empty file instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha. o Major bugfixes (security, directory authority, denial-of-service): - Fix a bug that could have allowed an attacker to force a directory authority to use up all its RAM by passing it a maliciously crafted protocol versions string. Fixes bug 25517; bugfix on 0.2.9.4-alpha. This issue is also tracked as TROVE-2018-005. o Major bugfixes (crash, backport from 0.3.4.1-alpha): - Avoid a rare assertion failure in the circuit build timeout code if we fail to allow any circuits to actually complete. Fixes bug 25733; bugfix on 0.2.2.2-alpha. o Major bugfixes (netflow padding): - Stop adding unneeded channel padding right after we finish flushing to a connection that has been trying to flush for many seconds. Instead, treat all partial or complete flushes as activity on the channel, which will defer the time until we need to add padding. This fix should resolve confusing and scary log messages like "Channel padding timeout scheduled 221453ms in the past." Fixes bug 22212; bugfix on 0.3.1.1-alpha. o Major bugfixes (networking): - Tor will no longer reject IPv6 address strings from Tor Browser when they are passed as hostnames in SOCKS5 requests. Fixes bug 25036, bugfix on Tor 0.3.1.2. o Major bugfixes (onion service, backport from 0.3.4.1-alpha): - Correctly detect when onion services get disabled after HUP. Fixes bug 25761; bugfix on 0.3.2.1. o Major bugfixes (performance, load balancing): - Directory authorities no longer vote in favor of the Guard flag for relays without directory support. Starting in Tor 0.3.0.1-alpha, clients have been avoiding using such relays in the Guard position, leading to increasingly broken load balancing for the 5%-or-so of Guards that don't advertise directory support. Fixes bug 22310; bugfix on 0.3.0.6. o Major bugfixes (relay): - If we have failed to connect to a relay and received a connection refused, timeout, or similar error (at the TCP level), do not try that same address/port again for 60 seconds after the failure has occurred. Fixes bug 24767; bugfix on 0.0.6. o Major bugfixes (relay, denial of service, backport from 0.3.4.1-alpha): - Impose a limit on circuit cell queue size. The limit can be controlled by a consensus parameter. Fixes bug 25226; bugfix on 0.2.4.14-alpha. o Minor features (cleanup): - Tor now deletes the CookieAuthFile and ExtORPortCookieAuthFile when it stops. Closes ticket 23271. o Minor features (compatibility, backport from 0.3.4.1-alpha): - Avoid some compilation warnings with recent versions of LibreSSL. Closes ticket 26006. o Minor features (config options): - Change the way the default value for MaxMemInQueues is calculated. We now use 40% of the hardware RAM if the system has 8 GB RAM or more. Otherwise we use the former value of 75%. Closes ticket 24782. o Minor features (continuous integration): - Update the Travis CI configuration to use the stable Rust channel, now that we have decided to require that. Closes ticket 25714. o Minor features (continuous integration, backport from 0.3.4.1-alpha): - Our .travis.yml configuration now includes support for testing the results of "make distcheck". (It's not uncommon for "make check" to pass but "make distcheck" to fail.) Closes ticket 25814. - Our Travis CI configuration now integrates with the Coveralls coverage analysis tool. Closes ticket 25818. o Minor features (defensive programming): - Most of the functions in Tor that free objects have been replaced with macros that free the objects and set the corresponding pointers to NULL. This change should help prevent a large class of dangling pointer bugs. Closes ticket 24337. - Where possible, the tor_free() macro now only evaluates its input once. Part of ticket 24337. - Check that microdesc ed25519 ids are non-zero in node_get_ed25519_id() before returning them. Implements ticket 24001, patch by "aruna1234". o Minor features (directory authority): - When directory authorities are unable to add signatures to a pending consensus, log the reason why. Closes ticket 24849. o Minor features (embedding): - Tor can now start with a preauthenticated control connection created by the process that launched it. This feature is meant for use by programs that want to launch and manage a Tor process without allowing other programs to manage it as well. For more information, see the __OwningControllerFD option documented in control-spec.txt. Closes ticket 23900. - On most errors that would cause Tor to exit, it now tries to return from the tor_main() function, rather than calling the system exit() function. Most users won't notice a difference here, but it should be significant for programs that run Tor inside a separate thread: they should now be able to survive Tor's exit conditions rather than having Tor shut down the entire process. Closes ticket 23848. - Applications that want to embed Tor can now tell Tor not to register any of its own POSIX signal handlers, using the __DisableSignalHandlers option. Closes ticket 24588. o Minor features (fallback directory list): - Avoid selecting fallbacks that change their IP addresses too often. Select more fallbacks by ignoring the Guard flag, and allowing lower cutoffs for the Running and V2Dir flags. Also allow a lower bandwidth, and a higher number of fallbacks per operator (5% of the list). Implements ticket 24785. - Update the fallback whitelist and blacklist based on opt-ins and relay changes. Closes tickets 22321, 24678, 22527, 24135, and 24695. o Minor features (fallback directory mirror configuration): - Add a nickname to each fallback in a C comment. This makes it easier for operators to find their relays, and allows stem to use nicknames to identify fallbacks. Implements ticket 24600. - Add a type and version header to the fallback directory mirror file. Also add a delimiter to the end of each fallback entry. This helps external parsers like stem and Relay Search. Implements ticket 24725. - Add an extrainfo cache flag for each fallback in a C comment. This allows stem to use fallbacks to fetch extra-info documents, rather than using authorities. Implements ticket 22759. - Add the generateFallbackDirLine.py script for automatically generating fallback directory mirror lines from relay fingerprints. No more typos! Add the lookupFallbackDirContact.py script for automatically looking up operator contact info from relay fingerprints. Implements ticket 24706, patch by teor and atagar. - Reject any fallback directory mirror that serves an expired consensus. Implements ticket 20942, patch by "minik". - Remove commas and equals signs from external string inputs to the fallback list. This avoids format confusion attacks. Implements ticket 24726. - Remove the "weight=10" line from fallback directory mirror entries. Ticket 24681 will maintain the current fallback weights by changing Tor's default fallback weight to 10. Implements ticket 24679. - Stop logging excessive information about fallback netblocks. Implements ticket 24791. o Minor features (forward-compatibility): - If a relay supports some link authentication protocol that we do not recognize, then include that relay's ed25519 key when telling other relays to extend to it. Previously, we treated future versions as if they were too old to support ed25519 link authentication. Closes ticket 20895. o Minor features (geoip): - Update geoip and geoip6 to the May 1 2018 Maxmind GeoLite2 Country database. Closes ticket 26104. o Minor features (heartbeat): - Add onion service information to our heartbeat logs, displaying stats about the activity of configured onion services. Closes ticket 24896. o Minor features (instrumentation, development): - Add the MainloopStats option to allow developers to get instrumentation information from the main event loop via the heartbeat messages. We hope to use this to improve Tor's behavior when it's trying to sleep. Closes ticket 24605. o Minor features (IPv6): - Make IPv6-only clients wait for microdescs for relays, even if we were previously using descriptors (or were using them as a bridge) and have a cached descriptor for them. Implements ticket 23827. - When a consensus has IPv6 ORPorts, make IPv6-only clients use them, rather than waiting to download microdescriptors. Implements ticket 23827. o Minor features (log messages): - Improve log message in the out-of-memory handler to include information about memory usage from the different compression backends. Closes ticket 25372. - Improve a warning message that happens when we fail to re-parse an old router because of an expired certificate. Closes ticket 20020. - Make the log more quantitative when we hit MaxMemInQueues threshold exposing some values. Closes ticket 24501. o Minor features (logging): - Clarify the log messages produced when getrandom() or a related entropy-generation mechanism gives an error. Closes ticket 25120. - Added support for the Android logging subsystem. Closes ticket 24362. o Minor features (performance): - Support predictive circuit building for onion service circuits with multiple layers of guards. Closes ticket 23101. - Use stdatomic.h where available, rather than mutexes, to implement atomic_counter_t. Closes ticket 23953. o Minor features (performance, 32-bit): - Improve performance on 32-bit systems by avoiding 64-bit division when calculating the timestamp in milliseconds for channel padding computations. Implements ticket 24613. - Improve performance on 32-bit systems by avoiding 64-bit division when timestamping cells and buffer chunks for OOM calculations. Implements ticket 24374. o Minor features (performance, OSX, iOS): - Use the mach_approximate_time() function (when available) to implement coarse monotonic time. Having a coarse time function should avoid a large number of system calls, and improve performance slightly, especially under load. Closes ticket 24427. o Minor features (performance, windows): - Improve performance on Windows Vista and Windows 7 by adjusting TCP send window size according to the recommendation from SIO_IDEAL_SEND_BACKLOG_QUERY. Closes ticket 22798. Patch from Vort. o Minor features (sandbox): - Explicitly permit the poll() system call when the Linux seccomp2-based sandbox is enabled: apparently, some versions of libc use poll() when calling getpwnam(). Closes ticket 25313. o Minor features (storage, configuration): - Users can store cached directory documents somewhere other than the DataDirectory by using the CacheDirectory option. Similarly, the storage location for relay's keys can be overridden with the KeyDirectory option. Closes ticket 22703. o Minor features (testing): - Add a "make test-rust" target to run the rust tests only. Closes ticket 25071. o Minor features (testing, debugging, embedding): - For development purposes, Tor now has a mode in which it runs for a few seconds, then stops, and starts again without exiting the process. This mode is meant to help us debug various issues with ticket 23847. To use this feature, compile with --enable-restart-debugging, and set the TOR_DEBUG_RESTART environment variable. This is expected to crash a lot, and is really meant for developers only. It will likely be removed in a future release. Implements ticket 24583. o Minor bugfixes (build, rust): - Fix output of autoconf checks to display success messages for Rust dependencies and a suitable rustc compiler version. Fixes bug 24612; bugfix on 0.3.1.3-alpha. - Don't pass the --quiet option to cargo: it seems to suppress some errors, which is not what we want to do when building. Fixes bug 24518; bugfix on 0.3.1.7. - Build correctly when building from outside Tor's source tree with the TOR_RUST_DEPENDENCIES option set. Fixes bug 22768; bugfix on 0.3.1.7. o Minor bugfixes (C correctness): - Fix a very unlikely (impossible, we believe) null pointer dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by Coverity; this is CID 1430932. o Minor bugfixes (channel, client): - Better identify client connection when reporting to the geoip client cache. Fixes bug 24904; bugfix on 0.3.1.7. o Minor bugfixes (circuit, cannibalization): - Don't cannibalize preemptively-built circuits if we no longer recognize their first hop. This situation can happen if our Guard relay went off the consensus after the circuit was created. Fixes bug 24469; bugfix on 0.0.6. o Minor bugfixes (client, backport from 0.3.4.1-alpha): - Don't consider Tor running as a client if the ControlPort is open, but no actual client ports are open. Fixes bug 26062; bugfix on 0.2.9.4-alpha. o Minor bugfixes (compilation): - Fix a C99 compliance issue in our configuration script that caused compilation issues when compiling Tor with certain versions of xtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha. o Minor bugfixes (controller): - Restore the correct operation of the RESOLVE command, which had been broken since we added the ability to enable/disable DNS on specific listener ports. Fixes bug 25617; bugfix on 0.2.9.3-alpha. - Avoid a (nonfatal) assertion failure when extending a one-hop circuit from the controller to become a multihop circuit. Fixes bug 24903; bugfix on 0.2.5.2-alpha. o Minor bugfixes (correctness): - Remove a nonworking, unnecessary check to see whether a circuit hop's identity digest was set when the circuit failed. Fixes bug 24927; bugfix on 0.2.4.4-alpha. o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha): - Upon receiving a malformed connected cell, stop processing the cell immediately. Previously we would mark the connection for close, but continue processing the cell as if the connection were open. Fixes bug 26072; bugfix on 0.2.4.7-alpha. o Minor bugfixes (directory authorities, IPv6): - When creating a routerstatus (vote) from a routerinfo (descriptor), set the IPv6 address to the unspecified IPv6 address, and explicitly initialize the port to zero. Fixes bug 24488; bugfix on 0.2.4.1-alpha. o Minor bugfixes (documentation): - Document that the PerConnBW{Rate,Burst} options will fall back to their corresponding consensus parameters only if those parameters are set. Previously we had claimed that these values would always be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha. o Minor bugfixes (documentation, backport from 0.3.4.1-alpha): - Stop saying in the manual that clients cache ipv4 dns answers from exit relays. We haven't used them since 0.2.6.3-alpha, and in ticket 24050 we stopped even caching them as of 0.3.2.6-alpha, but we forgot to say so in the man page. Fixes bug 26052; bugfix on 0.3.2.6-alpha. o Minor bugfixes (exit relay DNS retries): - Re-attempt timed-out DNS queries 3 times before failure, since our timeout is 5 seconds for them, but clients wait 10-15. Also allow slightly more timeouts per resolver when an exit has multiple resolvers configured. Fixes bug 21394; bugfix on 0.3.1.9. o Minor bugfixes (fallback directory mirrors): - Make updateFallbackDirs.py search harder for python. (Some OSs don't put it in /usr/bin.) Fixes bug 24708; bugfix on 0.2.8.1-alpha. o Minor bugfixes (hibernation, bandwidth accounting, shutdown): - When hibernating, close connections normally and allow them to flush. Fixes bug 23571; bugfix on 0.2.4.7-alpha. Also fixes bug 7267. - Do not attempt to launch self-reachability tests when entering hibernation. Fixes a case of bug 12062; bugfix on 0.0.9pre5. - Resolve several bugs related to descriptor fetching on bridge clients with bandwidth accounting enabled. (This combination is not recommended!) Fixes a case of bug 12062; bugfix on 0.2.0.3-alpha. - When hibernating, do not attempt to launch DNS checks. Fixes a case of bug 12062; bugfix on 0.1.2.2-alpha. - When hibernating, do not try to upload or download descriptors. Fixes a case of bug 12062; bugfix on 0.0.9pre5. o Minor bugfixes (IPv6, bridges): - Tor now always sets IPv6 preferences for bridges. Fixes bug 24573; bugfix on 0.2.8.2-alpha. - Tor now sets IPv6 address in the routerstatus as well as in the router descriptors when updating addresses for a bridge. Closes ticket 24572; bugfix on 0.2.4.5-alpha. Patch by "ffmancera". o Minor bugfixes (Linux seccomp2 sandbox): - When running with the sandbox enabled, reload configuration files correctly even when %include was used. Previously we would crash. Fixes bug 22605; bugfix on 0.3.1. Patch from Daniel Pinto. o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha): - Allow the nanosleep() system call, which glibc uses to implement sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha. o Minor bugfixes (logging): - Fix a (mostly harmless) race condition when invoking LOG_PROTOCOL_WARN message from a subthread while the torrc options are changing. Fixes bug 23954; bugfix on 0.1.1.9-alpha. o Minor bugfixes (man page, SocksPort): - Remove dead code from the old "SocksSocket" option, and rename SocksSocketsGroupWritable to UnixSocksGroupWritable. The old option still works, but is deprecated. Fixes bug 24343; bugfix on 0.2.6.3. o Minor bugfixes (memory leaks): - Avoid possible at-exit memory leaks related to use of Libevent's event_base_once() function. (This function tends to leak memory if the event_base is closed before the event fires.) Fixes bug 24584; bugfix on 0.2.8.1-alpha. - Fix a harmless memory leak in tor-resolve. Fixes bug 24582; bugfix on 0.2.1.1-alpha. o Minor bugfixes (network IPv6 test): - Tor's test scripts now check if "ping -6 ::1" works when the user runs "make test-network-all". Fixes bug 24677; bugfix on 0.2.9.3-alpha. Patch by "ffmancera". o Minor bugfixes (networking): - string_is_valid_hostname() will not consider IP strings to be valid hostnames. Fixes bug 25055; bugfix on Tor 0.2.5.5. o Minor bugfixes (onion service v3): - Avoid an assertion failure when the next onion service descriptor rotation type is out of sync with the consensus's valid-after time. Instead, log a warning message with extra information, so we can better hunt down the cause of this assertion. Fixes bug 25306; bugfix on 0.3.2.1-alpha. o Minor bugfixes (onion service, backport from 0.3.4.1-alpha): - Fix a memory leak when a v3 onion service is configured and gets a SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha. - When parsing the descriptor signature, look for the token plus an extra white-space at the end. This is more correct but also will allow us to support new fields that might start with "signature". Fixes bug 26069; bugfix on 0.3.0.1-alpha. o Minor bugfixes (onion services): - If we are configured to offer a single onion service, don't log long-term established one hop rendezvous points in the heartbeat. Fixes bug 25116; bugfix on 0.2.9.6-rc. o Minor bugfixes (performance): - Reduce the number of circuits that will be opened at once during the circuit build timeout phase. This is done by increasing the idle timeout to 3 minutes, and lowering the maximum number of concurrent learning circuits to 10. Fixes bug 24769; bugfix on 0.3.1.1-alpha. - Avoid calling protocol_list_supports_protocol() from inside tight loops when running with cached routerinfo_t objects. Instead, summarize the relevant protocols as flags in the routerinfo_t, as we do for routerstatus_t objects. This change simplifies our code a little, and saves a large amount of short-term memory allocation operations. Fixes bug 25008; bugfix on 0.2.9.4-alpha. o Minor bugfixes (performance, timeouts): - Consider circuits for timeout as soon as they complete a hop. This is more accurate than applying the timeout in circuit_expire_building() because that function is only called once per second, which is now too slow for typical timeouts on the current network. Fixes bug 23114; bugfix on 0.2.2.2-alpha. - Use onion service circuits (and other circuits longer than 3 hops) to calculate a circuit build timeout. Previously, Tor only calculated its build timeout based on circuits that planned to be exactly 3 hops long. With this change, we include measurements from all circuits at the point where they complete their third hop. Fixes bug 23100; bugfix on 0.2.2.2-alpha. o Minor bugfixes (relay, crash, backport from 0.3.4.1-alpha): - Avoid a crash when running with DirPort set but ORPort turned off. Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha. o Minor bugfixes (Rust FFI): - Fix a minor memory leak which would happen whenever the C code would call the Rust implementation of protover_get_supported_protocols(). This was due to the C version returning a static string, whereas the Rust version newly allocated a CString to pass across the FFI boundary. Consequently, the C code was not expecting to need to free() what it was given. Fixes bug 25127; bugfix on 0.3.2.1-alpha. o Minor bugfixes (spelling): - Use the "misspell" tool to detect and fix typos throughout the source code. Fixes bug 23650; bugfix on various versions of Tor. Patch from Deepesh Pathak. o Minor bugfixes (testing): - Avoid intermittent test failures due to a test that had relied on onion service introduction point creation finishing within 5 seconds of real clock time. Fixes bug 25450; bugfix on 0.3.1.3-alpha. - Give out Exit flags in bootstrapping networks. Fixes bug 24137; bugfix on 0.2.3.1-alpha. o Minor bugfixes (unit test, monotonic time): - Increase a constant (1msec to 10msec) in the monotonic time test that makes sure the nsec/usec/msec times read are synchronized. This change was needed to accommodate slow systems like armel or when the clock_gettime() is not a VDSO on the running kernel. Fixes bug 25113; bugfix on 0.2.9.1. o Code simplification and refactoring: - Move the list of default directory authorities to its own file. Closes ticket 24854. Patch by "beastr0". - Remove the old (deterministic) directory retry logic entirely: We've used exponential backoff exclusively for some time. Closes ticket 23814. - Remove the unused nodelist_recompute_all_hsdir_indices(). Closes ticket 25108. - Remove a series of counters used to track circuit extend attempts and connection status but that in reality we aren't using for anything other than stats logged by a SIGUSR1 signal. Closes ticket 25163. - Remove /usr/athena from search path in configure.ac. Closes ticket 24363. - Remove duplicate code in node_has_curve25519_onion_key() and node_get_curve25519_onion_key(), and add a check for a zero microdesc curve25519 onion key. Closes ticket 23966, patch by "aruna1234" and teor. - Rewrite channel_rsa_id_group_set_badness to reduce temporary memory allocations with large numbers of OR connections (e.g. relays). Closes ticket 24119. - Separate the function that deletes ephemeral files when Tor stops gracefully. - Small changes to Tor's buf_t API to make it suitable for use as a general-purpose safe string constructor. Closes ticket 22342. - Switch -Wnormalized=id to -Wnormalized=nfkc in configure.ac to avoid source code identifier confusion. Closes ticket 24467. - The tor_git_revision[] constant no longer needs to be redeclared by everything that links against the rest of Tor. Done as part of ticket 23845, to simplify our external API. - We make extend_info_from_node() use node_get_curve25519_onion_key() introduced in ticket 23577 to access the curve25519 public keys rather than accessing it directly. Closes ticket 23760. Patch by Neel Chauhan. - Add a function to log channels' scheduler state changes to aid debugging efforts. Closes ticket 24531. o Documentation: - Improved the documentation of AccountingStart parameter. Closes ticket 23635. - Update the documentation for "Log" to include the current list of logging domains. Closes ticket 25378. - Add documentation on how to build tor with Rust dependencies without having to be online. Closes ticket 22907; bugfix on 0.3.0.3-alpha. - Clarify the behavior of RelayBandwidth{Rate,Burst} with client traffic. Closes ticket 24318. - Document that OutboundBindAddress doesn't apply to DNS requests. Closes ticket 22145. Patch from Aruna Maurya. o Code simplification and refactoring (channels): - Remove the incoming and outgoing channel queues. These were never used, but still took up a step in our fast path. - The majority of the channel unit tests have been rewritten and the code coverage has now been raised to 83.6% for channel.c. Closes ticket 23709. - Remove other dead code from the channel subsystem: All together, this cleanup has removed more than 1500 lines of code overall and adding very little except for unit test. o Code simplification and refactoring (circuit rendezvous): - Split the client-side rendezvous circuit lookup into two functions: one that returns only established circuits and another that returns all kinds of circuits. Closes ticket 23459. o Code simplification and refactoring (controller): - Make most of the variables in networkstatus_getinfo_by_purpose() const. Implements ticket 24489. o Documentation (backport from 0.3.4.1-alpha): - Correct an IPv6 error in the documentation for ExitPolicy. Closes ticket 25857. Patch from "CTassisF". o Documentation (man page): - The HiddenServiceVersion torrc option accepts only one number: either version 2 or 3. Closes ticket 25026; bugfix on 0.3.2.2-alpha. o Documentation (manpage, denial of service): - Provide more detail about the denial-of-service options, by listing each mitigation and explaining how they relate. Closes ticket 25248. Changes in version 0.3.1.10 - 2018-03-03 Tor 0.3.1.10 backports a number of bugfixes, including important fixes for security issues. It includes an important security fix for a remote crash attack against directory authorities, tracked as TROVE-2018-001. This release also backports our new system for improved resistance to denial-of-service attacks against relays. This release also fixes several minor bugs and annoyances from earlier releases. All directory authorities should upgrade to one of the versions released today. Relays running 0.3.1.x may wish to update to one of the versions released today, for the DoS mitigations. Please note: according to our release calendar, Tor 0.3.1 will no longer be supported after 1 July 2018. If you will be running Tor after that date, you should make sure to plan to upgrade to the latest stable version, or downgrade to 0.2.9 (which will receive long-term support). o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha): - Fix a protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception. Fixes bug 25074; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and CVE-2018-0490. o Major features (denial-of-service mitigation, backport from 0.3.3.2-alpha): - Give relays some defenses against the recent network overload. We start with three defenses (default parameters in parentheses). First: if a single client address makes too many concurrent connections (>100), hang up on further connections. Second: if a single client address makes circuits too quickly (more than 3 per second, with an allowed burst of 90) while also having too many connections open (3), refuse new create cells for the next while (1-2 hours). Third: if a client asks to establish a rendezvous point to you directly, ignore the request. These defenses can be manually controlled by new torrc options, but relays will also take guidance from consensus parameters, so there's no need to configure anything manually. Implements ticket 24902. o Minor features (linux seccomp2 sandbox, backport from 0.3.2.5-alpha): - Update the sandbox rules so that they should now work correctly with Glibc 2.26. Closes ticket 24315. o Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha): - Fix an "off by 2" error in counting rendezvous failures on the onion service side. While we thought we would stop the rendezvous attempt after one failed circuit, we were actually making three circuit attempts before giving up. Now switch to a default of 2, and allow the consensus parameter "hs_service_max_rdv_failures" to override. Fixes bug 24895; bugfix on 0.0.6. o Major bugfixes (protocol versions, backport from 0.3.3.2-alpha): - Add Link protocol version 5 to the supported protocols list. Fixes bug 25070; bugfix on 0.3.1.1-alpha. o Major bugfixes (relay, backport from 0.3.3.1-alpha): - Fix a set of false positives where relays would consider connections to other relays as being client-only connections (and thus e.g. deserving different link padding schemes) if those relays fell out of the consensus briefly. Now we look only at the initial handshake and whether the connection authenticated as a relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha. o Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha): - Make our OOM handler aware of the geoip client history cache so it doesn't fill up the memory. This check is important for IPv6 and our DoS mitigation subsystem. Closes ticket 25122. o Minor feature (relay statistics, backport from 0.3.2.6-alpha): - Change relay bandwidth reporting stats interval from 4 hours to 24 hours in order to reduce the efficiency of guard discovery attacks. Fixes ticket 23856. o Minor features (compatibility, OpenSSL, backport from 0.3.3.3-alpha): - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. Previous versions of Tor would not have worked with OpenSSL 1.1.1, since they neither disabled TLS 1.3 nor enabled any of the ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. Closes ticket 24978. o Minor features (fallback directory mirrors, backport from 0.3.2.9): - The fallback directory list has been re-generated based on the current status of the network. Tor uses fallback directories to bootstrap when it doesn't yet have up-to-date directory information. Closes ticket 24801. - Make the default DirAuthorityFallbackRate 0.1, so that clients prefer to bootstrap from fallback directory mirrors. This is a follow-up to 24679, which removed weights from the default fallbacks. Implements ticket 24681. o Minor features (geoip): - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 Country database. o Minor bugfix (channel connection, backport from 0.3.3.2-alpha): - Use the actual observed address of an incoming relay connection, not the canonical address of the relay from its descriptor, when making decisions about how to handle the incoming connection. Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera". o Minor bugfix (directory authority, backport from 0.3.3.2-alpha): - Directory authorities, when refusing a descriptor from a rejected relay, now explicitly tell the relay (in its logs) to set a valid ContactInfo address and contact the bad-relays@ mailing list. Fixes bug 25170; bugfix on 0.2.9.1. o Minor bugfixes (address selection, backport from 0.3.2.9): - When the fascist_firewall_choose_address_ functions don't find a reachable address, set the returned address to the null address and port. This is a precautionary measure, because some callers do not check the return value. Fixes bug 24736; bugfix on 0.2.8.2-alpha. o Major bugfixes (bootstrapping, backport from 0.3.2.5-alpha): - Fetch descriptors aggressively whenever we lack enough to build circuits, regardless of how many descriptors we are missing. Previously, we would delay launching the fetch when we had fewer than 15 missing descriptors, even if some of those descriptors were blocking circuits from building. Fixes bug 23985; bugfix on 0.1.1.11-alpha. The effects of this bug became worse in 0.3.0.3-alpha, when we began treating missing descriptors from our primary guards as a reason to delay circuits. - Don't try fetching microdescriptors from relays that have failed to deliver them in the past. Fixes bug 23817; bugfix on 0.3.0.1-alpha. o Minor bugfixes (compilation, backport from 0.3.2.7-rc): - Fix a signed/unsigned comparison warning introduced by our fix to TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16. o Minor bugfixes (control port, linux seccomp2 sandbox, backport from 0.3.2.5-alpha): - Avoid a crash when attempting to use the seccomp2 sandbox together with the OwningControllerProcess feature. Fixes bug 24198; bugfix on 0.2.5.1-alpha. o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha): - Fix a possible crash on malformed consensus. If a consensus had contained an unparseable protocol line, it could have made clients and relays crash with a null-pointer exception. To exploit this issue, however, an attacker would need to be able to subvert the directory authority system. Fixes bug 25251; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-004. o Minor bugfixes (directory cache, backport from 0.3.2.5-alpha): - Recover better from empty or corrupt files in the consensus cache directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha. - When a consensus diff calculation is only partially successful, only record the successful parts as having succeeded. Partial success can happen if (for example) one compression method fails but the others succeed. Previously we misrecorded all the calculations as having succeeded, which would later cause a nonfatal assertion failure. Fixes bug 24086; bugfix on 0.3.1.1-alpha. o Minor bugfixes (entry guards, backport from 0.3.2.3-alpha): - Tor now updates its guard state when it reads a consensus regardless of whether it's missing descriptors. That makes tor use its primary guards to fetch descriptors in some edge cases where it would previously have used fallback directories. Fixes bug 23862; bugfix on 0.3.0.1-alpha. o Minor bugfixes (logging, backport from 0.3.3.2-alpha): - Don't treat inability to store a cached consensus object as a bug: it can happen normally when we are out of disk space. Fixes bug 24859; bugfix on 0.3.1.1-alpha. o Minor bugfixes (memory usage, backport from 0.3.2.8-rc): - When queuing DESTROY cells on a channel, only queue the circuit-id and reason fields: not the entire 514-byte cell. This fix should help mitigate any bugs or attacks that fill up these queues, and free more RAM for other uses. Fixes bug 24666; bugfix on 0.2.5.1-alpha. o Minor bugfixes (network layer, backport from 0.3.2.5-alpha): - When closing a connection via close_connection_immediately(), we mark it as "not blocked on bandwidth", to prevent later calls from trying to unblock it, and give it permission to read. This fixes a backtrace warning that can happen on relays under various circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc. o Minor bugfixes (path selection, backport from 0.3.2.4-alpha): - When selecting relays by bandwidth, avoid a rounding error that could sometimes cause load to be imbalanced incorrectly. Previously, we would always round upwards; now, we round towards the nearest integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha. - When calculating the fraction of nodes that have descriptors, and all nodes in the network have zero bandwidths, count the number of nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha. - Actually log the total bandwidth in compute_weighted_bandwidths(). Fixes bug 24170; bugfix on 0.2.4.3-alpha. o Minor bugfixes (performance, fragile-hardening, backport from 0.3.3.1-alpha): - Improve the performance of our consensus-diff application code when Tor is built with the --enable-fragile-hardening option set. Fixes bug 24826; bugfix on 0.3.1.1-alpha. o Minor bugfixes (OSX, backport from 0.3.3.1-alpha): - Don't exit the Tor process if setrlimit() fails to change the file limit (which can happen sometimes on some versions of OSX). Fixes bug 21074; bugfix on 0.0.9pre5. o Minor bugfixes (portability, msvc, backport from 0.3.2.9): - Fix a bug in the bit-counting parts of our timing-wheel code on MSVC. (Note that MSVC is still not a supported build platform, due to cyptographic timing channel risks.) Fixes bug 24633; bugfix on 0.2.9.1-alpha. o Minor bugfixes (relay, partial backport): - Make the internal channel_is_client() function look at what sort of connection handshake the other side used, rather than whether the other side ever sent a create_fast cell to us. Backports part of the fixes from bugs 22805 and 24898. o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha): - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. o Code simplification and refactoring (backport from 0.3.3.3-alpha): - Update the "rust dependencies" submodule to be a project-level repository, rather than a user repository. Closes ticket 25323. Changes in version 0.2.9.15 - 2018-03-03 Tor 0.2.9.15 backports important security and stability bugfixes from later Tor releases. It includes an important security fix for a remote crash attack against directory authorities, tracked as TROVE-2018-001. This release also backports our new system for improved resistance to denial-of-service attacks against relays. This release also fixes several minor bugs and annoyances from earlier releases. All directory authorities should upgrade to one of the versions released today. Relays running 0.2.9.x may wish to update to one of the versions released today, for the DoS mitigations. o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha): - Fix a protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception. Fixes bug 25074; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and CVE-2018-0490. o Major features (denial-of-service mitigation): - Give relays some defenses against the recent network overload. We start with three defenses (default parameters in parentheses). First: if a single client address makes too many concurrent connections (>100), hang up on further connections. Second: if a single client address makes circuits too quickly (more than 3 per second, with an allowed burst of 90) while also having too many connections open (3), refuse new create cells for the next while (1-2 hours). Third: if a client asks to establish a rendezvous point to you directly, ignore the request. These defenses can be manually controlled by new torrc options, but relays will also take guidance from consensus parameters, so there's no need to configure anything manually. Implements ticket 24902. o Major bugfixes (bootstrapping): - Fetch descriptors aggressively whenever we lack enough to build circuits, regardless of how many descriptors we are missing. Previously, we would delay launching the fetch when we had fewer than 15 missing descriptors, even if some of those descriptors were blocking circuits from building. Fixes bug 23985; bugfix on 0.1.1.11-alpha. The effects of this bug became worse in 0.3.0.3-alpha, when we began treating missing descriptors from our primary guards as a reason to delay circuits. o Major bugfixes (onion services, retry behavior): - Fix an "off by 2" error in counting rendezvous failures on the onion service side. While we thought we would stop the rendezvous attempt after one failed circuit, we were actually making three circuit attempts before giving up. Now switch to a default of 2, and allow the consensus parameter "hs_service_max_rdv_failures" to override. Fixes bug 24895; bugfix on 0.0.6. o Minor feature (relay statistics): - Change relay bandwidth reporting stats interval from 4 hours to 24 hours in order to reduce the efficiency of guard discovery attacks. Fixes ticket 23856. o Minor features (compatibility, OpenSSL): - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. Previous versions of Tor would not have worked with OpenSSL 1.1.1, since they neither disabled TLS 1.3 nor enabled any of the ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. Closes ticket 24978. o Minor features (denial-of-service avoidance): - Make our OOM handler aware of the geoip client history cache so it doesn't fill up the memory. This check is important for IPv6 and our DoS mitigation subsystem. Closes ticket 25122. o Minor features (fallback directory mirrors): - The fallback directory list has been re-generated based on the current status of the network. Tor uses fallback directories to bootstrap when it doesn't yet have up-to-date directory information. Closes ticket 24801. - Make the default DirAuthorityFallbackRate 0.1, so that clients prefer to bootstrap from fallback directory mirrors. This is a follow-up to 24679, which removed weights from the default fallbacks. Implements ticket 24681. o Minor features (geoip): - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 Country database. o Minor features (linux seccomp2 sandbox): - Update the sandbox rules so that they should now work correctly with Glibc 2.26. Closes ticket 24315. o Minor bugfix (channel connection): - Use the actual observed address of an incoming relay connection, not the canonical address of the relay from its descriptor, when making decisions about how to handle the incoming connection. Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera". o Minor bugfix (directory authority): - Directory authorities, when refusing a descriptor from a rejected relay, now explicitly tell the relay (in its logs) to set a valid ContactInfo address and contact the bad-relays@ mailing list. Fixes bug 25170; bugfix on 0.2.9.1. o Minor bugfixes (address selection): - When the fascist_firewall_choose_address_ functions don't find a reachable address, set the returned address to the null address and port. This is a precautionary measure, because some callers do not check the return value. Fixes bug 24736; bugfix on 0.2.8.2-alpha. o Minor bugfixes (compilation): - Fix a signed/unsigned comparison warning introduced by our fix to TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16. o Minor bugfixes (control port, linux seccomp2 sandbox): - Avoid a crash when attempting to use the seccomp2 sandbox together with the OwningControllerProcess feature. Fixes bug 24198; bugfix on 0.2.5.1-alpha. o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha): - Fix a possible crash on malformed consensus. If a consensus had contained an unparseable protocol line, it could have made clients and relays crash with a null-pointer exception. To exploit this issue, however, an attacker would need to be able to subvert the directory authority system. Fixes bug 25251; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-004. o Minor bugfixes (memory usage): - When queuing DESTROY cells on a channel, only queue the circuit-id and reason fields: not the entire 514-byte cell. This fix should help mitigate any bugs or attacks that fill up these queues, and free more RAM for other uses. Fixes bug 24666; bugfix on 0.2.5.1-alpha. o Minor bugfixes (network layer): - When closing a connection via close_connection_immediately(), we mark it as "not blocked on bandwidth", to prevent later calls from trying to unblock it, and give it permission to read. This fixes a backtrace warning that can happen on relays under various circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc. o Minor bugfixes (OSX): - Don't exit the Tor process if setrlimit() fails to change the file limit (which can happen sometimes on some versions of OSX). Fixes bug 21074; bugfix on 0.0.9pre5. o Minor bugfixes (path selection): - When selecting relays by bandwidth, avoid a rounding error that could sometimes cause load to be imbalanced incorrectly. Previously, we would always round upwards; now, we round towards the nearest integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha. - When calculating the fraction of nodes that have descriptors, and all nodes in the network have zero bandwidths, count the number of nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha. - Actually log the total bandwidth in compute_weighted_bandwidths(). Fixes bug 24170; bugfix on 0.2.4.3-alpha. o Minor bugfixes (portability, msvc): - Fix a bug in the bit-counting parts of our timing-wheel code on MSVC. (Note that MSVC is still not a supported build platform, due to cryptographic timing channel risks.) Fixes bug 24633; bugfix on 0.2.9.1-alpha. o Minor bugfixes (relay): - Make the internal channel_is_client() function look at what sort of connection handshake the other side used, rather than whether the other side ever sent a create_fast cell to us. Backports part of the fixes from bugs 22805 and 24898. o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha): - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. Changes in version 0.3.2.10 - 2018-03-03 Tor 0.3.2.10 is the second stable release in the 0.3.2 series. It backports a number of bugfixes, including important fixes for security issues. It includes an important security fix for a remote crash attack against directory authorities, tracked as TROVE-2018-001. Additionally, it backports a fix for a bug whose severity we have upgraded: Bug 24700, which was fixed in 0.3.3.2-alpha, can be remotely triggered in order to crash relays with a use-after-free pattern. As such, we are now tracking that bug as TROVE-2018-002 and CVE-2018-0491, and backporting it to earlier releases. This bug affected versions 0.3.2.1-alpha through 0.3.2.9, as well as version 0.3.3.1-alpha. This release also backports our new system for improved resistance to denial-of-service attacks against relays. This release also fixes several minor bugs and annoyances from earlier releases. Relays running 0.3.2.x SHOULD upgrade to one of the versions released today, for the fix to TROVE-2018-002. Directory authorities should also upgrade. (Relays on earlier versions might want to update too for the DoS mitigations.) o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha): - Fix a protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception. Fixes bug 25074; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and CVE-2018-0490. o Major bugfixes (scheduler, KIST, denial-of-service, backport from 0.3.3.2-alpha): - Avoid adding the same channel twice in the KIST scheduler pending list, which could lead to remote denial-of-service use-after-free attacks against relays. Fixes bug 24700; bugfix on 0.3.2.1-alpha. o Major features (denial-of-service mitigation, backport from 0.3.3.2-alpha): - Give relays some defenses against the recent network overload. We start with three defenses (default parameters in parentheses). First: if a single client address makes too many concurrent connections (>100), hang up on further connections. Second: if a single client address makes circuits too quickly (more than 3 per second, with an allowed burst of 90) while also having too many connections open (3), refuse new create cells for the next while (1-2 hours). Third: if a client asks to establish a rendezvous point to you directly, ignore the request. These defenses can be manually controlled by new torrc options, but relays will also take guidance from consensus parameters, so there's no need to configure anything manually. Implements ticket 24902. o Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha): - Fix an "off by 2" error in counting rendezvous failures on the onion service side. While we thought we would stop the rendezvous attempt after one failed circuit, we were actually making three circuit attempts before giving up. Now switch to a default of 2, and allow the consensus parameter "hs_service_max_rdv_failures" to override. Fixes bug 24895; bugfix on 0.0.6. - New-style (v3) onion services now obey the "max rendezvous circuit attempts" logic. Previously they would make as many rendezvous circuit attempts as they could fit in the MAX_REND_TIMEOUT second window before giving up. Fixes bug 24894; bugfix on 0.3.2.1-alpha. o Major bugfixes (protocol versions, backport from 0.3.3.2-alpha): - Add Link protocol version 5 to the supported protocols list. Fixes bug 25070; bugfix on 0.3.1.1-alpha. o Major bugfixes (relay, backport from 0.3.3.1-alpha): - Fix a set of false positives where relays would consider connections to other relays as being client-only connections (and thus e.g. deserving different link padding schemes) if those relays fell out of the consensus briefly. Now we look only at the initial handshake and whether the connection authenticated as a relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha. o Major bugfixes (scheduler, consensus, backport from 0.3.3.2-alpha): - The scheduler subsystem was failing to promptly notice changes in consensus parameters, making it harder to switch schedulers network-wide. Fixes bug 24975; bugfix on 0.3.2.1-alpha. o Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha): - Make our OOM handler aware of the geoip client history cache so it doesn't fill up the memory. This check is important for IPv6 and our DoS mitigation subsystem. Closes ticket 25122. o Minor features (compatibility, OpenSSL, backport from 0.3.3.3-alpha): - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. Previous versions of Tor would not have worked with OpenSSL 1.1.1, since they neither disabled TLS 1.3 nor enabled any of the ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. Closes ticket 24978. o Minor features (geoip): - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 Country database. o Minor features (logging, diagnostic, backport from 0.3.3.2-alpha): - When logging a failure to create an onion service's descriptor, also log what the problem with the descriptor was. Diagnostic for ticket 24972. o Minor bugfix (channel connection, backport from 0.3.3.2-alpha): - Use the actual observed address of an incoming relay connection, not the canonical address of the relay from its descriptor, when making decisions about how to handle the incoming connection. Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera". o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha): - Fix a possible crash on malformed consensus. If a consensus had contained an unparseable protocol line, it could have made clients and relays crash with a null-pointer exception. To exploit this issue, however, an attacker would need to be able to subvert the directory authority system. Fixes bug 25251; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-004. o Minor bugfix (directory authority, backport from 0.3.3.2-alpha): - Directory authorities, when refusing a descriptor from a rejected relay, now explicitly tell the relay (in its logs) to set a valid ContactInfo address and contact the bad-relays@ mailing list. Fixes bug 25170; bugfix on 0.2.9.1. o Minor bugfixes (build, rust, backport from 0.3.3.1-alpha): - When building with Rust on OSX, link against libresolv, to work around the issue at https://github.com/rust-lang/rust/issues/46797. Fixes bug 24652; bugfix on 0.3.1.1-alpha. o Minor bugfixes (onion services, backport from 0.3.3.2-alpha): - Remove a BUG() statement when a client fetches an onion descriptor that has a lower revision counter than the one in its cache. This can happen in normal circumstances due to HSDir desync. Fixes bug 24976; bugfix on 0.3.2.1-alpha. o Minor bugfixes (logging, backport from 0.3.3.2-alpha): - Don't treat inability to store a cached consensus object as a bug: it can happen normally when we are out of disk space. Fixes bug 24859; bugfix on 0.3.1.1-alpha. o Minor bugfixes (performance, fragile-hardening, backport from 0.3.3.1-alpha): - Improve the performance of our consensus-diff application code when Tor is built with the --enable-fragile-hardening option set. Fixes bug 24826; bugfix on 0.3.1.1-alpha. o Minor bugfixes (OSX, backport from 0.3.3.1-alpha): - Don't exit the Tor process if setrlimit() fails to change the file limit (which can happen sometimes on some versions of OSX). Fixes bug 21074; bugfix on 0.0.9pre5. o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha): - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha. o Minor bugfixes (testing, backport from 0.3.3.1-alpha): - Fix a memory leak in the scheduler/loop_kist unit test. Fixes bug 25005; bugfix on 0.3.2.7-rc. o Minor bugfixes (v3 onion services, backport from 0.3.3.2-alpha): - Look at the "HSRend" protocol version, not the "HSDir" protocol version, when deciding whether a consensus entry can support the v3 onion service protocol as a rendezvous point. Fixes bug 25105; bugfix on 0.3.2.1-alpha. o Code simplification and refactoring (backport from 0.3.3.3-alpha): - Update the "rust dependencies" submodule to be a project-level repository, rather than a user repository. Closes ticket 25323. o Documentation (backport from 0.3.3.1-alpha) - Document that operators who run more than one relay or bridge are expected to set MyFamily and ContactInfo correctly. Closes ticket 24526. Changes in version 0.3.2.9 - 2018-01-09 Tor 0.3.2.9 is the first stable release in the 0.3.2 series. The 0.3.2 series includes our long-anticipated new onion service design, with numerous security features. (For more information, see our blog post at https://blog.torproject.org/fall-harvest.) We also have a new circuit scheduler algorithm for improved performance on relays everywhere (see https://blog.torproject.org/kist-and-tell), along with many smaller features and bugfixes. Per our stable release policy, we plan to support each stable release series for at least the next nine months, or for three months after the first stable release of the next series: whichever is longer. If you need a release with long-term support, we recommend that you stay with the 0.2.9 series. Below is a list of the changes since 0.3.1.7. For a list of all changes since 0.3.2.8-rc, see the ChangeLog file. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. - Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760. - Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394. o Major features (next-generation onion services): - Tor now supports the next-generation onion services protocol for clients and services! As part of this release, the core of proposal 224 has been implemented and is available for experimentation and testing by our users. This newer version of onion services ("v3") features many improvements over the legacy system, including: a) Better crypto (replaced SHA1/DH/RSA1024 with SHA3/ed25519/curve25519) b) Improved directory protocol, leaking much less information to directory servers. c) Improved directory protocol, with smaller surface for targeted attacks. d) Better onion address security against impersonation. e) More extensible introduction/rendezvous protocol. f) A cleaner and more modular codebase. You can identify a next-generation onion address by its length: they are 56 characters long, as in "4acth47i6kxnvkewtm6q7ib2s3ufpo5sqbsnzjpbi7utijcltosqemad.onion". In the future, we will release more options and features for v3 onion services, but we first need a testing period, so that the current codebase matures and becomes more robust. Planned features include: offline keys, advanced client authorization, improved guard algorithms, and statistics. For full details, see proposal 224. Legacy ("v2") onion services will still work for the foreseeable future, and will remain the default until this new codebase gets tested and hardened. Service operators who want to experiment with the new system can use the 'HiddenServiceVersion 3' torrc directive along with the regular onion service configuration options. For more information, see our blog post at "https://blog.torproject.org/fall-harvest". Enjoy! o Major feature (scheduler, channel): - Tor now uses new schedulers to decide which circuits should deliver cells first, in order to improve congestion at relays. The first type is called "KIST" ("Kernel Informed Socket Transport"), and is only available on Linux-like systems: it uses feedback from the kernel to prevent the kernel's TCP buffers from growing too full. The second new scheduler type is called "KISTLite": it behaves the same as KIST, but runs on systems without kernel support for inspecting TCP implementation details. The old scheduler is still available, under the name "Vanilla". To change the default scheduler preference order, use the new "Schedulers" option. (The default preference order is "KIST,KISTLite,Vanilla".) Matt Traudt implemented KIST, based on research by Rob Jansen, John Geddes, Christ Wacek, Micah Sherr, and Paul Syverson. For more information, see the design paper at http://www.robgjansen.com/publications/kist-sec2014.pdf and the followup implementation paper at https://arxiv.org/abs/1709.01044. Closes ticket 12541. For more information, see our blog post at "https://blog.torproject.org/kist-and-tell". o Major bugfixes (security, general): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. o Major bugfixes (security, directory authority): - Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820. o Major bugfixes (security, onion service v2): - Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, relay): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. - When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Major bugfixes (bootstrapping): - Fetch descriptors aggressively whenever we lack enough to build circuits, regardless of how many descriptors we are missing. Previously, we would delay launching the fetch when we had fewer than 15 missing descriptors, even if some of those descriptors were blocking circuits from building. Fixes bug 23985; bugfix on 0.1.1.11-alpha. The effects of this bug became worse in 0.3.0.3-alpha, when we began treating missing descriptors from our primary guards as a reason to delay circuits. - Don't try fetching microdescriptors from relays that have failed to deliver them in the past. Fixes bug 23817; bugfix on 0.3.0.1-alpha. o Major bugfixes (circuit prediction): - Fix circuit prediction logic so that a client doesn't treat a port as being "handled" by a circuit if that circuit already has isolation settings on it. This change should make Tor clients more responsive by improving their chances of having a pre-created circuit ready for use when a request arrives. Fixes bug 18859; bugfix on 0.2.3.3-alpha. o Major bugfixes (exit relays, DNS): - Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it. o Major bugfixes (relay, crash, assertion failure): - Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha. o Major bugfixes (usability, control port): - Report trusted clock skew indications as bootstrap errors, so controllers can more easily alert users when their clocks are wrong. Fixes bug 23506; bugfix on 0.1.2.6-alpha. o Minor features (bridge): - Bridge relays can now set the BridgeDistribution config option to add a "bridge-distribution-request" line to their bridge descriptor, which tells BridgeDB how they'd like their bridge address to be given out. (Note that as of Oct 2017, BridgeDB does not yet implement this feature.) As a side benefit, this feature provides a way to distinguish bridge descriptors from non-bridge descriptors. Implements tickets 18329. - When handling the USERADDR command on an ExtOrPort, warn when the transports provides a USERADDR with no port. In a future version, USERADDR commands of this format may be rejected. Detects problems related to ticket 23080. o Minor features (bug detection): - Log a warning message with a stack trace for any attempt to call get_options() during option validation. This pattern has caused subtle bugs in the past. Closes ticket 22281. o Minor features (build, compilation): - The "check-changes" feature is now part of the "make check" tests; we'll use it to try to prevent misformed changes files from accumulating. Closes ticket 23564. - Tor builds should now fail if there are any mismatches between the C type representing a configuration variable and the C type the data-driven parser uses to store a value there. Previously, we needed to check these by hand, which sometimes led to mistakes. Closes ticket 23643. o Minor features (client): - You can now use Tor as a tunneled HTTP proxy: use the new HTTPTunnelPort option to open a port that accepts HTTP CONNECT requests. Closes ticket 22407. - Add an extra check to make sure that we always use the newer guard selection code for picking our guards. Closes ticket 22779. - When downloading (micro)descriptors, don't split the list into multiple requests unless we want at least 32 descriptors. Previously, we split at 4, not 32, which led to significant overhead in HTTP request size and degradation in compression performance. Closes ticket 23220. - Improve log messages when missing descriptors for primary guards. Resolves ticket 23670. o Minor features (command line): - Add a new commandline option, --key-expiration, which prints when the current signing key is going to expire. Implements ticket 17639; patch by Isis Lovecruft. o Minor features (control port): - If an application tries to use the control port as an HTTP proxy, respond with a meaningful "This is the Tor control port" message, and log the event. Closes ticket 1667. Patch from Ravi Chandra Padmala. - Provide better error message for GETINFO desc/(id|name) when not fetching router descriptors. Closes ticket 5847. Patch by Kevin Butler. - Add GETINFO "{desc,md}/download-enabled", to inform the controller whether Tor will try to download router descriptors and microdescriptors respectively. Closes ticket 22684. - Added new GETINFO targets "ip-to-country/{ipv4,ipv6}-available", so controllers can tell whether the geoip databases are loaded. Closes ticket 23237. - Adds a timestamp field to the CIRC_BW and STREAM_BW bandwidth events. Closes ticket 19254. Patch by "DonnchaC". o Minor features (development support): - Developers can now generate a call-graph for Tor using the "calltool" python program, which post-processes object dumps. It should work okay on many Linux and OSX platforms, and might work elsewhere too. To run it, install calltool from https://gitweb.torproject.org/user/nickm/calltool.git and run "make callgraph". Closes ticket 19307. o Minor features (directory authority): - Make the "Exit" flag assignment only depend on whether the exit policy allows connections to ports 80 and 443. Previously relays would get the Exit flag if they allowed connections to one of these ports and also port 6667. Resolves ticket 23637. o Minor features (ed25519): - Add validation function to checks for torsion components in ed25519 public keys, used by prop224 client-side code. Closes ticket 22006. Math help by Ian Goldberg. o Minor features (exit relay, DNS): - Improve the clarity and safety of the log message from evdns when receiving an apparently spoofed DNS reply. Closes ticket 3056. o Minor features (fallback directory mirrors): - The fallback directory list has been re-generated based on the current status of the network. Tor uses fallback directories to bootstrap when it doesn't yet have up-to-date directory information. Closes ticket 24801. - Make the default DirAuthorityFallbackRate 0.1, so that clients prefer to bootstrap from fallback directory mirrors. This is a follow-up to 24679, which removed weights from the default fallbacks. Implements ticket 24681. o Minor features (geoip): - Update geoip and geoip6 to the January 5 2018 Maxmind GeoLite2 Country database. o Minor features (integration, hardening): - Add a new NoExec option to prevent Tor from running other programs. When this option is set to 1, Tor will never try to run another program, regardless of the settings of PortForwardingHelper, ClientTransportPlugin, or ServerTransportPlugin. Once NoExec is set, it cannot be disabled without restarting Tor. Closes ticket 22976. o Minor features (linux seccomp2 sandbox): - Update the sandbox rules so that they should now work correctly with Glibc 2.26. Closes ticket 24315. o Minor features (logging): - Provide better warnings when the getrandom() syscall fails. Closes ticket 24500. - Downgrade a pair of log messages that could occur when an exit's resolver gave us an unusual (but not forbidden) response. Closes ticket 24097. - Improve the message we log when re-enabling circuit build timeouts after having received a consensus. Closes ticket 20963. - Log more circuit information whenever we are about to try to package a relay cell on a circuit with a nonexistent n_chan. Attempt to diagnose ticket 8185. - Improve info-level log identification of particular circuits, to help with debugging. Closes ticket 23645. - Improve the warning message for specifying a relay by nickname. The previous message implied that nickname registration was still part of the Tor network design, which it isn't. Closes ticket 20488. - If the sandbox filter fails to load, suggest to the user that their kernel might not support seccomp2. Closes ticket 23090. o Minor features (onion service, circuit, logging): - Improve logging of many callsite in the circuit subsystem to print the circuit identifier(s). - Log when we cleanup an intro point from a service so we know when and for what reason it happened. Closes ticket 23604. o Minor features (portability): - Tor now compiles correctly on arm64 with libseccomp-dev installed. (It doesn't yet work with the sandbox enabled.) Closes ticket 24424. - Check at configure time whether uint8_t is the same type as unsigned char. Lots of existing code already makes this assumption, and there could be strict aliasing issues if the assumption is violated. Closes ticket 22410. o Minor features (relay): - When choosing which circuits can be expired as unused, consider circuits from clients even if those clients used regular CREATE cells to make them; and do not consider circuits from relays even if they were made with CREATE_FAST. Part of ticket 22805. - Reject attempts to use relative file paths when RunAsDaemon is set. Previously, Tor would accept these, but the directory- changing step of RunAsDaemon would give strange and/or confusing results. Closes ticket 22731. o Minor features (relay statistics): - Change relay bandwidth reporting stats interval from 4 hours to 24 hours in order to reduce the efficiency of guard discovery attacks. Fixes ticket 23856. o Minor features (reverted deprecations): - The ClientDNSRejectInternalAddresses flag can once again be set in non-testing Tor networks, so long as they do not use the default directory authorities. This change also removes the deprecation of this flag from 0.2.9.2-alpha. Closes ticket 21031. o Minor features (robustness): - Change several fatal assertions when flushing buffers into non- fatal assertions, to prevent any recurrence of 23690. o Minor features (startup, safety): - When configured to write a PID file, Tor now exits if it is unable to do so. Previously, it would warn and continue. Closes ticket 20119. o Minor features (static analysis): - The BUG() macro has been changed slightly so that Coverity no longer complains about dead code if the bug is impossible. Closes ticket 23054. o Minor features (testing): - Our fuzzing tests now test the encrypted portions of v3 onion service descriptors. Implements more of 21509. - Add a unit test to make sure that our own generated platform string will be accepted by directory authorities. Closes ticket 22109. - The default chutney network tests now include tests for the v3 onion service design. Make sure you have the latest version of chutney if you want to run these. Closes ticket 22437. - Add a unit test to verify that we can parse a hardcoded v2 onion service descriptor. Closes ticket 15554. o Minor bugfixes (address selection): - When the fascist_firewall_choose_address_ functions don't find a reachable address, set the returned address to the null address and port. This is a precautionary measure, because some callers do not check the return value. Fixes bug 24736; bugfix on 0.2.8.2-alpha. o Minor bugfixes (bootstrapping): - When warning about state file clock skew, report the correct direction for the detected skew. Fixes bug 23606; bugfix on 0.2.8.1-alpha. o Minor bugfixes (bridge clients, bootstrap): - Retry directory downloads when we get our first bridge descriptor during bootstrap or while reconnecting to the network. Keep retrying every time we get a bridge descriptor, until we have a reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha. - Stop delaying bridge descriptor fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when we have at least one reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha. - Stop delaying directory fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when all our bridges are definitely unreachable. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha. o Minor bugfixes (bridge): - Overwrite the bridge address earlier in the process of retrieving its descriptor, to make sure we reach it on the configured address. Fixes bug 20532; bugfix on 0.2.0.10-alpha. o Minor bugfixes (build, compilation): - Fix a compilation warning when building with zstd support on 32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found and fixed by Andreas Stieger. - When searching for OpenSSL, don't accept any OpenSSL library that lacks TLSv1_1_method(): Tor doesn't build with those versions. Additionally, look in /usr/local/opt/openssl, if it's present. These changes together repair the default build on OSX systems with Homebrew installed. Fixes bug 23602; bugfix on 0.2.7.2-alpha. - Fix a signed/unsigned comparison warning introduced by our fix to TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16. - Fix a memory leak warning in one of the libevent-related configuration tests that could occur when manually specifying -fsanitize=address. Fixes bug 24279; bugfix on 0.3.0.2-alpha. Found and patched by Alex Xu. - Fix unused-variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha. o Minor bugfixes (certificate handling): - Fix a time handling bug in Tor certificates set to expire after the year 2106. Fixes bug 23055; bugfix on 0.3.0.1-alpha. Found by Coverity as CID 1415728. o Minor bugfixes (client): - By default, do not enable storage of client-side DNS values. These values were unused by default previously, but they should not have been cached at all. Fixes bug 24050; bugfix on 0.2.6.3-alpha. o Minor bugfixes (client, usability): - Refrain from needlessly rejecting SOCKS5-with-hostnames and SOCKS4a requests that contain IP address strings, even when SafeSocks in enabled, as this prevents user from connecting to known IP addresses without relying on DNS for resolving. SafeSocks still rejects SOCKS connections that connect to IP addresses when those addresses are _not_ encoded as hostnames. Fixes bug 22461; bugfix on Tor 0.2.6.2-alpha. o Minor bugfixes (code correctness): - Call htons() in extend_cell_format() for encoding a 16-bit value. Previously we used ntohs(), which happens to behave the same on all the platforms we support, but which isn't really correct. Fixes bug 23106; bugfix on 0.2.4.8-alpha. - For defense-in-depth, make the controller's write_escaped_data() function robust to extremely long inputs. Fixes bug 19281; bugfix on 0.1.1.1-alpha. Reported by Guido Vranken. - Fix several places in our codebase where a C compiler would be likely to eliminate a check, based on assuming that undefined behavior had not happened elsewhere in the code. These cases are usually a sign of redundant checking or dubious arithmetic. Found by Georg Koppen using the "STACK" tool from Wang, Zeldovich, Kaashoek, and Solar-Lezama. Fixes bug 24423; bugfix on various Tor versions. o Minor bugfixes (compression): - Handle a pathological case when decompressing Zstandard data when the output buffer size is zero. Fixes bug 23551; bugfix on 0.3.1.1-alpha. o Minor bugfixes (consensus expiry): - Check for adequate directory information correctly. Previously, Tor would reconsider whether it had sufficient directory information every 2 minutes. Fixes bug 23091; bugfix on 0.2.0.19-alpha. o Minor bugfixes (control port, linux seccomp2 sandbox): - Avoid a crash when attempting to use the seccomp2 sandbox together with the OwningControllerProcess feature. Fixes bug 24198; bugfix on 0.2.5.1-alpha. o Minor bugfixes (control port, onion services): - Report "FAILED" instead of "UPLOAD_FAILED" "FAILED" for the HS_DESC event when a service is not able to upload a descriptor. Fixes bug 24230; bugfix on 0.2.7.1-alpha. o Minor bugfixes (directory cache): - Recover better from empty or corrupt files in the consensus cache directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha. - When a consensus diff calculation is only partially successful, only record the successful parts as having succeeded. Partial success can happen if (for example) one compression method fails but the others succeed. Previously we misrecorded all the calculations as having succeeded, which would later cause a nonfatal assertion failure. Fixes bug 24086; bugfix on 0.3.1.1-alpha. o Minor bugfixes (directory client): - On failure to download directory information, delay retry attempts by a random amount based on the "decorrelated jitter" algorithm. Our previous delay algorithm tended to produce extra-long delays too easily. Fixes bug 23816; bugfix on 0.2.9.1-alpha. o Minor bugfixes (directory protocol): - Directory servers now include a "Date:" http header for response codes other than 200. Clients starting with a skewed clock and a recent consensus were getting "304 Not modified" responses from directory authorities, so without the Date header, the client would never hear about a wrong clock. Fixes bug 23499; bugfix on 0.0.8rc1. - Make clients wait for 6 seconds before trying to download a consensus from an authority. Fixes bug 17750; bugfix on 0.2.8.1-alpha. o Minor bugfixes (documentation): - Document better how to read gcov, and what our gcov postprocessing scripts do. Fixes bug 23739; bugfix on 0.2.9.1-alpha. - Fix manpage to not refer to the obsolete (and misspelled) UseEntryGuardsAsDirectoryGuards parameter in the description of NumDirectoryGuards. Fixes bug 23611; bugfix on 0.2.4.8-alpha. o Minor bugfixes (DoS-resistance): - If future code asks if there are any running bridges, without checking if bridges are enabled, log a BUG warning rather than crashing. Fixes bug 23524; bugfix on 0.3.0.1-alpha. o Minor bugfixes (entry guards): - Tor now updates its guard state when it reads a consensus regardless of whether it's missing descriptors. That makes tor use its primary guards to fetch descriptors in some edge cases where it would previously have used fallback directories. Fixes bug 23862; bugfix on 0.3.0.1-alpha. o Minor bugfixes (format strictness): - Restrict several data formats to decimal. Previously, the BuildTimeHistogram entries in the state file, the "bw=" entries in the bandwidth authority file, and the process IDs passed to the __OwningControllerProcess option could all be specified in hex or octal as well as in decimal. This was not an intentional feature. Fixes bug 22802; bugfixes on 0.2.2.1-alpha, 0.2.2.2-alpha, and 0.2.2.28-beta. o Minor bugfixes (heartbeat): - If we fail to write a heartbeat message, schedule a retry for the minimum heartbeat interval number of seconds in the future. Fixes bug 19476; bugfix on 0.2.3.1-alpha. o Minor bugfixes (logging): - Suppress a log notice when relay descriptors arrive. We already have a bootstrap progress for this so no need to log notice everytime tor receives relay descriptors. Microdescriptors behave the same. Fixes bug 23861; bugfix on 0.2.8.2-alpha. - Remove duplicate log messages regarding opening non-local SocksPorts upon parsing config and opening listeners at startup. Fixes bug 4019; bugfix on 0.2.3.3-alpha. - Use a more comprehensible log message when telling the user they've excluded every running exit node. Fixes bug 7890; bugfix on 0.2.2.25-alpha. - When logging the number of descriptors we intend to download per directory request, do not log a number higher than then the number of descriptors we're fetching in total. Fixes bug 19648; bugfix on 0.1.1.8-alpha. - When warning about a directory owned by the wrong user, log the actual name of the user owning the directory. Previously, we'd log the name of the process owner twice. Fixes bug 23487; bugfix on 0.2.9.1-alpha. - Fix some messages on unexpected errors from the seccomp2 library. Fixes bug 22750; bugfix on 0.2.5.1-alpha. Patch from "cypherpunks". - The tor specification says hop counts are 1-based, so fix two log messages that mistakenly logged 0-based hop counts. Fixes bug 18982; bugfix on 0.2.6.2-alpha and 0.2.4.5-alpha. Patch by teor. Credit to Xiaofan Li for reporting this issue. o Minor bugfixes (logging, relay shutdown, annoyance): - When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha. o Minor bugfixes (memory safety, defensive programming): - Clear the target address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha. o Minor bugfixes (memory usage): - When queuing DESTROY cells on a channel, only queue the circuit-id and reason fields: not the entire 514-byte cell. This fix should help mitigate any bugs or attacks that fill up these queues, and free more RAM for other uses. Fixes bug 24666; bugfix on 0.2.5.1-alpha. o Minor bugfixes (network layer): - When closing a connection via close_connection_immediately(), we mark it as "not blocked on bandwidth", to prevent later calls from trying to unblock it, and give it permission to read. This fixes a backtrace warning that can happen on relays under various circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc. o Minor bugfixes (onion services): - The introduction circuit was being timed out too quickly while waiting for the rendezvous circuit to complete. Keep the intro circuit around longer instead of timing out and reopening new ones constantly. Fixes bug 23681; bugfix on 0.2.4.8-alpha. - Rename the consensus parameter "hsdir-interval" to "hsdir_interval" so it matches dir-spec.txt. Fixes bug 24262; bugfix on 0.3.1.1-alpha. - When handling multiple SOCKS request for the same .onion address, only fetch the service descriptor once. - Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha. - When reloading configured onion services, copy all information from the old service object. Previously, some data was omitted, causing delays in descriptor upload, and other bugs. Fixes bug 23790; bugfix on 0.2.1.9-alpha. o Minor bugfixes (path selection): - When selecting relays by bandwidth, avoid a rounding error that could sometimes cause load to be imbalanced incorrectly. Previously, we would always round upwards; now, we round towards the nearest integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha. - When calculating the fraction of nodes that have descriptors, and all nodes in the network have zero bandwidths, count the number of nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha. - Actually log the total bandwidth in compute_weighted_bandwidths(). Fixes bug 24170; bugfix on 0.2.4.3-alpha. o Minor bugfixes (portability): - Stop using the PATH_MAX variable, which is not defined on GNU Hurd. Fixes bug 23098; bugfix on 0.3.1.1-alpha. - Fix a bug in the bit-counting parts of our timing-wheel code on MSVC. (Note that MSVC is still not a supported build platform, due to cryptographic timing channel risks.) Fixes bug 24633; bugfix on 0.2.9.1-alpha. o Minor bugfixes (relay): - When uploading our descriptor for the first time after startup, report the reason for uploading as "Tor just started" rather than leaving it blank. Fixes bug 22885; bugfix on 0.2.3.4-alpha. - Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha. - Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha. o Minor bugfixes (testing): - Fix a spurious fuzzing-only use of an uninitialized value. Found by Brian Carpenter. Fixes bug 24082; bugfix on 0.3.0.3-alpha. - Test that IPv6-only clients can use microdescriptors when running "make test-network-all". Requires chutney master 61c28b9 or later. Closes ticket 24109. - Prevent scripts/test/coverage from attempting to move gcov output to the root directory. Fixes bug 23741; bugfix on 0.2.5.1-alpha. - Capture and detect several "Result does not fit" warnings in unit tests on platforms with 32-bit time_t. Fixes bug 21800; bugfix on 0.2.9.3-alpha. - Fix additional channelpadding unit test failures by using mocked time instead of actual time for all tests. Fixes bug 23608; bugfix on 0.3.1.1-alpha. - Fix a bug in our fuzzing mock replacement for crypto_pk_checksig(), to correctly handle cases where a caller gives it an RSA key of under 160 bits. (This is not actually a bug in Tor itself, but rather in our fuzzing code.) Fixes bug 24247; bugfix on 0.3.0.3-alpha. Found by OSS-Fuzz as issue 4177. - Fix a broken unit test for the OutboundAddress option: the parsing function was never returning an error on failure. Fixes bug 23366; bugfix on 0.3.0.3-alpha. - Fix a signed-integer overflow in the unit tests for dir/download_status_random_backoff, which was untriggered until we fixed bug 17750. Fixes bug 22924; bugfix on 0.2.9.1-alpha. o Minor bugfixes (usability, control port): - Stop making an unnecessary routerlist check in NETINFO clock skew detection; this was preventing clients from reporting NETINFO clock skew to controllers. Fixes bug 23532; bugfix on 0.2.4.4-alpha. o Code simplification and refactoring: - Remove various ways of testing circuits and connections for "clientness"; instead, favor channel_is_client(). Part of ticket 22805. - Extract the code for handling newly-open channels into a separate function from the general code to handle channel state transitions. This change simplifies our callgraph, reducing the size of the largest strongly connected component by roughly a factor of two. Closes ticket 22608. - Remove dead code for largely unused statistics on the number of times we've attempted various public key operations. Fixes bug 19871; bugfix on 0.1.2.4-alpha. Fix by Isis Lovecruft. - Remove several now-obsolete functions for asking about old variants directory authority status. Closes ticket 22311; patch from "huyvq". - Remove some of the code that once supported "Named" and "Unnamed" routers. Authorities no longer vote for these flags. Closes ticket 22215. - Rename the obsolete malleable hybrid_encrypt functions used in TAP and old hidden services, to indicate that they aren't suitable for new protocols or formats. Closes ticket 23026. - Replace our STRUCT_OFFSET() macro with offsetof(). Closes ticket 22521. Patch from Neel Chauhan. - Split the enormous circuit_send_next_onion_skin() function into multiple subfunctions. Closes ticket 22804. - Split the portions of the buffer.c module that handle particular protocols into separate modules. Part of ticket 23149. - Use our test macros more consistently, to produce more useful error messages when our unit tests fail. Add coccinelle patches to allow us to re-check for test macro uses. Closes ticket 22497. o Deprecated features: - The ReachableDirAddresses and ClientPreferIPv6DirPort options are now deprecated; they do not apply to relays, and they have had no effect on clients since 0.2.8.x. Closes ticket 19704. - Deprecate HTTPProxy/HTTPProxyAuthenticator config options. They only applies to direct unencrypted HTTP connections to your directory server, which your Tor probably isn't using. Closes ticket 20575. o Documentation: - Add notes in man page regarding OS support for the various scheduler types. Attempt to use less jargon in the scheduler section. Closes ticket 24254. - Clarify that the Address option is entirely about setting an advertised IPv4 address. Closes ticket 18891. - Clarify the manpage's use of the term "address" to clarify what kind of address is intended. Closes ticket 21405. - Document that onion service subdomains are allowed, and ignored. Closes ticket 18736. - Clarify in the manual that "Sandbox 1" is only supported on Linux kernels. Closes ticket 22677. - Document all values of PublishServerDescriptor in the manpage. Closes ticket 15645. - Improve the documentation for the directory port part of the DirAuthority line. Closes ticket 20152. - Restore documentation for the authorities' "approved-routers" file. Closes ticket 21148. o Removed features: - The AllowDotExit option has been removed as unsafe. It has been deprecated since 0.2.9.2-alpha. Closes ticket 23426. - The ClientDNSRejectInternalAddresses flag can no longer be set on non-testing networks. It has been deprecated since 0.2.9.2-alpha. Closes ticket 21031. - The controller API no longer includes an AUTHDIR_NEWDESCS event: nobody was using it any longer. Closes ticket 22377. Changes in version 0.3.1.9 - 2017-12-01: Tor 0.3.1.9 backports important security and stability fixes from the 0.3.2 development series. All Tor users should upgrade to this release, or to another of the releases coming out today. o Major bugfixes (security, backport from 0.3.2.6-alpha): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. - Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha): - Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823. o Major bugfixes (security, relay, backport from 0.3.2.6-alpha): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. - When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha): - Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it. o Minor features (bridge): - Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later. o Minor features (directory authority, backport from 0.3.2.6-alpha): - Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database. o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha): - Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha. o Minor bugfixes (compilation, backport from 0.3.2.1-alpha): - Fix unused variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha. o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha): - When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha. o Minor bugfixes (onion service, backport from 0.3.2.5-alpha): - Rename the consensus parameter "hsdir-interval" to "hsdir_interval" so it matches dir-spec.txt. Fixes bug 24262; bugfix on 0.3.1.1-alpha. o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha): - Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha. Changes in version 0.3.0.13 - 2017-12-01 Tor 0.3.0.13 backports important security and stability bugfixes from later Tor releases. All Tor users should upgrade to this release, or to another of the releases coming out today. Note: the Tor 0.3.0 series will no longer be supported after 26 Jan 2018. If you need a release with long-term support, please stick with the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Major bugfixes (security, backport from 0.3.2.6-alpha): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. - Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha): - Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823. o Major bugfixes (security, relay, backport from 0.3.2.6-alpha): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. - When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha): - Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it. o Minor features (security, windows, backport from 0.3.1.1-alpha): - Enable a couple of pieces of Windows hardening: one (HeapEnableTerminationOnCorruption) that has been on-by-default since Windows 8, and unavailable before Windows 7; and one (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't affect us, but shouldn't do any harm. Closes ticket 21953. o Minor features (bridge, backport from 0.3.1.9): - Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later. o Minor features (directory authority, backport from 0.3.2.6-alpha): - Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database. o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha): - Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha. o Minor bugfixes (compilation, backport from 0.3.2.1-alpha): - Fix unused variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha. o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha): - When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha. o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha): - Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha. o Minor bugfixes (testing, backport from 0.3.1.6-rc): - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij. Changes in version 0.2.9.14 - 2017-12-01 Tor 0.3.0.13 backports important security and stability bugfixes from later Tor releases. All Tor users should upgrade to this release, or to another of the releases coming out today. o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha): - Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it. o Major bugfixes (security, backport from 0.3.2.6-alpha): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. - Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha): - Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823. o Major bugfixes (security, relay, backport from 0.3.2.6-alpha): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Minor features (bridge, backport from 0.3.1.9): - Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later. o Minor features (directory authority, backport from 0.3.2.6-alpha): - Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database. o Minor features (security, windows, backport from 0.3.1.1-alpha): - Enable a couple of pieces of Windows hardening: one (HeapEnableTerminationOnCorruption) that has been on-by-default since Windows 8, and unavailable before Windows 7; and one (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't affect us, but shouldn't do any harm. Closes ticket 21953. o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha): - Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha. o Minor bugfixes (compilation, backport from 0.3.2.1-alpha): - Fix unused variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha. o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha): - When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha. o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha): - Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha. o Minor bugfixes (testing, backport from 0.3.1.6-rc): - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij. Changes in version 0.2.8.17 - 2017-12-01 Tor 0.2.8.17 backports important security and stability bugfixes from later Tor releases. All Tor users should upgrade to this release, or to another of the releases coming out today. Note: the Tor 0.2.8 series will no longer be supported after 1 Jan 2018. If you need a release with long-term support, please upgrade with the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Major bugfixes (security, backport from 0.3.2.6-alpha): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha): - Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823. o Major bugfixes (security, relay, backport from 0.3.2.6-alpha): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Minor features (bridge, backport from 0.3.1.9): - Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later. o Minor features (directory authority, backport from 0.3.2.6-alpha): - Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (testing, backport from 0.3.1.6-rc): - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij. Changes in version 0.2.5.16 - 2017-12-01 Tor 0.2.5.13 backports important security and stability bugfixes from later Tor releases. All Tor users should upgrade to this release, or to another of the releases coming out today. Note: the Tor 0.2.5 series will no longer be supported after 1 May 2018. If you need a release with long-term support, please upgrade to the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Major bugfixes (security, backport from 0.3.2.6-alpha): - Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. - When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819. o Major bugfixes (security, relay, backport from 0.3.2.6-alpha): - When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822. o Minor features (bridge, backport from 0.3.1.9): - Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later. o Minor features (geoip): - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database. Changes in version 0.2.5.15 - 2017-10-25 Tor 0.2.5.15 backports a collection of bugfixes from later Tor release series. It also adds a new directory authority, Bastet. Note: the Tor 0.2.5 series will no longer be supported after 1 May 2018. If you need a release with long-term support, please upgrade to the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha): - Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xx" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007. o Minor features (geoip): - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha): - Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591. o Build features (backport from 0.3.1.5-alpha): - Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636. Changes in version 0.2.8.16 - 2017-10-25 Tor 0.2.8.16 backports a collection of bugfixes from later Tor release series, including a bugfix for a crash issue that had affected relays under memory pressure. It also adds a new directory authority, Bastet. Note: the Tor 0.2.8 series will no longer be supported after 1 Jan 2018. If you need a release with long-term support, please stick with the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha): - Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha. o Minor features (directory authorities, backport from 0.3.2.2-alpha): - Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760. o Minor features (geoip): - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database. Changes in version 0.2.9.13 - 2017-10-25 Tor 0.2.9.13 backports a collection of bugfixes from later Tor release series, including a bugfix for a crash issue that had affected relays under memory pressure. It also adds a new directory authority, Bastet. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha): - Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha. o Minor features (directory authorities, backport from 0.3.2.2-alpha): - Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760. o Minor features (geoip): - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (directory authority, backport from 0.3.1.5-alpha): - When a directory authority rejects a descriptor or extrainfo with a given digest, mark that digest as undownloadable, so that we do not attempt to download it again over and over. We previously tried to avoid downloading such descriptors by other means, but we didn't notice if we accidentally downloaded one anyway. This behavior became problematic in 0.2.7.2-alpha, when authorities began pinning Ed25519 keys. Fixes bug 22349; bugfix on 0.2.1.19-alpha. o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha): - Clear the address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha. o Minor bugfixes (Windows service, backport from 0.3.1.6-rc): - When running as a Windows service, set the ID of the main thread correctly. Failure to do so made us fail to send log messages to the controller in 0.2.1.16-rc, slowed down controller event delivery in 0.2.7.3-rc and later, and crash with an assertion failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha. Patch and diagnosis from "Vort". Changes in version 0.3.0.12 - 2017-10-25 Tor 0.3.0.12 backports a collection of bugfixes from later Tor release series, including a bugfix for a crash issue that had affected relays under memory pressure. It also adds a new directory authority, Bastet. Note: the Tor 0.3.0 series will no longer be supported after 26 Jan 2018. If you need a release with long-term support, please stick with the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha): - Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha. o Minor features (directory authorities, backport from 0.3.2.2-alpha): - Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760. o Minor features (geoip): - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (directory authority, backport from 0.3.1.5-alpha): - When a directory authority rejects a descriptor or extrainfo with a given digest, mark that digest as undownloadable, so that we do not attempt to download it again over and over. We previously tried to avoid downloading such descriptors by other means, but we didn't notice if we accidentally downloaded one anyway. This behavior became problematic in 0.2.7.2-alpha, when authorities began pinning Ed25519 keys. Fixes bug 22349; bugfix on 0.2.1.19-alpha. o Minor bugfixes (hidden service, relay, backport from 0.3.2.2-alpha): - Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha. o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha): - Clear the address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha. o Minor bugfixes (Windows service, backport from 0.3.1.6-rc): - When running as a Windows service, set the ID of the main thread correctly. Failure to do so made us fail to send log messages to the controller in 0.2.1.16-rc, slowed down controller event delivery in 0.2.7.3-rc and later, and crash with an assertion failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha. Patch and diagnosis from "Vort". Changes in version 0.3.1.8 - 2017-10-25 Tor 0.3.1.8 is the second stable release in the 0.3.1 series. It includes several bugfixes, including a bugfix for a crash issue that had affected relays under memory pressure. It also adds a new directory authority, Bastet. o Directory authority changes: - Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910. - The directory authority "Longclaw" has changed its IP address. Closes ticket 23592. o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha): - Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha. o Minor features (directory authorities, backport from 0.3.2.2-alpha): - Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760. o Minor features (geoip): - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (compilation, backport from 0.3.2.2-alpha): - Fix a compilation warning when building with zstd support on 32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found and fixed by Andreas Stieger. o Minor bugfixes (compression, backport from 0.3.2.2-alpha): - Handle a pathological case when decompressing Zstandard data when the output buffer size is zero. Fixes bug 23551; bugfix on 0.3.1.1-alpha. o Minor bugfixes (directory authority, backport from 0.3.2.1-alpha): - Remove the length limit on HTTP status lines that authorities can send in their replies. Fixes bug 23499; bugfix on 0.3.1.6-rc. o Minor bugfixes (hidden service, relay, backport from 0.3.2.2-alpha): - Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha. o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha): - Clear the address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha. o Minor bugfixes (unit tests, backport from 0.3.2.2-alpha): - Fix additional channelpadding unit test failures by using mocked time instead of actual time for all tests. Fixes bug 23608; bugfix on 0.3.1.1-alpha. Changes in version 0.2.8.15 - 2017-09-18 Tor 0.2.8.15 backports a collection of bugfixes from later Tor series. Most significantly, it includes a fix for TROVE-2017-008, a security bug that affects hidden services running with the SafeLogging option disabled. For more information, see https://trac.torproject.org/projects/tor/ticket/23490 Note that Tor 0.2.8.x will no longer be supported after 1 Jan 2018. We suggest that you upgrade to the latest stable release if possible. If you can't, we recommend that you upgrade at least to 0.2.9, which will be supported until 2020. o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha): - Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xx" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007. o Minor features: - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha): - Backport a fix for an "unused variable" warning that appeared in some versions of mingw. Fixes bug 22838; bugfix on 0.2.8.1-alpha. o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha): - Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591. o Build features (backport from 0.3.1.5-alpha): - Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636. Changes in version 0.2.9.12 - 2017-09-18 Tor 0.2.9.12 backports a collection of bugfixes from later Tor series. Most significantly, it includes a fix for TROVE-2017-008, a security bug that affects hidden services running with the SafeLogging option disabled. For more information, see https://trac.torproject.org/projects/tor/ticket/23490 o Major features (security, backport from 0.3.0.2-alpha): - Change the algorithm used to decide DNS TTLs on client and server side, to better resist DNS-based correlation attacks like the DefecTor attack of Greschbach, Pulls, Roberts, Winter, and Feamster. Now relays only return one of two possible DNS TTL values, and clients are willing to believe DNS TTL values up to 3 hours long. Closes ticket 19769. o Major bugfixes (crash, directory connections, backport from 0.3.0.5-rc): - Fix a rare crash when sending a begin cell on a circuit whose linked directory connection had already been closed. Fixes bug 21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett. o Major bugfixes (DNS, backport from 0.3.0.2-alpha): - Fix a bug that prevented exit nodes from caching DNS records for more than 60 seconds. Fixes bug 19025; bugfix on 0.2.4.7-alpha. o Major bugfixes (linux TPROXY support, backport from 0.3.1.1-alpha): - Fix a typo that had prevented TPROXY-based transparent proxying from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha. Patch from "d4fq0fQAgoJ". o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha): - Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xx" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007. o Minor features (code style, backport from 0.3.1.3-alpha): - Add "Falls through" comments to our codebase, in order to silence GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas Stieger. Closes ticket 22446. o Minor features (geoip): - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (bandwidth accounting, backport from 0.3.1.1-alpha): - Roll over monthly accounting at the configured hour and minute, rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1. Found by Andrey Karpov with PVS-Studio. o Minor bugfixes (compilation, backport from 0.3.1.5-alpha): - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha. - Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha. - When building with certain versions the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha. o Minor bugfixes (compilation, backport from 0.3.1.7): - Avoid compiler warnings in the unit tests for running tor_sscanf() with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha. o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha): - Backport a fix for an "unused variable" warning that appeared in some versions of mingw. Fixes bug 22838; bugfix on 0.2.8.1-alpha. o Minor bugfixes (controller, backport from 0.3.1.7): - Do not crash when receiving a HSPOST command with an empty body. Fixes part of bug 22644; bugfix on 0.2.7.1-alpha. - Do not crash when receiving a POSTDESCRIPTOR command with an empty body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha. o Minor bugfixes (coverity build support, backport from 0.3.1.5-alpha): - Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha. o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha): - Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591. o Minor bugfixes (file limits, osx, backport from 0.3.1.5-alpha): - When setting the maximum number of connections allowed by the OS, always allow some extra file descriptors for other files. Fixes bug 22797; bugfix on 0.2.0.10-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.5-alpha): - Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.4-alpha): - Permit the fchmod system call, to avoid crashing on startup when starting with the seccomp2 sandbox and an unexpected set of permissions on the data directory or its contents. Fixes bug 22516; bugfix on 0.2.5.4-alpha. o Minor bugfixes (relay, backport from 0.3.0.5-rc): - Avoid a double-marked-circuit warning that could happen when we receive DESTROY cells under heavy load. Fixes bug 20059; bugfix on 0.1.0.1-rc. o Minor bugfixes (voting consistency, backport from 0.3.1.1-alpha): - Reject version numbers with non-numeric prefixes (such as +, -, or whitespace). Disallowing whitespace prevents differential version parsing between POSIX-based and Windows platforms. Fixes bug 21507 and part of 21508; bugfix on 0.0.8pre1. o Build features (backport from 0.3.1.5-alpha): - Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636. Changes in version 0.3.0.11 - 2017-09-18 Tor 0.3.0.11 backports a collection of bugfixes from Tor the 0.3.1 series. Most significantly, it includes a fix for TROVE-2017-008, a security bug that affects hidden services running with the SafeLogging option disabled. For more information, see https://trac.torproject.org/projects/tor/ticket/23490 o Minor features (code style, backport from 0.3.1.7): - Add "Falls through" comments to our codebase, in order to silence GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas Stieger. Closes ticket 22446. o Minor features: - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (compilation, backport from 0.3.1.7): - Avoid compiler warnings in the unit tests for calling tor_sscanf() with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha. o Minor bugfixes (controller, backport from 0.3.1.7): - Do not crash when receiving a HSPOST command with an empty body. Fixes part of bug 22644; bugfix on 0.2.7.1-alpha. - Do not crash when receiving a POSTDESCRIPTOR command with an empty body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha. o Minor bugfixes (file limits, osx, backport from 0.3.1.5-alpha): - When setting the maximum number of connections allowed by the OS, always allow some extra file descriptors for other files. Fixes bug 22797; bugfix on 0.2.0.10-alpha. o Minor bugfixes (logging, relay, backport from 0.3.1.6-rc): - Remove a forgotten debugging message when an introduction point successfully establishes a hidden service prop224 circuit with a client. - Change three other log_warn() for an introduction point to protocol warnings, because they can be failure from the network and are not relevant to the operator. Fixes bug 23078; bugfix on 0.3.0.1-alpha and 0.3.0.2-alpha. Changes in version 0.3.1.7 - 2017-09-18 Tor 0.3.1.7 is the first stable release in the 0.3.1 series. With the 0.3.1 series, Tor now serves and downloads directory information in more compact formats, to save on bandwidth overhead. It also contains a new padding system to resist netflow-based traffic analysis, and experimental support for building parts of Tor in Rust (though no parts of Tor are in Rust yet). There are also numerous small features, bugfixes on earlier release series, and groundwork for the hidden services revamp of 0.3.2. This release also includes a fix for TROVE-2017-008, a security bug that affects hidden services running with the SafeLogging option disabled. For more information, see https://trac.torproject.org/projects/tor/ticket/23490 Per our stable release policy, we plan to support each stable release series for at least the next nine months, or for three months after the first stable release of the next series: whichever is longer. If you need a release with long-term support, we recommend that you stay with the 0.2.9 series. Below is a list of the changes since 0.3.0. For a list of all changes since 0.3.1.6-rc, see the ChangeLog file. o New dependencies: - To build with zstd and lzma support, Tor now requires the pkg-config tool at build time. o Major bugfixes (security, hidden services, loggging): - Fix a bug where we could log uninitialized stack when a certain hidden service error occurred while SafeLogging was disabled. Fixes bug #23490; bugfix on 0.2.7.2-alpha. This is also tracked as TROVE-2017-008 and CVE-2017-0380. o Major features (build system, continuous integration): - Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636. o Major features (directory protocol): - Tor relays and authorities can now serve clients an abbreviated version of the consensus document, containing only the changes since an older consensus document that the client holds. Clients now request these documents when available. When both client and server use this new protocol, they will use far less bandwidth (up to 94% less) to keep the client's consensus up-to-date. Implements proposal 140; closes ticket 13339. Based on work by Daniel Martí. - Tor can now compress directory traffic with lzma or with zstd compression algorithms, which can deliver better bandwidth performance. Because lzma is computationally expensive, it's only used for documents that can be compressed once and served many times. Support for these algorithms requires that tor is built with the libzstd and/or liblzma libraries available. Implements proposal 278; closes ticket 21662. - Relays now perform the more expensive compression operations, and consensus diff generation, in worker threads. This separation avoids delaying the main thread when a new consensus arrives. o Major features (experimental): - Tor can now build modules written in Rust. To turn this on, pass the "--enable-rust" flag to the configure script. It's not time to get excited yet: currently, there is no actual Rust functionality beyond some simple glue code, and a notice at startup to tell you that Rust is running. Still, we hope that programmers and packagers will try building Tor with Rust support, so that we can find issues and solve portability problems. Closes ticket 22106. o Major features (traffic analysis resistance): - Connections between clients and relays now send a padding cell in each direction every 1.5 to 9.5 seconds (tunable via consensus parameters). This padding will not resist specialized eavesdroppers, but it should be enough to make many ISPs' routine network flow logging less useful in traffic analysis against Tor users. Padding is negotiated using Tor's link protocol, so both relays and clients must upgrade for this to take effect. Clients may still send padding despite the relay's version by setting ConnectionPadding 1 in torrc, and may disable padding by setting ConnectionPadding 0 in torrc. Padding may be minimized for mobile users with the torrc option ReducedConnectionPadding. Implements Proposal 251 and Section 2 of Proposal 254; closes ticket 16861. - Relays will publish 24 hour totals of padding and non-padding cell counts to their extra-info descriptors, unless PaddingStatistics 0 is set in torrc. These 24 hour totals are also rounded to multiples of 10000. o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure when a hidden service handles a malformed BEGIN cell. Fixes bug 22493, tracked as TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha. - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Major bugfixes (path selection, security): - When choosing which guard to use for a circuit, avoid the exit's family along with the exit itself. Previously, the new guard selection logic avoided the exit, but did not consider its family. Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2017- 006 and CVE-2017-0377. o Major bugfixes (connection usage): - We use NETINFO cells to try to determine if both relays involved in a connection will agree on the canonical status of that connection. We prefer the connections where this is the case for extend cells, and try to close connections where relays disagree on their canonical status early. Also, we now prefer the oldest valid connection for extend cells. These two changes should reduce the number of long-term connections that are kept open between relays. Fixes bug 17604; bugfix on 0.2.5.5-alpha. - Relays now log hourly statistics (look for "channel_check_for_duplicates" lines) on the total number of connections to other relays. If the number of connections per relay is unexpectedly large, this log message is at notice level. Otherwise it is at info. o Major bugfixes (entry guards): - When starting with an old consensus, do not add new entry guards unless the consensus is "reasonably live" (under 1 day old). Fixes one root cause of bug 22400; bugfix on 0.3.0.1-alpha. - Don't block bootstrapping when a primary bridge is offline and we can't get its descriptor. Fixes bug 22325; fixes one case of bug 21969; bugfix on 0.3.0.3-alpha. o Major bugfixes (linux TPROXY support): - Fix a typo that had prevented TPROXY-based transparent proxying from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha. Patch from "d4fq0fQAgoJ". o Major bugfixes (openbsd, denial-of-service): - Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xx" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007. o Major bugfixes (relay, link handshake): - When performing the v3 link handshake on a TLS connection, report that we have the x509 certificate that we actually used on that connection, even if we have changed certificates since that connection was first opened. Previously, we would claim to have used our most recent x509 link certificate, which would sometimes make the link handshake fail. Fixes one case of bug 22460; bugfix on 0.2.3.6-alpha. o Major bugfixes (relays, key management): - Regenerate link and authentication certificates whenever the key that signs them changes; also, regenerate link certificates whenever the signed key changes. Previously, these processes were only weakly coupled, and we relays could (for minutes to hours) wind up with an inconsistent set of keys and certificates, which other relays would not accept. Fixes two cases of bug 22460; bugfix on 0.3.0.1-alpha. - When sending an Ed25519 signing->link certificate in a CERTS cell, send the certificate that matches the x509 certificate that we used on the TLS connection. Previously, there was a race condition if the TLS context rotated after we began the TLS handshake but before we sent the CERTS cell. Fixes a case of bug 22460; bugfix on 0.3.0.1-alpha. o Minor features (security, windows): - Enable a couple of pieces of Windows hardening: one (HeapEnableTerminationOnCorruption) that has been on-by-default since Windows 8, and unavailable before Windows 7; and one (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't affect us, but shouldn't do any harm. Closes ticket 21953. o Minor features (bridge authority): - Add "fingerprint" lines to the networkstatus-bridges file produced by bridge authorities. Closes ticket 22207. o Minor features (code style): - Add "Falls through" comments to our codebase, in order to silence GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas Stieger. Closes ticket 22446. o Minor features (config options): - Allow "%include" directives in torrc configuration files. These directives import the settings from other files, or from all the files in a directory. Closes ticket 1922. Code by Daniel Pinto. - Make SAVECONF return an error when overwriting a torrc that has includes. Using SAVECONF with the FORCE option will allow it to overwrite torrc even if includes are used. Related to ticket 1922. - Add "GETINFO config-can-saveconf" to tell controllers if SAVECONF will work without the FORCE option. Related to ticket 1922. o Minor features (controller): - Warn the first time that a controller requests data in the long- deprecated 'GETINFO network-status' format. Closes ticket 21703. o Minor features (defaults): - The default value for UseCreateFast is now 0: clients which haven't yet received a consensus document will now use a proper ntor handshake to talk to their directory servers whenever they can. Closes ticket 21407. - Onion key rotation and expiry intervals are now defined as a network consensus parameter, per proposal 274. The default lifetime of an onion key is increased from 7 to 28 days. Old onion keys will expire after 7 days by default. This change will make consensus diffs much smaller, and save significant bandwidth. Closes ticket 21641. o Minor features (defensive programming): - Create a pair of consensus parameters, nf_pad_tor2web and nf_pad_single_onion, to disable netflow padding in the consensus for non-anonymous connections in case the overhead is high. Closes ticket 17857. o Minor features (diagnostic): - Add a stack trace to the bug warnings that can be logged when trying to send an outgoing relay cell with n_chan == 0. Diagnostic attempt for bug 23105. - Add logging messages to try to diagnose a rare bug that seems to generate RSA->Ed25519 cross-certificates dated in the 1970s. We think this is happening because of incorrect system clocks, but we'd like to know for certain. Diagnostic for bug 22466. - Avoid an assertion failure, and log a better error message, when unable to remove a file from the consensus cache on Windows. Attempts to mitigate and diagnose bug 22752. o Minor features (directory authority): - Improve the message that authorities report to relays that present RSA/Ed25519 keypairs that conflict with previously pinned keys. Closes ticket 22348. o Minor features (directory cache, consensus diff): - Add a new MaxConsensusAgeForDiffs option to allow directory cache operators with low-resource environments to adjust the number of consensuses they'll store and generate diffs from. Most cache operators should leave it unchanged. Helps to work around bug 22883. o Minor features (fallback directory list): - Update the fallback directory mirror whitelist and blacklist based on operator emails. Closes task 21121. - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564. o Minor features (geoip): - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2 Country database. o Minor features (hidden services, logging): - Log a message when a hidden service descriptor has fewer introduction points than specified in HiddenServiceNumIntroductionPoints. Closes tickets 21598. - Log a message when a hidden service reaches its introduction point circuit limit, and when that limit is reset. Follow up to ticket 21594; closes ticket 21622. - Warn user if multiple entries in EntryNodes and at least one HiddenService are used together. Pinning EntryNodes along with a hidden service can be possibly harmful; for instance see ticket 14917 or 21155. Closes ticket 21155. o Minor features (linux seccomp2 sandbox): - We now have a document storage backend compatible with the Linux seccomp2 sandbox. This backend is used for consensus documents and diffs between them; in the long term, we'd like to use it for unparseable directory material too. Closes ticket 21645 - Increase the maximum allowed size passed to mprotect(PROT_WRITE) from 1MB to 16MB. This was necessary with the glibc allocator in order to allow worker threads to allocate more memory -- which in turn is necessary because of our new use of worker threads for compression. Closes ticket 22096. o Minor features (logging): - Log files are no longer created world-readable by default. (Previously, most distributors would store the logs in a non- world-readable location to prevent inappropriate access. This change is an extra precaution.) Closes ticket 21729; patch from toralf. o Minor features (performance): - Our Keccak (SHA-3) implementation now accesses memory more efficiently, especially on little-endian systems. Closes ticket 21737. - Add an O(1) implementation of channel_find_by_global_id(), to speed some controller functions. o Minor features (relay, configuration): - The MyFamily option may now be repeated as many times as desired, for relays that want to configure large families. Closes ticket 4998; patch by Daniel Pinto. o Minor features (relay, performance): - Always start relays with at least two worker threads, to prevent priority inversion on slow tasks. Part of the fix for bug 22883. - Allow background work to be queued with different priorities, so that a big pile of slow low-priority jobs will not starve out higher priority jobs. This lays the groundwork for a fix for bug 22883. o Minor features (safety): - Add an explicit check to extrainfo_parse_entry_from_string() for NULL inputs. We don't believe this can actually happen, but it may help silence a warning from the Clang analyzer. Closes ticket 21496. o Minor features (testing): - Add more tests for compression backend initialization. Closes ticket 22286. - Add a "--disable-memory-sentinels" feature to help with fuzzing. When Tor is compiled with this option, we disable a number of redundant memory-safety failsafes that are intended to stop bugs from becoming security issues. This makes it easier to hunt for bugs that would be security issues without the failsafes turned on. Closes ticket 21439. - Add a general event-tracing instrumentation support to Tor. This subsystem will enable developers and researchers to add fine- grained instrumentation to their Tor instances, for use when examining Tor network performance issues. There are no trace events yet, and event-tracing is off by default unless enabled at compile time. Implements ticket 13802. - Improve our version parsing tests: add tests for typical version components, add tests for invalid versions, including numeric range and non-numeric prefixes. Unit tests 21278, 21450, and 21507. Partially implements 21470. o Minor bugfixes (bandwidth accounting): - Roll over monthly accounting at the configured hour and minute, rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1. Found by Andrey Karpov with PVS-Studio. o Minor bugfixes (code correctness): - Accurately identify client connections by their lack of peer authentication. This means that we bail out earlier if asked to extend to a client. Follow-up to 21407. Fixes bug 21406; bugfix on 0.2.4.23. o Minor bugfixes (compilation warnings): - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha. - Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha. - When building with certain versions of the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha. o Minor bugfixes (compilation): - Avoid compiler warnings in the unit tests for calling tor_sscanf() with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha. o Minor bugfixes (compression): - When spooling compressed data to an output buffer, don't try to spool more data when there is no more data to spool and we are not trying to flush the input. Previously, we would sometimes launch compression requests with nothing to do, which interferes with our 22672 checks. Fixes bug 22719; bugfix on 0.2.0.16-alpha. o Minor bugfixes (configuration): - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes bug 22252; bugfix on 0.2.9.3-alpha. o Minor bugfixes (connection lifespan): - Allow more control over how long TLS connections are kept open: unify CircuitIdleTimeout and PredictedPortsRelevanceTime into a single option called CircuitsAvailableTimeout. Also, allow the consensus to control the default values for both this preference and the lifespan of relay-to-relay connections. Fixes bug 17592; bugfix on 0.2.5.5-alpha. - Increase the initial circuit build timeout testing frequency, to help ensure that ReducedConnectionPadding clients finish learning a timeout before their orconn would expire. The initial testing rate was set back in the days of TAP and before the Tor Browser updater, when we had to be much more careful about new clients making lots of circuits. With this change, a circuit build timeout is learned in about 15-20 minutes, instead of 100-120 minutes. o Minor bugfixes (controller): - Do not crash when receiving a HSPOST command with an empty body. Fixes part of bug 22644; bugfix on 0.2.7.1-alpha. - Do not crash when receiving a POSTDESCRIPTOR command with an empty body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha. - GETINFO onions/current and onions/detached no longer respond with 551 on empty lists. Fixes bug 21329; bugfix on 0.2.7.1-alpha. - Trigger HS descriptor events on the control port when the client fails to pick a hidden service directory for a hidden service. This can happen if all the hidden service directories are in ExcludeNodes, or they have all been queried within the last 15 minutes. Fixes bug 22042; bugfix on 0.2.5.2-alpha. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. o Minor bugfixes (coverity build support): - Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha. o Minor bugfixes (defensive programming): - Detect and break out of infinite loops in our compression code. We don't think that any such loops exist now, but it's best to be safe. Closes ticket 22672. - Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591. o Minor bugfixes (directory authority): - When a directory authority rejects a descriptor or extrainfo with a given digest, mark that digest as undownloadable, so that we do not attempt to download it again over and over. We previously tried to avoid downloading such descriptors by other means, but we didn't notice if we accidentally downloaded one anyway. This behavior became problematic in 0.2.7.2-alpha, when authorities began pinning Ed25519 keys. Fixes bug 22349; bugfix on 0.2.1.19-alpha. - When rejecting a router descriptor for running an obsolete version of Tor without ntor support, warn about the obsolete tor version, not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha. - Prevent the shared randomness subsystem from asserting when initialized by a bridge authority with an incomplete configuration file. Fixes bug 21586; bugfix on 0.2.9.8. o Minor bugfixes (error reporting, windows): - When formatting Windows error messages, use the English format to avoid codepage issues. Fixes bug 22520; bugfix on 0.1.2.8-alpha. Patch from "Vort". o Minor bugfixes (exit-side DNS): - Fix an untriggerable assertion that checked the output of a libevent DNS error, so that the assertion actually behaves as expected. Fixes bug 22244; bugfix on 0.2.0.20-rc. Found by Andrey Karpov using PVS-Studio. o Minor bugfixes (fallback directories): - Make the usage example in updateFallbackDirs.py actually work, and explain what it does. Fixes bug 22270; bugfix on 0.3.0.3-alpha. - Decrease the guard flag average required to be a fallback. This allows us to keep relays that have their guard flag removed when they restart. Fixes bug 20913; bugfix on 0.2.8.1-alpha. - Decrease the minimum number of fallbacks to 100. Fixes bug 20913; bugfix on 0.2.8.1-alpha. - Make sure fallback directory mirrors have the same address, port, and relay identity key for at least 30 days before they are selected. Fixes bug 20913; bugfix on 0.2.8.1-alpha. o Minor bugfixes (file limits, osx): - When setting the maximum number of connections allowed by the OS, always allow some extra file descriptors for other files. Fixes bug 22797; bugfix on 0.2.0.10-alpha. o Minor bugfixes (hidden services): - Increase the number of circuits that a service is allowed to open over a specific period of time. The value was lower than it should be (8 vs 12) in the normal case of 3 introduction points. Fixes bug 22159; bugfix on 0.3.0.5-rc. - Fix a BUG warning during HSv3 descriptor decoding that could be cause by a specially crafted descriptor. Fixes bug 23233; bugfix on 0.3.0.1-alpha. Bug found by "haxxpop". - Stop printing a cryptic warning when a hidden service gets a request to connect to a virtual port that it hasn't configured. Fixes bug 16706; bugfix on 0.2.6.3-alpha. - Simplify hidden service descriptor creation by using an existing flag to check if an introduction point is established. Fixes bug 21599; bugfix on 0.2.7.2-alpha. o Minor bugfixes (link handshake): - Lower the lifetime of the RSA->Ed25519 cross-certificate to six months, and regenerate it when it is within one month of expiring. Previously, we had generated this certificate at startup with a ten-year lifetime, but that could lead to weird behavior when Tor was started with a grossly inaccurate clock. Mitigates bug 22466; mitigation on 0.3.0.1-alpha. o Minor bugfixes (linux seccomp2 sandbox): - Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha. - Permit the fchmod system call, to avoid crashing on startup when starting with the seccomp2 sandbox and an unexpected set of permissions on the data directory or its contents. Fixes bug 22516; bugfix on 0.2.5.4-alpha. o Minor bugfixes (logging): - When decompressing, do not warn if we fail to decompress using a compression method that we merely guessed. Fixes part of bug 22670; bugfix on 0.1.1.14-alpha. - When decompressing, treat mismatch between content-encoding and actual compression type as a protocol warning. Fixes part of bug 22670; bugfix on 0.1.1.9-alpha. - Downgrade "assigned_to_cpuworker failed" message to info-level severity. In every case that can reach it, either a better warning has already been logged, or no warning is warranted. Fixes bug 22356; bugfix on 0.2.6.3-alpha. - Log a better message when a directory authority replies to an upload with an unexpected status code. Fixes bug 11121; bugfix on 0.1.0.1-rc. - Downgrade a log statement about unexpected relay cells from "bug" to "protocol warning", because there is at least one use case where it can be triggered by a buggy tor implementation. Fixes bug 21293; bugfix on 0.1.1.14-alpha. o Minor bugfixes (logging, relay): - Remove a forgotten debugging message when an introduction point successfully establishes a hidden service prop224 circuit with a client. - Change three other log_warn() for an introduction point to protocol warnings, because they can be failure from the network and are not relevant to the operator. Fixes bug 23078; bugfix on 0.3.0.1-alpha and 0.3.0.2-alpha. o Minor bugfixes (relay): - Inform the geoip and rephist modules about all requests, even on relays that are only fetching microdescriptors. Fixes a bug related to 21585; bugfix on 0.3.0.1-alpha. o Minor bugfixes (memory leaks): - Fix a small memory leak at exit from the backtrace handler code. Fixes bug 21788; bugfix on 0.2.5.2-alpha. Patch from Daniel Pinto. - When directory authorities reject a router descriptor due to keypinning, free the router descriptor rather than leaking the memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha. - Fix a small memory leak when validating a configuration that uses two or more AF_UNIX sockets for the same port type. Fixes bug 23053; bugfix on 0.2.6.3-alpha. This is CID 1415725. o Minor bugfixes (process behavior): - When exiting because of an error, always exit with a nonzero exit status. Previously, we would fail to report an error in our exit status in cases related to __OwningControllerProcess failure, lockfile contention, and Ed25519 key initialization. Fixes bug 22720; bugfix on versions 0.2.1.6-alpha, 0.2.2.28-beta, and 0.2.7.2-alpha respectively. Reported by "f55jwk4f"; patch from "huyvq". o Minor bugfixes (robustness, error handling): - Improve our handling of the cases where OpenSSL encounters a memory error while encoding keys and certificates. We haven't observed these errors in the wild, but if they do happen, we now detect and respond better. Fixes bug 19418; bugfix on all versions of Tor. Reported by Guido Vranken. o Minor bugfixes (testing): - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij. - Use unbuffered I/O for utility functions around the process_handle_t type. This fixes unit test failures reported on OpenBSD and FreeBSD. Fixes bug 21654; bugfix on 0.2.3.1-alpha. - Make display of captured unit test log messages consistent. Fixes bug 21510; bugfix on 0.2.9.3-alpha. - Make test-network.sh always call chutney's test-network.sh. Previously, this only worked on systems which had bash installed, due to some bash-specific code in the script. Fixes bug 19699; bugfix on 0.3.0.4-rc. Follow-up to ticket 21581. - Fix a memory leak in the link-handshake/certs_ok_ed25519 test. Fixes bug 22803; bugfix on 0.3.0.1-alpha. - The unit tests now pass on systems where localhost is misconfigured to some IPv4 address other than 127.0.0.1. Fixes bug 6298; bugfix on 0.0.9pre2. o Minor bugfixes (voting consistency): - Reject version numbers with non-numeric prefixes (such as +, -, or whitespace). Disallowing whitespace prevents differential version parsing between POSIX-based and Windows platforms. Fixes bug 21507 and part of 21508; bugfix on 0.0.8pre1. o Minor bugfixes (Windows service): - When running as a Windows service, set the ID of the main thread correctly. Failure to do so made us fail to send log messages to the controller in 0.2.1.16-rc, slowed down controller event delivery in 0.2.7.3-rc and later, and crash with an assertion failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha. Patch and diagnosis from "Vort". o Minor bugfixes (windows, relay): - Resolve "Failure from drain_fd: No error" warnings on Windows relays. Fixes bug 21540; bugfix on 0.2.6.3-alpha. o Code simplification and refactoring: - Break up the 630-line function connection_dir_client_reached_eof() into a dozen smaller functions. This change should help maintainability and readability of the client directory code. - Isolate our use of the openssl headers so that they are only included from our crypto wrapper modules, and from tests that examine those modules' internals. Closes ticket 21841. - Simplify our API to launch directory requests, making it more extensible and less error-prone. Now it's easier to add extra headers to directory requests. Closes ticket 21646. - Our base64 decoding functions no longer overestimate the output space that they need when parsing unpadded inputs. Closes ticket 17868. - Remove unused "ROUTER_ADDED_NOTIFY_GENERATOR" internal value. Resolves ticket 22213. - The logic that directory caches use to spool request to clients, serving them one part at a time so as not to allocate too much memory, has been refactored for consistency. Previously there was a separate spooling implementation per type of spoolable data. Now there is one common spooling implementation, with extensible data types. Closes ticket 21651. - Tor's compression module now supports multiple backends. Part of the implementation for proposal 278; closes ticket 21663. o Documentation: - Add a manpage description for the key-pinning-journal file. Closes ticket 22347. - Correctly note that bandwidth accounting values are stored in the state file, and the bw_accounting file is now obsolete. Closes ticket 16082. - Document more of the files in the Tor data directory, including cached-extrainfo, secret_onion_key{,_ntor}.old, hidserv-stats, approved-routers, sr-random, and diff-cache. Found while fixing ticket 22347. - Clarify the manpage for the (deprecated) torify script. Closes ticket 6892. - Clarify the behavior of the KeepAliveIsolateSOCKSAuth sub-option. Closes ticket 21873. - Correct documentation about the default DataDirectory value. Closes ticket 21151. - Document the default behavior of NumEntryGuards and NumDirectoryGuards correctly. Fixes bug 21715; bugfix on 0.3.0.1-alpha. - Document key=value pluggable transport arguments for Bridge lines in torrc. Fixes bug 20341; bugfix on 0.2.5.1-alpha. - Note that bandwidth-limiting options don't affect TCP headers or DNS. Closes ticket 17170. o Removed features (configuration options, all in ticket 22060): - These configuration options are now marked Obsolete, and no longer have any effect: AllowInvalidNodes, AllowSingleHopCircuits, AllowSingleHopExits, ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup, WarnUnsafeSocks. They were first marked as deprecated in 0.2.9.2-alpha and have now been removed. The previous default behavior is now always chosen; the previous (less secure) non- default behavior is now unavailable. - CloseHSClientCircuitsImmediatelyOnTimeout and CloseHSServiceRendCircuitsImmediatelyOnTimeout were deprecated in 0.2.9.2-alpha and now have been removed. HS circuits never close on circuit build timeout; they have a longer timeout period. - {Control,DNS,Dir,Socks,Trans,NATD,OR}ListenAddress were deprecated in 0.2.9.2-alpha and now have been removed. Use the ORPort option (and others) to configure listen-only and advertise-only addresses. o Removed features (tools): - We've removed the tor-checkkey tool from src/tools. Long ago, we used it to help people detect RSA keys that were generated by versions of Debian affected by CVE-2008-0166. But those keys have been out of circulation for ages, and this tool is no longer required. Closes ticket 21842. Changes in version 0.3.0.10 - 2017-08-02 Tor 0.3.0.10 backports a collection of small-to-medium bugfixes from the current Tor alpha series. OpenBSD users and TPROXY users should upgrade; others are probably okay sticking with 0.3.0.9. o Major features (build system, continuous integration, backport from 0.3.1.5-alpha): - Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636. o Major bugfixes (linux TPROXY support, backport from 0.3.1.1-alpha): - Fix a typo that had prevented TPROXY-based transparent proxying from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha. Patch from "d4fq0fQAgoJ". o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha): - Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xbar" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007. o Minor features (backport from 0.3.1.5-alpha): - Update geoip and geoip6 to the July 4 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (bandwidth accounting, backport from 0.3.1.2-alpha): - Roll over monthly accounting at the configured hour and minute, rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1. Found by Andrey Karpov with PVS-Studio. o Minor bugfixes (compilation warnings, backport from 0.3.1.5-alpha): - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha. - Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha. - When building with certain versions of the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha. o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha): - Backport a fix for an "unused variable" warning that appeared in some versions of mingw. Fixes bug 22838; bugfix on 0.2.8.1-alpha. o Minor bugfixes (coverity build support, backport from 0.3.1.5-alpha): - Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha. o Minor bugfixes (directory authority, backport from 0.3.1.1-alpha): - When rejecting a router descriptor for running an obsolete version of Tor without ntor support, warn about the obsolete tor version, not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.5-alpha): - Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha. o Minor bugfixes (unit tests, backport from 0.3.1.5-alpha) - Fix a memory leak in the link-handshake/certs_ok_ed25519 test. Fixes bug 22803; bugfix on 0.3.0.1-alpha. Changes in version 0.3.0.9 - 2017-06-29 Tor 0.3.0.9 fixes a path selection bug that would allow a client to use a guard that was in the same network family as a chosen exit relay. This is a security regression; all clients running earlier versions of 0.3.0.x or 0.3.1.x should upgrade to 0.3.0.9 or 0.3.1.4-alpha. This release also backports several other bugfixes from the 0.3.1.x series. o Major bugfixes (path selection, security, backport from 0.3.1.4-alpha): - When choosing which guard to use for a circuit, avoid the exit's family along with the exit itself. Previously, the new guard selection logic avoided the exit, but did not consider its family. Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2017- 006 and CVE-2017-0377. o Major bugfixes (entry guards, backport from 0.3.1.1-alpha): - Don't block bootstrapping when a primary bridge is offline and we can't get its descriptor. Fixes bug 22325; fixes one case of bug 21969; bugfix on 0.3.0.3-alpha. o Major bugfixes (entry guards, backport from 0.3.1.4-alpha): - When starting with an old consensus, do not add new entry guards unless the consensus is "reasonably live" (under 1 day old). Fixes one root cause of bug 22400; bugfix on 0.3.0.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the June 8 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (voting consistency, backport from 0.3.1.1-alpha): - Reject version numbers with non-numeric prefixes (such as +, -, or whitespace). Disallowing whitespace prevents differential version parsing between POSIX-based and Windows platforms. Fixes bug 21507 and part of 21508; bugfix on 0.0.8pre1. o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.4-alpha): - Permit the fchmod system call, to avoid crashing on startup when starting with the seccomp2 sandbox and an unexpected set of permissions on the data directory or its contents. Fixes bug 22516; bugfix on 0.2.5.4-alpha. o Minor bugfixes (defensive programming, backport from 0.3.1.4-alpha): - Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591. Changes in version 0.3.0.8 - 2017-06-08 Tor 0.3.0.8 fixes a pair of bugs that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-004 and TROVE-2017-005. Tor 0.3.0.8 also includes fixes for several key management bugs that sometimes made relays unreliable, as well as several other bugfixes described below. o Major bugfixes (hidden service, relay, security, backport from 0.3.1.3-alpha): - Fix a remotely triggerable assertion failure when a hidden service handles a malformed BEGIN cell. Fixes bug 22493, tracked as TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha. - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha): - When performing the v3 link handshake on a TLS connection, report that we have the x509 certificate that we actually used on that connection, even if we have changed certificates since that connection was first opened. Previously, we would claim to have used our most recent x509 link certificate, which would sometimes make the link handshake fail. Fixes one case of bug 22460; bugfix on 0.2.3.6-alpha. o Major bugfixes (relays, key management, backport from 0.3.1.3-alpha): - Regenerate link and authentication certificates whenever the key that signs them changes; also, regenerate link certificates whenever the signed key changes. Previously, these processes were only weakly coupled, and we relays could (for minutes to hours) wind up with an inconsistent set of keys and certificates, which other relays would not accept. Fixes two cases of bug 22460; bugfix on 0.3.0.1-alpha. - When sending an Ed25519 signing->link certificate in a CERTS cell, send the certificate that matches the x509 certificate that we used on the TLS connection. Previously, there was a race condition if the TLS context rotated after we began the TLS handshake but before we sent the CERTS cell. Fixes a case of bug 22460; bugfix on 0.3.0.1-alpha. o Major bugfixes (hidden service v3, backport from 0.3.1.1-alpha): - Stop rejecting v3 hidden service descriptors because their size did not match an old padding rule. Fixes bug 22447; bugfix on tor-0.3.0.1-alpha. o Minor features (fallback directory list, backport from 0.3.1.3-alpha): - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564. o Minor bugfixes (configuration, backport from 0.3.1.1-alpha): - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes bug 22252; bugfix on 0.2.9.3-alpha. o Minor bugfixes (correctness, backport from 0.3.1.3-alpha): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. o Minor bugfixes (link handshake, backport from 0.3.1.3-alpha): - Lower the lifetime of the RSA->Ed25519 cross-certificate to six months, and regenerate it when it is within one month of expiring. Previously, we had generated this certificate at startup with a ten-year lifetime, but that could lead to weird behavior when Tor was started with a grossly inaccurate clock. Mitigates bug 22466; mitigation on 0.3.0.1-alpha. o Minor bugfixes (memory leak, directory authority, backport from 0.3.1.2-alpha): - When directory authorities reject a router descriptor due to keypinning, free the router descriptor rather than leaking the memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha. Changes in version 0.2.9.11 - 2017-06-08 Tor 0.2.9.11 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) Tor 0.2.9.11 also backports fixes for several key management bugs that sometimes made relays unreliable, as well as several other bugfixes described below. o Major bugfixes (hidden service, relay, security, backport from 0.3.1.3-alpha): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha): - When performing the v3 link handshake on a TLS connection, report that we have the x509 certificate that we actually used on that connection, even if we have changed certificates since that connection was first opened. Previously, we would claim to have used our most recent x509 link certificate, which would sometimes make the link handshake fail. Fixes one case of bug 22460; bugfix on 0.2.3.6-alpha. o Minor features (fallback directory list, backport from 0.3.1.3-alpha): - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564. o Minor features (future-proofing, backport from 0.3.0.7): - Tor no longer refuses to download microdescriptors or descriptors if they are listed as "published in the future". This change will eventually allow us to stop listing meaningful "published" dates in microdescriptor consensuses, and thereby allow us to reduce the resources required to download consensus diffs by over 50%. Implements part of ticket 21642; implements part of proposal 275. o Minor features (directory authorities, backport from 0.3.0.4-rc) - Directory authorities now reject relays running versions 0.2.9.1-alpha through 0.2.9.4-alpha, because those relays suffer from bug 20499 and don't keep their consensus cache up-to-date. Resolves ticket 20509. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (control port, backport from 0.3.0.6): - The GETINFO extra-info/digest/ command was broken because of a wrong base16 decode return value check, introduced when refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha. o Minor bugfixes (correctness, backport from 0.3.1.3-alpha): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.0.7): - The getpid() system call is now permitted under the Linux seccomp2 sandbox, to avoid crashing with versions of OpenSSL (and other libraries) that attempt to learn the process's PID by using the syscall rather than the VDSO code. Fixes bug 21943; bugfix on 0.2.5.1-alpha. o Minor bugfixes (memory leak, directory authority, backport from 0.3.1.2-alpha): - When directory authorities reject a router descriptor due to keypinning, free the router descriptor rather than leaking the memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha. Changes in version 0.2.8.14 - 2017-06-08 Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor features (fallback directory list, backport from 0.3.1.3-alpha): - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. Changes in version 0.2.7.8 - 2017-06-08 Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. Changes in version 0.2.6.12 - 2017-06-08 Tor 0.2.6.12 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. Changes in version 0.2.5.14 - 2017-06-08 Tor 0.2.5.14 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. Changes in version 0.2.4.29 - 2017-06-08 Tor 0.2.4.29 backports a fix for a bug that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-005. (Versions before 0.3.0 are not affected by TROVE-2017-004.) o Major bugfixes (hidden service, relay, security): - Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha. o Minor features (geoip): - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor bugfixes (correctness): - Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. Changes in version 0.3.0.7 - 2017-05-15 Tor 0.3.0.7 fixes a medium-severity security bug in earlier versions of Tor 0.3.0.x, where an attacker could cause a Tor relay process to exit. Relays running earlier versions of Tor 0.3.0.x should upgrade; clients are not affected. o Major bugfixes (hidden service directory, security): - Fix an assertion failure in the hidden service directory code, which could be used by an attacker to remotely cause a Tor relay process to exit. Relays running earlier versions of Tor 0.3.0.x should upgrade. should upgrade. This security issue is tracked as TROVE-2017-002. Fixes bug 22246; bugfix on 0.3.0.1-alpha. o Minor features: - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2 Country database. o Minor features (future-proofing): - Tor no longer refuses to download microdescriptors or descriptors if they are listed as "published in the future". This change will eventually allow us to stop listing meaningful "published" dates in microdescriptor consensuses, and thereby allow us to reduce the resources required to download consensus diffs by over 50%. Implements part of ticket 21642; implements part of proposal 275. o Minor bugfixes (Linux seccomp2 sandbox): - The getpid() system call is now permitted under the Linux seccomp2 sandbox, to avoid crashing with versions of OpenSSL (and other libraries) that attempt to learn the process's PID by using the syscall rather than the VDSO code. Fixes bug 21943; bugfix on 0.2.5.1-alpha. Changes in version 0.3.0.6 - 2017-04-26 Tor 0.3.0.6 is the first stable release of the Tor 0.3.0 series. With the 0.3.0 series, clients and relays now use Ed25519 keys to authenticate their link connections to relays, rather than the old RSA1024 keys that they used before. (Circuit crypto has been Curve25519-authenticated since 0.2.4.8-alpha.) We have also replaced the guard selection and replacement algorithm to behave more robustly in the presence of unreliable networks, and to resist guard- capture attacks. This series also includes numerous other small features and bugfixes, along with more groundwork for the upcoming hidden-services revamp. Per our stable release policy, we plan to support the Tor 0.3.0 release series for at least the next nine months, or for three months after the first stable release of the 0.3.1 series: whichever is longer. If you need a release with long-term support, we recommend that you stay with the 0.2.9 series. Below are the changes since 0.2.9.10. For a list of only the changes since 0.3.0.5-rc, see the ChangeLog file. o Major features (directory authority, security): - The default for AuthDirPinKeys is now 1: directory authorities will reject relays where the RSA identity key matches a previously seen value, but the Ed25519 key has changed. Closes ticket 18319. o Major features (guard selection algorithm): - Tor's guard selection algorithm has been redesigned from the ground up, to better support unreliable networks and restrictive sets of entry nodes, and to better resist guard-capture attacks by hostile local networks. Implements proposal 271; closes ticket 19877. o Major features (next-generation hidden services): - Relays can now handle v3 ESTABLISH_INTRO cells as specified by prop224 aka "Next Generation Hidden Services". Service and clients don't use this functionality yet. Closes ticket 19043. Based on initial code by Alec Heifetz. - Relays now support the HSDir version 3 protocol, so that they can can store and serve v3 descriptors. This is part of the next- generation onion service work detailed in proposal 224. Closes ticket 17238. o Major features (protocol, ed25519 identity keys): - Clients now support including Ed25519 identity keys in the EXTEND2 cells they generate. By default, this is controlled by a consensus parameter, currently disabled. You can turn this feature on for testing by setting ExtendByEd25519ID in your configuration. This might make your traffic appear different than the traffic generated by other users, however. Implements part of ticket 15056; part of proposal 220. - Relays now understand requests to extend to other relays by their Ed25519 identity keys. When an Ed25519 identity key is included in an EXTEND2 cell, the relay will only extend the circuit if the other relay can prove ownership of that identity. Implements part of ticket 15056; part of proposal 220. - Relays now use Ed25519 to prove their Ed25519 identities and to one another, and to clients. This algorithm is faster and more secure than the RSA-based handshake we've been doing until now. Implements the second big part of proposal 220; Closes ticket 15055. o Major features (security): - Change the algorithm used to decide DNS TTLs on client and server side, to better resist DNS-based correlation attacks like the DefecTor attack of Greschbach, Pulls, Roberts, Winter, and Feamster. Now relays only return one of two possible DNS TTL values, and clients are willing to believe DNS TTL values up to 3 hours long. Closes ticket 19769. o Major bugfixes (client, onion service, also in 0.2.9.9): - Fix a client-side onion service reachability bug, where multiple socks requests to an onion service (or a single slow request) could cause us to mistakenly mark some of the service's introduction points as failed, and we cache that failure so eventually we run out and can't reach the service. Also resolves a mysterious "Remote server sent bogus reason code 65021" log warning. The bug was introduced in ticket 17218, where we tried to remember the circuit end reason as a uint16_t, which mangled negative values. Partially fixes bug 21056 and fixes bug 20307; bugfix on 0.2.8.1-alpha. o Major bugfixes (crash, directory connections): - Fix a rare crash when sending a begin cell on a circuit whose linked directory connection had already been closed. Fixes bug 21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett. o Major bugfixes (directory authority): - During voting, when marking a relay as a probable sybil, do not clear its BadExit flag: sybils can still be bad in other ways too. (We still clear the other flags.) Fixes bug 21108; bugfix on 0.2.0.13-alpha. o Major bugfixes (DNS): - Fix a bug that prevented exit nodes from caching DNS records for more than 60 seconds. Fixes bug 19025; bugfix on 0.2.4.7-alpha. o Major bugfixes (IPv6 Exits): - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects any IPv6 addresses. Instead, only reject a port over IPv6 if the exit policy rejects that port on more than an IPv6 /16 of addresses. This bug was made worse by 17027 in 0.2.8.1-alpha, which rejected a relay's own IPv6 address by default. Fixes bug 21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha. o Major bugfixes (parsing): - Fix an integer underflow bug when comparing malformed Tor versions. This bug could crash Tor when built with --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor 0.2.9.8, which were built with -ftrapv by default. In other cases it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix on 0.0.8pre1. Found by OSS-Fuzz. - When parsing a malformed content-length field from an HTTP message, do not read off the end of the buffer. This bug was a potential remote denial-of-service attack against Tor clients and relays. A workaround was released in October 2016, to prevent this bug from crashing Tor. This is a fix for the underlying issue, which should no longer matter (if you applied the earlier patch). Fixes bug 20894; bugfix on 0.2.0.16-alpha. Bug found by fuzzing using AFL (http://lcamtuf.coredump.cx/afl/). o Major bugfixes (scheduler): - Actually compare circuit policies in ewma_cmp_cmux(). This bug caused the channel scheduler to behave more or less randomly, rather than preferring channels with higher-priority circuits. Fixes bug 20459; bugfix on 0.2.6.2-alpha. o Major bugfixes (security, also in 0.2.9.9): - Downgrade the "-ftrapv" option from "always on" to "only on when --enable-expensive-hardening is provided." This hardening option, like others, can turn survivable bugs into crashes--and having it on by default made a (relatively harmless) integer overflow bug into a denial-of-service bug. Fixes bug 21278 (TROVE-2017-001); bugfix on 0.2.9.1-alpha. o Minor feature (client): - Enable IPv6 traffic on the SocksPort by default. To disable this, a user will have to specify "NoIPv6Traffic". Closes ticket 21269. o Minor feature (fallback scripts): - Add a check_existing mode to updateFallbackDirs.py, which checks if fallbacks in the hard-coded list are working. Closes ticket 20174. Patch by haxxpop. o Minor feature (protocol versioning): - Add new protocol version for proposal 224. HSIntro now advertises version "3-4" and HSDir version "1-2". Fixes ticket 20656. o Minor features (ciphersuite selection): - Allow relays to accept a wider range of ciphersuites, including chacha20-poly1305 and AES-CCM. Closes the other part of 15426. - Clients now advertise a list of ciphersuites closer to the ones preferred by Firefox. Closes part of ticket 15426. o Minor features (controller): - Add "GETINFO sr/current" and "GETINFO sr/previous" keys, to expose shared-random values to the controller. Closes ticket 19925. - When HSFETCH arguments cannot be parsed, say "Invalid argument" rather than "unrecognized." Closes ticket 20389; patch from Ivan Markin. o Minor features (controller, configuration): - Each of the *Port options, such as SocksPort, ORPort, ControlPort, and so on, now comes with a __*Port variant that will not be saved to the torrc file by the controller's SAVECONF command. This change allows TorBrowser to set up a single-use domain socket for each time it launches Tor. Closes ticket 20956. - The GETCONF command can now query options that may only be meaningful in context-sensitive lists. This allows the controller to query the mixed SocksPort/__SocksPort style options introduced in feature 20956. Implements ticket 21300. o Minor features (diagnostic, directory client): - Warn when we find an unexpected inconsistency in directory download status objects. Prevents some negative consequences of bug 20593. o Minor features (directory authorities): - Directory authorities now reject descriptors that claim to be malformed versions of Tor. Helps prevent exploitation of bug 21278. - Reject version numbers with components that exceed INT32_MAX. Otherwise 32-bit and 64-bit platforms would behave inconsistently. Fixes bug 21450; bugfix on 0.0.8pre1. o Minor features (directory authority): - Add a new authority-only AuthDirTestEd25519LinkKeys option (on by default) to control whether authorities should try to probe relays by their Ed25519 link keys. This option will go away in a few releases--unless we encounter major trouble in our ed25519 link protocol rollout, in which case it will serve as a safety option. o Minor features (directory cache): - Relays and bridges will now refuse to serve the consensus they have if they know it is too old for a client to use. Closes ticket 20511. o Minor features (ed25519 link handshake): - Advertise support for the ed25519 link handshake using the subprotocol-versions mechanism, so that clients can tell which relays can identity themselves by Ed25519 ID. Closes ticket 20552. o Minor features (entry guards): - Add UseEntryGuards to TEST_OPTIONS_DEFAULT_VALUES in order to not break regression tests. - Require UseEntryGuards when UseBridges is set, in order to make sure bridges aren't bypassed. Resolves ticket 20502. o Minor features (fallback directories): - Allow 3 fallback relays per operator, which is safe now that we are choosing 200 fallback relays. Closes ticket 20912. - Annotate updateFallbackDirs.py with the bandwidth and consensus weight for each candidate fallback. Closes ticket 20878. - Display the relay fingerprint when downloading consensuses from fallbacks. Closes ticket 20908. - Exclude relays affected by bug 20499 from the fallback list. Exclude relays from the fallback list if they are running versions known to be affected by bug 20499, or if in our tests they deliver a stale consensus (i.e. one that expired more than 24 hours ago). Closes ticket 20539. - Make it easier to change the output sort order of fallbacks. Closes ticket 20822. - Reduce the minimum fallback bandwidth to 1 MByte/s. Part of ticket 18828. - Require fallback directories to have the same address and port for 7 days (now that we have enough relays with this stability). Relays whose OnionOO stability timer is reset on restart by bug 18050 should upgrade to Tor 0.2.8.7 or later, which has a fix for this issue. Closes ticket 20880; maintains short-term fix in 0.2.8.2-alpha. - Require fallbacks to have flags for 90% of the time (weighted decaying average), rather than 95%. This allows at least 73% of clients to bootstrap in the first 5 seconds without contacting an authority. Part of ticket 18828. - Select 200 fallback directories for each release. Closes ticket 20881. o Minor features (fingerprinting resistance, authentication): - Extend the length of RSA keys used for TLS link authentication to 2048 bits. (These weren't used for forward secrecy; for forward secrecy, we used P256.) Closes ticket 13752. o Minor features (geoip): - Update geoip and geoip6 to the April 4 2017 Maxmind GeoLite2 Country database. o Minor features (geoip, also in 0.2.9.9): - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2 Country database. o Minor features (infrastructure): - Implement smartlist_add_strdup() function. Replaces the use of smartlist_add(sl, tor_strdup(str)). Closes ticket 20048. o Minor features (linting): - Enhance the changes file linter to warn on Tor versions that are prefixed with "tor-". Closes ticket 21096. o Minor features (logging): - In several places, describe unset ed25519 keys as "", rather than the scary "AAAAAAAA...AAA". Closes ticket 21037. o Minor features (portability, compilation): - Autoconf now checks to determine if OpenSSL structures are opaque, instead of explicitly checking for OpenSSL version numbers. Part of ticket 21359. - Support building with recent LibreSSL code that uses opaque structures. Closes ticket 21359. o Minor features (relay): - We now allow separation of exit and relay traffic to different source IP addresses, using the OutboundBindAddressExit and OutboundBindAddressOR options respectively. Closes ticket 17975. Written by Michael Sonntag. o Minor features (reliability, crash): - Try better to detect problems in buffers where they might grow (or think they have grown) over 2 GB in size. Diagnostic for bug 21369. o Minor features (testing): - During 'make test-network-all', if tor logs any warnings, ask chutney to output them. Requires a recent version of chutney with the 21572 patch. Implements 21570. o Minor bugfix (control protocol): - The reply to a "GETINFO config/names" request via the control protocol now spells the type "Dependent" correctly. This is a breaking change in the control protocol. (The field seems to be ignored by the most common known controllers.) Fixes bug 18146; bugfix on 0.1.1.4-alpha. - The GETINFO extra-info/digest/ command was broken because of a wrong base16 decode return value check, introduced when refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha. o Minor bugfix (logging): - Don't recommend the use of Tor2web in non-anonymous mode. Recommending Tor2web is a bad idea because the client loses all anonymity. Tor2web should only be used in specific cases by users who *know* and understand the issues. Fixes bug 21294; bugfix on 0.2.9.3-alpha. o Minor bugfixes (bug resilience): - Fix an unreachable size_t overflow in base64_decode(). Fixes bug 19222; bugfix on 0.2.0.9-alpha. Found by Guido Vranken; fixed by Hans Jerry Illikainen. o Minor bugfixes (build): - Replace obsolete Autoconf macros with their modern equivalent and prevent similar issues in the future. Fixes bug 20990; bugfix on 0.1.0.1-rc. o Minor bugfixes (certificate expiration time): - Avoid using link certificates that don't become valid till some time in the future. Fixes bug 21420; bugfix on 0.2.4.11-alpha o Minor bugfixes (client): - Always recover from failures in extend_info_from_node(), in an attempt to prevent any recurrence of bug 21242. Fixes bug 21372; bugfix on 0.2.3.1-alpha. - When clients that use bridges start up with a cached consensus on disk, they were ignoring it and downloading a new one. Now they use the cached one. Fixes bug 20269; bugfix on 0.2.3.12-alpha. o Minor bugfixes (code correctness): - Repair a couple of (unreachable or harmless) cases of the risky comparison-by-subtraction pattern that caused bug 21278. o Minor bugfixes (config): - Don't assert on startup when trying to get the options list and LearnCircuitBuildTimeout is set to 0: we are currently parsing the options so of course they aren't ready yet. Fixes bug 21062; bugfix on 0.2.9.3-alpha. o Minor bugfixes (configuration): - Accept non-space whitespace characters after the severity level in the `Log` option. Fixes bug 19965; bugfix on 0.2.1.1-alpha. - Support "TByte" and "TBytes" units in options given in bytes. "TB", "terabyte(s)", "TBit(s)" and "terabit(s)" were already supported. Fixes bug 20622; bugfix on 0.2.0.14-alpha. o Minor bugfixes (configure, autoconf): - Rename the configure option --enable-expensive-hardening to --enable-fragile-hardening. Expensive hardening makes the tor daemon abort when some kinds of issues are detected. Thus, it makes tor more at risk of remote crashes but safer against RCE or heartbleed bug category. We now try to explain this issue in a message from the configure script. Fixes bug 21290; bugfix on 0.2.5.4-alpha. o Minor bugfixes (consensus weight): - Add new consensus method that initializes bw weights to 1 instead of 0. This prevents a zero weight from making it all the way to the end (happens in small testing networks) and causing an error. Fixes bug 14881; bugfix on 0.2.2.17-alpha. o Minor bugfixes (crash prevention): - Fix an (currently untriggerable, but potentially dangerous) crash bug when base32-encoding inputs whose sizes are not a multiple of 5. Fixes bug 21894; bugfix on 0.2.9.1-alpha. o Minor bugfixes (dead code): - Remove a redundant check for PidFile changes at runtime in options_transition_allowed(): this check is already performed regardless of whether the sandbox is active. Fixes bug 21123; bugfix on 0.2.5.4-alpha. o Minor bugfixes (descriptors): - Correctly recognise downloaded full descriptors as valid, even when using microdescriptors as circuits. This affects clients with FetchUselessDescriptors set, and may affect directory authorities. Fixes bug 20839; bugfix on 0.2.3.2-alpha. o Minor bugfixes (directory mirrors): - Allow relays to use directory mirrors without a DirPort: these relays need to be contacted over their ORPorts using a begindir connection. Fixes one case of bug 20711; bugfix on 0.2.8.2-alpha. - Clarify the message logged when a remote relay is unexpectedly missing an ORPort or DirPort: users were confusing this with a local port. Fixes another case of bug 20711; bugfix on 0.2.8.2-alpha. o Minor bugfixes (directory system): - Bridges and relays now use microdescriptors (like clients do) rather than old-style router descriptors. Now bridges will blend in with clients in terms of the circuits they build. Fixes bug 6769; bugfix on 0.2.3.2-alpha. - Download all consensus flavors, descriptors, and authority certificates when FetchUselessDescriptors is set, regardless of whether tor is a directory cache or not. Fixes bug 20667; bugfix on all recent tor versions. o Minor bugfixes (documentation): - Update the tor manual page to document every option that can not be changed while tor is running. Fixes bug 21122. o Minor bugfixes (ed25519 certificates): - Correctly interpret ed25519 certificates that would expire some time after 19 Jan 2038. Fixes bug 20027; bugfix on 0.2.7.2-alpha. o Minor bugfixes (fallback directories): - Avoid checking fallback candidates' DirPorts if they are down in OnionOO. When a relay operator has multiple relays, this prioritizes relays that are up over relays that are down. Fixes bug 20926; bugfix on 0.2.8.3-alpha. - Stop failing when OUTPUT_COMMENTS is True in updateFallbackDirs.py. Fixes bug 20877; bugfix on 0.2.8.3-alpha. - Stop failing when a relay has no uptime data in updateFallbackDirs.py. Fixes bug 20945; bugfix on 0.2.8.1-alpha. o Minor bugfixes (hidden service): - Clean up the code for expiring intro points with no associated circuits. It was causing, rarely, a service with some expiring introduction points to not open enough additional introduction points. Fixes part of bug 21302; bugfix on 0.2.7.2-alpha. - Resolve two possible underflows which could lead to creating and closing a lot of introduction point circuits in a non-stop loop. Fixes bug 21302; bugfix on 0.2.7.2-alpha. - Stop setting the torrc option HiddenServiceStatistics to "0" just because we're not a bridge or relay. Instead, we preserve whatever value the user set (or didn't set). Fixes bug 21150; bugfix on 0.2.6.2-alpha. o Minor bugfixes (hidden services): - Make hidden services check for failed intro point connections, even when they have exceeded their intro point creation limit. Fixes bug 21596; bugfix on 0.2.7.2-alpha. Reported by Alec Muffett. - Make hidden services with 8 to 10 introduction points check for failed circuits immediately after startup. Previously, they would wait for 5 minutes before performing their first checks. Fixes bug 21594; bugfix on 0.2.3.9-alpha. Reported by Alec Muffett. - Stop ignoring misconfigured hidden services. Instead, refuse to start tor until the misconfigurations have been corrected. Fixes bug 20559; bugfix on multiple commits in 0.2.7.1-alpha and earlier. o Minor bugfixes (IPv6): - Make IPv6-using clients try harder to find an IPv6 directory server. Fixes bug 20999; bugfix on 0.2.8.2-alpha. - When IPv6 addresses have not been downloaded yet (microdesc consensus documents don't list relay IPv6 addresses), use hard- coded addresses for authorities, fallbacks, and configured bridges. Now IPv6-only clients can use microdescriptors. Fixes bug 20996; bugfix on b167e82 from 19608 in 0.2.8.5-alpha. o Minor bugfixes (memory leak at exit): - Fix a small harmless memory leak at exit of the previously unused RSA->Ed identity cross-certificate. Fixes bug 17779; bugfix on 0.2.7.2-alpha. o Minor bugfixes (onion services): - Allow the number of introduction points to be as low as 0, rather than as low as 3. Fixes bug 21033; bugfix on 0.2.7.2-alpha. o Minor bugfixes (portability): - Use "OpenBSD" compiler macro instead of "OPENBSD" or "__OpenBSD__". It is supported by OpenBSD itself, and also by most OpenBSD variants (such as Bitrig). Fixes bug 20980; bugfix on 0.1.2.1-alpha. o Minor bugfixes (portability, also in 0.2.9.9): - Avoid crashing when Tor is built using headers that contain CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix on 0.2.9.1-alpha. - Fix Libevent detection on platforms without Libevent 1 headers installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha. o Minor bugfixes (relay): - Avoid a double-marked-circuit warning that could happen when we receive DESTROY cells under heavy load. Fixes bug 20059; bugfix on 0.1.0.1-rc. - Honor DataDirectoryGroupReadable when tor is a relay. Previously, initializing the keys would reset the DataDirectory to 0700 instead of 0750 even if DataDirectoryGroupReadable was set to 1. Fixes bug 19953; bugfix on 0.0.2pre16. Patch by "redfish". o Minor bugfixes (testing): - Fix Raspbian build issues related to missing socket errno in test_util.c. Fixes bug 21116; bugfix on 0.2.8.2. Patch by "hein". - Remove undefined behavior from the backtrace generator by removing its signal handler. Fixes bug 21026; bugfix on 0.2.5.2-alpha. - Use bash in src/test/test-network.sh. This ensures we reliably call chutney's newer tools/test-network.sh when available. Fixes bug 21562; bugfix on 0.2.9.1-alpha. o Minor bugfixes (tor-resolve): - The tor-resolve command line tool now rejects hostnames over 255 characters in length. Previously, it would silently truncate them, which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5. Patch by "junglefowl". o Minor bugfixes (unit tests): - Allow the unit tests to pass even when DNS lookups of bogus addresses do not fail as expected. Fixes bug 20862 and 20863; bugfix on unit tests introduced in 0.2.8.1-alpha through 0.2.9.4-alpha. o Minor bugfixes (util): - When finishing writing a file to disk, if we were about to replace the file with the temporary file created before and we fail to replace it, remove the temporary file so it doesn't stay on disk. Fixes bug 20646; bugfix on 0.2.0.7-alpha. Patch by fk. o Minor bugfixes (Windows services): - Be sure to initialize the monotonic time subsystem before using it, even when running as an NT service. Fixes bug 21356; bugfix on 0.2.9.1-alpha. o Minor bugfixes (Windows): - Check for getpagesize before using it to mmap files. This fixes compilation in some MinGW environments. Fixes bug 20530; bugfix on 0.1.2.1-alpha. Reported by "ice". o Code simplification and refactoring: - Abolish all global guard context in entrynodes.c; replace with new guard_selection_t structure as preparation for proposal 271. Closes ticket 19858. - Extract magic numbers in circuituse.c into defined variables. - Introduce rend_service_is_ephemeral() that tells if given onion service is ephemeral. Replace unclear NULL-checkings for service directory with this function. Closes ticket 20526. - Refactor circuit_is_available_for_use to remove unnecessary check. - Refactor circuit_predict_and_launch_new for readability and testability. Closes ticket 18873. - Refactor code to manipulate global_origin_circuit_list into separate functions. Closes ticket 20921. - Refactor large if statement in purpose_needs_anonymity to use switch statement instead. Closes part of ticket 20077. - Refactor the hashing API to return negative values for errors, as is done as throughout the codebase. Closes ticket 20717. - Remove data structures that were used to index or_connection objects by their RSA identity digests. These structures are fully redundant with the similar structures used in the channel abstraction. - Remove duplicate code in the channel_write_*cell() functions. Closes ticket 13827; patch from Pingl. - Remove redundant behavior of is_sensitive_dir_purpose, refactor to use only purpose_needs_anonymity. Closes part of ticket 20077. - The code to generate and parse EXTEND and EXTEND2 cells has been replaced with code automatically generated by the "trunnel" utility. o Documentation (formatting): - Clean up formatting of tor.1 man page and HTML doc, where 
      blocks were incorrectly appearing. Closes ticket 20885.

  o Documentation (man page):
    - Clarify many options in tor.1 and add some min/max values for
      HiddenService options. Closes ticket 21058.

  o Documentation:
    - Change '1' to 'weight_scale' in consensus bw weights calculation
      comments, as that is reality. Closes ticket 20273. Patch
      from pastly.
    - Clarify that when ClientRejectInternalAddresses is enabled (which
      is the default), multicast DNS hostnames for machines on the local
      network (of the form *.local) are also rejected. Closes
      ticket 17070.
    - Correct the value for AuthDirGuardBWGuarantee in the manpage, from
      250 KBytes to 2 MBytes. Fixes bug 20435; bugfix on 0.2.5.6-alpha.
    - Include the "TBits" unit in Tor's man page. Fixes part of bug
      20622; bugfix on 0.2.5.1-alpha.
    - Small fixes to the fuzzing documentation. Closes ticket 21472.
    - Stop the man page from incorrectly stating that HiddenServiceDir
      must already exist. Fixes 20486.
    - Update the description of the directory server options in the
      manual page, to clarify that a relay no longer needs to set
      DirPort in order to be a directory cache. Closes ticket 21720.

  o Removed features:
    - The AuthDirMaxServersPerAuthAddr option no longer exists: The same
      limit for relays running on a single IP applies to authority IP
      addresses as well as to non-authority IP addresses. Closes
      ticket 20960.
    - The UseDirectoryGuards torrc option no longer exists: all users
      that use entry guards will also use directory guards. Related to
      proposal 271; implements part of ticket 20831.

  o Testing:
    - Add tests for networkstatus_compute_bw_weights_v10.
    - Add unit tests circuit_predict_and_launch_new.
    - Extract dummy_origin_circuit_new so it can be used by other
      test functions.
    - New unit tests for tor_htonll(). Closes ticket 19563. Patch
      from "overcaffeinated".
    - Perform the coding style checks when running the tests and fail
      when coding style violations are found. Closes ticket 5500.


Changes in version 0.2.8.13 - 2017-03-03
  Tor 0.2.8.13 backports a security fix from later Tor
  releases.  Anybody running Tor 0.2.8.12 or earlier should upgrade to this
  this release, if for some reason they cannot upgrade to a later
  release series, and if they build Tor with the --enable-expensive-hardening
  option.

  Note that support for Tor 0.2.8.x is ending next year: we will not issue
  any fixes for the Tor 0.2.8.x series after 1 Jan 2018.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.


Changes in version 0.2.7.7 - 2017-03-03
  Tor 0.2.7.7 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.7.6 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.7.x is ending this year: we will not issue
  any fixes for the Tor 0.2.7.x series after 1 August 2017.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.


Changes in version 0.2.6.11 - 2017-03-03
  Tor 0.2.6.11 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.6.10 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.6.x is ending this year: we will not issue
  any fixes for the Tor 0.2.6.x series after 1 August 2017.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.


Changes in version 0.2.5.13 - 2017-03-03
  Tor 0.2.5.13 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.5.13 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.5.x is ending next year: we will not issue
  any fixes for the Tor 0.2.5.x series after 1 May 2018.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (crypto error-handling, backport from 0.2.7.2-alpha):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.


Changes in version 0.2.4.28 - 2017-03-03
  Tor 0.2.4.28 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.4.27 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.4.x is ending soon: we will not issue
  any fixes for the Tor 0.2.4.x series after 1 August 2017.  If you need
  a Tor release series with long-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (DoS-resistance, backport from 0.2.7.1-alpha):
    - Make it harder for attackers to overload hidden services with
      introductions, by blocking multiple introduction requests on the
      same circuit. Resolves ticket 15515.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.


Changes in version 0.2.9.10 - 2017-03-01
  Tor 0.2.9.10 backports a security fix from later Tor release.  It also
  includes fixes for some major issues affecting directory authorities,
  LibreSSL compatibility, and IPv6 correctness.

  The Tor 0.2.9.x release series is now marked as a long-term-support
  series.  We intend to backport security fixes to 0.2.9.x until at
  least January of 2020.

  o Major bugfixes (directory authority, 0.3.0.3-alpha):
    - During voting, when marking a relay as a probable sybil, do not
      clear its BadExit flag: sybils can still be bad in other ways
      too. (We still clear the other flags.) Fixes bug 21108; bugfix
      on 0.2.0.13-alpha.

  o Major bugfixes (IPv6 Exits, backport from 0.3.0.3-alpha):
    - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects
      any IPv6 addresses. Instead, only reject a port over IPv6 if the
      exit policy rejects that port on more than an IPv6 /16 of
      addresses. This bug was made worse by 17027 in 0.2.8.1-alpha,
      which rejected a relay's own IPv6 address by default. Fixes bug
      21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.

  o Major bugfixes (parsing, also in 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (directory authorities, also in 0.3.0.4-rc):
    - Directory authorities now reject descriptors that claim to be
      malformed versions of Tor. Helps prevent exploitation of
      bug 21278.
    - Reject version numbers with components that exceed INT32_MAX.
      Otherwise 32-bit and 64-bit platforms would behave inconsistently.
      Fixes bug 21450; bugfix on 0.0.8pre1.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor features (portability, compilation, backport from 0.3.0.3-alpha):
    - Autoconf now checks to determine if OpenSSL structures are opaque,
      instead of explicitly checking for OpenSSL version numbers. Part
      of ticket 21359.
    - Support building with recent LibreSSL code that uses opaque
      structures. Closes ticket 21359.

  o Minor bugfixes (code correctness, also in 0.3.0.4-rc):
    - Repair a couple of (unreachable or harmless) cases of the risky
      comparison-by-subtraction pattern that caused bug 21278.

  o Minor bugfixes (tor-resolve, backport from 0.3.0.3-alpha):
    - The tor-resolve command line tool now rejects hostnames over 255
      characters in length. Previously, it would silently truncate them,
      which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5.
      Patch by "junglefowl".


Changes in version 0.2.9.9 - 2017-01-23
  Tor 0.2.9.9 fixes a denial-of-service bug where an attacker could
  cause relays and clients to crash, even if they were not built with
  the --enable-expensive-hardening option. This bug affects all 0.2.9.x
  versions, and also affects 0.3.0.1-alpha: all relays running an affected
  version should upgrade.

  This release also resolves a client-side onion service reachability
  bug, and resolves a pair of small portability issues.

  o Major bugfixes (security):
    - Downgrade the "-ftrapv" option from "always on" to "only on when
      --enable-expensive-hardening is provided." This hardening option,
      like others, can turn survivable bugs into crashes -- and having
      it on by default made a (relatively harmless) integer overflow bug
      into a denial-of-service bug. Fixes bug 21278 (TROVE-2017-001);
      bugfix on 0.2.9.1-alpha.

  o Major bugfixes (client, onion service):
    - Fix a client-side onion service reachability bug, where multiple
      socks requests to an onion service (or a single slow request)
      could cause us to mistakenly mark some of the service's
      introduction points as failed, and we cache that failure so
      eventually we run out and can't reach the service. Also resolves a
      mysterious "Remote server sent bogus reason code 65021" log
      warning. The bug was introduced in ticket 17218, where we tried to
      remember the circuit end reason as a uint16_t, which mangled
      negative values. Partially fixes bug 21056 and fixes bug 20307;
      bugfix on 0.2.8.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (portability):
    - Avoid crashing when Tor is built using headers that contain
      CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel
      without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix
      on 0.2.9.1-alpha.
    - Fix Libevent detection on platforms without Libevent 1 headers
      installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha.


Changes in version 0.2.8.12 - 2016-12-19
  Tor 0.2.8.12 backports a fix for a medium-severity issue (bug 21018
  below) where Tor clients could crash when attempting to visit a
  hostile hidden service. Clients are recommended to upgrade as packages
  become available for their systems.

  It also includes an updated list of fallback directories, backported
  from 0.2.9.

  Now that the Tor 0.2.9 series is stable, only major bugfixes will be
  backported to 0.2.8 in the future.

  o Major bugfixes (parsing, security, backported from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Minor features (fallback directory list, backported from 0.2.9.8):
    - Replace the 81 remaining fallbacks of the 100 originally
      introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
      fallbacks (123 new, 54 existing, 27 removed) generated in December
      2016. Resolves ticket 20170.

  o Minor features (geoip, backported from 0.2.9.7-rc):
    - Update geoip and geoip6 to the December 7 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.9.8 - 2016-12-19
  Tor 0.2.9.8 is the first stable release of the Tor 0.2.9 series.

  The Tor 0.2.9 series makes mandatory a number of security features
  that were formerly optional. It includes support for a new shared-
  randomness protocol that will form the basis for next generation
  hidden services, includes a single-hop hidden service mode for
  optimizing .onion services that don't actually want to be hidden,
  tries harder not to overload the directory authorities with excessive
  downloads, and supports a better protocol versioning scheme for
  improved compatibility with other implementations of the Tor protocol.

  And of course, there are numerous other bugfixes and improvements.

  This release also includes a fix for a medium-severity issue (bug
  21018 below) where Tor clients could crash when attempting to visit a
  hostile hidden service. Clients are recommended to upgrade as packages
  become available for their systems.

  Below are listed the changes since Tor 0.2.8.11.  For a list of
  changes since 0.2.9.7-rc, see the ChangeLog file.

  o New system requirements:
    - When building with OpenSSL, Tor now requires version 1.0.1 or
      later. OpenSSL 1.0.0 and earlier are no longer supported by the
      OpenSSL team, and should not be used. Closes ticket 20303.
    - Tor now requires Libevent version 2.0.10-stable or later. Older
      versions of Libevent have less efficient backends for several
      platforms, and lack the DNS code that we use for our server-side
      DNS support. This implements ticket 19554.
    - Tor now requires zlib version 1.2 or later, for security,
      efficiency, and (eventually) gzip support. (Back when we started,
      zlib 1.1 and zlib 1.0 were still found in the wild. 1.2 was
      released in 2003. We recommend the latest version.)

  o Deprecated features:
    - A number of DNS-cache-related sub-options for client ports are now
      deprecated for security reasons, and may be removed in a future
      version of Tor. (We believe that client-side DNS caching is a bad
      idea for anonymity, and you should not turn it on.) The options
      are: CacheDNS, CacheIPv4DNS, CacheIPv6DNS, UseDNSCache,
      UseIPv4Cache, and UseIPv6Cache.
    - A number of options are deprecated for security reasons, and may
      be removed in a future version of Tor. The options are:
      AllowDotExit, AllowInvalidNodes, AllowSingleHopCircuits,
      AllowSingleHopExits, ClientDNSRejectInternalAddresses,
      CloseHSClientCircuitsImmediatelyOnTimeout,
      CloseHSServiceRendCircuitsImmediatelyOnTimeout,
      ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup,
      UseNTorHandshake, and WarnUnsafeSocks.
    - The *ListenAddress options are now deprecated as unnecessary: the
      corresponding *Port options should be used instead. These options
      may someday be removed. The affected options are:
      ControlListenAddress, DNSListenAddress, DirListenAddress,
      NATDListenAddress, ORListenAddress, SocksListenAddress,
      and TransListenAddress.

  o Major bugfixes (parsing, security, new since 0.2.9.7-rc):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major features (build, hardening):
    - Tor now builds with -ftrapv by default on compilers that support
      it. This option detects signed integer overflow (which C forbids),
      and turns it into a hard-failure. We do not apply this option to
      code that needs to run in constant time to avoid side-channels;
      instead, we use -fwrapv in that code. Closes ticket 17983.
    - When --enable-expensive-hardening is selected, stop applying the
      clang/gcc sanitizers to code that needs to run in constant time.
      Although we are aware of no introduced side-channels, we are not
      able to prove that there are none. Related to ticket 17983.

  o Major features (circuit building, security):
    - Authorities, relays, and clients now require ntor keys in all
      descriptors, for all hops (except for rare hidden service protocol
      cases), for all circuits, and for all other roles. Part of
      ticket 19163.
    - Authorities, relays, and clients only use ntor, except for
      rare cases in the hidden service protocol. Part of ticket 19163.

  o Major features (compilation):
    - Our big list of extra GCC warnings is now enabled by default when
      building with GCC (or with anything like Clang that claims to be
      GCC-compatible). To make all warnings into fatal compilation
      errors, pass --enable-fatal-warnings to configure. Closes
      ticket 19044.
    - Use the Autoconf macro AC_USE_SYSTEM_EXTENSIONS to automatically
      turn on C and POSIX extensions. (Previously, we attempted to do
      this on an ad hoc basis.) Closes ticket 19139.

  o Major features (directory authorities, hidden services):
    - Directory authorities can now perform the shared randomness
      protocol specified by proposal 250. Using this protocol, directory
      authorities generate a global fresh random value every day. In the
      future, this value will be used by hidden services to select
      HSDirs. This release implements the directory authority feature;
      the hidden service side will be implemented in the future as part
      of proposal 224. Resolves ticket 16943; implements proposal 250.

  o Major features (downloading, random exponential backoff):
    - When we fail to download an object from a directory service, wait
      for an (exponentially increasing) randomized amount of time before
      retrying, rather than a fixed interval as we did before. This
      prevents a group of Tor instances from becoming too synchronized,
      or a single Tor instance from becoming too predictable, in its
      download schedule. Closes ticket 15942.

  o Major features (resource management):
    - Tor can now notice it is about to run out of sockets, and
      preemptively close connections of lower priority. (This feature is
      off by default for now, since the current prioritizing method is
      yet not mature enough. You can enable it by setting
      "DisableOOSCheck 0", but watch out: it might close some sockets
      you would rather have it keep.) Closes ticket 18640.

  o Major features (single-hop "hidden" services):
    - Add experimental HiddenServiceSingleHopMode and
      HiddenServiceNonAnonymousMode options. When both are set to 1,
      every hidden service on that Tor instance becomes a non-anonymous
      Single Onion Service. Single Onions make one-hop (direct)
      connections to their introduction and rendezvous points. One-hop
      circuits make Single Onion servers easily locatable, but clients
      remain location-anonymous. This is compatible with the existing
      hidden service implementation, and works on the current Tor
      network without any changes to older relays or clients. Implements
      proposal 260, completes ticket 17178. Patch by teor and asn.

  o Major features (subprotocol versions):
    - Tor directory authorities now vote on a set of recommended
      "subprotocol versions", and on a set of required subprotocol
      versions. Clients and relays that lack support for a _required_
      subprotocol version will not start; those that lack support for a
      _recommended_ subprotocol version will warn the user to upgrade.
      This change allows compatible implementations of the Tor protocol(s)
      to exist without pretending to be 100% bug-compatible with
      particular releases of Tor itself. Closes ticket 19958; implements
      part of proposal 264.

  o Major bugfixes (circuit building):
    - Hidden service client-to-intro-point and service-to-rendezvous-
      point circuits use the TAP key supplied by the protocol, to avoid
      epistemic attacks. Fixes bug 19163; bugfix on 0.2.4.18-rc.

  o Major bugfixes (download scheduling):
    - Avoid resetting download status for consensuses hourly, since we
      already have another, smarter retry mechanism. Fixes bug 8625;
      bugfix on 0.2.0.9-alpha.
    - If a consensus expires while we are waiting for certificates to
      download, stop waiting for certificates.
    - If we stop waiting for certificates less than a minute after we
      started downloading them, do not consider the certificate download
      failure a separate failure. Fixes bug 20533; bugfix
      on 0.2.0.9-alpha.
    - When using exponential backoff in test networks, use a lower
      exponent, so the delays do not vary as much. This helps test
      networks bootstrap consistently. Fixes bug 20597; bugfix on 20499.

  o Major bugfixes (exit policies):
    - Avoid disclosing exit outbound bind addresses, configured port
      bind addresses, and local interface addresses in relay descriptors
      by default under ExitPolicyRejectPrivate. Instead, only reject
      these (otherwise unlisted) addresses if
      ExitPolicyRejectLocalInterfaces is set. Fixes bug 18456; bugfix on
      0.2.7.2-alpha. Patch by teor.

  o Major bugfixes (hidden services):
    - Allow Tor clients with appropriate controllers to work with
      FetchHidServDescriptors set to 0. Previously, this option also
      disabled descriptor cache lookup, thus breaking hidden services
      entirely. Fixes bug 18704; bugfix on 0.2.0.20-rc. Patch by "twim".
    - Clients now require hidden services to include the TAP keys for
      their intro points in the hidden service descriptor. This prevents
      an inadvertent upgrade to ntor, which a malicious hidden service
      could use to distinguish clients by consensus version. Fixes bug
      20012; bugfix on 0.2.4.8-alpha. Patch by teor.

  o Major bugfixes (relay, resolver, logging):
    - For relays that don't know their own address, avoid attempting a
      local hostname resolve for each descriptor we download. This
      will cut down on the number of "Success: chose address 'x.x.x.x'"
      log lines, and also avoid confusing clock jumps if the resolver
      is slow. Fixes bugs 20423 and 20610; bugfix on 0.2.8.1-alpha.

  o Minor features (port flags):
    - Add new flags to the *Port options to give finer control over which
      requests are allowed. The flags are NoDNSRequest, NoOnionTraffic,
      and the synthetic flag OnionTrafficOnly, which is equivalent to
      NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic. Closes enhancement
      18693; patch by "teor".

  o Minor features (build, hardening):
    - Detect and work around a libclang_rt problem that would prevent
      clang from finding __mulodi4() on some 32-bit platforms, and thus
      keep -ftrapv from linking on those systems. Closes ticket 19079.
    - When building on a system without runtime support for the runtime
      hardening options, try to log a useful warning at configuration
      time, rather than an incomprehensible warning at link time. If
      expensive hardening was requested, this warning becomes an error.
      Closes ticket 18895.

  o Minor features (client, directory):
    - Since authorities now omit all routers that lack the Running and
      Valid flags, we assume that any relay listed in the consensus must
      have those flags. Closes ticket 20001; implements part of
      proposal 272.

  o Minor features (code safety):
    - In our integer-parsing functions, ensure that the maximum value we
      allow is no smaller than the minimum value. Closes ticket 19063;
      patch from "U+039b".

  o Minor features (compilation, portability):
    - Compile correctly on MacOS 10.12 (aka "Sierra"). Closes
      ticket 20241.

  o Minor features (config):
    - Warn users when descriptor and port addresses are inconsistent.
      Mitigates bug 13953; patch by teor.

  o Minor features (controller):
    - Allow controllers to configure basic client authorization on
      hidden services when they create them with the ADD_ONION controller
      command. Implements ticket 15588. Patch by "special".
    - Fire a STATUS_SERVER controller event whenever the hibernation
      status changes between "awake"/"soft"/"hard". Closes ticket 18685.
    - Implement new GETINFO queries for all downloads that use
      download_status_t to schedule retries. This allows controllers to
      examine the schedule for pending downloads. Closes ticket 19323.

  o Minor features (development tools, etags):
    - Teach the "make tags" Makefile target how to correctly find
      "MOCK_IMPL" function definitions. Patch from nherring; closes
      ticket 16869.

  o Minor features (directory authority):
    - After voting, if the authorities decide that a relay is not
      "Valid", they no longer include it in the consensus at all. Closes
      ticket 20002; implements part of proposal 272.
    - Directory authorities now only give the Guard flag to a relay if
      they are also giving it the Stable flag. This change allows us to
      simplify path selection for clients. It should have minimal effect
      in practice, since >99% of Guards already have the Stable flag.
      Implements ticket 18624.
    - Directory authorities now write their v3-status-votes file out to
      disk earlier in the consensus process, so we have a record of the
      votes even if we abort the consensus process. Resolves
      ticket 19036.

  o Minor features (fallback directory list, new since 0.2.9.7-rc):
    - Replace the 81 remaining fallbacks of the 100 originally
      introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
      fallbacks (123 new, 54 existing, 27 removed) generated in December
      2016. Resolves ticket 20170.

  o Minor features (hidden service):
    - Stop being so strict about the payload length of "rendezvous1"
      cells. We used to be locked in to the "TAP" handshake length, and
      now we can handle better handshakes like "ntor". Resolves
      ticket 18998.

  o Minor features (infrastructure, time):
    - Tor now includes an improved timer backend, so that we can
      efficiently support tens or hundreds of thousands of concurrent
      timers, as will be needed for some of our planned anti-traffic-
      analysis work. This code is based on William Ahern's "timeout.c"
      project, which implements a "tickless hierarchical timing wheel".
      Closes ticket 18365.
    - Tor now uses the operating system's monotonic timers (where
      available) for internal fine-grained timing. Previously we would
      look at the system clock, and then attempt to compensate for the
      clock running backwards. Closes ticket 18908.

  o Minor features (logging):
    - Add a set of macros to check nonfatal assertions, for internal
      use. Migrating more of our checks to these should help us avoid
      needless crash bugs. Closes ticket 18613.
    - Provide a more useful warning message when configured with an
      invalid Nickname. Closes ticket 18300; patch from "icanhasaccount".
    - When dumping unparseable router descriptors, optionally store them
      in separate files, named by digest, up to a configurable size
      limit. You can change the size limit by setting the
      MaxUnparseableDescSizeToLog option, and disable this feature by
      setting that option to 0. Closes ticket 18322.

  o Minor features (performance):
    - Change the "optimistic data" extension from "off by default" to
      "on by default". The default was ordinarily overridden by a
      consensus option, but when clients were bootstrapping for the
      first time, they would not have a consensus to get the option
      from. Changing this default saves a round-trip during startup.
      Closes ticket 18815.

  o Minor features (relay, usability):
    - When the directory authorities refuse a bad relay's descriptor,
      encourage the relay operator to contact us. Many relay operators
      won't notice this line in their logs, but it's a win if even a few
      learn why we don't like what their relay was doing. Resolves
      ticket 18760.

  o Minor features (security, TLS):
    - Servers no longer support clients that lack AES ciphersuites.
      (3DES is no longer considered an acceptable cipher.) We believe
      that no such Tor clients currently exist, since Tor has required
      OpenSSL 0.9.7 or later since 2009. Closes ticket 19998.

  o Minor features (testing):
    - Disable memory protections on OpenBSD when performing our unit
      tests for memwipe(). The test deliberately invokes undefined
      behavior, and the OpenBSD protections interfere with this. Patch
      from "rubiate". Closes ticket 20066.
    - Move the test-network.sh script to chutney, and modify tor's test-
      network.sh to call the (newer) chutney version when available.
      Resolves ticket 19116. Patch by teor.
    - Use the lcov convention for marking lines as unreachable, so that
      we don't count them when we're generating test coverage data.
      Update our coverage tools to understand this convention. Closes
      ticket 16792.
    - Our link-handshake unit tests now check that when invalid
      handshakes fail, they fail with the error messages we expected.
    - Our unit testing code that captures log messages no longer
      prevents them from being written out if the user asked for them
      (by passing --debug or --info or --notice or --warn to the "test"
      binary). This change prevents us from missing unexpected log
      messages simply because we were looking for others. Related to
      ticket 19999.
    - The unit tests now log all warning messages with the "BUG" flag.
      Previously, they only logged errors by default. This change will
      help us make our testing code more correct, and make sure that we
      only hit this code when we mean to. In the meantime, however,
      there will be more warnings in the unit test logs than before.
      This is preparatory work for ticket 19999.
    - The unit tests now treat any failure of a "tor_assert_nonfatal()"
      assertion as a test failure.
    - We've done significant work to make the unit tests run faster.

  o Minor features (testing, ipv6):
    - Add the hs-ipv6 chutney target to make test-network-all's IPv6
      tests. Remove bridges+hs, as it's somewhat redundant. This
      requires a recent chutney version that supports IPv6 clients,
      relays, and authorities. Closes ticket 20069; patch by teor.
    - Add the single-onion and single-onion-ipv6 chutney targets to
      "make test-network-all". This requires a recent chutney version
      with the single onion network flavors (git c72a652 or later).
      Closes ticket 20072; patch by teor.

  o Minor features (Tor2web):
    - Make Tor2web clients respect ReachableAddresses. This feature was
      inadvertently enabled in 0.2.8.6, then removed by bugfix 19973 on
      0.2.8.7. Implements feature 20034. Patch by teor.

  o Minor features (unix domain sockets):
    - When configuring a unix domain socket for a SocksPort,
      ControlPort, or Hidden service, you can now wrap the address in
      quotes, using C-style escapes inside the quotes. This allows unix
      domain socket paths to contain spaces. Resolves ticket 18753.

  o Minor features (user interface):
    - Tor now supports the ability to declare options deprecated, so
      that we can recommend that people stop using them. Previously, this
      was done in an ad-hoc way. There is a new --list-deprecated-options
      command-line option to list all of the deprecated options. Closes
      ticket 19820.

  o Minor features (virtual addresses):
    - Increase the maximum number of bits for the IPv6 virtual network
      prefix from 16 to 104. In this way, the condition for address
      allocation is less restrictive. Closes ticket 20151; feature
      on 0.2.4.7-alpha.

  o Minor bug fixes (circuits):
    - Use the CircuitBuildTimeout option whenever
      LearnCircuitBuildTimeout is disabled. Previously, we would respect
      the option when a user disabled it, but not when it was disabled
      because some other option was set. Fixes bug 20073; bugfix on
      0.2.4.12-alpha. Patch by teor.

  o Minor bugfixes (build):
    - The current Git revision when building from a local repository is
      now detected correctly when using git worktrees. Fixes bug 20492;
      bugfix on 0.2.3.9-alpha.

  o Minor bugfixes (relay address discovery):
    - Stop reordering IP addresses returned by the OS. This makes it
      more likely that Tor will guess the same relay IP address every
      time. Fixes issue 20163; bugfix on 0.2.7.1-alpha, ticket 17027.
      Reported by René Mayrhofer, patch by "cypherpunks".

  o Minor bugfixes (memory allocation):
    - Change how we allocate memory for large chunks on buffers, to
      avoid a (currently impossible) integer overflow, and to waste less
      space when allocating unusually large chunks. Fixes bug 20081;
      bugfix on 0.2.0.16-alpha. Issue identified by Guido Vranken.

  o Minor bugfixes (bootstrap):
    - Remember the directory server we fetched the consensus or previous
      certificates from, and use it to fetch future authority
      certificates. This change improves bootstrapping performance.
      Fixes bug 18963; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (circuits):
    - Make sure extend_info_from_router() is only called on servers.
      Fixes bug 19639; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (client, fascistfirewall):
    - Avoid spurious warnings when ReachableAddresses or FascistFirewall
      is set. Fixes bug 20306; bugfix on 0.2.8.2-alpha.

  o Minor bugfixes (client, unix domain sockets):
    - Disable IsolateClientAddr when using AF_UNIX backed SocksPorts as
      the client address is meaningless. Fixes bug 20261; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (code style):
    - Fix an integer signedness conversion issue in the case conversion
      tables. Fixes bug 19168; bugfix on 0.2.1.11-alpha.

  o Minor bugfixes (compilation):
    - Build correctly on versions of libevent2 without support for
      evutil_secure_rng_add_bytes(). Fixes bug 19904; bugfix
      on 0.2.5.4-alpha.
    - When building with Clang, use a full set of GCC warnings.
      (Previously, we included only a subset, because of the way we
      detected them.) Fixes bug 19216; bugfix on 0.2.0.1-alpha.
    - Detect Libevent2 functions correctly on systems that provide
      libevent2, but where libevent1 is linked with -levent. Fixes bug
      19904; bugfix on 0.2.2.24-alpha. Patch from Rubiate.
    - Run correctly when built on Windows build environments that
      require _vcsprintf(). Fixes bug 20560; bugfix on 0.2.2.11-alpha.

  o Minor bugfixes (configuration):
    - When parsing quoted configuration values from the torrc file,
      handle Windows line endings correctly. Fixes bug 19167; bugfix on
      0.2.0.16-alpha. Patch from "Pingl".

  o Minor bugfixes (directory authority):
    - Authorities now sort the "package" lines in their votes, for ease
      of debugging. (They are already sorted in consensus documents.)
      Fixes bug 18840; bugfix on 0.2.6.3-alpha.
    - Die with a more useful error when the operator forgets to place
      the authority_signing_key file into the keys directory. This
      avoids an uninformative assert & traceback about having an invalid
      key. Fixes bug 20065; bugfix on 0.2.0.1-alpha.
    - When allowing private addresses, mark Exits that only exit to
      private locations as such. Fixes bug 20064; bugfix
      on 0.2.2.9-alpha.
    - When parsing a detached signature, make sure we use the length of
      the digest algorithm instead of a hardcoded DIGEST256_LEN in
      order to avoid comparing bytes out-of-bounds with a smaller digest
      length such as SHA1. Fixes bug 19066; bugfix on 0.2.2.6-alpha.

  o Minor bugfixes (getpass):
    - Defensively fix a non-triggerable heap corruption at do_getpass()
      to protect ourselves from mistakes in the future. Fixes bug
      19223; bugfix on 0.2.7.3-rc. Bug found by Guido Vranken, patch
      by nherring.

  o Minor bugfixes (guard selection):
    - Don't mark guards as unreachable if connection_connect() fails.
      That function fails for local reasons, so it shouldn't reveal
      anything about the status of the guard. Fixes bug 14334; bugfix
      on 0.2.3.10-alpha.
    - Use a single entry guard even if the NumEntryGuards consensus
      parameter is not provided. Fixes bug 17688; bugfix
      on 0.2.5.6-alpha.

  o Minor bugfixes (hidden services):
    - Increase the minimum number of internal circuits we preemptively
      build from 2 to 3, so a circuit is available when a client
      connects to another onion service. Fixes bug 13239; bugfix
      on 0.1.0.1-rc.
    - Allow hidden services to run on IPv6 addresses even when the
      IPv6Exit option is not set. Fixes bug 18357; bugfix
      on 0.2.4.7-alpha.
    - Stop logging intro point details to the client log on certain
      error conditions. Fixed as part of bug 20012; bugfix on
      0.2.4.8-alpha. Patch by teor.
    - When deleting an ephemeral hidden service, close its intro points
      even if they are not completely open. Fixes bug 18604; bugfix
      on 0.2.7.1-alpha.
    - When configuring hidden services, check every hidden service
      directory's permissions. Previously, we only checked the last
      hidden service. Fixes bug 20529; bugfix on 0.2.6.2-alpha.

  o Minor bugfixes (IPv6, testing):
    - Check for IPv6 correctly on Linux when running test networks.
      Fixes bug 19905; bugfix on 0.2.7.3-rc; patch by teor.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Add permission to run the sched_yield() and sigaltstack() system
      calls, in order to support versions of Tor compiled with asan or
      ubsan code that use these calls. Now "sandbox 1" and
      "--enable-expensive-hardening" should be compatible on more
      systems. Fixes bug 20063; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (logging):
    - Downgrade a harmless log message about the
      pending_entry_connections list from "warn" to "info". Mitigates
      bug 19926.
    - Log a more accurate message when we fail to dump a microdescriptor.
      Fixes bug 17758; bugfix on 0.2.2.8-alpha. Patch from Daniel Pinto.
    - When logging a directory ownership mismatch, log the owning
      username correctly. Fixes bug 19578; bugfix on 0.2.2.29-beta.
    - When we are unable to remove the bw_accounting file, do not warn
      if the reason we couldn't remove it was that it didn't exist.
      Fixes bug 19964; bugfix on 0.2.5.4-alpha. Patch from pastly.

  o Minor bugfixes (memory leak):
    - Fix a series of slow memory leaks related to parsing torrc files
      and options. Fixes bug 19466; bugfix on 0.2.1.6-alpha.
    - Avoid a small memory leak when informing worker threads about
      rotated onion keys. Fixes bug 20401; bugfix on 0.2.6.3-alpha.
    - Fix a small memory leak when receiving AF_UNIX connections on a
      SocksPort. Fixes bug 20716; bugfix on 0.2.6.3-alpha.
    - When moving a signed descriptor object from a source to an
      existing destination, free the allocated memory inside that
      destination object. Fixes bug 20715; bugfix on 0.2.8.3-alpha.
    - Fix a memory leak and use-after-free error when removing entries
      from the sandbox's getaddrinfo() cache. Fixes bug 20710; bugfix on
      0.2.5.5-alpha. Patch from "cypherpunks".
    - Fix a small, uncommon memory leak that could occur when reading a
      truncated ed25519 key file. Fixes bug 18956; bugfix
      on 0.2.6.1-alpha.

  o Minor bugfixes (option parsing):
    - Count unix sockets when counting client listeners (SOCKS, Trans,
      NATD, and DNS). This has no user-visible behavior changes: these
      options are set once, and never read. Required for correct
      behavior in ticket 17178. Fixes bug 19677; bugfix on
      0.2.6.3-alpha. Patch by teor.

  o Minor bugfixes (options):
    - Check the consistency of UseEntryGuards and EntryNodes more
      reliably. Fixes bug 20074; bugfix on 0.2.4.12-alpha. Patch
      by teor.
    - Stop changing the configured value of UseEntryGuards on
      authorities and Tor2web clients. Fixes bug 20074; bugfix on
      commits 51fc6799 in 0.1.1.16-rc and acda1735 in 0.2.4.3-alpha.
      Patch by teor.

  o Minor bugfixes (relay):
    - Ensure relays don't make multiple connections during bootstrap.
      Fixes bug 20591; bugfix on 0.2.8.1-alpha.
    - Do not try to parallelize workers more than 16x without the user
      explicitly configuring us to do so, even if we do detect more than
      16 CPU cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (testing):
    - The test-stem and test-network makefile targets now depend only on
      the tor binary that they are testing. Previously, they depended on
      "make all". Fixes bug 18240; bugfix on 0.2.8.2-alpha. Based on a
      patch from "cypherpunks".
    - Allow clients to retry HSDirs much faster in test networks. Fixes
      bug 19702; bugfix on 0.2.7.1-alpha. Patch by teor.
    - Avoid a unit test failure on systems with over 16 detectable CPU
      cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.
    - Let backtrace tests work correctly under AddressSanitizer:
      disable ASAN's detection of segmentation faults while running
      test_bt.sh, so that we can make sure that our own backtrace
      generation code works. Fixes bug 18934; bugfix
      on 0.2.5.2-alpha. Patch from "cypherpunks".
    - Fix the test-network-all target on out-of-tree builds by using the
      correct path to the test driver script. Fixes bug 19421; bugfix
      on 0.2.7.3-rc.
    - Stop spurious failures in the local interface address discovery
      unit tests. Fixes bug 20634; bugfix on 0.2.8.1-alpha; patch by
      Neel Chauhan.
    - Use ECDHE ciphers instead of ECDH in tortls tests. LibreSSL has
      removed the ECDH ciphers which caused the tests to fail on
      platforms which use it. Fixes bug 20460; bugfix on 0.2.8.1-alpha.
    - The tor_tls_server_info_callback unit test no longer crashes when
      debug-level logging is turned on. Fixes bug 20041; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (time):
    - Improve overflow checks in tv_udiff and tv_mdiff. Fixes bug 19483;
      bugfix on all released tor versions.
    - When computing the difference between two times in milliseconds,
      we now round to the nearest millisecond correctly. Previously, we
      could sometimes round in the wrong direction. Fixes bug 19428;
      bugfix on 0.2.2.2-alpha.

  o Minor bugfixes (Tor2web):
    - Prevent Tor2web clients from running hidden services: these services
      are not anonymous due to the one-hop client paths. Fixes bug
      19678. Patch by teor.

  o Minor bugfixes (user interface):
    - Display a more accurate number of suppressed messages in the log
      rate-limiter. Previously, there was a potential integer overflow
      in the counter. Now, if the number of messages hits a maximum, the
      rate-limiter doesn't count any further. Fixes bug 19435; bugfix
      on 0.2.4.11-alpha.
    - Fix a typo in the passphrase prompt for the ed25519 identity key.
      Fixes bug 19503; bugfix on 0.2.7.2-alpha.

  o Code simplification and refactoring:
    - Remove redundant declarations of the MIN macro. Closes
      ticket 18889.
    - Rename tor_dup_addr() to tor_addr_to_str_dup() to avoid confusion.
      Closes ticket 18462; patch from "icanhasaccount".
    - Split the 600-line directory_handle_command_get function into
      separate functions for different URL types. Closes ticket 16698.

  o Documentation:
    - Add module-level internal documentation for 36 C files that
      previously didn't have a high-level overview. Closes ticket 20385.
    - Correct the IPv6 syntax in our documentation for the
      VirtualAddrNetworkIPv6 torrc option. Closes ticket 19743.
    - Correct the minimum bandwidth value in torrc.sample, and queue a
      corresponding change for torrc.minimal. Closes ticket 20085.
    - Fix spelling of "--enable-tor2web-mode" in the manpage. Closes
      ticket 19153. Patch from "U+039b".
    - Module-level documentation for several more modules. Closes
      tickets 19287 and 19290.
    - Document the --passphrase-fd option in the tor manpage. Fixes bug
      19504; bugfix on 0.2.7.3-rc.
    - Document the default PathsNeededToBuildCircuits value that's used
      by clients when the directory authorities don't set
      min_paths_for_circs_pct. Fixes bug 20117; bugfix on 0.2.4.10-alpha.
      Patch by teor, reported by Jesse V.
    - Fix manual for the User option: it takes a username, not a UID.
      Fixes bug 19122; bugfix on 0.0.2pre16 (the first version to have
      a manpage!).
    - Fix the description of the --passphrase-fd option in the
      tor-gencert manpage. The option is used to pass the number of a
      file descriptor to read the passphrase from, not to read the file
      descriptor from. Fixes bug 19505; bugfix on 0.2.0.20-alpha.

  o Removed code:
    - We no longer include the (dead, deprecated) bufferevent code in
      Tor. Closes ticket 19450. Based on a patch from "U+039b".

  o Removed features:
    - Remove support for "GET /tor/bytes.txt" DirPort request, and
      "GETINFO dir-usage" controller request, which were only available
      via a compile-time option in Tor anyway. Feature was added in
      0.2.2.1-alpha. Resolves ticket 19035.
    - There is no longer a compile-time option to disable support for
      TransPort. (If you don't want TransPort, just don't use it.) Patch
      from "U+039b". Closes ticket 19449.

  o Testing:
    - Run more workqueue tests as part of "make check". These had
      previously been implemented, but you needed to know special
      command-line options to enable them.
    - We now have unit tests for our code to reject zlib "compression
      bombs". (Fortunately, the code works fine.)


Changes in version 0.2.8.11 - 2016-12-08
  Tor 0.2.8.11 backports fixes for additional portability issues that
  could prevent Tor from building correctly on OSX Sierra, or with
  OpenSSL 1.1. Affected users should upgrade; others can safely stay
  with 0.2.8.10.

  o Minor bugfixes (portability):
    - Avoid compilation errors when building on OSX Sierra. Sierra began
      to support the getentropy() and clock_gettime() APIs, but created
      a few problems in doing so. Tor 0.2.9 has a more thorough set of
      workarounds; in 0.2.8, we are just using the /dev/urandom and mach
      monotonic time interfaces. Fixes bug 20865. Bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
    - Fix compilation with OpenSSL 1.1 and less commonly-used CPU
      architectures. Closes ticket 20588.


Changes in version 0.2.8.10 - 2016-12-02
  Tor 0.2.8.10 backports a fix for a bug that would sometimes make clients
  unusable after they left standby mode. It also backports fixes for
  a few portability issues and a small but problematic memory leak.

  o Major bugfixes (client reliability, backport from 0.2.9.5-alpha):
    - When Tor leaves standby because of a new application request, open
      circuits as needed to serve that request. Previously, we would
      potentially wait a very long time. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Major bugfixes (client performance, backport from 0.2.9.5-alpha):
    - Clients now respond to new application stream requests immediately
      when they arrive, rather than waiting up to one second before
      starting to handle them. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (portability, backport from 0.2.9.6-rc):
    - Work around a bug in the OSX 10.12 SDK that would prevent us from
      successfully targeting earlier versions of OSX. Resolves
      ticket 20235.

  o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
    - Fix implicit conversion warnings under OpenSSL 1.1. Fixes bug
      20551; bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (relay, backport from 0.2.9.5-alpha):
    - Work around a memory leak in OpenSSL 1.1 when encoding public
      keys. Fixes bug 20553; bugfix on 0.0.2pre8.

  o Minor features (geoip):
    - Update geoip and geoip6 to the November 3 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.8.9 - 2016-10-17
  Tor 0.2.8.9 backports a fix for a security hole in previous versions
  of Tor that would allow a remote attacker to crash a Tor client,
  hidden service, relay, or authority. All Tor users should upgrade to
  this version, or to 0.2.9.4-alpha. Patches will be released for older
  versions of Tor.

  o Major features (security fixes, also in 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Minor features (geoip):
    - Update geoip and geoip6 to the October 4 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.8.8 - 2016-09-23
  Tor 0.2.8.8 fixes two crash bugs present in previous versions of the
  0.2.8.x series. Relays running 0.2.8.x should upgrade, as should users
  who select public relays as their bridges.

  o Major bugfixes (crash):
    - Fix a complicated crash bug that could affect Tor clients
      configured to use bridges when replacing a networkstatus consensus
      in which one of their bridges was mentioned. OpenBSD users saw
      more crashes here, but all platforms were potentially affected.
      Fixes bug 20103; bugfix on 0.2.8.2-alpha.

  o Major bugfixes (relay, OOM handler):
    - Fix a timing-dependent assertion failure that could occur when we
      tried to flush from a circuit after having freed its cells because
      of an out-of-memory condition. Fixes bug 20203; bugfix on
      0.2.8.1-alpha. Thanks to "cypherpunks" for help diagnosing
      this one.

  o Minor feature (fallback directories):
    - Remove broken fallbacks from the hard-coded fallback directory
      list. Closes ticket 20190; patch by teor.

  o Minor features (geoip):
    - Update geoip and geoip6 to the September 6 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.8.7 - 2016-08-24
  Tor 0.2.8.7 fixes an important bug related to the ReachableAddresses
  option in 0.2.8.6, and replaces a retiring bridge authority. Everyone
  who sets the ReachableAddresses option, and all bridges, are strongly
  encouraged to upgrade.

  o Directory authority changes:
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Major bugfixes (client, security):
    - Only use the ReachableAddresses option to restrict the first hop
      in a path. In earlier versions of 0.2.8.x, it would apply to
      every hop in the path, with a possible degradation in anonymity
      for anyone using an uncommon ReachableAddress setting. Fixes bug
      19973; bugfix on 0.2.8.2-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 2 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - Remove an inappropriate "inline" in tortls.c that was causing
      warnings on older versions of GCC. Fixes bug 19903; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (fallback directories):
    - Avoid logging a NULL string pointer when loading fallback
      directory information. Fixes bug 19947; bugfix on 0.2.4.7-alpha
      and 0.2.8.1-alpha. Report and patch by "rubiate".


Changes in version 0.2.8.6 - 2016-08-02

  Tor 0.2.8.6 is the first stable version of the Tor 0.2.8 series.

  The Tor 0.2.8 series improves client bootstrapping performance,
  completes the authority-side implementation of improved identity
  keys for relays, and includes numerous bugfixes and performance
  improvements throughout the program. This release continues to
  improve the coverage of Tor's test suite.  For a full list of
  changes since Tor 0.2.7, see the ReleaseNotes file.

  Below is a list of the changes since Tor 0.2.7.

  o New system requirements:
    - Tor no longer attempts to support platforms where the "time_t"
      type is unsigned. (To the best of our knowledge, only OpenVMS does
      this, and Tor has never actually built on OpenVMS.) Closes
      ticket 18184.
    - Tor no longer supports versions of OpenSSL with a broken
      implementation of counter mode. (This bug was present in OpenSSL
      1.0.0, and was fixed in OpenSSL 1.0.0a.) Tor still detects, but no
      longer runs with, these versions.
    - Tor now uses Autoconf version 2.63 or later, and Automake 1.11 or
      later (released in 2008 and 2009 respectively). If you are
      building Tor from the git repository instead of from the source
      distribution, and your tools are older than this, you will need to
      upgrade. Closes ticket 17732.

  o Directory authority changes:
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by teor.
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Major features (directory system):
    - Include a trial list of default fallback directories, based on an
      opt-in survey of suitable relays. Doing this should make clients
      bootstrap more quickly and reliably, and reduce the load on the
      directory authorities. Closes ticket 15775. Patch by teor.
      Candidates identified using an OnionOO script by weasel, teor,
      gsathya, and karsten.
    - Previously only relays that explicitly opened a directory port
      (DirPort) accepted directory requests from clients. Now all
      relays, with and without a DirPort, accept and serve tunneled
      directory requests that they receive through their ORPort. You can
      disable this behavior using the new DirCache option. Closes
      ticket 12538.
    - When bootstrapping multiple consensus downloads at a time, use the
      first one that starts downloading, and close the rest. This
      reduces failures when authorities or fallback directories are slow
      or down. Together with the code for feature 15775, this feature
      should reduces failures due to fallback churn. Implements ticket
      4483. Patch by teor. Implements IPv4 portions of proposal 210 by
      mikeperry and teor.

  o Major features (security, Linux):
    - When Tor starts as root on Linux and is told to switch user ID, it
      can now retain the capability to bind to low ports. By default,
      Tor will do this only when it's switching user ID and some low
      ports have been configured. You can change this behavior with the
      new option KeepBindCapabilities. Closes ticket 8195.

  o Major bugfixes (client, bootstrapping):
    - Check if bootstrap consensus downloads are still needed when the
      linked connection attaches. This prevents tor making unnecessary
      begindir-style connections, which are the only directory
      connections tor clients make since the fix for 18483 was merged.
    - Fix some edge cases where consensus download connections may not
      have been closed, even though they were not needed. Related to fix
      for 18809.
    - Make relays retry consensus downloads the correct number of times,
      rather than the more aggressive client retry count. Fixes part of
      ticket 18809.

  o Major bugfixes (dns proxy mode, crash):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (ed25519, voting):
    - Actually enable support for authorities to match routers by their
      Ed25519 identities. Previously, the code had been written, but
      some debugging code that had accidentally been left in the
      codebase made it stay turned off. Fixes bug 17702; bugfix
      on 0.2.7.2-alpha.
    - When collating votes by Ed25519 identities, authorities now
      include a "NoEdConsensus" flag if the ed25519 value (or lack
      thereof) for a server does not reflect the majority consensus.
      Related to bug 17668; bugfix on 0.2.7.2-alpha.
    - When generating a vote with keypinning disabled, never include two
      entries for the same ed25519 identity. This bug was causing
      authorities to generate votes that they could not parse when a
      router violated key pinning by changing its RSA identity but
      keeping its Ed25519 identity. Fixes bug 17668; fixes part of bug
      18318. Bugfix on 0.2.7.2-alpha.

  o Major bugfixes (key management):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (security, client, DNS proxy):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, compilation):
    - Correctly detect compiler flags on systems where _FORTIFY_SOURCE
      is predefined. Previously, our use of -D_FORTIFY_SOURCE would
      cause a compiler warning, thereby making other checks fail, and
      needlessly disabling compiler-hardening support. Fixes one case of
      bug 18841; bugfix on 0.2.3.17-beta. Patch from "trudokal".
    - Repair hardened builds under the clang compiler. Previously, our
      use of _FORTIFY_SOURCE would conflict with clang's address
      sanitizer. Fixes bug 14821; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, pointers):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (testing):
    - Fix a bug that would block 'make test-network-all' on systems where
      IPv6 packets were lost. Fixes bug 19008; bugfix on 0.2.7.3-rc.

  o Major bugfixes (user interface):
    - Correctly give a warning in the cases where a relay is specified
      by nickname, and one such relay is found, but it is not officially
      Named. Fixes bug 19203; bugfix on 0.2.3.1-alpha.

  o Minor features (accounting):
    - Added two modes to the AccountingRule option: One for limiting
      only the number of bytes sent ("AccountingRule out"), and one for
      limiting only the number of bytes received ("AccountingRule in").
      Closes ticket 15989; patch from "unixninja92".

  o Minor features (bug-resistance):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.
    - Use tor_snprintf() and tor_vsnprintf() even in external and low-
      level code, to harden against accidental failures to NUL-
      terminate. Part of ticket 17852. Patch from jsturgix. Found
      with Flawfinder.

  o Minor features (build):
    - Detect systems with FreeBSD-derived kernels (such as GNU/kFreeBSD)
      as having possible IPFW support. Closes ticket 18448. Patch from
      Steven Chamberlain.
    - Since our build process now uses "make distcheck", we no longer
      force "make dist" to depend on "make check". Closes ticket 17893;
      patch from "cypherpunks".
    - Tor now builds once again with the recent OpenSSL 1.1 development
      branch (tested against 1.1.0-pre5 and 1.1.0-pre6-dev). We have been
      tracking OpenSSL 1.1 development as it has progressed, and fixing
      numerous compatibility issues as they arose. See tickets
      17549, 17921, 17984, 19499, and 18286.
    - When building manual pages, set the timezone to "UTC", so that the
      output is reproducible. Fixes bug 19558; bugfix on 0.2.2.9-alpha.
      Patch from intrigeri.

  o Minor features (clients):
    - Make clients, onion services, and bridge relays always use an
      encrypted begindir connection for directory requests. Resolves
      ticket 18483. Patch by teor.

  o Minor features (controller):
    - Add 'GETINFO exit-policy/reject-private/[default,relay]', so
      controllers can examine the the reject rules added by
      ExitPolicyRejectPrivate. This makes it easier for stem to display
      exit policies.
    - Adds the FallbackDir entries to 'GETINFO config/defaults'. Closes
      tickets 16774 and 17817. Patch by George Tankersley.
    - New 'GETINFO hs/service/desc/id/' command to retrieve a hidden
      service descriptor from a service's local hidden service
      descriptor cache. Closes ticket 14846.

  o Minor features (crypto):
    - Add SHA3 and SHAKE support to crypto.c. Closes ticket 17783.
    - Add SHA512 support to crypto.c. Closes ticket 17663; patch from
      George Tankersley.
    - Improve performance when hashing non-multiple of 8 sized buffers,
      based on Andrew Moon's public domain SipHash-2-4 implementation.
      Fixes bug 17544; bugfix on 0.2.5.3-alpha.
    - Validate the hard-coded Diffie-Hellman parameters and ensure that
      p is a safe prime, and g is a suitable generator. Closes
      ticket 18221.
    - When allocating a digest state object, allocate no more space than
      we actually need. Previously, we would allocate as much space as
      the state for the largest algorithm would need. This change saves
      up to 672 bytes per circuit. Closes ticket 17796.

  o Minor features (directory downloads):
    - Add UseDefaultFallbackDirs, which enables any hard-coded fallback
      directory mirrors. The default is 1; set it to 0 to disable
      fallbacks. Implements ticket 17576. Patch by teor.
    - Wait for busy authorities and fallback directories to become non-
      busy when bootstrapping. (A similar change was made in 6c443e987d
      for directory caches chosen from the consensus.) Closes ticket
      17864; patch by teor.

  o Minor features (geoip):
    - Update geoip and geoip6 to the July 6 2016 Maxmind GeoLite2
      Country database.

  o Minor features (hidden service directory):
    - Streamline relay-side hsdir handling: when relays consider whether
      to accept an uploaded hidden service descriptor, they no longer
      check whether they are one of the relays in the network that is
      "supposed" to handle that descriptor. Implements ticket 18332.

  o Minor features (IPv6):
    - Add ClientPreferIPv6DirPort, which is set to 0 by default. If set
      to 1, tor prefers IPv6 directory addresses.
    - Add ClientUseIPv4, which is set to 1 by default. If set to 0, tor
      avoids using IPv4 for client OR and directory connections.
    - Add address policy assume_action support for IPv6 addresses.
    - Add an argument 'ipv6=address:orport' to the DirAuthority and
      FallbackDir torrc options, to specify an IPv6 address for an
      authority or fallback directory. Add hard-coded ipv6 addresses for
      directory authorities that have them. Closes ticket 17327; patch
      from Nick Mathewson and teor.
    - Allow users to configure directory authorities and fallback
      directory servers with IPv6 addresses and ORPorts. Resolves
      ticket 6027.
    - Limit IPv6 mask bits to 128.
    - Make tor_ersatz_socketpair work on IPv6-only systems. Fixes bug
      17638; bugfix on 0.0.2pre8. Patch by teor.
    - Try harder to obey the IP version restrictions "ClientUseIPv4 0",
      "ClientUseIPv6 0", "ClientPreferIPv6ORPort", and
      "ClientPreferIPv6DirPort". Closes ticket 17840; patch by teor.
    - Warn when comparing against an AF_UNSPEC address in a policy, it's
      almost always a bug. Closes ticket 17863; patch by teor.
    - routerset_parse now accepts IPv6 literal addresses. Fixes bug
      17060; bugfix on 0.2.1.3-alpha. Patch by teor.

  o Minor features (Linux seccomp2 sandbox):
    - Reject attempts to change our Address with "Sandbox 1" enabled.
      Changing Address with Sandbox turned on would never actually work,
      but previously it would fail in strange and confusing ways. Found
      while fixing 18548.

  o Minor features (logging):
    - When logging to syslog, allow a tag to be added to the syslog
      identity (the string prepended to every log message). The tag can
      be configured with SyslogIdentityTag and defaults to none. Setting
      it to "foo" will cause logs to be tagged as "Tor-foo". Closes
      ticket 17194.

  o Minor features (portability):
    - Use timingsafe_memcmp() where available. Closes ticket 17944;
      patch from .

  o Minor features (relay, address discovery):
    - Add a family argument to get_interface_addresses_raw() and
      subfunctions to make network interface address interogation more
      efficient. Now Tor can specifically ask for IPv4, IPv6 or both
      types of interfaces from the operating system. Resolves
      ticket 17950.
    - When get_interface_address6_list(.,AF_UNSPEC,.) is called and
      fails to enumerate interface addresses using the platform-specific
      API, have it rely on the UDP socket fallback technique to try and
      find out what IP addresses (both IPv4 and IPv6) our machine has.
      Resolves ticket 17951.

  o Minor features (replay cache):
    - The replay cache now uses SHA256 instead of SHA1. Implements
      feature 8961. Patch by teor, issue reported by rransom.

  o Minor features (robustness):
    - Exit immediately with an error message if the code attempts to use
      Libevent without having initialized it. This should resolve some
      frequently-made mistakes in our unit tests. Closes ticket 18241.

  o Minor features (security, clock):
    - Warn when the system clock appears to move back in time (when the
      state file was last written in the future). Tor doesn't know that
      consensuses have expired if the clock is in the past. Patch by
      teor. Implements ticket 17188.

  o Minor features (security, exit policies):
    - ExitPolicyRejectPrivate now rejects more private addresses by
      default. Specifically, it now rejects the relay's outbound bind
      addresses (if configured), and the relay's configured port
      addresses (such as ORPort and DirPort). Fixes bug 17027; bugfix on
      0.2.0.11-alpha. Patch by teor.

  o Minor features (security, memory erasure):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by teor.
    - Set the unused entries in a smartlist to NULL. This helped catch
      a (harmless) bug, and shouldn't affect performance too much.
      Implements ticket 17026.
    - Use SecureMemoryWipe() function to securely clean memory on
      Windows. Previously we'd use OpenSSL's OPENSSL_cleanse() function.
      Implements feature 17986.
    - Use explicit_bzero or memset_s when present. Previously, we'd use
      OpenSSL's OPENSSL_cleanse() function. Closes ticket 7419; patches
      from  and .

  o Minor features (security, RNG):
    - Adjust Tor's use of OpenSSL's RNG APIs so that they absolutely,
      positively are not allowed to fail. Previously we depended on
      internal details of OpenSSL's behavior. Closes ticket 17686.
    - Never use the system entropy output directly for anything besides
      seeding the PRNG. When we want to generate important keys, instead
      of using system entropy directly, we now hash it with the PRNG
      stream. This may help resist certain attacks based on broken OS
      entropy implementations. Closes part of ticket 17694.
    - Use modern system calls (like getentropy() or getrandom()) to
      generate strong entropy on platforms that have them. Closes
      ticket 13696.

  o Minor features (security, win32):
    - Set SO_EXCLUSIVEADDRUSE on Win32 to avoid a local port-stealing
      attack. Fixes bug 18123; bugfix on all tor versions. Patch
      by teor.

  o Minor features (unix domain sockets):
    - Add a new per-socket option, RelaxDirModeCheck, to allow creating
      Unix domain sockets without checking the permissions on the parent
      directory. (Tor checks permissions by default because some
      operating systems only check permissions on the parent directory.
      However, some operating systems do look at permissions on the
      socket, and tor's default check is unneeded.) Closes ticket 18458.
      Patch by weasel.

  o Minor features (unix file permissions):
    - Defer creation of Unix sockets until after setuid. This avoids
      needing CAP_CHOWN and CAP_FOWNER when using systemd's
      CapabilityBoundingSet, or chown and fowner when using SELinux.
      Implements part of ticket 17562. Patch from Jamie Nguyen.
    - If any directory created by Tor is marked as group readable, the
      filesystem group is allowed to be either the default GID or the
      root user. Allowing root to read the DataDirectory prevents the
      need for CAP_READ_SEARCH when using systemd's
      CapabilityBoundingSet, or dac_read_search when using SELinux.
      Implements part of ticket 17562. Patch from Jamie Nguyen.
    - Introduce a new DataDirectoryGroupReadable option. If it is set to
      1, the DataDirectory will be made readable by the default GID.
      Implements part of ticket 17562. Patch from Jamie Nguyen.

  o Minor bugfixes (accounting):
    - The max bandwidth when using 'AccountRule sum' is now correctly
      logged. Fixes bug 18024; bugfix on 0.2.6.1-alpha. Patch
      from "unixninja92".

  o Minor bugfixes (assert, portability):
    - Fix an assertion failure in memarea.c on systems where "long" is
      shorter than the size of a pointer. Fixes bug 18716; bugfix
      on 0.2.1.1-alpha.

  o Minor bugfixes (bootstrap):
    - Consistently use the consensus download schedule for authority
      certificates. Fixes bug 18816; bugfix on 0.2.4.13-alpha.

  o Minor bugfixes (build):
    - Avoid spurious failures from configure files related to calling
      exit(0) in TOR_SEARCH_LIBRARY. Fixes bug 18626; bugfix on
      0.2.0.1-alpha. Patch from "cypherpunks".
    - Do not link the unit tests against both the testing and non-
      testing versions of the static libraries. Fixes bug 18490; bugfix
      on 0.2.7.1-alpha.
    - Resolve warnings when building on systems that are concerned with
      signed char. Fixes bug 18728; bugfix on 0.2.7.2-alpha
      and 0.2.6.1-alpha.
    - Silence spurious clang-scan warnings in the ed25519_donna code by
      explicitly initializing some objects. Fixes bug 18384; bugfix on
      0.2.7.2-alpha. Patch by teor.
    - When libscrypt.h is found, but no libscrypt library can be linked,
      treat libscrypt as absent. Fixes bug 19161; bugfix
      on 0.2.6.1-alpha.
    - Cause the unit tests to compile correctly on mingw64 versions that
      lack sscanf. Fixes bug 19213; bugfix on 0.2.7.1-alpha.
    - Don't try to use the pthread_condattr_setclock() function unless
      it actually exists. Fixes compilation on NetBSD-6.x. Fixes bug
      17819; bugfix on 0.2.6.3-alpha.
    - Fix backtrace compilation on FreeBSD. Fixes bug 17827; bugfix
      on 0.2.5.2-alpha.
    - Fix search for libevent libraries on OpenBSD (and other systems
      that install libevent 1 and libevent 2 in parallel). Fixes bug
      16651; bugfix on 0.1.0.7-rc. Patch from "rubiate".
    - Isolate environment variables meant for tests from the rest of the
      build system. Fixes bug 17818; bugfix on 0.2.7.3-rc.
    - Mark all object files that include micro-revision.i as depending
      on it, so as to make parallel builds more reliable. Fixes bug
      17826; bugfix on 0.2.5.1-alpha.
    - Remove config.log only from make distclean, not from make clean.
      Fixes bug 17924; bugfix on 0.2.4.1-alpha.
    - Replace usage of 'INLINE' with 'inline'. Fixes bug 17804; bugfix
      on 0.0.2pre8.
    - Remove an #endif from configure.ac so that we correctly detect the
      presence of in6_addr.s6_addr32. Fixes bug 17923; bugfix
      on 0.2.0.13-alpha.

  o Minor bugfixes (client, bootstrap):
    - Count receipt of new microdescriptors as progress towards
      bootstrapping. Previously, with EntryNodes set, Tor might not
      successfully repopulate the guard set on bootstrapping. Fixes bug
      16825; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (code correctness):
    - Fix a bad memory handling bug that would occur if we had queued a
      cell on a channel's incoming queue. Fortunately, we can't actually
      queue a cell like that as our code is constructed today, but it's
      best to avoid this kind of error, even if there isn't any code
      that triggers it today. Fixes bug 18570; bugfix on 0.2.4.4-alpha.
    - Assert that allocated memory held by the reputation code is freed
      according to its internal counters. Fixes bug 17753; bugfix
      on 0.1.1.1-alpha.
    - Assert when the TLS contexts fail to initialize. Fixes bug 17683;
      bugfix on 0.0.6.
    - Update to the latest version of Trunnel, which tries harder to
      avoid generating code that can invoke memcpy(p,NULL,0). Bug found
      by clang address sanitizer. Fixes bug 18373; bugfix
      on 0.2.7.2-alpha.
    - When closing an entry connection, generate a warning if we should
      have sent an end cell for it but we haven't. Fixes bug 17876;
      bugfix on 0.2.3.2-alpha.

  o Minor bugfixes (configuration):
    - Fix a tiny memory leak when parsing a port configuration ending in
      ":auto". Fixes bug 18374; bugfix on 0.2.3.3-alpha.

  o Minor bugfixes (containers):
    - If we somehow attempt to construct a heap with more than
      1073741822 elements, avoid an integer overflow when maintaining
      the heap property. Fixes bug 18296; bugfix on 0.1.2.1-alpha.

  o Minor bugfixes (controller, microdescriptors):
    - Make GETINFO dir/status-vote/current/consensus conform to the
      control specification by returning "551 Could not open cached
      consensus..." when not caching consensuses. Fixes bug 18920;
      bugfix on 0.2.2.6-alpha.

  o Minor bugfixes (crypto):
    - Check the return value of HMAC() and assert on failure. Fixes bug
      17658; bugfix on 0.2.3.6-alpha. Patch by teor.

  o Minor bugfixes (directories):
    - When fetching extrainfo documents, compare their SHA256 digests
      and Ed25519 signing key certificates with the routerinfo that led
      us to fetch them, rather than with the most recent routerinfo.
      Otherwise we generate many spurious warnings about mismatches.
      Fixes bug 17150; bugfix on 0.2.7.2-alpha.
    - When generating a URL for a directory server on an IPv6 address,
      wrap the IPv6 address in square brackets. Fixes bug 18051; bugfix
      on 0.2.3.9-alpha. Patch from Malek.

  o Minor bugfixes (downloading):
    - Predict more correctly whether we'll be downloading over HTTP when
      we determine the maximum length of a URL. This should avoid a
      "BUG" warning about the Squid HTTP proxy and its URL limits. Fixes
      bug 19191.

  o Minor bugfixes (exit policies, security):
    - Refresh an exit relay's exit policy when interface addresses
      change. Previously, tor only refreshed the exit policy when the
      configured external address changed. Fixes bug 18208; bugfix on
      0.2.7.3-rc. Patch by teor.

  o Minor bugfixes (fallback directories):
    - Mark fallbacks as "too busy" when they return a 503 response,
      rather than just marking authorities. Fixes bug 17572; bugfix on
      0.2.4.7-alpha. Patch by teor.
    - When requesting extrainfo descriptors from a trusted directory
      server, check whether it is an authority or a fallback directory
      which supports extrainfo descriptors. Fixes bug 18489; bugfix on
      0.2.4.7-alpha. Reported by atagar, patch by teor.

  o Minor bugfixes (hidden service, client):
    - Handle the case where the user makes several fast consecutive
      requests to the same .onion address. Previously, the first six
      requests would each trigger a descriptor fetch, each picking a
      directory (there are 6 overall) and the seventh one would fail
      because no directories were left, thereby triggering a close on
      all current directory connections asking for the hidden service.
      The solution here is to not close the connections if we have
      pending directory fetches. Fixes bug 15937; bugfix
      on 0.2.7.1-alpha.

  o Minor bugfixes (hidden service, control port):
    - Add the onion address to the HS_DESC event for the UPLOADED action
      both on success or failure. It was previously hardcoded with
      UNKNOWN. Fixes bug 16023; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (hidden service, directory):
    - Bridges now refuse "rendezvous2" (hidden service descriptor)
      publish attempts. Suggested by ticket 18332.

  o Minor bugfixes (IPv6):
    - Update the limits in max_dl_per_request for IPv6 address length.
      Fixes bug 17573; bugfix on 0.2.1.5-alpha.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Allow more syscalls when running with "Sandbox 1" enabled:
      sysinfo, getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On
      some systems, these are required for Tor to start. Fixes bug
      18397; bugfix on 0.2.5.1-alpha. Patch from Daniel Pinto.
    - Allow IPPROTO_UDP datagram sockets when running with "Sandbox 1",
      so that get_interface_address6_via_udp_socket_hack() can work.
      Fixes bug 19660; bugfix on 0.2.5.1-alpha.
    - Allow the setrlimit syscall, and the prlimit and prlimit64
      syscalls, which some libc implementations use under the hood.
      Fixes bug 15221; bugfix on 0.2.5.1-alpha.
    - Avoid a 10-second delay when starting as a client with "Sandbox 1"
      enabled and no DNS resolvers configured. This should help TAILS
      start up faster. Fixes bug 18548; bugfix on 0.2.5.1-alpha.
    - Fix a crash when using offline master ed25519 keys with the Linux
      seccomp2 sandbox enabled. Fixes bug 17675; bugfix on 0.2.7.3-rc.
    - Allow statistics to be written to disk when "Sandbox 1" is
      enabled. Fixes bugs 19556 and 19957; bugfix on 0.2.5.1-alpha and
      0.2.6.1-alpha respectively.

  o Minor bugfixes (logging):
    - In log messages that include a function name, use __FUNCTION__
      instead of __PRETTY_FUNCTION__. In GCC, these are synonymous, but
      with clang __PRETTY_FUNCTION__ has extra information we don't
      need. Fixes bug 16563; bugfix on 0.0.2pre8. Fix by Tom van
      der Woerdt.
    - Remove needless quotes from a log message about unparseable
      addresses. Fixes bug 17843; bugfix on 0.2.3.3-alpha.
    - Scrub service name in "unrecognized service ID" log messages.
      Fixes bug 18600; bugfix on 0.2.4.11-alpha.
    - When logging information about an unparsable networkstatus vote or
      consensus, do not say "vote" when we mean consensus. Fixes bug
      18368; bugfix on 0.2.0.8-alpha.
    - When we can't generate a signing key because OfflineMasterKey is
      set, do not imply that we should have been able to load it. Fixes
      bug 18133; bugfix on 0.2.7.2-alpha.
    - When logging a malformed hostname received through socks4, scrub
      it if SafeLogging says we should. Fixes bug 17419; bugfix
      on 0.1.1.16-rc.

  o Minor bugfixes (memory safety):
    - Avoid freeing an uninitialized pointer when opening a socket fails
      in get_interface_addresses_ioctl(). Fixes bug 18454; bugfix on
      0.2.3.11-alpha. Reported by toralf and "cypherpunks", patch
      by teor.
    - Fix a memory leak in "tor --list-fingerprint". Fixes part of bug
      18672; bugfix on 0.2.5.1-alpha.
    - Fix a memory leak in tor-gencert. Fixes part of bug 18672; bugfix
      on 0.2.0.1-alpha.

  o Minor bugfixes (pluggable transports):
    - Avoid reporting a spurious error when we decide that we don't need
      to terminate a pluggable transport because it has already exited.
      Fixes bug 18686; bugfix on 0.2.5.5-alpha.

  o Minor bugfixes (pointer arithmetic):
    - Fix a bug in memarea_alloc() that could have resulted in remote
      heap write access, if Tor had ever passed an unchecked size to
      memarea_alloc(). Fortunately, all the sizes we pass to
      memarea_alloc() are pre-checked to be less than 128 kilobytes.
      Fixes bug 19150; bugfix on 0.2.1.1-alpha. Bug found by
      Guido Vranken.

  o Minor bugfixes (private directory):
    - Prevent a race condition when creating private directories. Fixes
      part of bug 17852; bugfix on 0.0.2pre13. Part of ticket 17852.
      Patch from jsturgix. Found with Flawfinder.

  o Minor bugfixes (relays):
    - Check that both the ORPort and DirPort (if present) are reachable
      before publishing a relay descriptor. Otherwise, relays publish a
      descriptor with DirPort 0 when the DirPort reachability test takes
      longer than the ORPort reachability test. Fixes bug 18050; bugfix
      on 0.1.0.1-rc. Reported by "starlight", patch by teor.
    - Resolve some edge cases where we might launch an ORPort
      reachability check even when DisableNetwork is set. Noticed while
      fixing bug 18616; bugfix on 0.2.3.9-alpha.

  o Minor bugfixes (relays, hidden services):
    - Refuse connection requests to private OR addresses unless
      ExtendAllowPrivateAddresses is set. Previously, tor would connect,
      then refuse to send any cells to a private address. Fixes bugs
      17674 and 8976; bugfix on 0.2.3.21-rc. Patch by teor.

  o Minor bugfixes (security, hidden services):
    - Prevent hidden services connecting to client-supplied rendezvous
      addresses that are reserved as internal or multicast. Fixes bug
      8976; bugfix on 0.2.3.21-rc. Patch by dgoulet and teor.

  o Minor bugfixes (statistics):
    - Consistently check for overflow in round_*_to_next_multiple_of
      functions, and add unit tests with additional and maximal values.
      Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.
    - Handle edge cases in the laplace functions: avoid division by
      zero, avoid taking the log of zero, and silence clang type
      conversion warnings using round and trunc. Add unit tests for edge
      cases with maximal values. Fixes part of bug 13192; bugfix
      on 0.2.6.2-alpha.
    - We now include consensus downloads via IPv6 in our directory-
      request statistics. Fixes bug 18460; bugfix on 0.2.3.14-alpha.

  o Minor bugfixes (test networks, IPv6):
    - Allow internal IPv6 addresses in descriptors in test networks.
      Fixes bug 17153; bugfix on 0.2.3.16-alpha. Patch by teor, reported
      by karsten.

  o Minor bugfixes (testing):
    - Check the full results of SHA256 and SHA512 digests in the unit
      tests. Bugfix on 0.2.2.4-alpha. Patch by teor.
    - Fix a memory leak in the ntor test. Fixes bug 17778; bugfix
      on 0.2.4.8-alpha.
    - Fix a small memory leak that would occur when the
      TestingEnableCellStatsEvent option was turned on. Fixes bug 18673;
      bugfix on 0.2.5.2-alpha.
    - Make unit tests pass on IPv6-only systems, and systems without
      localhost addresses (like some FreeBSD jails). Fixes bug 17632;
      bugfix on 0.2.7.3-rc. Patch by teor.
    - The test for log_heartbeat was incorrectly failing in timezones
      with non-integer offsets. Instead of comparing the end of the time
      string against a constant, compare it to the output of
      format_local_iso_time when given the correct input. Fixes bug
      18039; bugfix on 0.2.5.4-alpha.
    - We no longer disable assertions in the unit tests when coverage is
      enabled. Instead, we require you to say --disable-asserts-in-tests
      to the configure script if you need assertions disabled in the
      unit tests (for example, if you want to perform branch coverage).
      Fixes bug 18242; bugfix on 0.2.7.1-alpha.

  o Minor bugfixes (time handling):
    - When correcting a corrupt 'struct tm' value, fill in the tm_wday
      field. Otherwise, our unit tests crash on Windows. Fixes bug
      18977; bugfix on 0.2.2.25-alpha.
    - Avoid overflow in tor_timegm when parsing dates in and after 2038
      on platforms with 32-bit time_t. Fixes bug 18479; bugfix on
      0.0.2pre14. Patch by teor.

  o Minor bugfixes (tor-gencert):
    - Correctly handle the case where an authority operator enters a
      passphrase but sends an EOF before sending a newline. Fixes bug
      17443; bugfix on 0.2.0.20-rc. Found by junglefowl.

  o Code simplification and refactoring:
    - Clean up a little duplicated code in
      crypto_expand_key_material_TAP(). Closes ticket 17587; patch
      from "pfrankw".
    - Decouple the list of streams waiting to be attached to circuits
      from the overall connection list. This change makes it possible to
      attach streams quickly while simplifying Tor's callgraph and
      avoiding O(N) scans of the entire connection list. Closes
      ticket 17590.
    - Extract the more complicated parts of circuit_mark_for_close()
      into a new function that we run periodically before circuits are
      freed. This change removes more than half of the functions
      currently in the "blob". Closes ticket 17218.
    - Move logging of redundant policy entries in
      policies_parse_exit_policy_internal into its own function. Closes
      ticket 17608; patch from "juce".
    - Quote all the string interpolations in configure.ac -- even those
      which we are pretty sure can't contain spaces. Closes ticket
      17744. Patch from zerosion.
    - Remove code for configuring OpenSSL dynamic locks; OpenSSL doesn't
      use them. Closes ticket 17926.
    - Remove specialized code for non-inplace AES_CTR. 99% of our AES is
      inplace, so there's no need to have a separate implementation for
      the non-inplace code. Closes ticket 18258. Patch from Malek.
    - Simplify return types for some crypto functions that can't
      actually fail. Patch from Hassan Alsibyani. Closes ticket 18259.
    - When a direct directory request fails immediately on launch,
      instead of relaunching that request from inside the code that
      launches it, instead mark the connection for teardown. This change
      simplifies Tor's callback and prevents the directory-request
      launching code from invoking itself recursively. Closes
      ticket 17589.

  o Documentation:
    - Add a description of the correct use of the '--keygen' command-
      line option. Closes ticket 17583; based on text by 's7r'.
    - Change build messages to refer to "Fedora" instead of "Fedora
      Core", and "dnf" instead of "yum". Closes tickets 18459 and 18426.
      Patches from "icanhasaccount" and "cypherpunks".
    - Document the contents of the 'datadir/keys' subdirectory in the
      manual page. Closes ticket 17621.
    - Document the minimum HeartbeatPeriod value. Closes ticket 15638.
    - Explain actual minima for BandwidthRate. Closes ticket 16382.
    - Fix a minor formatting typo in the manpage. Closes ticket 17791.
    - Mention torspec URL in the manpage and point the reader to it
      whenever we mention a document that belongs in torspce. Fixes
      issue 17392.
    - Stop recommending use of nicknames to identify relays in our
      MapAddress documentation. Closes ticket 18312.

  o Removed features:
    - Remove client-side support for connecting to Tor relays running
      versions of Tor before 0.2.3.6-alpha. These relays didn't support
      the v3 TLS handshake protocol, and are no longer allowed on the
      Tor network. Implements the client side of ticket 11150. Based on
      patches by Tom van der Woerdt.
    - We no longer maintain an internal freelist in memarea.c.
      Allocators should be good enough to make this code unnecessary,
      and it's doubtful that it ever had any performance benefit.

  o Testing:
    - Add unit tests to check for common RNG failure modes, such as
      returning all zeroes, identical values, or incrementing values
      (OpenSSL's rand_predictable feature). Patch by teor.
    - Always test both ed25519 backends, so that we can be sure that our
      batch-open replacement code works. Part of ticket 16794.
    - Cover dns_resolve_impl() in dns.c with unit tests. Implements a
      portion of ticket 16831.
    - Fix several warnings from clang's address sanitizer produced in
      the unit tests.
    - Log more information when the backtrace tests fail. Closes ticket
      17892. Patch from "cypherpunks."
    - More unit tests for compat_libevent.c, procmon.c, tortls.c,
      util_format.c, directory.c, and options_validate.c. Closes tickets
      17075, 17082, 17084, 17003, and 17076 respectively. Patches from
      Ola Bini.
    - Treat backtrace test failures as expected on FreeBSD until we
      solve bug 17808. Closes ticket 18204.
    - Unit tests for directory_handle_command_get. Closes ticket 17004.
      Patch from Reinaldo de Souza Jr.


Changes in version 0.2.7.6 - 2015-12-10
  Tor version 0.2.7.6 fixes a major bug in entry guard selection, as
  well as a minor bug in hidden service reliability.

  o Major bugfixes (guard selection):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Minor features (geoip):
    - Update geoip and geoip6 to the December 1 2015 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - When checking for net/pfvar.h, include netinet/in.h if possible.
      This fixes transparent proxy detection on OpenBSD. Fixes bug
      17551; bugfix on 0.1.2.1-alpha. Patch from "rubiate".
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (correctness):
    - When displaying an IPv6 exit policy, include the mask bits
      correctly even when the number is greater than 31. Fixes bug
      16056; bugfix on 0.2.4.7-alpha. Patch from "gturner".
    - The wrong list was used when looking up expired intro points in a
      rend service object, causing what we think could be reachability
      issues for hidden services, and triggering a BUG log. Fixes bug
      16702; bugfix on 0.2.7.2-alpha.
    - Fix undefined behavior in the tor_cert_checksig function. Fixes
      bug 17722; bugfix on 0.2.7.2-alpha.


Changes in version 0.2.7.5 - 2015-11-20
  The Tor 0.2.7 release series is dedicated to the memory of Tor user
  and privacy advocate Caspar Bowden (1961-2015). Caspar worked
  tirelessly to advocate human rights regardless of national borders,
  and oppose the encroachments of mass surveillance. He opposed national
  exceptionalism, he brought clarity to legal and policy debates, he
  understood and predicted the impact of mass surveillance on the world,
  and he laid the groundwork for resisting it. While serving on the Tor
  Project's board of directors, he brought us his uncompromising focus
  on technical excellence in the service of humankind. Caspar was an
  inimitable force for good and a wonderful friend. He was kind,
  humorous, generous, gallant, and believed we should protect one
  another without exception. We honor him here for his ideals, his
  efforts, and his accomplishments. Please honor his memory with works
  that would make him proud.

  Tor 0.2.7.5 is the first stable release in the Tor 0.2.7 series.

  The 0.2.7 series adds a more secure identity key type for relays,
  improves cryptography performance, resolves several longstanding
  hidden-service performance issues, improves controller support for
  hidden services, and includes small bugfixes and performance
  improvements throughout the program. This release series also includes
  more tests than before, and significant simplifications to which parts
  of Tor invoke which others. For a full list of changes, see below.

  o New system requirements:
    - Tor no longer includes workarounds to support Libevent versions
      before 1.3e. Libevent 2.0 or later is recommended. Closes
      ticket 15248.
    - Tor no longer supports copies of OpenSSL that are missing support
      for Elliptic Curve Cryptography. (We began using ECC when
      available in 0.2.4.8-alpha, for more safe and efficient key
      negotiation.) In particular, support for at least one of P256 or
      P224 is now required, with manual configuration needed if only
      P224 is available. Resolves ticket 16140.
    - Tor no longer supports versions of OpenSSL before 1.0. (If you are
      on an operating system that has not upgraded to OpenSSL 1.0 or
      later, and you compile Tor from source, you will need to install a
      more recent OpenSSL to link Tor against.) These versions of
      OpenSSL are still supported by the OpenSSL, but the numerous
      cryptographic improvements in later OpenSSL releases makes them a
      clear choice. Resolves ticket 16034.

  o Major features (controller):
    - Add the ADD_ONION and DEL_ONION commands that allow the creation
      and management of hidden services via the controller. Closes
      ticket 6411.
    - New "GETINFO onions/current" and "GETINFO onions/detached"
      commands to get information about hidden services created via the
      controller. Part of ticket 6411.
    - New HSFETCH command to launch a request for a hidden service
      descriptor. Closes ticket 14847.
    - New HSPOST command to upload a hidden service descriptor. Closes
      ticket 3523. Patch by "DonnchaC".

  o Major features (Ed25519 identity keys, Proposal 220):
    - Add support for offline encrypted Ed25519 master keys. To use this
      feature on your tor relay, run "tor --keygen" to make a new master
      key (or to make a new signing key if you already have a master
      key). Closes ticket 13642.
    - All relays now maintain a stronger identity key, using the Ed25519
      elliptic curve signature format. This master key is designed so
      that it can be kept offline. Relays also generate an online
      signing key, and a set of other Ed25519 keys and certificates.
      These are all automatically regenerated and rotated as needed.
      Implements part of ticket 12498.
    - Directory authorities now vote on Ed25519 identity keys along with
      RSA1024 keys. Implements part of ticket 12498.
    - Directory authorities track which Ed25519 identity keys have been
      used with which RSA1024 identity keys, and do not allow them to
      vary freely. Implements part of ticket 12498.
    - Microdescriptors now include Ed25519 identity keys. Implements
      part of ticket 12498.
    - Add a --newpass option to allow changing or removing the
      passphrase of an encrypted key with tor --keygen. Implements part
      of ticket 16769.
    - Add a new OfflineMasterKey option to tell Tor never to try loading
      or generating a secret Ed25519 identity key. You can use this in
      combination with tor --keygen to manage offline and/or encrypted
      Ed25519 keys. Implements ticket 16944.
    - On receiving a HUP signal, check to see whether the Ed25519
      signing key has changed, and reload it if so. Closes ticket 16790.
    - Significant usability improvements for Ed25519 key management. Log
      messages are better, and the code can recover from far more
      failure conditions. Thanks to "s7r" for reporting and diagnosing
      so many of these!

  o Major features (ECC performance):
    - Improve the runtime speed of Ed25519 signature verification by
      using Ed25519-donna's batch verification support. Implements
      ticket 16533.
    - Improve the speed of Ed25519 operations and Curve25519 keypair
      generation when built targeting 32 bit x86 platforms with SSE2
      available. Implements ticket 16535.
    - Improve the runtime speed of Ed25519 operations by using the
      public-domain Ed25519-donna by Andrew M. ("floodyberry").
      Implements ticket 16467.
    - Improve the runtime speed of the ntor handshake by using an
      optimized curve25519 basepoint scalarmult implementation from the
      public-domain Ed25519-donna by Andrew M. ("floodyberry"), based on
      ideas by Adam Langley. Implements ticket 9663.

  o Major features (Hidden services):
    - Hidden services, if using the EntryNodes option, are required to
      use more than one EntryNode, in order to avoid a guard discovery
      attack. (This would only affect people who had configured hidden
      services and manually specified the EntryNodes option with a
      single entry-node. The impact was that it would be easy to
      remotely identify the guard node used by such a hidden service.
      See ticket for more information.) Fixes ticket 14917.
    - Add the torrc option HiddenServiceNumIntroductionPoints, to
      specify a fixed number of introduction points. Its maximum value
      is 10 and default is 3. Using this option can increase a hidden
      service's reliability under load, at the cost of making it more
      visible that the hidden service is facing extra load. Closes
      ticket 4862.
    - Remove the adaptive algorithm for choosing the number of
      introduction points, which used to change the number of
      introduction points (poorly) depending on the number of
      connections the HS sees. Closes ticket 4862.

  o Major features (onion key cross-certification):
    - Relay descriptors now include signatures of their own identity
      keys, made using the TAP and ntor onion keys. These signatures
      allow relays to prove ownership of their own onion keys. Because
      of this change, microdescriptors will no longer need to include
      RSA identity keys. Implements proposal 228; closes ticket 12499.

  o Major bugfixes (client-side privacy, also in 0.2.6.9):
    - Properly separate out each SOCKSPort when applying stream
      isolation. The error occurred because each port's session group
      was being overwritten by a default value when the listener
      connection was initialized. Fixes bug 16247; bugfix on
      0.2.6.3-alpha. Patch by "jojelino".

  o Major bugfixes (hidden service clients, stability, also in 0.2.6.10):
    - Stop refusing to store updated hidden service descriptors on a
      client. This reverts commit 9407040c59218 (which indeed fixed bug
      14219, but introduced a major hidden service reachability
      regression detailed in bug 16381). This is a temporary fix since
      we can live with the minor issue in bug 14219 (it just results in
      some load on the network) but the regression of 16381 is too much
      of a setback. First-round fix for bug 16381; bugfix
      on 0.2.6.3-alpha.

  o Major bugfixes (hidden services):
    - Revert commit that made directory authorities assign the HSDir
      flag to relays without a DirPort; this was bad because such relays
      can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
      on 0.2.6.3-alpha.
    - When cannibalizing a circuit for an introduction point, always
      extend to the chosen exit node (creating a 4 hop circuit).
      Previously Tor would use the current circuit exit node, which
      changed the original choice of introduction point, and could cause
      the hidden service to skip excluded introduction points or
      reconnect to a skipped introduction point. Fixes bug 16260; bugfix
      on 0.1.0.1-rc.

  o Major bugfixes (memory leaks):
    - Fix a memory leak in ed25519 batch signature checking. Fixes bug
      17398; bugfix on 0.2.6.1-alpha.

  o Major bugfixes (open file limit):
    - The open file limit wasn't checked before calling
      tor_accept_socket_nonblocking(), which would make Tor exceed the
      limit. Now, before opening a new socket, Tor validates the open
      file limit just before, and if the max has been reached, return an
      error. Fixes bug 16288; bugfix on 0.1.1.1-alpha.

  o Major bugfixes (security, correctness):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (stability, also in 0.2.6.10):
    - Stop crashing with an assertion failure when parsing certain kinds
      of malformed or truncated microdescriptors. Fixes bug 16400;
      bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
      by "cypherpunks_backup".
    - Stop random client-side assertion failures that could occur when
      connecting to a busy hidden service, or connecting to a hidden
      service while a NEWNYM is in progress. Fixes bug 16013; bugfix
      on 0.1.0.1-rc.

  o Minor features (client, SOCKS):
    - Add GroupWritable and WorldWritable options to unix-socket based
      SocksPort and ControlPort options. These options apply to a single
      socket, and override {Control,Socks}SocketsGroupWritable. Closes
      ticket 15220.
    - Relax the validation done to hostnames in SOCKS5 requests, and
      allow a single trailing '.' to cope with clients that pass FQDNs
      using that syntax to explicitly indicate that the domain name is
      fully-qualified. Fixes bug 16674; bugfix on 0.2.6.2-alpha.
    - Relax the validation of hostnames in SOCKS5 requests, allowing the
      character '_' to appear, in order to cope with domains observed in
      the wild that are serving non-RFC compliant records. Resolves
      ticket 16430.

  o Minor features (client-side privacy):
    - New KeepAliveIsolateSOCKSAuth option to indefinitely extend circuit
      lifespan when IsolateSOCKSAuth and streams with SOCKS
      authentication are attached to the circuit. This allows
      applications like TorBrowser to manage circuit lifetime on their
      own. Implements feature 15482.
    - When logging malformed hostnames from SOCKS5 requests, respect
      SafeLogging configuration. Fixes bug 16891; bugfix on 0.1.1.16-rc.

  o Minor features (clock-jump tolerance):
    - Recover better when our clock jumps back many hours, like might
      happen for Tails or Whonix users who start with a very wrong
      hardware clock, use Tor to discover a more accurate time, and then
      fix their clock. Resolves part of ticket 8766.

  o Minor features (command-line interface):
    - Make --hash-password imply --hush to prevent unnecessary noise.
      Closes ticket 15542. Patch from "cypherpunks".
    - Print a warning whenever we find a relative file path being used
      as torrc option. Resolves issue 14018.

  o Minor features (compilation):
    - Give a warning as early as possible when trying to build with an
      unsupported OpenSSL version. Closes ticket 16901.
    - Use C99 variadic macros when the compiler is not GCC. This avoids
      failing compilations on MSVC, and fixes a log-file-based race
      condition in our old workarounds. Original patch from Gisle Vanem.

  o Minor features (control protocol):
    - Support network-liveness GETINFO key and NETWORK_LIVENESS event in
      the control protocol. Resolves ticket 15358.

  o Minor features (controller):
    - Add DirAuthority lines for default directory authorities to the
      output of the "GETINFO config/defaults" command if not already
      present. Implements ticket 14840.
    - Controllers can now use "GETINFO hs/client/desc/id/..." to
      retrieve items from the client's hidden service descriptor cache.
      Closes ticket 14845.
    - Implement a new controller command "GETINFO status/fresh-relay-
      descs" to fetch a descriptor/extrainfo pair that was generated on
      demand just for the controller's use. Implements ticket 14784.

  o Minor features (directory authorities):
    - Directory authorities no longer vote against the "Fast", "Stable",
      and "HSDir" flags just because they were going to vote against
      "Running": if the consensus turns out to be that the router was
      running, then the authority's vote should count. Patch from Peter
      Retzlaff; closes issue 8712.

  o Minor features (directory authorities, security, also in 0.2.6.9):
    - The HSDir flag given by authorities now requires the Stable flag.
      For the current network, this results in going from 2887 to 2806
      HSDirs. Also, it makes it harder for an attacker to launch a sybil
      attack by raising the effort for a relay to become Stable to
      require at the very least 7 days, while maintaining the 96 hours
      uptime requirement for HSDir. Implements ticket 8243.

  o Minor features (DoS-resistance):
    - Make it harder for attackers to overload hidden services with
      introductions, by blocking multiple introduction requests on the
      same circuit. Resolves ticket 15515.

  o Minor features (geoip):
    - Update geoip and geoip6 to the October 9 2015 Maxmind GeoLite2
      Country database.

  o Minor features (hidden services):
    - Add the new options "HiddenServiceMaxStreams" and
      "HiddenServiceMaxStreamsCloseCircuit" to allow hidden services to
      limit the maximum number of simultaneous streams per circuit, and
      optionally tear down the circuit when the limit is exceeded. Part
      of ticket 16052.
    - Client now uses an introduction point failure cache to know when
      to fetch or keep a descriptor in their cache. Previously, failures
      were recorded implicitly, but not explicitly remembered. Closes
      ticket 16389.
    - Relays need to have the Fast flag to get the HSDir flag. As this
      is being written, we'll go from 2745 HSDirs down to 2342, a ~14%
      drop. This change should make some attacks against the hidden
      service directory system harder. Fixes ticket 15963.
    - Turn on hidden service statistics collection by setting the torrc
      option HiddenServiceStatistics to "1" by default. (This keeps
      track only of the fraction of traffic used by hidden services, and
      the total number of hidden services in existence.) Closes
      ticket 15254.
    - To avoid leaking HS popularity, don't cycle the introduction point
      when we've handled a fixed number of INTRODUCE2 cells but instead
      cycle it when a random number of introductions is reached, thus
      making it more difficult for an attacker to find out the amount of
      clients that have used the introduction point for a specific HS.
      Closes ticket 15745.

  o Minor features (logging):
    - Include the Tor version in all LD_BUG log messages, since people
      tend to cut and paste those into the bugtracker. Implements
      ticket 15026.

  o Minor features (pluggable transports):
    - When launching managed pluggable transports on Linux systems,
      attempt to have the kernel deliver a SIGTERM on tor exit if the
      pluggable transport process is still running. Resolves
      ticket 15471.
    - When launching managed pluggable transports, setup a valid open
      stdin in the child process that can be used to detect if tor has
      terminated. The "TOR_PT_EXIT_ON_STDIN_CLOSE" environment variable
      can be used by implementations to detect this new behavior.
      Resolves ticket 15435.

  o Minor bugfixes (torrc exit policies):
    - In each instance above, usage advice is provided to avoid the
      message. Resolves ticket 16069. Patch by "teor". Fixes part of bug
      16069; bugfix on 0.2.4.7-alpha.
    - In torrc, "accept6 *" and "reject6 *" ExitPolicy lines now only
      produce IPv6 wildcard addresses. Previously they would produce
      both IPv4 and IPv6 wildcard addresses. Patch by "teor". Fixes part
      of bug 16069; bugfix on 0.2.4.7-alpha.
    - When parsing torrc ExitPolicies, we now issue an info-level
      message when expanding an "accept/reject *" line to include both
      IPv4 and IPv6 wildcard addresses. Related to ticket 16069.
    - When parsing torrc ExitPolicies, we now warn for a number of cases
      where the user's intent is likely to differ from Tor's actual
      behavior. These include: using an IPv4 address with an accept6 or
      reject6 line; using "private" on an accept6 or reject6 line; and
      including any ExitPolicy lines after accept *:* or reject *:*.
      Related to ticket 16069.

  o Minor bugfixes (command-line interface):
    - When "--quiet" is provided along with "--validate-config", do not
      write anything to stdout on success. Fixes bug 14994; bugfix
      on 0.2.3.3-alpha.
    - When complaining about bad arguments to "--dump-config", use
      stderr, not stdout.
    - Print usage information for --dump-config when it is used without
      an argument. Also, fix the error message to use different wording
      and add newline at the end. Fixes bug 15541; bugfix
      on 0.2.5.1-alpha.

  o Minor bugfixes (compilation):
    - Fix compilation of sandbox.c with musl-libc. Fixes bug 17347;
      bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.
    - Repair compilation with the most recent (unreleased, alpha)
      vesions of OpenSSL 1.1. Fixes part of ticket 17237.

  o Minor bugfixes (compilation, also in 0.2.6.9):
    - Build with --enable-systemd correctly when libsystemd is
      installed, but systemd is not. Fixes bug 16164; bugfix on
      0.2.6.3-alpha. Patch from Peter Palfrader.

  o Minor bugfixes (configuration, unit tests):
    - Only add the default fallback directories when the DirAuthorities,
      AlternateDirAuthority, and FallbackDir directory config options
      are set to their defaults. The default fallback directory list is
      currently empty, this fix will only change tor's behavior when it
      has default fallback directories. Includes unit tests for
      consider_adding_dir_servers(). Fixes bug 15642; bugfix on
      90f6071d8dc0 in 0.2.4.7-alpha. Patch by "teor".

  o Minor bugfixes (controller):
    - Add the descriptor ID in each HS_DESC control event. It was
      missing, but specified in control-spec.txt. Fixes bug 15881;
      bugfix on 0.2.5.2-alpha.

  o Minor bugfixes (correctness):
    - For correctness, avoid modifying a constant string in
      handle_control_postdescriptor. Fixes bug 15546; bugfix
      on 0.1.1.16-rc.
    - Remove side-effects from tor_assert() calls. This was harmless,
      because we never disable assertions, but it is bad style and
      unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36,
      and 0.2.0.10.
    - When calling channel_free_list(), avoid calling smartlist_remove()
      while inside a FOREACH loop. This partially reverts commit
      17356fe7fd96af where the correct SMARTLIST_DEL_CURRENT was
      incorrectly removed. Fixes bug 16924; bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (crypto error-handling, also in 0.2.6.10):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (hidden service):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.
    - Remove an extraneous newline character from the end of hidden
      service descriptors. Fixes bug 15296; bugfix on 0.2.0.10-alpha.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Use the sandbox in tor_open_cloexec whether or not O_CLOEXEC is
      defined. Patch by "teor". Fixes bug 16515; bugfix on 0.2.3.1-alpha.
    - Allow bridge authorities to run correctly under the seccomp2
      sandbox. Fixes bug 16964; bugfix on 0.2.5.1-alpha.
    - Add the "hidserv-stats" filename to our sandbox filter for the
      HiddenServiceStatistics option to work properly. Fixes bug 17354;
      bugfix on 0.2.6.2-alpha. Patch from David Goulet.

  o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.10):
    - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
      these when eventfd2() support is missing. Fixes bug 16363; bugfix
      on 0.2.6.3-alpha. Patch from "teor".

  o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.9):
    - Allow systemd connections to work with the Linux seccomp2 sandbox
      code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
      Peter Palfrader.
    - Fix sandboxing to work when running as a relay, by allowing the
      renaming of secret_id_key, and allowing the eventfd2 and futex
      syscalls. Fixes bug 16244; bugfix on 0.2.6.1-alpha. Patch by
      Peter Palfrader.

  o Minor bugfixes (logging):
    - When building Tor under Clang, do not include an extra set of
      parentheses in log messages that include function names. Fixes bug
      15269; bugfix on every released version of Tor when compiled with
      recent enough Clang.

  o Minor bugfixes (network):
    - When attempting to use fallback technique for network interface
      lookup, disregard loopback and multicast addresses since they are
      unsuitable for public communications.

  o Minor bugfixes (open file limit):
    - Fix set_max_file_descriptors() to set by default the max open file
      limit to the current limit when setrlimit() fails. Fixes bug
      16274; bugfix on tor- 0.2.0.10-alpha. Patch by dgoulet.

  o Minor bugfixes (portability):
    - Check correctly for Windows socket errors in the workqueue
      backend. Fixes bug 16741; bugfix on 0.2.6.3-alpha.
    - Try harder to normalize the exit status of the Tor process to the
      standard-provided range. Fixes bug 16975; bugfix on every version
      of Tor ever.
    - Use libexecinfo on FreeBSD to enable backtrace support. Fixes part
      of bug 17151; bugfix on 0.2.5.2-alpha. Patch from Marcin Cieślak.

  o Minor bugfixes (relay):
    - Ensure that worker threads actually exit when a fatal error or
      shutdown is indicated. This fix doesn't currently affect the
      behavior of Tor, because Tor workers never indicates fatal error
      or shutdown except in the unit tests. Fixes bug 16868; bugfix
      on 0.2.6.3-alpha.
    - Fix a rarely-encountered memory leak when failing to initialize
      the thread pool. Fixes bug 16631; bugfix on 0.2.6.3-alpha. Patch
      from "cypherpunks".
    - Unblock threads before releasing the work queue mutex to ensure
      predictable scheduling behavior. Fixes bug 16644; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (security, exit policies):
    - ExitPolicyRejectPrivate now also rejects the relay's published
      IPv6 address (if any), and any publicly routable IPv4 or IPv6
      addresses on any local interfaces. ticket 17027. Patch by "teor".
      Fixes bug 17027; bugfix on 0.2.0.11-alpha.

  o Minor bugfixes (statistics):
    - Disregard the ConnDirectionStatistics torrc options when Tor is
      not a relay since in that mode of operation no sensible data is
      being collected and because Tor might run into measurement hiccups
      when running as a client for some time, then becoming a relay.
      Fixes bug 15604; bugfix on 0.2.2.35.

  o Minor bugfixes (systemd):
    - Tor's systemd unit file no longer contains extraneous spaces.
      These spaces would sometimes confuse tools like deb-systemd-
      helper. Fixes bug 16162; bugfix on 0.2.5.5-alpha.

  o Minor bugfixes (test networks):
    - When self-testing reachability, use ExtendAllowPrivateAddresses to
      determine if local/private addresses imply reachability. The
      previous fix used TestingTorNetwork, which implies
      ExtendAllowPrivateAddresses, but this excluded rare configurations
      where ExtendAllowPrivateAddresses is set but TestingTorNetwork is
      not. Fixes bug 15771; bugfix on 0.2.6.1-alpha. Patch by "teor",
      issue discovered by CJ Ess.

  o Minor bugfixes (tests, also in 0.2.6.9):
    - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
      16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".

  o Code simplification and refactoring:
    - Change the function that's called when we need to retry all
      downloads so that it only reschedules the downloads to happen
      immediately, rather than launching them all at once itself. This
      further simplifies Tor's callgraph.
    - Define WINVER and _WIN32_WINNT centrally, in orconfig.h, in order
      to ensure they remain consistent and visible everywhere.
    - Move some format-parsing functions out of crypto.c and
      crypto_curve25519.c into crypto_format.c and/or util_format.c.
    - Move the client-only parts of init_keys() into a separate
      function. Closes ticket 16763.
    - Move the hacky fallback code out of get_interface_address6() into
      separate function and get it covered with unit-tests. Resolves
      ticket 14710.
    - Refactor hidden service client-side cache lookup to intelligently
      report its various failure cases, and disentangle failure cases
      involving a lack of introduction points. Closes ticket 14391.
    - Remove some vestigial workarounds for the MSVC6 compiler. We
      haven't supported that in ages.
    - Remove the unused "nulterminate" argument from buf_pullup().
    - Simplify the microdesc_free() implementation so that it no longer
      appears (to code analysis tools) to potentially invoke a huge
      suite of other microdesc functions.
    - Simply the control graph further by deferring the inner body of
      directory_all_unreachable() into a callback. Closes ticket 16762.
    - The link authentication code has been refactored for better
      testability and reliability. It now uses code generated with the
      "trunnel" binary encoding generator, to reduce the risk of bugs
      due to programmer error. Done as part of ticket 12498.
    - Treat the loss of an owning controller as equivalent to a SIGTERM
      signal. This removes a tiny amount of duplicated code, and
      simplifies our callgraph. Closes ticket 16788.
    - Use our own Base64 encoder instead of OpenSSL's, to allow more
      control over the output. Part of ticket 15652.
    - When generating an event to send to the controller, we no longer
      put the event over the network immediately. Instead, we queue
      these events, and use a Libevent callback to deliver them. This
      change simplifies Tor's callgraph by reducing the number of
      functions from which all other Tor functions are reachable. Closes
      ticket 16695.
    - Wrap Windows-only C files inside '#ifdef _WIN32' so that tools
      that try to scan or compile every file on Unix won't decide that
      they are broken.

  o Documentation:
    - Fix capitalization of SOCKS in sample torrc. Closes ticket 15609.
    - Improve the descriptions of statistics-related torrc options in
      the manpage to describe rationale and possible uses cases. Fixes
      issue 15550.
    - Improve the layout and formatting of ./configure --help messages.
      Closes ticket 15024. Patch from "cypherpunks".
    - Include a specific and (hopefully) accurate documentation of the
      torrc file's meta-format in doc/torrc_format.txt. This is mainly
      of interest to people writing programs to parse or generate torrc
      files. This document is not a commitment to long-term
      compatibility; some aspects of the current format are a bit
      ridiculous. Closes ticket 2325.
    - Include the TUNING document in our source tarball. It is referred
      to in the ChangeLog and an error message. Fixes bug 16929; bugfix
      on 0.2.6.1-alpha.
    - Note that HiddenServicePorts can take a unix domain socket. Closes
      ticket 17364.
    - Recommend a 40 GB example AccountingMax in torrc.sample rather
      than a 4 GB max. Closes ticket 16742.
    - Standardize on the term "server descriptor" in the manual page.
      Previously, we had used "router descriptor", "server descriptor",
      and "relay descriptor" interchangeably. Part of ticket 14987.
    - Advise users on how to configure separate IPv4 and IPv6 exit
      policies in the manpage and sample torrcs. Related to ticket 16069.
    - Fix an error in the manual page and comments for
      TestingDirAuthVoteHSDir[IsStrict], which suggested that a HSDir
      required "ORPort connectivity". While this is true, it is in no
      way unique to the HSDir flag. Of all the flags, only HSDirs need a
      DirPort configured in order for the authorities to assign that
      particular flag. Patch by "teor". Fixed as part of 14882; bugfix
      on 0.2.6.3-alpha.
    - Fix the usage message of tor-resolve(1) so that it no longer lists
      the removed -F option. Fixes bug 16913; bugfix on 0.2.2.28-beta.

  o Removed code:
    - Remove `USE_OPENSSL_BASE64` and the corresponding fallback code
      and always use the internal Base64 decoder. The internal decoder
      has been part of tor since 0.2.0.10-alpha, and no one should
      be using the OpenSSL one. Part of ticket 15652.
    - Remove the 'tor_strclear()' function; use memwipe() instead.
      Closes ticket 14922.
    - Remove the code that would try to aggressively flush controller
      connections while writing to them. This code was introduced in
      0.1.2.7-alpha, in order to keep output buffers from exceeding
      their limits. But there is no longer a maximum output buffer size,
      and flushing data in this way caused some undesirable recursions
      in our call graph. Closes ticket 16480.
    - The internal pure-C tor-fw-helper tool is now removed from the Tor
      distribution, in favor of the pure-Go clone available from
      https://gitweb.torproject.org/tor-fw-helper.git/ . The libraries
      used by the C tor-fw-helper are not, in our opinion, very
      confidence- inspiring in their secure-programming techniques.
      Closes ticket 13338.

  o Removed features:
    - Remove the (seldom-used) DynamicDHGroups feature. For anti-
      fingerprinting we now recommend pluggable transports; for forward-
      secrecy in TLS, we now use the P-256 group. Closes ticket 13736.
    - Remove the HidServDirectoryV2 option. Now all relays offer to
      store hidden service descriptors. Related to 16543.
    - Remove the VoteOnHidServDirectoriesV2 option, since all
      authorities have long set it to 1. Closes ticket 16543.
    - Remove the undocumented "--digests" command-line option. It
      complicated our build process, caused subtle build issues on
      multiple platforms, and is now redundant since we started
      including git version identifiers. Closes ticket 14742.
    - Tor no longer contains checks for ancient directory cache versions
      that didn't know about microdescriptors.
    - Tor no longer contains workarounds for stat files generated by
      super-old versions of Tor that didn't choose guards sensibly.

  o Testing:
    - The test-network.sh script now supports performance testing.
      Requires corresponding chutney performance testing changes. Patch
      by "teor". Closes ticket 14175.
    - Add a new set of callgraph analysis scripts that use clang to
      produce a list of which Tor functions are reachable from which
      other Tor functions. We're planning to use these to help simplify
      our code structure by identifying illogical dependencies.
    - Add new 'test-full' and 'test-full-online' targets to run all
      tests, including integration tests with stem and chutney.
    - Autodetect CHUTNEY_PATH if the chutney and Tor sources are side-
      by-side in the same parent directory. Closes ticket 16903. Patch
      by "teor".
    - Document use of coverity, clang static analyzer, and clang dynamic
      undefined behavior and address sanitizers in doc/HACKING. Include
      detailed usage instructions in the blacklist. Patch by "teor".
      Closes ticket 15817.
    - Make "bridges+hs" the default test network. This tests almost all
      tor functionality during make test-network, while allowing tests
      to succeed on non-IPv6 systems. Requires chutney commit 396da92 in
      test-network-bridges-hs. Closes tickets 16945 (tor) and 16946
      (chutney). Patches by "teor".
    - Make the test-workqueue test work on Windows by initializing the
      network before we begin.
    - New make target (make test-network-all) to run multiple applicable
      chutney test cases. Patch from Teor; closes 16953.
    - Now that OpenSSL has its own scrypt implementation, add an unit
      test that checks for interoperability between libscrypt_scrypt()
      and OpenSSL's EVP_PBE_scrypt() so that we could not use libscrypt
      and rely on EVP_PBE_scrypt() whenever possible. Resolves
      ticket 16189.
    - The link authentication protocol code now has extensive tests.
    - The relay descriptor signature testing code now has
      extensive tests.
    - The test_workqueue program now runs faster, and is enabled by
      default as a part of "make check".
    - Unit test dns_resolve(), dns_clip_ttl() and dns_get_expiry_ttl()
      functions in dns.c. Implements a portion of ticket 16831.
    - Use environment variables rather than autoconf substitutions to
      send variables from the build system to the test scripts. This
      change should be easier to maintain, and cause 'make distcheck' to
      work better than before. Fixes bug 17148.
    - When building Tor with testing coverage enabled, run Chutney tests
      (if any) using the 'tor-cov' coverage binary.
    - When running test-network or test-stem, check for the absence of
      stem/chutney before doing any build operations.
    - Add a test to verify that the compiler does not eliminate our
      memwipe() implementation. Closes ticket 15377.
    - Add make rule `check-changes` to verify the format of changes
      files. Closes ticket 15180.
    - Add unit tests for control_event_is_interesting(). Add a compile-
      time check that the number of events doesn't exceed the capacity
      of control_event_t.event_mask. Closes ticket 15431, checks for
      bugs similar to 13085. Patch by "teor".
    - Command-line argument tests moved to Stem. Resolves ticket 14806.
    - Integrate the ntor, backtrace, and zero-length keys tests into the
      automake test suite. Closes ticket 15344.
    - Remove assertions during builds to determine Tor's test coverage.
      We don't want to trigger these even in assertions, so including
      them artificially makes our branch coverage look worse than it is.
      This patch provides the new test-stem-full and coverage-html-full
      configure options. Implements ticket 15400.
    - New TestingDirAuthVote{Exit,Guard,HSDir}IsStrict flags to
      explicitly manage consensus flags in testing networks. Patch by
      "robgjansen", modified by "teor". Implements part of ticket 14882.
    - Check for matching value in server response in ntor_ref.py. Fixes
      bug 15591; bugfix on 0.2.4.8-alpha. Reported and fixed
      by "joelanders".
    - Set the severity correctly when testing
      get_interface_addresses_ifaddrs() and
      get_interface_addresses_win32(), so that the tests fail gracefully
      instead of triggering an assertion. Fixes bug 15759; bugfix on
      0.2.6.3-alpha. Reported by Nicolas Derive.

Changes in version 0.2.6.10 - 2015-07-12
  Tor version 0.2.6.10 fixes some significant stability and hidden
  service client bugs, bulletproofs the cryptography init process, and
  fixes a bug when using the sandbox code with some older versions of
  Linux. Everyone running an older version, especially an older version
  of 0.2.6, should upgrade.

  o Major bugfixes (hidden service clients, stability):
    - Stop refusing to store updated hidden service descriptors on a
      client. This reverts commit 9407040c59218 (which indeed fixed bug
      14219, but introduced a major hidden service reachability
      regression detailed in bug 16381). This is a temporary fix since
      we can live with the minor issue in bug 14219 (it just results in
      some load on the network) but the regression of 16381 is too much
      of a setback. First-round fix for bug 16381; bugfix
      on 0.2.6.3-alpha.

  o Major bugfixes (stability):
    - Stop crashing with an assertion failure when parsing certain kinds
      of malformed or truncated microdescriptors. Fixes bug 16400;
      bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
      by "cypherpunks_backup".
    - Stop random client-side assertion failures that could occur when
      connecting to a busy hidden service, or connecting to a hidden
      service while a NEWNYM is in progress. Fixes bug 16013; bugfix
      on 0.1.0.1-rc.

  o Minor features (geoip):
    - Update geoip to the June 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the June 3 2015 Maxmind GeoLite2 Country database.

  o Minor bugfixes (crypto error-handling):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
      these when eventfd2() support is missing. Fixes bug 16363; bugfix
      on 0.2.6.3-alpha. Patch from "teor".


Changes in version 0.2.6.9 - 2015-06-11
  Tor 0.2.6.9 fixes a regression in the circuit isolation code, increases the
  requirements for receiving an HSDir flag, and addresses some other small
  bugs in the systemd and sandbox code. Clients using circuit isolation
  should upgrade; all directory authorities should upgrade.

  o Major bugfixes (client-side privacy):
    - Properly separate out each SOCKSPort when applying stream
      isolation. The error occurred because each port's session group was
      being overwritten by a default value when the listener connection
      was initialized. Fixes bug 16247; bugfix on 0.2.6.3-alpha. Patch
      by "jojelino".

  o Minor feature (directory authorities, security):
    - The HSDir flag given by authorities now requires the Stable flag.
      For the current network, this results in going from 2887 to 2806
      HSDirs. Also, it makes it harder for an attacker to launch a sybil
      attack by raising the effort for a relay to become Stable which
      takes at the very least 7 days to do so and by keeping the 96
      hours uptime requirement for HSDir. Implements ticket 8243.

  o Minor bugfixes (compilation):
    - Build with --enable-systemd correctly when libsystemd is
      installed, but systemd is not. Fixes bug 16164; bugfix on
      0.2.6.3-alpha. Patch from Peter Palfrader.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Fix sandboxing to work when running as a relaymby renaming of
      secret_id_key, and allowing the eventfd2 and futex syscalls. Fixes
      bug 16244; bugfix on 0.2.6.1-alpha. Patch by Peter Palfrader.
    - Allow systemd connections to work with the Linux seccomp2 sandbox
      code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
      Peter Palfrader.

  o Minor bugfixes (tests):
    - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
      16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".


Changes in version 0.2.6.8 - 2015-05-21
  Tor 0.2.6.8 fixes a bit of dodgy code in parsing INTRODUCE2 cells, and
  fixes an authority-side bug in assigning the HSDir flag. All directory
  authorities should upgrade.

  o Major bugfixes (hidden services, backport from 0.2.7.1-alpha):
    - Revert commit that made directory authorities assign the HSDir
      flag to relays without a DirPort; this was bad because such relays
      can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.

  o Minor features (geoip):
    - Update geoip to the April 8 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the April 8 2015 Maxmind GeoLite2
      Country database.


Changes in version 0.2.6.7 - 2015-04-06
  Tor 0.2.6.7 fixes two security issues that could be used by an
  attacker to crash hidden services, or crash clients visiting hidden
  services. Hidden services should upgrade as soon as possible; clients
  should upgrade whenever packages become available.

  This release also contains two simple improvements to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.
    - Decrease the amount of reattempts that a hidden service performs
      when its rendezvous circuits fail. This reduces the computational
      cost for running a hidden service under heavy load. Resolves
      ticket 11447.


Changes in version 0.2.5.12 - 2015-04-06
  Tor 0.2.5.12 backports two fixes from 0.2.6.7 for security issues that
  could be used by an attacker to crash hidden services, or crash clients
  visiting hidden services. Hidden services should upgrade as soon as
  possible; clients should upgrade whenever packages become available.

  This release also backports a simple improvement to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.


Changes in version 0.2.4.27 - 2015-04-06
  Tor 0.2.4.27 backports two fixes from 0.2.6.7 for security issues that
  could be used by an attacker to crash hidden services, or crash clients
  visiting hidden services. Hidden services should upgrade as soon as
  possible; clients should upgrade whenever packages become available.

  This release also backports a simple improvement to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.


Changes in version 0.2.6.6 - 2015-03-24
  Tor 0.2.6.6 is the first stable release in the 0.2.6 series.

  It adds numerous safety, security, correctness, and performance
  improvements. Client programs can be configured to use more kinds of
  sockets, AutomapHosts works better, the multithreading backend is
  improved, cell transmission is refactored, test coverage is much
  higher, more denial-of-service attacks are handled, guard selection is
  improved to handle long-term guards better, pluggable transports
  should work a bit better, and some annoying hidden service performance
  bugs should be addressed.

  o New compiler and system requirements:
    - Tor 0.2.6.x requires that your compiler support more of the C99
      language standard than before. The 'configure' script now detects
      whether your compiler supports C99 mid-block declarations and
      designated initializers. If it does not, Tor will not compile.

      We may revisit this requirement if it turns out that a significant
      number of people need to build Tor with compilers that don't
      bother implementing a 15-year-old standard. Closes ticket 13233.
    - Tor no longer supports systems without threading support. When we
      began working on Tor, there were several systems that didn't have
      threads, or where the thread support wasn't able to run the
      threads of a single process on multiple CPUs. That no longer
      holds: every system where Tor needs to run well now has threading
      support. Resolves ticket 12439.

  o Deprecated versions and removed support:
    - Tor relays older than 0.2.4.18-rc are no longer allowed to
      advertise themselves on the network. Closes ticket 13555.
    - Tor clients no longer support connecting to hidden services
      running on Tor 0.2.2.x and earlier; the Support022HiddenServices
      option has been removed. (There shouldn't be any hidden services
      running these versions on the network.) Closes ticket 7803.

  o Directory authority changes:
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.

  o Major features (bridges):
    - Expose the outgoing upstream HTTP/SOCKS proxy to pluggable
      transports if they are configured via the "TOR_PT_PROXY"
      environment variable. Implements proposal 232. Resolves
      ticket 8402.

  o Major features (changed defaults):
    - Prevent relay operators from unintentionally running exits: When a
      relay is configured as an exit node, we now warn the user unless
      the "ExitRelay" option is set to 1. We warn even more loudly if
      the relay is configured with the default exit policy, since this
      can indicate accidental misconfiguration. Setting "ExitRelay 0"
      stops Tor from running as an exit relay. Closes ticket 10067.

  o Major features (client performance, hidden services):
    - Allow clients to use optimistic data when connecting to a hidden
      service, which should remove a round-trip from hidden service
      initialization. See proposal 181 for details. Implements
      ticket 13211.

  o Major features (directory system):
    - Upon receiving an unparseable directory object, if its digest
      matches what we expected, then don't try to download it again.
      Previously, when we got a descriptor we didn't like, we would keep
      trying to download it over and over. Closes ticket 11243.
    - When downloading server- or microdescriptors from a directory
      server, we no longer launch multiple simultaneous requests to the
      same server. This reduces load on the directory servers,
      especially when directory guards are in use. Closes ticket 9969.
    - When downloading server- or microdescriptors over a tunneled
      connection, do not limit the length of our requests to what the
      Squid proxy is willing to handle. Part of ticket 9969.
    - Authorities can now vote on the correct digests and latest
      versions for different software packages. This allows packages
      that include Tor to use the Tor authority system as a way to get
      notified of updates and their correct digests. Implements proposal
      227. Closes ticket 10395.

  o Major features (guards):
    - Introduce the Guardfraction feature to improves load balancing on
      guard nodes. Specifically, it aims to reduce the traffic gap that
      guard nodes experience when they first get the Guard flag. This is
      a required step if we want to increase the guard lifetime to 9
      months or greater.  Closes ticket 9321.

  o Major features (hidden services):
    - Make HS port scanning more difficult by immediately closing the
      circuit when a user attempts to connect to a nonexistent port.
      Closes ticket 13667.
    - Add a HiddenServiceStatistics option that allows Tor relays to
      gather and publish statistics about the overall size and volume of
      hidden service usage. Specifically, when this option is turned on,
      an HSDir will publish an approximate number of hidden services
      that have published descriptors to it the past 24 hours. Also, if
      a relay has acted as a hidden service rendezvous point, it will
      publish the approximate amount of rendezvous cells it has relayed
      the past 24 hours. The statistics themselves are obfuscated so
      that the exact values cannot be derived. For more details see
      proposal 238, "Better hidden service stats from Tor relays". This
      feature is currently disabled by default. Implements feature 13192.

  o Major features (performance):
    - Make the CPU worker implementation more efficient by avoiding the
      kernel and lengthening pipelines. The original implementation used
      sockets to transfer data from the main thread to the workers, and
      didn't allow any thread to be assigned more than a single piece of
      work at once. The new implementation avoids communications
      overhead by making requests in shared memory, avoiding kernel IO
      where possible, and keeping more requests in flight at once.
      Implements ticket 9682.

  o Major features (relay):
    - Raise the minimum acceptable configured bandwidth rate for bridges
      to 50 KiB/sec and for relays to 75 KiB/sec. (The old values were
      20 KiB/sec.) Closes ticket 13822.
    - Complete revision of the code that relays use to decide which cell
      to send next. Formerly, we selected the best circuit to write on
      each channel, but we didn't select among channels in any
      sophisticated way. Now, we choose the best circuits globally from
      among those whose channels are ready to deliver traffic.

      This patch implements a new inter-cmux comparison API, a global
      high/low watermark mechanism and a global scheduler loop for
      transmission prioritization across all channels as well as among
      circuits on one channel. This schedule is currently tuned to
      (tolerantly) avoid making changes in network performance, but it
      should form the basis for major circuit performance increases in
      the future. Code by Andrea; tuning by Rob Jansen; implements
      ticket 9262.

  o Major features (sample torrc):
    - Add a new, infrequently-changed "torrc.minimal". This file is
      similar to torrc.sample, but it will change as infrequently as
      possible, for the benefit of users whose systems prompt them for
      intervention whenever a default configuration file is changed.
      Making this change allows us to update torrc.sample to be a more
      generally useful "sample torrc".

  o Major features (security, unix domain sockets):
    - Allow SocksPort to be an AF_UNIX Unix Domain Socket. Now high risk
      applications can reach Tor without having to create AF_INET or
      AF_INET6 sockets, meaning they can completely disable their
      ability to make non-Tor network connections. To create a socket of
      this type, use "SocksPort unix:/path/to/socket". Implements
      ticket 12585.
    - Support mapping hidden service virtual ports to AF_UNIX sockets.
      The syntax is "HiddenServicePort 80 unix:/path/to/socket".
      Implements ticket 11485.

  o Major bugfixes (client, automap):
    - Repair automapping with IPv6 addresses. This automapping should
      have worked previously, but one piece of debugging code that we
      inserted to detect a regression actually caused the regression to
      manifest itself again. Fixes bug 13811 and bug 12831; bugfix on
      0.2.4.7-alpha. Diagnosed and fixed by Francisco Blas
      Izquierdo Riera.

  o Major bugfixes (crash, OSX, security):
    - Fix a remote denial-of-service opportunity caused by a bug in
      OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
      in OSX 10.9.

  o Major bugfixes (directory authorities):
    - Do not assign the HSDir flag to relays if they are not Valid, or
      currently hibernating. Fixes 12573; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (directory bandwidth performance):
    - Don't flush the zlib buffer aggressively when compressing
      directory information for clients. This should save about 7% of
      the bandwidth currently used for compressed descriptors and
      microdescriptors. Fixes bug 11787; bugfix on 0.1.1.23.

  o Major bugfixes (exit node stability):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (FreeBSD IPFW transparent proxy):
    - Fix address detection with FreeBSD transparent proxies, when
      "TransProxyType ipfw" is in use. Fixes bug 15064; bugfix
      on 0.2.5.4-alpha.

  o Major bugfixes (hidden services):
    - When closing an introduction circuit that was opened in parallel
      with others, don't mark the introduction point as unreachable.
      Previously, the first successful connection to an introduction
      point would make the other introduction points get marked as
      having timed out. Fixes bug 13698; bugfix on 0.0.6rc2.

  o Major bugfixes (Linux seccomp2 sandbox):
    - Upon receiving sighup with the seccomp2 sandbox enabled, do not
      crash during attempts to call wait4. Fixes bug 15088; bugfix on
      0.2.5.1-alpha. Patch from "sanic".

  o Major bugfixes (mixed relay-client operation):
    - When running as a relay and client at the same time (not
      recommended), if we decide not to use a new guard because we want
      to retry older guards, only close the locally-originating circuits
      passing through that guard. Previously we would close all the
      circuits through that guard. Fixes bug 9819; bugfix on
      0.2.1.1-alpha. Reported by "skruffy".

  o Major bugfixes (pluggable transports):
    - Initialize the extended OR Port authentication cookie before
      launching pluggable transports. This prevents a race condition
      that occurred when server-side pluggable transports would cache the
      authentication cookie before it has been (re)generated. Fixes bug
      15240; bugfix on 0.2.5.1-alpha.

  o Major bugfixes (relay, stability, possible security):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout is passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from "cypherpunks".
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Minor features (build):
    - New --disable-system-torrc compile-time option to prevent Tor from
      looking for the system-wide torrc or torrc-defaults files.
      Resolves ticket 13037.

  o Minor features (client):
    - Clients are now willing to send optimistic data (before they
      receive a 'connected' cell) to relays of any version. (Relays
      without support for optimistic data are no longer supported on the
      Tor network.) Resolves ticket 13153.

  o Minor features (client):
    - Validate hostnames in SOCKS5 requests more strictly. If SafeSocks
      is enabled, reject requests with IP addresses as hostnames.
      Resolves ticket 13315.

  o Minor features (controller):
    - Add a "SIGNAL HEARTBEAT" controller command that tells Tor to
      write an unscheduled heartbeat message to the log. Implements
      feature 9503.
    - Include SOCKS_USERNAME and SOCKS_PASSWORD values in controller
      events so controllers can observe circuit isolation inputs. Closes
      ticket 8405.
    - ControlPort now supports the unix:/path/to/socket syntax as an
      alternative to the ControlSocket option, for consistency with
      SocksPort and HiddenServicePort. Closes ticket 14451.
    - New "GETINFO bw-event-cache" to get information about recent
      bandwidth events. Closes ticket 14128. Useful for controllers to
      get recent bandwidth history after the fix for ticket 13988.
    - Messages about problems in the bootstrap process now include
      information about the server we were trying to connect to when we
      noticed the problem. Closes ticket 15006.

  o Minor features (Denial of service resistance):
    - Count the total number of bytes used storing hidden service
      descriptors against the value of MaxMemInQueues. If we're low on
      memory, and more than 20% of our memory is used holding hidden
      service descriptors, free them until no more than 10% of our
      memory holds hidden service descriptors. Free the least recently
      fetched descriptors first. Resolves ticket 13806.
    - When we have recently been under memory pressure (over 3/4 of
      MaxMemInQueues is allocated), then allocate smaller zlib objects
      for small requests. Closes ticket 11791.

  o Minor features (directory authorities):
    - Don't list relays with a bandwidth estimate of 0 in the consensus.
      Implements a feature proposed during discussion of bug 13000.
    - In tor-gencert, report an error if the user provides the same
      argument more than once.
    - If a directory authority can't find a best consensus method in the
      votes that it holds, it now falls back to its favorite consensus
      method. Previously, it fell back to method 1. Neither of these is
      likely to get enough signatures, but "fall back to favorite"
      doesn't require us to maintain support an obsolete consensus
      method. Implements part of proposal 215.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

  o Minor features (guard nodes):
    - Reduce the time delay before saving guard status to disk from 10
      minutes to 30 seconds (or from one hour to 10 minutes if
      AvoidDiskWrites is set). Closes ticket 12485.

  o Minor features (heartbeat):
    - On relays, report how many connections we negotiated using each
      version of the Tor link protocols. This information will let us
      know if removing support for very old versions of the Tor
      protocols is harming the network. Closes ticket 15212.

  o Minor features (hidden service):
    - Make Sybil attacks against hidden services harder by changing the
      minimum time required to get the HSDir flag from 25 hours up to 96
      hours. Addresses ticket 14149.
    - New option "HiddenServiceAllowUnknownPorts" to allow hidden
      services to disable the anti-scanning feature introduced in
      0.2.6.2-alpha. With this option not set, a connection to an
      unlisted port closes the circuit. With this option set, only a
      RELAY_DONE cell is sent. Closes ticket 14084.
    - When re-enabling the network, don't try to build introduction
      circuits until we have successfully built a circuit. This makes
      hidden services come up faster when the network is re-enabled.
      Patch from "akwizgran". Closes ticket 13447.
    - When we fail to retrieve a hidden service descriptor, send the
      controller an "HS_DESC FAILED" controller event. Implements
      feature 13212.
    - New HiddenServiceDirGroupReadable option to cause hidden service
      directories and hostname files to be created group-readable. Patch
      from "anon", David Stainton, and "meejah". Closes ticket 11291.

  o Minor features (interface):
    - Implement "-f -" command-line option to read torrc configuration
      from standard input, if you don't want to store the torrc file in
      the file system. Implements feature 13865.

  o Minor features (logging):
    - Add a count of unique clients to the bridge heartbeat message.
      Resolves ticket 6852.
    - Suppress "router info incompatible with extra info" message when
      reading extrainfo documents from cache. (This message got loud
      around when we closed bug 9812 in 0.2.6.2-alpha.) Closes
      ticket 13762.
    - Elevate hidden service authorized-client message from DEBUG to
      INFO. Closes ticket 14015.
    - On Unix-like systems, you can now use named pipes as the target of
      the Log option, and other options that try to append to files.
      Closes ticket 12061. Patch from "carlo von lynX".
    - When opening a log file at startup, send it every log message that
      we generated between startup and opening it. Previously, log
      messages that were generated before opening the log file were only
      logged to stdout. Closes ticket 6938.
    - Add a TruncateLogFile option to overwrite logs instead of
      appending to them. Closes ticket 5583.
    - Quiet some log messages in the heartbeat and at startup. Closes
      ticket 14950.

  o Minor features (portability, Solaris):
    - Threads are no longer disabled by default on Solaris; we believe
      that the versions of Solaris with broken threading support are all
      obsolete by now. Resolves ticket 9495.

  o Minor features (relay):
    - Re-check our address after we detect a changed IP address from
      getsockname(). This ensures that the controller command "GETINFO
      address" will report the correct value. Resolves ticket 11582.
      Patch from "ra".
    - A new AccountingRule option lets Relays set whether they'd like
      AccountingMax to be applied separately to inbound and outbound
      traffic, or applied to the sum of inbound and outbound traffic.
      Resolves ticket 961. Patch by "chobe".
    - When identity keypair is generated for first time, log a
      congratulatory message that links to the new relay lifecycle
      document. Implements feature 10427.

  o Minor features (security, memory wiping):
    - Ensure we securely wipe keys from memory after
      crypto_digest_get_digest and init_curve25519_keypair_from_file
      have finished using them. Resolves ticket 13477.

  o Minor features (security, out-of-memory handling):
    - When handling an out-of-memory condition, allocate less memory for
      temporary data structures. Fixes issue 10115.
    - When handling an out-of-memory condition, consider more types of
      buffers, including those on directory connections, and zlib
      buffers. Resolves ticket 11792.

  o Minor features (stability):
    - Add assertions in our hash-table iteration code to check for
      corrupted values that could cause infinite loops. Closes
      ticket 11737.

  o Minor features (systemd):
    - Various improvements and modernizations in systemd hardening
      support. Closes ticket 13805. Patch from Craig Andrews.
    - Where supported, when running with systemd, report successful
      startup to systemd. Part of ticket 11016. Patch by Michael Scherer.
    - When running with systemd, support systemd watchdog messages. Part
      of ticket 11016. Patch by Michael Scherer.

  o Minor features (testing networks):
    - Add the TestingDirAuthVoteExit option, which lists nodes to assign
      the "Exit" flag regardless of their uptime, bandwidth, or exit
      policy. TestingTorNetwork must be set for this option to have any
      effect. Previously, authorities would take up to 35 minutes to
      give nodes the Exit flag in a test network. Partially implements
      ticket 13161.
    - Drop the minimum RendPostPeriod on a testing network to 5 seconds,
      and the default on a testing network to 2 minutes. Drop the
      MIN_REND_INITIAL_POST_DELAY on a testing network to 5 seconds, but
      keep the default on a testing network at 30 seconds. This reduces
      HS bootstrap time to around 25 seconds. Also, change the default
      time in test-network.sh to match. Closes ticket 13401. Patch
      by "teor".
    - Create TestingDirAuthVoteHSDir to correspond to
      TestingDirAuthVoteExit/Guard. Ensures that authorities vote the
      HSDir flag for the listed relays regardless of uptime or ORPort
      connectivity. Respects the value of VoteOnHidServDirectoriesV2.
      Partial implementation for ticket 14067. Patch by "teor".

  o Minor features (tor2web mode):
    - Introduce the config option Tor2webRendezvousPoints, which allows
      clients in Tor2webMode to select a specific Rendezvous Point to be
      used in HS circuits. This might allow better performance for
      Tor2Web nodes. Implements ticket 12844.

  o Minor features (transparent proxy):
    - Update the transparent proxy option checks to allow for both ipfw
      and pf on OS X. Closes ticket 14002.
    - Use the correct option when using IPv6 with transparent proxy
      support on Linux. Resolves 13808. Patch by Francisco Blas
      Izquierdo Riera.

  o Minor features (validation):
    - Check all date/time values passed to tor_timegm and
      parse_rfc1123_time for validity, taking leap years into account.
      Improves HTTP header validation. Implemented with bug 13476.
    - In correct_tm(), limit the range of values returned by system
      localtime(_r) and gmtime(_r) to be between the years 1 and 8099.
      This means we don't have to deal with negative or too large dates,
      even if a clock is wrong. Otherwise we might fail to read a file
      written by us which includes such a date. Fixes bug 13476.
    - Stop allowing invalid address patterns like "*/24" that contain
      both a wildcard address and a bit prefix length. This affects all
      our address-range parsing code. Fixes bug 7484; bugfix
      on 0.0.2pre14.

  o Minor bugfixes (bridge clients):
    - When configured to use a bridge without an identity digest (not
      recommended), avoid launching an extra channel to it when
      bootstrapping. Fixes bug 7733; bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (bridges):
    - When DisableNetwork is set, do not launch pluggable transport
      plugins, and if any are running, terminate them. Fixes bug 13213;
      bugfix on 0.2.3.6-alpha.

  o Minor bugfixes (C correctness):
    - Fix several instances of possible integer overflow/underflow/NaN.
      Fixes bug 13104; bugfix on 0.2.3.1-alpha and later. Patches
      from "teor".
    - In circuit_build_times_calculate_timeout() in circuitstats.c,
      avoid dividing by zero in the pareto calculations. This traps
      under clang's "undefined-trap" sanitizer. Fixes bug 13290; bugfix
      on 0.2.2.2-alpha.
    - Fix an integer overflow in format_time_interval(). Fixes bug
      13393; bugfix on 0.2.0.10-alpha.
    - Set the correct day of year value when the system's localtime(_r)
      or gmtime(_r) functions fail to set struct tm. Not externally
      visible. Fixes bug 13476; bugfix on 0.0.2pre14.
    - Avoid unlikely signed integer overflow in tor_timegm on systems
      with 32-bit time_t. Fixes bug 13476; bugfix on 0.0.2pre14.

  o Minor bugfixes (certificate handling):
    - If an authority operator accidentally makes a signing certificate
      with a future publication time, do not discard its real signing
      certificates. Fixes bug 11457; bugfix on 0.2.0.3-alpha.
    - Remove any old authority certificates that have been superseded
      for at least two days. Previously, we would keep superseded
      certificates until they expired, if they were published close in
      time to the certificate that superseded them. Fixes bug 11454;
      bugfix on 0.2.1.8-alpha.

  o Minor bugfixes (client):
    - Fix smartlist_choose_node_by_bandwidth() so that relays with the
      BadExit flag are not considered worthy candidates. Fixes bug
      13066; bugfix on 0.1.2.3-alpha.
    - Use the consensus schedule for downloading consensuses, and not
      the generic schedule. Fixes bug 11679; bugfix on 0.2.2.6-alpha.
    - Handle unsupported or malformed SOCKS5 requests properly by
      responding with the appropriate error message before closing the
      connection. Fixes bugs 12971 and 13314; bugfix on 0.0.2pre13.

  o Minor bugfixes (client, automapping):
    - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
      no value follows the option. Fixes bug 14142; bugfix on
      0.2.4.7-alpha. Patch by "teor".
    - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
      14195; bugfix on 0.1.0.1-rc.
    - Prevent changes to other options from removing the wildcard value
      "." from "AutomapHostsSuffixes". Fixes bug 12509; bugfix
      on 0.2.0.1-alpha.
    - Allow MapAddress and AutomapHostsOnResolve to work together when
      an address is mapped into another address type (like .onion) that
      must be automapped at resolve time. Fixes bug 7555; bugfix
      on 0.2.0.1-alpha.

  o Minor bugfixes (client, bridges):
    - When we are using bridges and we had a network connectivity
      problem, only retry connecting to our currently configured
      bridges, not all bridges we know about and remember using. Fixes
      bug 14216; bugfix on 0.2.2.17-alpha.

  o Minor bugfixes (client, DNS):
    - Report the correct cached DNS expiration times on SOCKS port or in
      DNS replies. Previously, we would report everything as "never
      expires." Fixes bug 14193; bugfix on 0.2.3.17-beta.
    - Avoid a small memory leak when we find a cached answer for a
      reverse DNS lookup in a client-side DNS cache. (Remember, client-
      side DNS caching is off by default, and is not recommended.) Fixes
      bug 14259; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (client, IPv6):
    - Reject socks requests to literal IPv6 addresses when IPv6Traffic
      flag is not set; and not because the NoIPv4Traffic flag was set.
      Previously we'd looked at the NoIPv4Traffic flag for both types of
      literal addresses. Fixes bug 14280; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (client, microdescriptors):
    - Use a full 256 bits of the SHA256 digest of a microdescriptor when
      computing which microdescriptors to download. This keeps us from
      erroneous download behavior if two microdescriptor digests ever
      have the same first 160 bits. Fixes part of bug 13399; bugfix
      on 0.2.3.1-alpha.
    - Reset a router's status if its microdescriptor digest changes,
      even if the first 160 bits remain the same. Fixes part of bug
      13399; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (client, torrc):
    - Stop modifying the value of our DirReqStatistics torrc option just
      because we're not a bridge or relay. This bug was causing Tor
      Browser users to write "DirReqStatistics 0" in their torrc files
      as if they had chosen to change the config. Fixes bug 4244; bugfix
      on 0.2.3.1-alpha.
    - When GeoIPExcludeUnknown is enabled, do not incorrectly decide
      that our options have changed every time we SIGHUP. Fixes bug
      9801; bugfix on 0.2.4.10-alpha. Patch from "qwerty1".

  o Minor bugfixes (compilation):
    - Fix a compilation warning on s390. Fixes bug 14988; bugfix
      on 0.2.5.2-alpha.
    - Silence clang warnings under --enable-expensive-hardening,
      including implicit truncation of 64 bit values to 32 bit, const
      char assignment to self, tautological compare, and additional
      parentheses around equality tests. Fixes bug 13577; bugfix
      on 0.2.5.4-alpha.
    - Fix a clang warning about checking whether an address in the
      middle of a structure is NULL. Fixes bug 14001; bugfix
      on 0.2.1.2-alpha.
    - The address of an array in the middle of a structure will always
      be non-NULL. clang recognises this and complains. Disable the
      tautologous and redundant check to silence this warning. Fixes bug
      14001; bugfix on 0.2.1.2-alpha.
    - Compile correctly with (unreleased) OpenSSL 1.1.0 headers.
      Addresses ticket 14188.
    - Build without warnings with the stock OpenSSL srtp.h header, which
      has a duplicate declaration of SSL_get_selected_srtp_profile().
      Fixes bug 14220; this is OpenSSL's bug, not ours.
    - Do not compile any code related to Tor2Web mode when Tor2Web mode
      is not enabled at compile time. Previously, this code was included
      in a disabled state. See discussion on ticket 12844.
    - Allow our configure script to build correctly with autoconf 2.62
      again. Fixes bug 12693; bugfix on 0.2.5.2-alpha.
    - Improve the error message from ./configure to make it clear that
      when asciidoc has not been found, the user will have to either add
      --disable-asciidoc argument or install asciidoc. Resolves
      ticket 13228.

  o Minor bugfixes (controller):
    - Report "down" in response to the "GETINFO entry-guards" command
      when relays are down with an unreachable_since value. Previously,
      we would report "up". Fixes bug 14184; bugfix on 0.1.2.2-alpha.
    - Avoid crashing on a malformed EXTENDCIRCUIT command. Fixes bug
      14116; bugfix on 0.2.2.9-alpha.

  o Minor bugfixes (controller):
    - Return an error when the second or later arguments of the
      "setevents" controller command are invalid events. Previously we
      would return success while silently skipping invalid events. Fixes
      bug 13205; bugfix on 0.2.3.2-alpha. Reported by "fpxnns".

  o Minor bugfixes (directory authority):
    - Allow directory authorities to fetch more data from one another if
      they find themselves missing lots of votes. Previously, they had
      been bumping against the 10 MB queued data limit. Fixes bug 14261;
      bugfix on 0.1.2.5-alpha.
    - Do not attempt to download extrainfo documents which we will be
      unable to validate with a matching server descriptor. Fixes bug
      13762; bugfix on 0.2.0.1-alpha.
    - Fix a bug that was truncating AUTHDIR_NEWDESC events sent to the
      control port. Fixes bug 14953; bugfix on 0.2.0.1-alpha.
    - Enlarge the buffer to read bwauth generated files to avoid an
      issue when parsing the file in dirserv_read_measured_bandwidths().
      Fixes bug 14125; bugfix on 0.2.2.1-alpha.
    - When running as a v3 directory authority, advertise that you serve
      extra-info documents so that clients who want them can find them
      from you too. Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (directory system):
    - Always believe that v3 directory authorities serve extra-info
      documents, whether they advertise "caches-extra-info" or not.
      Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.
    - Check the BRIDGE_DIRINFO flag bitwise rather than using equality.
      Previously, directories offering BRIDGE_DIRINFO and some other
      flag (i.e. microdescriptors or extrainfo) would be ignored when
      looking for bridges. Partially fixes bug 13163; bugfix
      on 0.2.0.7-alpha.

  o Minor bugfixes (file handling):
    - Stop failing when key files are zero-length. Instead, generate new
      keys, and overwrite the empty key files. Fixes bug 13111; bugfix
      on all versions of Tor. Patch by "teor".
    - Stop generating a fresh .old RSA onion key file when the .old file
      is missing. Fixes part of 13111; bugfix on 0.0.6rc1.
    - Avoid overwriting .old key files with empty key files.
    - Skip loading zero-length extrainfo store, router store, stats,
      state, and key files.
    - Avoid crashing when trying to reload a torrc specified as a
      relative path with RunAsDaemon turned on. Fixes bug 13397; bugfix
      on 0.2.3.11-alpha.

  o Minor bugfixes (hidden services):
    - Close the introduction circuit when we have no more usable intro
      points, instead of waiting for it to time out. This also ensures
      that no follow-up HS descriptor fetch is triggered when the
      circuit eventually times out. Fixes bug 14224; bugfix on 0.0.6.
    - When fetching a hidden service descriptor for a down service that
      was recently up, do not keep refetching until we try the same
      replica twice in a row. Fixes bug 14219; bugfix on 0.2.0.10-alpha.
    - Correctly send a controller event when we find that a rendezvous
      circuit has finished. Fixes bug 13936; bugfix on 0.1.1.5-alpha.
    - Pre-check directory permissions for new hidden-services to avoid
      at least one case of "Bug: Acting on config options left us in a
      broken state. Dying." Fixes bug 13942; bugfix on 0.0.6pre1.
    - When fetching hidden service descriptors, we now check not only
      for whether we got the hidden service we had in mind, but also
      whether we got the particular descriptors we wanted. This prevents
      a class of inefficient but annoying DoS attacks by hidden service
      directories. Fixes bug 13214; bugfix on 0.2.1.6-alpha. Reported
      by "special".

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Make transparent proxy support work along with the seccomp2
      sandbox. Fixes part of bug 13808; bugfix on 0.2.5.1-alpha. Patch
      by Francisco Blas Izquierdo Riera.
    - Fix a memory leak in tor-resolve when running with the sandbox
      enabled. Fixes bug 14050; bugfix on 0.2.5.9-rc.
    - Allow glibc fatal errors to be sent to stderr before Tor exits.
      Previously, glibc would try to write them to /dev/tty, and the
      sandbox would trap the call and make Tor exit prematurely. Fixes
      bug 14759; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (logging):
    - Avoid crashing when there are more log domains than entries in
      domain_list. Bugfix on 0.2.3.1-alpha.
    - Downgrade warnings about RSA signature failures to info log level.
      Emit a warning when an extra info document is found incompatible
      with a corresponding router descriptor. Fixes bug 9812; bugfix
      on 0.0.6rc3.
    - Make connection_ap_handshake_attach_circuit() log the circuit ID
      correctly. Fixes bug 13701; bugfix on 0.0.6.

  o Minor bugfixes (networking):
    - Check for orconns and use connection_or_close_for_error() rather
      than connection_mark_for_close() directly in the getsockopt()
      failure case of connection_handle_write_impl(). Fixes bug 11302;
      bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (parsing):
    - Stop accepting milliseconds (or other junk) at the end of
      descriptor publication times. Fixes bug 9286; bugfix on 0.0.2pre25.
    - Support two-number and three-number version numbers correctly, in
      case we change the Tor versioning system in the future. Fixes bug
      13661; bugfix on 0.0.8pre1.

  o Minor bugfixes (portability):
    - Fix the ioctl()-based network interface lookup code so that it
      will work on systems that have variable-length struct ifreq, for
      example Mac OS X.
    - Use the correct datatype in the SipHash-2-4 function to prevent
      compilers from assuming any sort of alignment. Fixes bug 15436;
      bugfix on 0.2.5.3-alpha.

  o Minor bugfixes (preventative security, C safety):
    - When reading a hexadecimal, base-32, or base-64 encoded value from
      a string, always overwrite the whole output buffer. This prevents
      some bugs where we would look at (but fortunately, not reveal)
      uninitialized memory on the stack. Fixes bug 14013; bugfix on all
      versions of Tor.
    - Clear all memory targeted by tor_addr_{to,from}_sockaddr(), not
      just the part that's used. This makes it harder for data leak bugs
      to occur in the event of other programming failures. Resolves
      ticket 14041.

  o Minor bugfixes (relay):
    - When generating our family list, remove spaces from around the
      entries. Fixes bug 12728; bugfix on 0.2.1.7-alpha.
    - If our previous bandwidth estimate was 0 bytes, allow publishing a
      new relay descriptor immediately. Fixes bug 13000; bugfix
      on 0.1.1.6-alpha.

  o Minor bugfixes (shutdown):
    - When shutting down, always call event_del() on lingering read or
      write events before freeing them. Otherwise, we risk double-frees
      or read-after-frees in event_base_free(). Fixes bug 12985; bugfix
      on 0.1.0.2-rc.

  o Minor bugfixes (small memory leaks):
    - Avoid leaking memory when using IPv6 virtual address mappings.
      Fixes bug 14123; bugfix on 0.2.4.7-alpha. Patch by Tom van
      der Woerdt.

  o Minor bugfixes (statistics):
    - Increase period over which bandwidth observations are aggregated
      from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.

  o Minor bugfixes (systemd support):
    - Run correctly under systemd with the RunAsDaemon option set. Fixes
      part of bug 14141; bugfix on 0.2.5.7-rc. Patch from Tomasz Torcz.
    - Inform the systemd supervisor about more changes in the Tor
      process status. Implements part of ticket 14141. Patch from
      Tomasz Torcz.

  o Minor bugfixes (testing networks):
    - Fix TestingDirAuthVoteGuard to properly give out Guard flags in a
      testing network. Fixes bug 13064; bugfix on 0.2.5.2-alpha.
    - Stop using the default authorities in networks which provide both
      AlternateDirAuthority and AlternateBridgeAuthority. Partially
      fixes bug 13163; bugfix on 0.2.0.13-alpha.

  o Minor bugfixes (testing networks, fast startup):
    - Allow Tor to build circuits using a consensus with no exits. If
      the consensus has no exits (typical of a bootstrapping test
      network), allow Tor to build circuits once enough descriptors have
      been downloaded. This assists in bootstrapping a testing Tor
      network. Fixes bug 13718; bugfix on 0.2.4.10-alpha. Patch
      by "teor".
    - When V3AuthVotingInterval is low, give a lower If-Modified-Since
      header to directory servers. This allows us to obtain consensuses
      promptly when the consensus interval is very short. This assists
      in bootstrapping a testing Tor network. Fixes parts of bugs 13718
      and 13963; bugfix on 0.2.0.3-alpha. Patch by "teor".
    - Stop assuming that private addresses are local when checking
      reachability in a TestingTorNetwork. Instead, when testing, assume
      all OR connections are remote. (This is necessary due to many test
      scenarios running all relays on localhost.) This assists in
      bootstrapping a testing Tor network. Fixes bug 13924; bugfix on
      0.1.0.1-rc. Patch by "teor".
    - Avoid building exit circuits from a consensus with no exits. Now
      thanks to our fix for 13718, we accept a no-exit network as not
      wholly lost, but we need to remember not to try to build exit
      circuits on it. Closes ticket 13814; patch by "teor".
    - Stop requiring exits to have non-zero bandwithcapacity in a
      TestingTorNetwork. Instead, when TestingMinExitFlagThreshold is 0,
      ignore exit bandwidthcapacity. This assists in bootstrapping a
      testing Tor network. Fixes parts of bugs 13718 and 13839; bugfix
      on 0.2.0.3-alpha. Patch by "teor".
    - Add "internal" to some bootstrap statuses when no exits are
      available. If the consensus does not contain Exits, Tor will only
      build internal circuits. In this case, relevant statuses will
      contain the word "internal" as indicated in the Tor control-
       spec.txt. When bootstrap completes, Tor will be ready to build
      internal circuits. If a future consensus contains Exits, exit
      circuits may become available. Fixes part of bug 13718; bugfix on
      0.2.4.10-alpha. Patch by "teor".
    - Decrease minimum consensus interval to 10 seconds when
      TestingTorNetwork is set, or 5 seconds for the first consensus.
      Fix assumptions throughout the code that assume larger intervals.
      Fixes bugs 13718 and 13823; bugfix on 0.2.0.3-alpha. Patch
      by "teor".
    - Avoid excluding guards from path building in minimal test
      networks, when we're in a test network and excluding guards would
      exclude all relays. This typically occurs in incredibly small tor
      networks, and those using "TestingAuthVoteGuard *". Fixes part of
      bug 13718; bugfix on 0.1.1.11-alpha. Patch by "teor".

  o Minor bugfixes (testing):
    - Avoid a side-effect in a tor_assert() in the unit tests. Fixes bug
      15188; bugfix on 0.1.2.3-alpha. Patch from Tom van der Woerdt.
    - Stop spawn test failures due to a race condition between the
      SIGCHLD handler updating the process status, and the test reading
      it. Fixes bug 13291; bugfix on 0.2.3.3-alpha.
    - Avoid passing an extra backslash when creating a temporary
      directory for running the unit tests on Windows. Fixes bug 12392;
      bugfix on 0.2.2.25-alpha. Patch from Gisle Vanem.

  o Minor bugfixes (TLS):
    - Check more thoroughly throughout the TLS code for possible
      unlogged TLS errors. Possible diagnostic or fix for bug 13319.

  o Minor bugfixes (transparent proxy):
    - Use getsockname, not getsockopt, to retrieve the address for a
      TPROXY-redirected connection. Fixes bug 13796; bugfix
      on 0.2.5.2-alpha.

  o Minor bugfixes (windows):
    - Remove code to special-case handling of NTE_BAD_KEYSET when
      acquiring windows CryptoAPI context. This error can't actually
      occur for the parameters we're providing. Fixes bug 10816; bugfix
      on 0.0.2pre26.

  o Minor bugfixes (zlib):
    - Avoid truncating a zlib stream when trying to finalize it with an
      empty output buffer. Fixes bug 11824; bugfix on 0.1.1.23.

  o Code simplification and refactoring:
    - Change the entry_is_live() function to take named bitfield
      elements instead of an unnamed list of booleans. Closes
      ticket 12202.
    - Refactor and unit-test entry_is_time_to_retry() in entrynodes.c.
      Resolves ticket 12205.
    - Use calloc and reallocarray functions instead of multiply-
      then-malloc. This makes it less likely for us to fall victim to an
      integer overflow attack when allocating. Resolves ticket 12855.
    - Use the standard macro name SIZE_MAX, instead of our
      own SIZE_T_MAX.
    - Document usage of the NO_DIRINFO and ALL_DIRINFO flags clearly in
      functions which take them as arguments. Replace 0 with NO_DIRINFO
      in a function call for clarity. Seeks to prevent future issues
      like 13163.
    - Avoid 4 null pointer errors under clang static analysis by using
      tor_assert() to prove that the pointers aren't null. Fixes
      bug 13284.
    - Rework the API of policies_parse_exit_policy() to use a bitmask to
      represent parsing options, instead of a confusing mess of
      booleans. Resolves ticket 8197.
    - Introduce a helper function to parse ExitPolicy in
      or_options_t structure.
    - Move fields related to isolating and configuring client ports into
      a shared structure. Previously, they were duplicated across
      port_cfg_t, listener_connection_t, and edge_connection_t. Failure
      to copy them correctly had been the cause of at least one bug in
      the past. Closes ticket 8546.
    - Refactor the get_interface_addresses_raw() doom-function into
      multiple smaller and simpler subfunctions. Cover the resulting
      subfunctions with unit-tests. Fixes a significant portion of
      issue 12376.
    - Remove workaround in dirserv_thinks_router_is_hs_dir() that was
      only for version <= 0.2.2.24 which is now deprecated. Closes
      ticket 14202.
    - Remove a test for a long-defunct broken version-one
      directory server.
    - Refactor main loop to extract the 'loop' part. This makes it
      easier to run Tor under Shadow. Closes ticket 15176.
    - Stop using can_complete_circuits as a global variable; access it
      with a function instead.
    - Avoid using operators directly as macro arguments: this lets us
      apply coccinelle transformations to our codebase more directly.
      Closes ticket 13172.
    - Combine the functions used to parse ClientTransportPlugin and
      ServerTransportPlugin into a single function. Closes ticket 6456.
    - Add inline functions and convenience macros for inspecting channel
      state. Refactor the code to use convenience macros instead of
      checking channel state directly. Fixes issue 7356.
    - Document all members of was_router_added_t and rename
      ROUTER_WAS_NOT_NEW to ROUTER_IS_ALREADY_KNOWN to make it less
      confusable with ROUTER_WAS_TOO_OLD. Fixes issue 13644.
    - In connection_exit_begin_conn(), use END_CIRC_REASON_TORPROTOCOL
      constant instead of hardcoded value. Fixes issue 13840.
    - Refactor our generic strmap and digestmap types into a single
      implementation, so that we can add a new digest256map
      type trivially.

  o Documentation:
    - Add a doc/TUNING document with tips for handling large numbers of
      TCP connections when running busy Tor relay. Update the warning
      message to point to this file when running out of sockets
      operating system is allowing to use simultaneously. Resolves
      ticket 9708.
    - Adding section on OpenBSD to our TUNING document. Thanks to mmcc
      for writing the OpenBSD-specific tips. Resolves ticket 13702.
    - Make the tor-resolve documentation match its help string and its
      options. Resolves part of ticket 14325.
    - Log a more useful error message from tor-resolve when failing to
      look up a hidden service address. Resolves part of ticket 14325.
    - Document the bridge-authority-only 'networkstatus-bridges' file.
      Closes ticket 13713; patch from "tom".
    - Fix typo in PredictedPortsRelevanceTime option description in
      manpage. Resolves issue 13707.
    - Stop suggesting that users specify relays by nickname: it isn't a
      good idea. Also, properly cross-reference how to specify relays in
      all parts of manual documenting options that take a list of
      relays. Closes ticket 13381.
    - Clarify the HiddenServiceDir option description in manpage to make
      it clear that relative paths are taken with respect to the current
      working directory. Also clarify that this behavior is not
      guaranteed to remain indefinitely. Fixes issue 13913.

  o Distribution (systemd):
    - systemd unit file: only allow tor to write to /var/lib/tor and
      /var/log/tor. The rest of the filesystem is accessible for reading
      only. Patch by intrigeri; resolves ticket 12751.
    - systemd unit file: ensure that the process and all its children
      can never gain new privileges. Patch by intrigeri; resolves
      ticket 12939.
    - systemd unit file: set up /var/run/tor as writable for the Tor
      service. Patch by intrigeri; resolves ticket 13196.

  o Downgraded warnings:
    - Don't warn when we've attempted to contact a relay using the wrong
      ntor onion key. Closes ticket 9635.

  o Removed code:
    - Remove some lingering dead code that once supported mempools.
      Mempools were disabled by default in 0.2.5, and removed entirely
      in 0.2.6.3-alpha. Closes more of ticket 14848; patch
      by "cypherpunks".

  o Removed features (directory authorities):
    - Remove code that prevented authorities from listing Tor relays
      affected by CVE-2011-2769 as guards. These relays are already
      rejected altogether due to the minimum version requirement of
      0.2.3.16-alpha. Closes ticket 13152.
    - The "AuthDirRejectUnlisted" option no longer has any effect, as
      the fingerprints file (approved-routers) has been deprecated.
    - Directory authorities do not support being Naming dirauths anymore.
      The "NamingAuthoritativeDir" config option is now obsolete.
    - Directory authorities do not support giving out the BadDirectory
      flag anymore.
    - Directory authorities no longer advertise or support consensus
      methods 1 through 12 inclusive. These consensus methods were
      obsolete and/or insecure: maintaining the ability to support them
      served no good purpose. Implements part of proposal 215; closes
      ticket 10163.

  o Removed features:
    - To avoid confusion with the "ExitRelay" option, "ExitNode" is no
      longer silently accepted as an alias for "ExitNodes".
    - The --enable-mempool and --enable-buf-freelists options, which
      were originally created to work around bad malloc implementations,
      no longer exist. They were off-by-default in 0.2.5. Closes
      ticket 14848.
    - We no longer remind the user about configuration options that have
      been obsolete since 0.2.3.x or earlier. Patch by Adrien Bak.
    - Remove our old, non-weighted bandwidth-based node selection code.
      Previously, we used it as a fallback when we couldn't perform
      weighted bandwidth-based node selection. But that would only
      happen in the cases where we had no consensus, or when we had a
      consensus generated by buggy or ancient directory authorities. In
      either case, it's better to use the more modern, better maintained
      algorithm, with reasonable defaults for the weights. Closes
      ticket 13126.
    - Remove the --disable-curve25519 configure option. Relays and
      clients now are required to support curve25519 and the
      ntor handshake.
    - The old "StrictEntryNodes" and "StrictExitNodes" options, which
      used to be deprecated synonyms for "StrictNodes", are now marked
      obsolete. Resolves ticket 12226.
    - Clients don't understand the BadDirectory flag in the consensus
      anymore, and ignore it.

  o Removed platform support:
    - We no longer include special code to build on Windows CE; as far
      as we know, nobody has used Tor on Windows CE in a very long time.
      Closes ticket 11446.

  o Testing (test-network.sh):
    - Stop using "echo -n", as some shells' built-in echo doesn't
      support "-n". Instead, use "/bin/echo -n". Partially fixes
      bug 13161.
    - Stop an apparent test-network hang when used with make -j2. Fixes
      bug 13331.
    - Add a --delay option to test-network.sh, which configures the
      delay before the chutney network tests for data transmission.
      Partially implements ticket 13161.

  o Testing:
    - Test that tor does not fail when key files are zero-length. Check
      that tor generates new keys, and overwrites the empty key files.
    - Test that tor generates new keys when keys are missing
      (existing behavior).
    - Test that tor does not overwrite key files that already contain
      data (existing behavior). Tests bug 13111. Patch by "teor".
    - New "make test-stem" target to run stem integration tests.
      Requires that the "STEM_SOURCE_DIR" environment variable be set.
      Closes ticket 14107.
    - Make the test_cmdline_args.py script work correctly on Windows.
      Patch from Gisle Vanem.
    - Move the slower unit tests into a new "./src/test/test-slow"
      binary that can be run independently of the other tests. Closes
      ticket 13243.
    - New tests for many parts of channel, relay, and circuitmux
      functionality. Code by Andrea; part of 9262.
    - New tests for parse_transport_line(). Part of ticket 6456.
    - In the unit tests, use chgrp() to change the group of the unit
      test temporary directory to the current user, so that the sticky
      bit doesn't interfere with tests that check directory groups.
      Closes 13678.
    - Add unit tests for resolve_my_addr(). Part of ticket 12376; patch
      by 'rl1987'.
    - Refactor the function that chooses guard nodes so that it can more
      easily be tested; write some tests for it.
    - Fix and re-enable the fgets_eagain unit test. Fixes bug 12503;
      bugfix on 0.2.3.1-alpha. Patch from "cypherpunks."
    - Create unit tests for format_time_interval(). With bug 13393.
    - Add unit tests for tor_timegm signed overflow, tor_timegm and
      parse_rfc1123_time validity checks, correct_tm year clamping. Unit
      tests (visible) fixes in bug 13476.
    - Add a "coverage-html" make target to generate HTML-visualized
      coverage results when building with --enable-coverage. (Requires
      lcov.) Patch from Kevin Murray.
    - Enable the backtrace handler (where supported) when running the
      unit tests.
    - Revise all unit tests that used the legacy test_* macros to
      instead use the recommended tt_* macros. This patch was generated
      with coccinelle, to avoid manual errors. Closes ticket 13119.

Changes in version 0.2.5.11 - 2015-03-17
  Tor 0.2.5.11 is the second stable release in the 0.2.5 series.

  It backports several bugfixes from the 0.2.6 branch, including a
  couple of medium-level security fixes for relays and exit nodes.
  It also updates the list of directory authorities.

  o Directory authority changes:
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.

  o Major bugfixes (crash, OSX, security):
    - Fix a remote denial-of-service opportunity caused by a bug in
      OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
      in OSX 10.9.

  o Major bugfixes (relay, stability, possible security):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout was passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from 'cypherpunks'.
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (exit node stability):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (Linux seccomp2 sandbox):
    - Upon receiving sighup with the seccomp2 sandbox enabled, do not
      crash during attempts to call wait4. Fixes bug 15088; bugfix on
      0.2.5.1-alpha. Patch from "sanic".

  o Minor features (controller):
    - New "GETINFO bw-event-cache" to get information about recent
      bandwidth events. Closes ticket 14128. Useful for controllers to
      get recent bandwidth history after the fix for ticket 13988.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (client, automapping):
    - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
      no value follows the option. Fixes bug 14142; bugfix on
      0.2.4.7-alpha. Patch by "teor".
    - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
      14195; bugfix on 0.1.0.1-rc.

  o Minor bugfixes (compilation):
    - Build without warnings with the stock OpenSSL srtp.h header, which
      has a duplicate declaration of SSL_get_selected_srtp_profile().
      Fixes bug 14220; this is OpenSSL's bug, not ours.

  o Minor bugfixes (directory authority):
    - Allow directory authorities to fetch more data from one another if
      they find themselves missing lots of votes. Previously, they had
      been bumping against the 10 MB queued data limit. Fixes bug 14261;
      bugfix on 0.1.2.5-alpha.
    - Enlarge the buffer to read bwauth generated files to avoid an
      issue when parsing the file in dirserv_read_measured_bandwidths().
      Fixes bug 14125; bugfix on 0.2.2.1-alpha.

  o Minor bugfixes (statistics):
    - Increase period over which bandwidth observations are aggregated
      from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.

  o Minor bugfixes (preventative security, C safety):
    - When reading a hexadecimal, base-32, or base-64 encoded value from
      a string, always overwrite the whole output buffer. This prevents
      some bugs where we would look at (but fortunately, not reveal)
      uninitialized memory on the stack. Fixes bug 14013; bugfix on all
      versions of Tor.


Changes in version 0.2.4.26 - 2015-03-17
  Tor 0.2.4.26 includes an updated list of directory authorities.  It
  also backports a couple of stability and security bugfixes from 0.2.5
  and beyond.

  o Directory authority changes:
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.

  o Major bugfixes (exit node stability, also in 0.2.6.3-alpha):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (relay, stability, possible security, also in 0.2.6.4-rc):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout was passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from 'cypherpunks'.
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

Changes in version 0.2.5.10 - 2014-10-24
  Tor 0.2.5.10 is the first stable release in the 0.2.5 series.

  It adds several new security features, including improved
  denial-of-service resistance for relays, new compiler hardening
  options, and a system-call sandbox for hardened installations on Linux
  (requires seccomp2). The controller protocol has several new features,
  resolving IPv6 addresses should work better than before, and relays
  should be a little more CPU-efficient. We've added support for more
  OpenBSD and FreeBSD transparent proxy types. We've improved the build
  system and testing infrastructure to allow unit testing of more parts
  of the Tor codebase. Finally, we've addressed several nagging pluggable
  transport usability issues, and included numerous other small bugfixes
  and features mentioned below.

  This release marks end-of-life for Tor 0.2.3.x; those Tor versions
  have accumulated many known flaws; everyone should upgrade.

  o Major features (security):
    - The ntor handshake is now on-by-default, no matter what the
      directory authorities recommend. Implements ticket 8561.
    - Make the "tor-gencert" tool used by directory authority operators
      create 2048-bit signing keys by default (rather than 1024-bit, since
      1024-bit is uncomfortably small these days). Addresses ticket 10324.
    - Warn about attempts to run hidden services and relays in the same
      process: that's probably not a good idea. Closes ticket 12908.
    - Disable support for SSLv3. All versions of OpenSSL in use with Tor
      today support TLS 1.0 or later, so we can safely turn off support
      for this old (and insecure) protocol. Fixes bug 13426.

  o Major features (relay security, DoS-resistance):
    - When deciding whether we have run out of memory and we need to
      close circuits, also consider memory allocated in buffers for
      streams attached to each circuit.

      This change, which extends an anti-DoS feature introduced in
      0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit relays
      better resist more memory-based DoS attacks than before. Since the
      MaxMemInCellQueues option now applies to all queues, it is renamed
      to MaxMemInQueues. This feature fixes bug 10169.
    - Avoid hash-flooding denial-of-service attacks by using the secure
      SipHash-2-4 hash function for our hashtables. Without this
      feature, an attacker could degrade performance of a targeted
      client or server by flooding their data structures with a large
      number of entries to be stored at the same hash table position,
      thereby slowing down the Tor instance. With this feature, hash
      table positions are derived from a randomized cryptographic key,
      and an attacker cannot predict which entries will collide. Closes
      ticket 4900.
    - If you don't specify MaxMemInQueues yourself, Tor now tries to
      pick a good value based on your total system memory. Previously,
      the default was always 8 GB. You can still override the default by
      setting MaxMemInQueues yourself. Resolves ticket 11396.

  o Major features (bridges and pluggable transports):
    - Add support for passing arguments to managed pluggable transport
      proxies. Implements ticket 3594.
    - Bridges now track GeoIP information and the number of their users
      even when pluggable transports are in use, and report usage
      statistics in their extra-info descriptors. Resolves tickets 4773
      and 5040.
    - Don't launch pluggable transport proxies if we don't have any
      bridges configured that would use them. Now we can list many
      pluggable transports, and Tor will dynamically start one when it
      hears a bridge address that needs it. Resolves ticket 5018.
    - The bridge directory authority now assigns status flags (Stable,
      Guard, etc) to bridges based on thresholds calculated over all
      Running bridges. Now bridgedb can finally make use of its features
      to e.g. include at least one Stable bridge in its answers. Fixes
      bug 9859.

  o Major features (controller):
    - Extend ORCONN controller event to include an "ID" parameter,
      and add four new controller event types CONN_BW, CIRC_BW,
      CELL_STATS, and TB_EMPTY that show connection and circuit usage.
      The new events are emitted in private Tor networks only, with the
      goal of being able to better track performance and load during
      full-network simulations. Implements proposal 218 and ticket 7359.

  o Major features (relay performance):
    - Speed up server-side lookups of rendezvous and introduction point
      circuits by using hashtables instead of linear searches. These
      functions previously accounted between 3 and 7% of CPU usage on
      some busy relays. Resolves ticket 9841.
    - Avoid wasting CPU when extending a circuit over a channel that is
      nearly out of circuit IDs. Previously, we would do a linear scan
      over possible circuit IDs before finding one or deciding that we
      had exhausted our possibilities. Now, we try at most 64 random
      circuit IDs before deciding that we probably won't succeed. Fixes
      a possible root cause of ticket 11553.

  o Major features (seccomp2 sandbox, Linux only):
    - Use the seccomp2 syscall filtering facility on Linux to limit
      which system calls Tor can invoke. This is an experimental,
      Linux-only feature to provide defense-in-depth against unknown
      attacks. To try turning it on, set "Sandbox 1" in your torrc
      file. Please be ready to report bugs. We hope to add support
      for better sandboxing in the future, including more fine-grained
      filters, better division of responsibility, and support for more
      platforms. This work has been done by Cristian-Matei Toader for
      Google Summer of Code. Resolves tickets 11351 and 11465.

  o Major features (testing networks):
    - Make testing Tor networks bootstrap better: lower directory fetch
      retry schedules and maximum interval without directory requests,
      and raise maximum download tries. Implements ticket 6752.
    - Add make target 'test-network' to run tests on a Chutney network.
      Implements ticket 8530.

  o Major features (other):
    - On some platforms (currently: recent OSX versions, glibc-based
      platforms that support the ELF format, and a few other
      Unix-like operating systems), Tor can now dump stack traces
      when a crash occurs or an assertion fails. By default, traces
      are dumped to stderr (if possible) and to any logs that are
      reporting errors. Implements ticket 9299.

  o Deprecated versions:
    - Tor 0.2.3.x has reached end-of-life; it has received no patches or
      attention for some while.

  o Major bugfixes (security, directory authorities):
    - Directory authorities now include a digest of each relay's
      identity key as a part of its microdescriptor.

      This is a workaround for bug 11743 (reported by "cypherpunks"),
      where Tor clients do not support receiving multiple
      microdescriptors with the same SHA256 digest in the same
      consensus. When clients receive a consensus like this, they only
      use one of the relays. Without this fix, a hostile relay could
      selectively disable some client use of target relays by
      constructing a router descriptor with a different identity and the
      same microdescriptor parameters and getting the authorities to
      list it in a microdescriptor consensus. This fix prevents an
      attacker from causing a microdescriptor collision, because the
      router's identity is not forgeable.

  o Major bugfixes (openssl bug workaround):
    - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
      1.0.1j, built with the 'no-ssl3' configuration option. Fixes
      bug 13471. This is a workaround for an OpenSSL bug.

  o Major bugfixes (client):
    - Perform circuit cleanup operations even when circuit
      construction operations are disabled (because the network is
      disabled, or because there isn't enough directory information).
      Previously, when we were not building predictive circuits, we
      were not closing expired circuits either. Fixes bug 8387; bugfix on
      0.1.1.11-alpha. This bug became visible in 0.2.4.10-alpha when we
      became more strict about when we have "enough directory information
      to build circuits".

  o Major bugfixes (client, pluggable transports):
    - When managing pluggable transports, use OS notification facilities
      to learn if they have crashed, and don't attempt to kill any
      process that has already exited. Fixes bug 8746; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (relay denial of service):
    - Instead of writing destroy cells directly to outgoing connection
      buffers, queue them and intersperse them with other outgoing cells.
      This can prevent a set of resource starvation conditions where too
      many pending destroy cells prevent data cells from actually getting
      delivered. Reported by "oftc_must_be_destroyed". Fixes bug 7912;
      bugfix on 0.2.0.1-alpha.

  o Major bugfixes (relay):
    - Avoid queuing or sending destroy cells for circuit ID zero when we
      fail to send a CREATE cell. Fixes bug 12848; bugfix on 0.0.8pre1.
      Found and fixed by "cypherpunks".
    - Fix ORPort reachability detection on relays running behind a
      proxy, by correctly updating the "local" mark on the controlling
      channel when changing the address of an or_connection_t after the
      handshake. Fixes bug 12160; bugfix on 0.2.4.4-alpha.
    - Use a direct dirport connection when uploading non-anonymous
      descriptors to the directory authorities. Previously, relays would
      incorrectly use tunnel connections under a fairly wide variety of
      circumstances. Fixes bug 11469; bugfix on 0.2.4.3-alpha.
    - When a circuit accidentally has the same circuit ID for its
      forward and reverse direction, correctly detect the direction of
      cells using that circuit. Previously, this bug made roughly one
      circuit in a million non-functional. Fixes bug 12195; this is a
      bugfix on every version of Tor.

  o Minor features (security):
    - New --enable-expensive-hardening option to enable security
      hardening options that consume nontrivial amounts of CPU and
      memory. Right now, this includes AddressSanitizer and UbSan, which
      are supported in newer versions of GCC and Clang. Closes ticket
      11477.
    - Authorities now assign the Guard flag to the fastest 25% of the
      network (it used to be the fastest 50%). Also raise the consensus
      weight that guarantees the Guard flag from 250 to 2000. For the
      current network, this results in about 1100 guards, down from 2500.
      This step paves the way for moving the number of entry guards
      down to 1 (proposal 236) while still providing reasonable expected
      performance for most users. Implements ticket 12690.

  o Minor features (security, memory management):
    - Memory allocation tricks (mempools and buffer freelists) are now
      disabled by default. You can turn them back on with
      --enable-mempools and --enable-buf-freelists respectively. We're
      disabling these features because malloc performance is good enough
      on most platforms, and a similar feature in OpenSSL exacerbated
      exploitation of the Heartbleed attack. Resolves ticket 11476.

  o Minor features (bridge client):
    - Report a more useful failure message when we can't connect to a
      bridge because we don't have the right pluggable transport
      configured. Resolves ticket 9665. Patch from Fábio J. Bertinatto.

  o Minor features (bridge):
    - Add an ExtORPortCookieAuthFileGroupReadable option to make the
      cookie file for the ExtORPort g+r by default.

  o Minor features (bridges, pluggable transports):
    - Bridges now write the SHA1 digest of their identity key
      fingerprint (that is, a hash of a hash of their public key) to
      notice-level logs, and to a new hashed-fingerprint file. This
      information will help bridge operators look up their bridge in
      Globe and similar tools. Resolves ticket 10884.
    - Improve the message that Tor displays when running as a bridge
      using pluggable transports without an Extended ORPort listener.
      Also, log the message in the log file too. Resolves ticket 11043.
    - Add threshold cutoffs to the networkstatus document created by
      the Bridge Authority. Fixes bug 1117.
    - On Windows, spawn background processes using the CREATE_NO_WINDOW
      flag. Now Tor Browser Bundle 3.5 with pluggable transports enabled
      doesn't pop up a blank console window. (In Tor Browser Bundle 2.x,
      Vidalia set this option for us.) Implements ticket 10297.

  o Minor features (build):
    - The configure script has a --disable-seccomp option to turn off
      support for libseccomp on systems that have it, in case it (or
      Tor's use of it) is broken. Resolves ticket 11628.
    - Assume that a user using ./configure --host wants to cross-compile,
      and give an error if we cannot find a properly named
      tool-chain. Add a --disable-tool-name-check option to proceed
      nevertheless. Addresses ticket 9869. Patch by Benedikt Gollatz.
    - If we run ./configure and the compiler recognizes -fstack-protector
      but the linker rejects it, warn the user about a potentially missing
      libssp package. Addresses ticket 9948. Patch from Benedikt Gollatz.
    - Add support for `--library-versions` flag. Implements ticket 6384.
    - Return the "unexpected sendme" warnings to a warn severity, but make
      them rate limited, to help diagnose ticket 8093.
    - Detect a missing asciidoc, and warn the user about it, during
      configure rather than at build time. Fixes issue 6506. Patch from
      Arlo Breault.

  o Minor features (client):
    - Add a new option, PredictedPortsRelevanceTime, to control how long
      after having received a request to connect to a given port Tor
      will try to keep circuits ready in anticipation of future requests
      for that port. Patch from "unixninja92"; implements ticket 9176.

  o Minor features (config options and command line):
    - Add an --allow-missing-torrc commandline option that tells Tor to
      run even if the configuration file specified by -f is not available.
      Implements ticket 10060.
    - Add support for the TPROXY transparent proxying facility on Linux.
      See documentation for the new TransProxyType option for more
      details. Implementation by "thomo". Closes ticket 10582.

  o Minor features (config options):
    - Config (torrc) lines now handle fingerprints which are missing
      their initial '$'. Resolves ticket 4341; improvement over 0.0.9pre5.
    - Support a --dump-config option to print some or all of the
      configured options. Mainly useful for debugging the command-line
      option parsing code. Helps resolve ticket 4647.
    - Raise awareness of safer logging: notify user of potentially
      unsafe config options, like logging more verbosely than severity
      "notice" or setting SafeLogging to 0. Resolves ticket 5584.
    - Add a new configuration option TestingV3AuthVotingStartOffset
      that bootstraps a network faster by changing the timing for
      consensus votes. Addresses ticket 8532.
    - Add a new torrc option "ServerTransportOptions" that allows
      bridge operators to pass configuration parameters to their
      pluggable transports. Resolves ticket 8929.
    - The config (torrc) file now accepts bandwidth and space limits in
      bits as well as bytes. (Anywhere that you can say "2 Kilobytes",
      you can now say "16 kilobits", and so on.) Resolves ticket 9214.
      Patch by CharlieB.

  o Minor features (controller):
    - Make the entire exit policy available from the control port via
      GETINFO exit-policy/*. Implements enhancement 7952. Patch from
      "rl1987".
    - Because of the fix for ticket 11396, the real limit for memory
      usage may no longer match the configured MaxMemInQueues value. The
      real limit is now exposed via GETINFO limits/max-mem-in-queues.
    - Add a new "HS_DESC" controller event that reports activities
      related to hidden service descriptors. Resolves ticket 8510.
    - New "DROPGUARDS" controller command to forget all current entry
      guards. Not recommended for ordinary use, since replacing guards
      too frequently makes several attacks easier. Resolves ticket 9934;
      patch from "ra".
    - Implement the TRANSPORT_LAUNCHED control port event that
      notifies controllers about new launched pluggable
      transports. Resolves ticket 5609.

  o Minor features (diagnostic):
    - When logging a warning because of bug 7164, additionally check the
      hash table for consistency (as proposed on ticket 11737). This may
      help diagnose bug 7164.
    - When we log a heartbeat, log how many one-hop circuits we have
      that are at least 30 minutes old, and log status information about
      a few of them. This is an attempt to track down bug 8387.
    - When encountering an unexpected CR while writing text to a file on
      Windows, log the name of the file. Should help diagnosing
      bug 11233.
    - Give more specific warnings when a client notices that an onion
      handshake has failed. Fixes ticket 9635.
    - Add significant new logging code to attempt to diagnose bug 12184,
      where relays seem to run out of available circuit IDs.
    - Improve the diagnostic log message for bug 8387 even further to
      try to improve our odds of figuring out why one-hop directory
      circuits sometimes do not get closed.
    - Add more log messages to diagnose bug 7164, which causes
      intermittent "microdesc_free() called but md was still referenced"
      warnings. We now include more information, to figure out why we
      might be cleaning a microdescriptor for being too old if it's
      still referenced by a live node_t object.
    - Log current accounting state (bytes sent and received + remaining
      time for the current accounting period) in the relay's heartbeat
      message. Implements ticket 5526; patch from Peter Retzlaff.

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
      Country database.

  o Minor features (interface):
    - Generate a warning if any ports are listed in the SocksPolicy,
      DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or
      AuthDirBadExit options. (These options only support address
      ranges.) Fixes part of ticket 11108.

  o Minor features (kernel API usage):
    - Use the SOCK_NONBLOCK socket type, if supported, to open nonblocking
      sockets in a single system call. Implements ticket 5129.

  o Minor features (log messages):
    - When ServerTransportPlugin is set on a bridge, Tor can write more
      useful statistics about bridge use in its extrainfo descriptors,
      but only if the Extended ORPort ("ExtORPort") is set too. Add a
      log message to inform the user in this case. Resolves ticket 9651.
    - When receiving a new controller connection, log the origin address.
      Resolves ticket 9698; patch from "sigpipe".
    - When logging OpenSSL engine status at startup, log the status of
      more engines. Fixes ticket 10043; patch from Joshua Datko.

  o Minor features (log verbosity):
    - Demote the message that we give when a flushing connection times
      out for too long from NOTICE to INFO. It was usually meaningless.
      Resolves ticket 5286.
    - Don't log so many notice-level bootstrapping messages at startup
      about downloading descriptors. Previously, we'd log a notice
      whenever we learned about more routers. Now, we only log a notice
      at every 5% of progress. Fixes bug 9963.
    - Warn less verbosely when receiving a malformed
      ESTABLISH_RENDEZVOUS cell. Fixes ticket 11279.

  o Minor features (performance):
    - If we're using the pure-C 32-bit curve25519_donna implementation
      of curve25519, build it with the -fomit-frame-pointer option to
      make it go faster on register-starved hosts. This improves our
      handshake performance by about 6% on i386 hosts without nacl.
      Closes ticket 8109.

  o Minor features (relay):
    - If a circuit timed out for at least 3 minutes, check if we have a
      new external IP address, and publish a new descriptor with the new
      IP address if it changed. Resolves ticket 2454.

  o Minor features (testing):
    - If Python is installed, "make check" now runs extra tests beyond
      the unit test scripts.
    - When bootstrapping a test network, sometimes very few relays get
      the Guard flag. Now a new option "TestingDirAuthVoteGuard" can
      specify a set of relays which should be voted Guard regardless of
      their uptime or bandwidth. Addresses ticket 9206.

  o Minor features (transparent proxy, *BSD):
    - Support FreeBSD's ipfw firewall interface for TransPort ports on
      FreeBSD. To enable it, set "TransProxyType ipfw". Resolves ticket
      10267; patch from "yurivict".
    - Support OpenBSD's divert-to rules with the pf firewall for
      transparent proxy ports. To enable it, set "TransProxyType
      pf-divert". This allows Tor to run a TransPort transparent proxy
      port on OpenBSD 4.4 or later without root privileges. See the
      pf.conf(5) manual page for information on configuring pf to use
      divert-to rules. Closes ticket 10896; patch from Dana Koch.

  o Minor bugfixes (bridge client):
    - Stop accepting bridge lines containing hostnames. Doing so would
      cause clients to perform DNS requests on the hostnames, which was
      not sensible behavior. Fixes bug 10801; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (bridges):
    - Avoid potential crashes or bad behavior when launching a
      server-side managed proxy with ORPort or ExtORPort temporarily
      disabled. Fixes bug 9650; bugfix on 0.2.3.16-alpha.
    - Fix a bug where the first connection works to a bridge that uses a
      pluggable transport with client-side parameters, but we don't send
      the client-side parameters on subsequent connections. (We don't
      use any pluggable transports with client-side parameters yet,
      but ScrambleSuit will soon become the first one.) Fixes bug 9162;
      bugfix on 0.2.0.3-alpha. Based on a patch from "rl1987".

  o Minor bugfixes (build, auxiliary programs):
    - Stop preprocessing the "torify" script with autoconf, since
      it no longer refers to LOCALSTATEDIR. Fixes bug 5505; patch
      from Guilhem.
    - The tor-fw-helper program now follows the standard convention and
      exits with status code "0" on success. Fixes bug 9030; bugfix on
      0.2.3.1-alpha. Patch by Arlo Breault.
    - Corrected ./configure advice for what openssl dev package you should
      install on Debian. Fixes bug 9207; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (client):
    - Avoid "Tried to open a socket with DisableNetwork set" warnings
      when starting a client with bridges configured and DisableNetwork
      set. (Tor launcher starts Tor with DisableNetwork set the first
      time it runs.) Fixes bug 10405; bugfix on 0.2.3.9-alpha.
    - Improve the log message when we can't connect to a hidden service
      because all of the hidden service directory nodes hosting its
      descriptor are excluded. Improves on our fix for bug 10722, which
      was a bugfix on 0.2.0.10-alpha.
    - Raise a control port warning when we fail to connect to all of
      our bridges. Previously, we didn't inform the controller, and
      the bootstrap process would stall. Fixes bug 11069; bugfix on
      0.2.1.2-alpha.
    - Exit immediately when a process-owning controller exits.
      Previously, tor relays would wait for a little while after their
      controller exited, as if they had gotten an INT signal -- but this
      was problematic, since there was no feedback for the user. To do a
      clean shutdown, controllers should send an INT signal and give Tor
      a chance to clean up. Fixes bug 10449; bugfix on 0.2.2.28-beta.
    - Stop attempting to connect to bridges before our pluggable
      transports are configured (harmless but resulted in some erroneous
      log messages). Fixes bug 11156; bugfix on 0.2.3.2-alpha.
    - Fix connections to IPv6 addresses over SOCKS5. Previously, we were
      generating incorrect SOCKS5 responses, and confusing client
      applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (client, DNSPort):
    - When using DNSPort, try to respond to AAAA requests with AAAA
      answers. Previously, we hadn't looked at the request type when
      deciding which answer type to prefer. Fixes bug 10468; bugfix on
      0.2.4.7-alpha.
    - When receiving a DNS query for an unsupported record type, reply
      with no answer rather than with a NOTIMPL error. This behavior
      isn't correct either, but it will break fewer client programs, we
      hope. Fixes bug 10268; bugfix on 0.2.0.1-alpha. Original patch
      from "epoch".

  o Minor bugfixes (client, logging during bootstrap):
    - Only report the first fatal bootstrap error on a given OR
      connection. This stops us from telling the controller bogus error
      messages like "DONE". Fixes bug 10431; bugfix on 0.2.1.1-alpha.
    - Avoid generating spurious warnings when starting with
      DisableNetwork enabled. Fixes bug 11200 and bug 10405; bugfix on
      0.2.3.9-alpha.

  o Minor bugfixes (closing OR connections):
    - If write_to_buf() in connection_write_to_buf_impl_() ever fails,
      check if it's an or_connection_t and correctly call
      connection_or_close_for_error() rather than
      connection_mark_for_close() directly. Fixes bug 11304; bugfix on
      0.2.4.4-alpha.
    - When closing all connections on setting DisableNetwork to 1, use
      connection_or_close_normally() rather than closing OR connections
      out from under the channel layer. Fixes bug 11306; bugfix on
      0.2.4.4-alpha.

  o Minor bugfixes (code correctness):
    - Previously we used two temporary files when writing descriptors to
      disk; now we only use one. Fixes bug 1376.
    - Remove an erroneous (but impossible and thus harmless) pointer
      comparison that would have allowed compilers to skip a bounds
      check in channeltls.c. Fixes bugs 10313 and 9980; bugfix on
      0.2.0.10-alpha. Noticed by Jared L Wong and David Fifield.
    - Fix an always-true assertion in pluggable transports code so it
      actually checks what it was trying to check. Fixes bug 10046;
      bugfix on 0.2.3.9-alpha. Found by "dcb".

  o Minor bugfixes (command line):
    - Use a single command-line parser for parsing torrc options on the
      command line and for finding special command-line options to avoid
      inconsistent behavior for torrc option arguments that have the same
      names as command-line options. Fixes bugs 4647 and 9578; bugfix on
      0.0.9pre5.
    - No longer allow 'tor --hash-password' with no arguments. Fixes bug
      9573; bugfix on 0.0.9pre5.

  o Minor bugfixes (compilation):
    - Compile correctly with builds and forks of OpenSSL (such as
      LibreSSL) that disable compression. Fixes bug 12602; bugfix on
      0.2.1.1-alpha. Patch from "dhill".
    - Restore the ability to compile Tor with V2_HANDSHAKE_SERVER
      turned off (that is, without support for v2 link handshakes). Fixes
      bug 4677; bugfix on 0.2.3.2-alpha. Patch from "piet".
    - In routerlist_assert_ok(), don't take the address of a
      routerinfo's cache_info member unless that routerinfo is non-NULL.
      Fixes bug 13096; bugfix on 0.1.1.9-alpha. Patch by "teor".
    - Fix a large number of false positive warnings from the clang
      analyzer static analysis tool. This should make real warnings
      easier for clang analyzer to find. Patch from "teor". Closes
      ticket 13036.
    - Resolve GCC complaints on OpenBSD about discarding constness in
      TO_{ORIGIN,OR}_CIRCUIT functions. Fixes part of bug 11633; bugfix
      on 0.1.1.23. Patch from Dana Koch.
    - Resolve clang complaints on OpenBSD with -Wshorten-64-to-32 due to
      treatment of long and time_t as comparable types. Fixes part of
      bug 11633. Patch from Dana Koch.
    - When deciding whether to build the 64-bit curve25519
      implementation, detect platforms where we can compile 128-bit
      arithmetic but cannot link it. Fixes bug 11729; bugfix on
      0.2.4.8-alpha. Patch from "conradev".
    - Fix compilation when DNS_CACHE_DEBUG is enabled. Fixes bug 11761;
      bugfix on 0.2.3.13-alpha. Found by "cypherpunks".
    - Fix compilation with dmalloc. Fixes bug 11605; bugfix
      on 0.2.4.10-alpha.
    - Build and run correctly on systems like OpenBSD-current that have
      patched OpenSSL to remove get_cipher_by_char and/or its
      implementations. Fixes issue 13325.

  o Minor bugfixes (controller and command-line):
    - If changing a config option via "setconf" fails in a recoverable
      way, we used to nonetheless write our new control ports to the
      file described by the "ControlPortWriteToFile" option. Now we only
      write out that file if we successfully switch to the new config
      option. Fixes bug 5605; bugfix on 0.2.2.26-beta. Patch from "Ryman".

  o Minor bugfixes (directory server):
    - No longer accept malformed http headers when parsing urls from
      headers. Now we reply with Bad Request ("400"). Fixes bug 2767;
      bugfix on 0.0.6pre1.
    - When sending a compressed set of descriptors or microdescriptors,
      make sure to finalize the zlib stream. Previously, we would write
      all the compressed data, but if the last descriptor we wanted to
      send was missing or too old, we would not mark the stream as
      finished. This caused problems for decompression tools. Fixes bug
      11648; bugfix on 0.1.1.23.

  o Minor bugfixes (hidden service):
    - Only retry attempts to connect to a chosen rendezvous point 8
      times, not 30. Fixes bug 4241; bugfix on 0.1.0.1-rc.

  o Minor bugfixes (interface):
    - Reject relative control socket paths and emit a warning. Previously,
      single-component control socket paths would be rejected, but Tor
      would not log why it could not validate the config. Fixes bug 9258;
      bugfix on 0.2.3.16-alpha.

  o Minor bugfixes (log messages):
    - Fix a bug where clients using bridges would report themselves
      as 50% bootstrapped even without a live consensus document.
      Fixes bug 9922; bugfix on 0.2.1.1-alpha.
    - Suppress a warning where, if there's only one directory authority
      in the network, we would complain that votes and signatures cannot
      be uploaded to other directory authorities. Fixes bug 10842;
      bugfix on 0.2.2.26-beta.
    - Report bootstrapping progress correctly when we're downloading
      microdescriptors. We had updated our "do we have enough microdescs
      to begin building circuits?" logic most recently in 0.2.4.10-alpha
      (see bug 5956), but we left the bootstrap status event logic at
      "how far through getting 1/4 of them are we?" Fixes bug 9958;
      bugfix on 0.2.2.36, which is where they diverged (see bug 5343).

  o Minor bugfixes (logging):
    - Downgrade "Unexpected onionskin length after decryption" warning
      to a protocol-warn, since there's nothing relay operators can do
      about a client that sends them a malformed create cell. Resolves
      bug 12996; bugfix on 0.0.6rc1.
    - Log more specific warnings when we get an ESTABLISH_RENDEZVOUS
      cell on a cannibalized or non-OR circuit. Resolves ticket 12997.
    - When logging information about an EXTEND2 or EXTENDED2 cell, log
      their names correctly. Fixes part of bug 12700; bugfix
      on 0.2.4.8-alpha.
    - When logging information about a relay cell whose command we don't
      recognize, log its command as an integer. Fixes part of bug 12700;
      bugfix on 0.2.1.10-alpha.
    - Escape all strings from the directory connection before logging
      them. Fixes bug 13071; bugfix on 0.1.1.15. Patch from "teor".
    - Squelch a spurious LD_BUG message "No origin circuit for
      successful SOCKS stream" in certain hidden service failure cases;
      fixes bug 10616.
    - Downgrade the severity of the 'unexpected sendme cell from client'
      from 'warn' to 'protocol warning'. Closes ticket 8093.

  o Minor bugfixes (misc code correctness):
    - In munge_extrainfo_into_routerinfo(), check the return value of
      memchr(). This would have been a serious issue if we ever passed
      it a non-extrainfo. Fixes bug 8791; bugfix on 0.2.0.6-alpha. Patch
      from Arlo Breault.
    - On the chance that somebody manages to build Tor on a
      platform where time_t is unsigned, correct the way that
      microdesc_add_to_cache() handles negative time arguments.
      Fixes bug 8042; bugfix on 0.2.3.1-alpha.
    - Fix various instances of undefined behavior in channeltls.c,
      tor_memmem(), and eventdns.c that would cause us to construct
      pointers to memory outside an allocated object. (These invalid
      pointers were not accessed, but C does not even allow them to
      exist.) Fixes bug 10363; bugfixes on 0.1.1.1-alpha, 0.1.2.1-alpha,
      0.2.0.10-alpha, and 0.2.3.6-alpha. Reported by "bobnomnom".
    - Use the AddressSanitizer and Ubsan sanitizers (in clang-3.4) to
      fix some miscellaneous errors in our tests and codebase. Fixes bug
      11232. Bugfixes on versions back as far as 0.2.1.11-alpha.
    - Always check return values for unlink, munmap, UnmapViewOfFile;
      check strftime return values more often. In some cases all we can
      do is report a warning, but this may help prevent deeper bugs from
      going unnoticed. Closes ticket 8787; bugfixes on many, many tor
      versions.
    - Fix numerous warnings from the clang "scan-build" static analyzer.
      Some of these are programming style issues; some of them are false
      positives that indicated awkward code; some are undefined behavior
      cases related to constructing (but not using) invalid pointers;
      some are assumptions about API behavior; some are (harmlessly)
      logging sizeof(ptr) bytes from a token when sizeof(*ptr) would be
      correct; and one or two are genuine bugs that weren't reachable
      from the rest of the program. Fixes bug 8793; bugfixes on many,
      many tor versions.

  o Minor bugfixes (node selection):
    - If ExcludeNodes is set, consider non-excluded hidden service
      directory servers before excluded ones. Do not consider excluded
      hidden service directory servers at all if StrictNodes is
      set. (Previously, we would sometimes decide to connect to those
      servers, and then realize before we initiated a connection that
      we had excluded them.) Fixes bug 10722; bugfix on 0.2.0.10-alpha.
      Reported by "mr-4".
    - If we set the ExitNodes option but it doesn't include any nodes
      that have the Exit flag, we would choose not to bootstrap. Now we
      bootstrap so long as ExitNodes includes nodes which can exit to
      some port. Fixes bug 10543; bugfix on 0.2.4.10-alpha.

  o Minor bugfixes (performance):
    - Avoid a bug where every successful connection made us recompute
      the flag telling us whether we have sufficient information to
      build circuits. Previously, we would forget our cached value
      whenever we successfully opened a channel (or marked a router as
      running or not running for any other reason), regardless of
      whether we had previously believed the router to be running. This
      forced us to run an expensive update operation far too often.
      Fixes bug 12170; bugfix on 0.1.2.1-alpha.
    - Avoid using tor_memeq() for checking relay cell integrity. This
      removes a possible performance bottleneck. Fixes part of bug
      12169; bugfix on 0.2.1.31.

  o Minor bugfixes (platform-specific):
    - When dumping a malformed directory object to disk, save it in
      binary mode on Windows, not text mode. Fixes bug 11342; bugfix on
      0.2.2.1-alpha.
    - Don't report failures from make_socket_reuseable() on incoming
      sockets on OSX: this can happen when incoming connections close
      early. Fixes bug 10081.

  o Minor bugfixes (pluggable transports):
    - Avoid another 60-second delay when starting Tor in a pluggable-
      transport-using configuration when we already have cached
      descriptors for our bridges. Fixes bug 11965; bugfix
      on 0.2.3.6-alpha.

  o Minor bugfixes (protocol correctness):
    - When receiving a VERSIONS cell with an odd number of bytes, close
      the connection immediately since the cell is malformed. Fixes bug
      10365; bugfix on 0.2.0.10-alpha. Spotted by "bobnomnom"; fix by
      "rl1987".

  o Minor bugfixes (relay, other):
    - We now drop CREATE cells for already-existent circuit IDs and for
      zero-valued circuit IDs, regardless of other factors that might
      otherwise have called for DESTROY cells. Fixes bug 12191; bugfix
      on 0.0.8pre1.
    - When rejecting DATA cells for stream_id zero, still count them
      against the circuit's deliver window so that we don't fail to send
      a SENDME. Fixes bug 11246; bugfix on 0.2.4.10-alpha.

  o Minor bugfixes (relay, threading):
    - Check return code on spawn_func() in cpuworker code, so that we
      don't think we've spawned a nonworking cpuworker and write junk to
      it forever. Fix related to bug 4345; bugfix on all released Tor
      versions. Found by "skruffy".
    - Use a pthread_attr to make sure that spawn_func() cannot return an
      error while at the same time launching a thread. Fix related to
      bug 4345; bugfix on all released Tor versions. Reported
      by "cypherpunks".

  o Minor bugfixes (relays and bridges):
    - Avoid crashing on a malformed resolv.conf file when running a
      relay using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.
    - Non-exit relays no longer launch mock DNS requests to check for
      DNS hijacking. This has been unnecessary since 0.2.1.7-alpha, when
      non-exit relays stopped servicing DNS requests. Fixes bug 965;
      bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.
    - Bridges now report complete directory request statistics. Related
      to bug 5824; bugfix on 0.2.2.1-alpha.
    - Bridges now never collect statistics that were designed for
      relays. Fixes bug 5824; bugfix on 0.2.3.8-alpha.

  o Minor bugfixes (testing):
    - Fix all valgrind warnings produced by the unit tests. There were
      over a thousand memory leak warnings previously, mostly produced
      by forgetting to free things in the unit test code. Fixes bug
      11618, bugfixes on many versions of Tor.

  o Minor bugfixes (tor-fw-helper):
    - Give a correct log message when tor-fw-helper fails to launch.
      (Previously, we would say something like "tor-fw-helper sent us a
      string we could not parse".) Fixes bug 9781; bugfix
      on 0.2.4.2-alpha.

  o Minor bugfixes (trivial memory leaks):
    - Fix a small memory leak when signing a directory object. Fixes bug
      11275; bugfix on 0.2.4.13-alpha.
    - Resolve some memory leaks found by coverity in the unit tests, on
      exit in tor-gencert, and on a failure to compute digests for our
      own keys when generating a v3 networkstatus vote. These leaks
      should never have affected anyone in practice.

  o Code simplification and refactoring:
    - Remove some old fallback code designed to keep Tor clients working
      in a network with only two working relays. Elsewhere in the code we
      have long since stopped supporting such networks, so there wasn't
      much point in keeping it around. Addresses ticket 9926.
    - Reject 0-length EXTEND2 cells more explicitly. Fixes bug 10536;
      bugfix on 0.2.4.8-alpha. Reported by "cypherpunks".
    - Extract the common duplicated code for creating a subdirectory
      of the data directory and writing to a file in it. Fixes ticket
      4282; patch from Peter Retzlaff.
    - Since OpenSSL 0.9.7, the i2d_*() functions support allocating output
      buffer. Avoid calling twice: i2d_RSAPublicKey(), i2d_DHparams(),
      i2d_X509(), and i2d_PublicKey(). Resolves ticket 5170.
    - Add a set of accessor functions for the circuit timeout data
      structure. Fixes ticket 6153; patch from "piet".
    - Clean up exit paths from connection_listener_new(). Closes ticket
      8789. Patch from Arlo Breault.
    - Since we rely on OpenSSL 0.9.8 now, we can use EVP_PKEY_cmp()
      and drop our own custom pkey_eq() implementation. Fixes bug 9043.
    - Use a doubly-linked list to implement the global circuit list.
      Resolves ticket 9108. Patch from Marek Majkowski.
    - Remove contrib/id_to_fp.c since it wasn't used anywhere.
    - Remove constants and tests for PKCS1 padding; it's insecure and
      shouldn't be used for anything new. Fixes bug 8792; patch
      from Arlo Breault.
    - Remove instances of strcpy() from the unit tests. They weren't
      hurting anything, since they were only in the unit tests, but it's
      embarrassing to have strcpy() in the code at all, and some analysis
      tools don't like it. Fixes bug 8790; bugfix on 0.2.3.6-alpha and
      0.2.3.8-alpha. Patch from Arlo Breault.
    - Remove is_internal_IP() function. Resolves ticket 4645.
    - Remove unused function circuit_dump_by_chan from circuitlist.c.
      Closes issue 9107; patch from "marek".
    - Change our use of the ENUM_BF macro to avoid declarations that
      confuse Doxygen.
    - Get rid of router->address, since in all cases it was just the
      string representation of router->addr. Resolves ticket 5528.

  o Documentation:
    - Adjust the URLs in the README to refer to the new locations of
      several documents on the website. Fixes bug 12830. Patch from
      Matt Pagan.
    - Document 'reject6' and 'accept6' ExitPolicy entries. Resolves
      ticket 12878.
    - Update manpage to describe some of the files you can expect to
      find in Tor's DataDirectory. Addresses ticket 9839.
    - Clean up several option names in the manpage to match their real
      names, add the missing documentation for a couple of testing and
      directory authority options, remove the documentation for a
      V2-directory fetching option that no longer exists. Resolves
      ticket 11634.
    - Correct the documentation so that it lists the correct directory
      for the stats files. (They are in a subdirectory called "stats",
      not "status".)
    - In the manpage, move more authority-only options into the
      directory authority section so that operators of regular directory
      caches don't get confused.
    - Fix the layout of the SOCKSPort flags in the manpage. Fixes bug
      11061; bugfix on 0.2.4.7-alpha.
    - Resolve warnings from Doxygen.
    - Document in the manpage that "KBytes" may also be written as
      "kilobytes" or "KB", that "Kbits" may also be written as
      "kilobits", and so forth. Closes ticket 9222.
    - Document that the ClientOnly config option overrides ORPort.
      Our old explanation made ClientOnly sound as though it did
      nothing at all. Resolves bug 9059.
    - Explain that SocksPolicy, DirPolicy, and similar options don't
      take port arguments. Fixes the other part of ticket 11108.
    - Fix a comment about the rend_server_descriptor_t.protocols field
      to more accurately describe its range. Also, make that field
      unsigned, to more accurately reflect its usage. Fixes bug 9099;
      bugfix on 0.2.1.5-alpha.
    - Fix the manpage's description of HiddenServiceAuthorizeClient:
      the maximum client name length is 16, not 19. Fixes bug 11118;
      bugfix on 0.2.1.6-alpha.

  o Package cleanup:
    - The contrib directory has been sorted and tidied. Before, it was
      an unsorted dumping ground for useful and not-so-useful things.
      Now, it is divided based on functionality, and the items which
      seemed to be nonfunctional or useless have been removed. Resolves
      ticket 8966; based on patches from "rl1987".

  o Removed code and features:
    - Clients now reject any directory authority certificates lacking
      a dir-key-crosscert element. These have been included since
      0.2.1.9-alpha, so there's no real reason for them to be optional
      any longer. Completes proposal 157. Resolves ticket 10162.
    - Remove all code that existed to support the v2 directory system,
      since there are no longer any v2 directory authorities. Resolves
      ticket 10758.
    - Remove the HSAuthoritativeDir and AlternateHSAuthority torrc
      options, which were used for designating authorities as "Hidden
      service authorities". There has been no use of hidden service
      authorities since 0.2.2.1-alpha, when we stopped uploading or
      downloading v0 hidden service descriptors. Fixes bug 10881; also
      part of a fix for bug 10841.
    - Remove /tor/dbg-stability.txt URL that was meant to help debug WFU
      and MTBF calculations, but that nobody was using. Fixes bug 11742.
    - The TunnelDirConns and PreferTunnelledDirConns options no longer
      exist; tunneled directory connections have been available since
      0.1.2.5-alpha, and turning them off is not a good idea. This is a
      brute-force fix for 10849, where "TunnelDirConns 0" would break
      hidden services.
    - Remove all code for the long unused v1 directory protocol.
      Resolves ticket 11070.
    - Remove all remaining code related to version-0 hidden service
      descriptors: they have not been in use since 0.2.2.1-alpha. Fixes
      the rest of bug 10841.
    - Remove migration code from when we renamed the "cached-routers"
      file to "cached-descriptors" back in 0.2.0.8-alpha. This
      incidentally resolves ticket 6502 by cleaning up the related code
      a bit. Patch from Akshay Hebbar.

  o Test infrastructure:
    - Tor now builds each source file in two modes: a mode that avoids
      exposing identifiers needlessly, and another mode that exposes
      more identifiers for testing. This lets the compiler do better at
      optimizing the production code, while enabling us to take more
      radical measures to let the unit tests test things.
    - The production builds no longer include functions used only in
      the unit tests; all functions exposed from a module only for
      unit-testing are now static in production builds.
    - Add an --enable-coverage configuration option to make the unit
      tests (and a new src/or/tor-cov target) to build with gcov test
      coverage support.
    - Update to the latest version of tinytest.
    - Improve the tinytest implementation of string operation tests so
      that comparisons with NULL strings no longer crash the tests; they
      now just fail, normally. Fixes bug 9004; bugfix on 0.2.2.4-alpha.
    - New macros in test.h to simplify writing mock-functions for unit
      tests. Part of ticket 11507. Patch from Dana Koch.
    - We now have rudimentary function mocking support that our unit
      tests can use to test functions in isolation. Function mocking
      lets the tests temporarily replace a function's dependencies with
      stub functions, so that the tests can check the function without
      invoking the other functions it calls.

  o Testing:
    - Complete tests for the status.c module. Resolves ticket 11507.
      Patch from Dana Koch.
    - Add more unit tests for the ->circuit map, and
      the destroy-cell-tracking code to fix bug 7912.
    - Unit tests for failing cases of the TAP onion handshake.
    - More unit tests for address-manipulation functions.

  o Distribution (systemd):
    - Include a tor.service file in contrib/dist for use with systemd.
      Some distributions will be able to use this file unmodified;
      others will need to tweak it, or write their own. Patch from Jamie
      Nguyen; resolves ticket 8368.
    - Verify configuration file via ExecStartPre in the systemd unit
      file. Patch from intrigeri; resolves ticket 12730.
    - Explicitly disable RunAsDaemon in the systemd unit file. Our
      current systemd unit uses "Type = simple", so systemd does not
      expect tor to fork. If the user has "RunAsDaemon 1" in their
      torrc, then things won't work as expected. This is e.g. the case
      on Debian (and derivatives), since there we pass "--defaults-torrc
      /usr/share/tor/tor-service-defaults-torrc" (that contains
      "RunAsDaemon 1") by default. Patch by intrigeri; resolves
      ticket 12731.


Changes in version 0.2.4.25 - 2014-10-20
  Tor 0.2.4.25 disables SSL3 in response to the recent "POODLE" attack
  (even though POODLE does not affect Tor). It also works around a crash
  bug caused by some operating systems' response to the "POODLE" attack
  (which does affect Tor).

  o Major security fixes (also in 0.2.5.9-rc):
    - Disable support for SSLv3. All versions of OpenSSL in use with Tor
      today support TLS 1.0 or later, so we can safely turn off support
      for this old (and insecure) protocol. Fixes bug 13426.

  o Major bugfixes (openssl bug workaround, also in 0.2.5.9-rc):
    - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
      1.0.1j, built with the 'no-ssl3' configuration option. Fixes bug
      13471. This is a workaround for an OpenSSL bug.


Changes in version 0.2.4.24 - 2014-09-22
  Tor 0.2.4.24 fixes a bug that affects consistency and speed when
  connecting to hidden services, and it updates the location of one of
  the directory authorities.

  o Major bugfixes:
    - Clients now send the correct address for their chosen rendezvous
      point when trying to access a hidden service. They used to send
      the wrong address, which would still work some of the time because
      they also sent the identity digest of the rendezvous point, and if
      the hidden service happened to try connecting to the rendezvous
      point from a relay that already had a connection open to it,
      the relay would reuse that connection. Now connections to hidden
      services should be more robust and faster. Also, this bug meant
      that clients were leaking to the hidden service whether they were
      on a little-endian (common) or big-endian (rare) system, which for
      some users might have reduced their anonymity. Fixes bug 13151;
      bugfix on 0.2.1.5-alpha.

  o Directory authority changes:
    - Change IP address for gabelmoo (v3 directory authority).

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
      Country database.


Changes in version 0.2.4.23 - 2014-07-28
  Tor 0.2.4.23 brings us a big step closer to slowing down the risk from
  guard rotation, and also backports several important fixes from the
  Tor 0.2.5 alpha release series.

  o Major features:
    - Clients now look at the "usecreatefast" consensus parameter to
      decide whether to use CREATE_FAST or CREATE cells for the first hop
      of their circuit. This approach can improve security on connections
      where Tor's circuit handshake is stronger than the available TLS
      connection security levels, but the tradeoff is more computational
      load on guard relays. Implements proposal 221. Resolves ticket 9386.
    - Make the number of entry guards configurable via a new
      NumEntryGuards consensus parameter, and the number of directory
      guards configurable via a new NumDirectoryGuards consensus
      parameter. Implements ticket 12688.

  o Major bugfixes:
    - Fix a bug in the bounds-checking in the 32-bit curve25519-donna
      implementation that caused incorrect results on 32-bit
      implementations when certain malformed inputs were used along with
      a small class of private ntor keys. This bug does not currently
      appear to allow an attacker to learn private keys or impersonate a
      Tor server, but it could provide a means to distinguish 32-bit Tor
      implementations from 64-bit Tor implementations. Fixes bug 12694;
      bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from
      Adam Langley.

  o Minor bugfixes:
    - Warn and drop the circuit if we receive an inbound 'relay early'
      cell. Those used to be normal to receive on hidden service circuits
      due to bug 1038, but the buggy Tor versions are long gone from
      the network so we can afford to resume watching for them. Resolves
      the rest of bug 1038; bugfix on 0.2.1.19.
    - Correct a confusing error message when trying to extend a circuit
      via the control protocol but we don't know a descriptor or
      microdescriptor for one of the specified relays. Fixes bug 12718;
      bugfix on 0.2.3.1-alpha.
    - Avoid an illegal read from stack when initializing the TLS
      module using a version of OpenSSL without all of the ciphers
      used by the v2 link handshake. Fixes bug 12227; bugfix on
      0.2.4.8-alpha.  Found by "starlight".

  o Minor features:
    - Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2
      Country database.


Changes in version 0.2.4.22 - 2014-05-16
  Tor 0.2.4.22 backports numerous high-priority fixes from the Tor 0.2.5
  alpha release series. These include blocking all authority signing
  keys that may have been affected by the OpenSSL "heartbleed" bug,
  choosing a far more secure set of TLS ciphersuites by default, closing
  a couple of memory leaks that could be used to run a target relay out
  of RAM, and several others.

  o Major features (security, backport from 0.2.5.4-alpha):
    - Block authority signing keys that were used on authorities
      vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We
      don't have any evidence that these keys _were_ compromised; we're
      doing this to be prudent.) Resolves ticket 11464.

  o Major bugfixes (security, OOM):
    - Fix a memory leak that could occur if a microdescriptor parse
      fails during the tokenizing step. This bug could enable a memory
      exhaustion attack by directory servers. Fixes bug 11649; bugfix
      on 0.2.2.6-alpha.

  o Major bugfixes (TLS cipher selection, backport from 0.2.5.4-alpha):
    - The relay ciphersuite list is now generated automatically based on
      uniform criteria, and includes all OpenSSL ciphersuites with
      acceptable strength and forward secrecy. Previously, we had left
      some perfectly fine ciphersuites unsupported due to omission or
      typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by
      'cypherpunks'. Bugfix on 0.2.4.8-alpha.
    - Relays now trust themselves to have a better view than clients of
      which TLS ciphersuites are better than others. (Thanks to bug
      11513, the relay list is now well-considered, whereas the client
      list has been chosen mainly for anti-fingerprinting purposes.)
      Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over
      CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over
      AES128. Resolves ticket 11528.
    - Clients now try to advertise the same list of ciphersuites as
      Firefox 28. This change enables selection of (fast) GCM
      ciphersuites, disables some strange old ciphers, and stops
      advertising the ECDH (not to be confused with ECDHE) ciphersuites.
      Resolves ticket 11438.

  o Minor bugfixes (configuration, security):
    - When running a hidden service, do not allow TunneledDirConns 0:
      trying to set that option together with a hidden service would
      otherwise prevent the hidden service from running, and also make
      it publish its descriptors directly over HTTP. Fixes bug 10849;
      bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (controller, backport from 0.2.5.4-alpha):
    - Avoid sending a garbage value to the controller when a circuit is
      cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.

  o Minor bugfixes (exit relay, backport from 0.2.5.4-alpha):
    - Stop leaking memory when we successfully resolve a PTR record.
      Fixes bug 11437; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (bridge client, backport from 0.2.5.4-alpha):
    - Avoid 60-second delays in the bootstrapping process when Tor is
      launching for a second time while using bridges. Fixes bug 9229;
      bugfix on 0.2.0.3-alpha.

  o Minor bugfixes (relays and bridges, backport from 0.2.5.4-alpha):
    - Give the correct URL in the warning message when trying to run a
      relay on an ancient version of Windows. Fixes bug 9393.

  o Minor bugfixes (compilation):
    - Fix a compilation error when compiling with --disable-curve25519.
      Fixes bug 9700; bugfix on 0.2.4.17-rc.

  o Minor bugfixes:
    - Downgrade the warning severity for the the "md was still
      referenced 1 node(s)" warning. Tor 0.2.5.4-alpha has better code
      for trying to diagnose this bug, and the current warning in
      earlier versions of tor achieves nothing useful. Addresses warning
      from bug 7164.

  o Minor features (log verbosity, backport from 0.2.5.4-alpha):
    - When we run out of usable circuit IDs on a channel, log only one
      warning for the whole channel, and describe how many circuits
      there were on the channel. Fixes part of ticket 11553.

  o Minor features (security, backport from 0.2.5.4-alpha):
    - Decrease the lower limit of MaxMemInCellQueues to 256 MBytes (but
      leave the default at 8GBytes), to better support Raspberry Pi
      users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.

  o Documentation (backport from 0.2.5.4-alpha):
    - Correctly document that we search for a system torrc file before
      looking in ~/.torrc. Fixes documentation side of 9213; bugfix on
      0.2.3.18-rc.


Changes in version 0.2.4.21 - 2014-02-28
  Tor 0.2.4.21 further improves security against potential adversaries who
  find breaking 1024-bit crypto doable, and backports several stability
  and robustness patches from the 0.2.5 branch.

  o Major features (client security):
    - When we choose a path for a 3-hop circuit, make sure it contains
      at least one relay that supports the NTor circuit extension
      handshake. Otherwise, there is a chance that we're building
      a circuit that's worth attacking by an adversary who finds
      breaking 1024-bit crypto doable, and that chance changes the game
      theory. Implements ticket 9777.

  o Major bugfixes:
    - Do not treat streams that fail with reason
      END_STREAM_REASON_INTERNAL as indicating a definite circuit failure,
      since it could also indicate an ENETUNREACH connection error. Fixes
      part of bug 10777; bugfix on 0.2.4.8-alpha.

  o Code simplification and refactoring:
    - Remove data structures which were introduced to implement the
      CellStatistics option: they are now redundant with the new timestamp
      field in the regular packed_cell_t data structure, which we did
      in 0.2.4.18-rc in order to resolve bug 9093. Resolves ticket 10870.

  o Minor features:
    - Always clear OpenSSL bignums before freeing them -- even bignums
      that don't contain secrets. Resolves ticket 10793. Patch by
      Florent Daigniere.
    - Build without warnings under clang 3.4. (We have some macros that
      define static functions only some of which will get used later in
      the module. Starting with clang 3.4, these give a warning unless the
      unused attribute is set on them.) Resolves ticket 10904.
    - Update geoip and geoip6 files to the February 7 2014 Maxmind
      GeoLite2 Country database.

  o Minor bugfixes:
    - Set the listen() backlog limit to the largest actually supported
      on the system, not to the value in a header file. Fixes bug 9716;
      bugfix on every released Tor.
    - Treat ENETUNREACH, EACCES, and EPERM connection failures at an
      exit node as a NOROUTE error, not an INTERNAL error, since they
      can apparently happen when trying to connect to the wrong sort
      of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
    - Fix build warnings about missing "a2x" comment when building the
      manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py".
      Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
    - Avoid a segfault on SIGUSR1, where we had freed a connection but did
      not entirely remove it from the connection lists. Fixes bug 9602;
      bugfix on 0.2.4.4-alpha.
    - Fix a segmentation fault in our benchmark code when running with
      Fedora's OpenSSL package, or any other OpenSSL that provides
      ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
    - Turn "circuit handshake stats since last time" log messages into a
      heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.

  o Documentation fixes:
    - Document that all but one DirPort entry must have the NoAdvertise
      flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.


Changes in version 0.2.4.20 - 2013-12-22
  Tor 0.2.4.20 fixes potentially poor random number generation for users
  who 1) use OpenSSL 1.0.0 or later, 2) set "HardwareAccel 1" in their
  torrc file, 3) have "Sandy Bridge" or "Ivy Bridge" Intel processors,
  and 4) have no state file in their DataDirectory (as would happen on
  first start). Users who generated relay or hidden service identity
  keys in such a situation should discard them and generate new ones.

  This release also fixes a logic error that caused Tor clients to build
  many more preemptive circuits than they actually need.

  o Major bugfixes:
    - Do not allow OpenSSL engines to replace the PRNG, even when
      HardwareAccel is set. The only default builtin PRNG engine uses
      the Intel RDRAND instruction to replace the entire PRNG, and
      ignores all attempts to seed it with more entropy. That's
      cryptographically stupid: the right response to a new alleged
      entropy source is never to discard all previously used entropy
      sources. Fixes bug 10402; works around behavior introduced in
      OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman"
      and "rl1987".
    - Fix assertion failure when AutomapHostsOnResolve yields an IPv6
      address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
    - Avoid launching spurious extra circuits when a stream is pending.
      This fixes a bug where any circuit that _wasn't_ unusable for new
      streams would be treated as if it were, causing extra circuits to
      be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.

  o Minor bugfixes:
    - Avoid a crash bug when starting with a corrupted microdescriptor
      cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
    - If we fail to dump a previously cached microdescriptor to disk, avoid
      freeing duplicate data later on. Fixes bug 10423; bugfix on
      0.2.4.13-alpha. Spotted by "bobnomnom".


Changes in version 0.2.4.19 - 2013-12-11
  The Tor 0.2.4 release series is dedicated to the memory of Aaron Swartz
  (1986-2013). Aaron worked on diverse projects including helping to guide
  Creative Commons, playing a key role in stopping SOPA/PIPA, bringing
  transparency to the U.S government's PACER documents, and contributing
  design and development for Tor and Tor2Web. Aaron was one of the latest
  martyrs in our collective fight for civil liberties and human rights,
  and his death is all the more painful because he was one of us.

  Tor 0.2.4.19, the first stable release in the 0.2.4 branch, features
  a new circuit handshake and link encryption that use ECC to provide
  better security and efficiency; makes relays better manage circuit
  creation requests; uses "directory guards" to reduce client enumeration
  risks; makes bridges collect and report statistics about the pluggable
  transports they support; cleans up and improves our geoip database;
  gets much closer to IPv6 support for clients, bridges, and relays; makes
  directory authorities use measured bandwidths rather than advertised
  ones when computing flags and thresholds; disables client-side DNS
  caching to reduce tracking risks; and fixes a big bug in bridge
  reachability testing. This release introduces two new design
  abstractions in the code: a new "channel" abstraction between circuits
  and or_connections to allow for implementing alternate relay-to-relay
  transports, and a new "circuitmux" abstraction storing the queue of
  circuits for a channel. The release also includes many stability,
  security, and privacy fixes.

  o Major features (new circuit handshake):
    - Tor now supports a new circuit extension handshake designed by Ian
      Goldberg, Douglas Stebila, and Berkant Ustaoglu. Our original
      circuit extension handshake, later called "TAP", was a bit slow
      (especially on the relay side), had a fragile security proof, and
      used weaker keys than we'd now prefer. The new circuit handshake
      uses Dan Bernstein's "curve25519" elliptic-curve Diffie-Hellman
      function, making it significantly more secure than the older
      handshake, and significantly faster. Tor can use one of two built-in
      pure-C curve25519-donna implementations by Adam Langley, or it
      can link against the "nacl" library for a tuned version if present.

      The built-in version is very fast for 64-bit systems when building
      with GCC. The built-in 32-bit version is still faster than the
      old TAP protocol, but using libnacl is better on most such hosts.

      Implements proposal 216; closes ticket 7202.

  o Major features (better link encryption):
    - Relays can now enable the ECDHE TLS ciphersuites when available
      and appropriate. These ciphersuites let us negotiate forward-secure
      TLS secret keys more safely and more efficiently than with our
      previous use of Diffie-Hellman modulo a 1024-bit prime. By default,
      public relays prefer the (faster) P224 group, and bridges prefer
      the (more common) P256 group; you can override this with the
      TLSECGroup option.

      This feature requires clients running 0.2.3.17-beta or later,
      and requires both sides to be running OpenSSL 1.0.0 or later
      with ECC support. OpenSSL 1.0.1, with the compile-time option
      "enable-ec_nistp_64_gcc_128", is highly recommended.

      Implements the relay side of proposal 198; closes ticket 7200.

    - Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later.
      Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or
      1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented
      renegotiation from working with TLS 1.1 or 1.2, so we had disabled
      them to solve bug 6033.)

  o Major features (relay performance):
    - Instead of limiting the number of queued onionskins (aka circuit
      create requests) to a fixed, hard-to-configure number, we limit
      the size of the queue based on how many we expect to be able to
      process in a given amount of time. We estimate the time it will
      take to process an onionskin based on average processing time
      of previous onionskins. Closes ticket 7291. You'll never have to
      configure MaxOnionsPending again.
    - Relays process the new "NTor" circuit-level handshake requests
      with higher priority than the old "TAP" circuit-level handshake
      requests. We still process some TAP requests to not totally starve
      0.2.3 clients when NTor becomes popular. A new consensus parameter
      "NumNTorsPerTAP" lets us tune the balance later if we need to.
      Implements ticket 9574.

  o Major features (client bootstrapping resilience):
    - Add a new "FallbackDir" torrc option to use when we can't use
      a directory mirror from the consensus (either because we lack a
      consensus, or because they're all down). Currently, all authorities
      are fallbacks by default, and there are no other default fallbacks,
      but that will change. This option will allow us to give clients a
      longer list of servers to try to get a consensus from when first
      connecting to the Tor network, and thereby reduce load on the
      directory authorities. Implements proposal 206, "Preconfigured
      directory sources for bootstrapping". We also removed the old
      "FallbackNetworkstatus" option, since we never got it working well
      enough to use it. Closes bug 572.
    - If we have no circuits open, use a relaxed timeout (the
      95th-percentile cutoff) until a circuit succeeds. This heuristic
      should allow Tor to succeed at building circuits even when the
      network connection drastically changes. Should help with bug 3443.

  o Major features (use of guards):
    - Support directory guards (proposal 207): when possible, clients now
      use their entry guards for non-anonymous directory requests. This
      can help prevent client enumeration. Note that this behavior only
      works when we have a usable consensus directory, and when options
      about what to download are more or less standard. In the future we
      should re-bootstrap from our guards, rather than re-bootstrapping
      from the preconfigured list of directory sources that ships with
      Tor. Resolves ticket 6526.
    - Raise the default time that a client keeps an entry guard from
      "1-2 months" to "2-3 months", as suggested by Tariq Elahi's WPES
      2012 paper. (We would make it even longer, but we need better client
      load balancing first.) Also, make the guard lifetime controllable
      via a new GuardLifetime torrc option and a GuardLifetime consensus
      parameter. Start of a fix for bug 8240; bugfix on 0.1.1.11-alpha.

  o Major features (bridges with pluggable transports):
    - Bridges now report the pluggable transports they support to the
      bridge authority, so it can pass the supported transports on to
      bridgedb and/or eventually do reachability testing. Implements
      ticket 3589.
    - Automatically forward the TCP ports of pluggable transport
      proxies using tor-fw-helper if PortForwarding is enabled. Implements
      ticket 4567.

  o Major features (geoip database):
    - Maxmind began labelling Tor relays as being in country "A1",
      which breaks by-country node selection inside Tor. Now we use a
      script to replace "A1" ("Anonymous Proxy") entries in our geoip
      file with real country codes. This script fixes about 90% of "A1"
      entries automatically and uses manual country code assignments to
      fix the remaining 10%. See src/config/README.geoip for details.
      Fixes bug 6266.
    - Add GeoIP database for IPv6 addresses. The new config option
      is GeoIPv6File.
    - Update to the October 2 2013 Maxmind GeoLite Country database.

  o Major features (IPv6):
    - Clients who set "ClientUseIPv6 1" may connect to entry nodes over
      IPv6. Set "ClientPreferIPv6ORPort 1" to make this even more likely
      to happen. Implements ticket 5535.
    - All kind of relays, not just bridges, can now advertise an IPv6
      OR port. Implements ticket 6362.
    - Relays can now exit to IPv6 addresses: make sure that you have IPv6
      connectivity, then set the IPv6Exit flag to 1. Also make sure your
      exit policy reads as you would like: the address * applies to all
      address families, whereas *4 is IPv4 address only, and *6 is IPv6
      addresses only. On the client side, you'll need to wait for enough
      exits to support IPv6, apply the "IPv6Traffic" flag to a SocksPort,
      and use Socks5. Closes ticket 5547, implements proposal 117 as
      revised in proposal 208.
    - Bridge authorities now accept IPv6 bridge addresses and include
      them in network status documents. Implements ticket 5534.
    - Directory authorities vote on IPv6 OR ports. Implements ticket 6363.

  o Major features (directory authorities):
    - Directory authorities now prefer using measured bandwidths to
      advertised ones when computing flags and thresholds. Resolves
      ticket 8273.
    - Directory authorities that vote measured bandwidths about more
      than a threshold number of relays now treat relays with
      unmeasured bandwidths as having bandwidth 0 when computing their
      flags. Resolves ticket 8435.
    - Directory authorities now support a new consensus method (17)
      where they cap the published bandwidth of relays for which
      insufficient bandwidth measurements exist. Fixes part of bug 2286.
    - Directory authorities that set "DisableV2DirectoryInfo_ 1" no longer
      serve any v2 directory information. Now we can test disabling the
      old deprecated v2 directory format, and see whether doing so has
      any effect on network load. Begins to fix bug 6783.

  o Major features (build and portability):
    - Switch to a nonrecursive Makefile structure. Now instead of each
      Makefile.am invoking other Makefile.am's, there is a master
      Makefile.am that includes the others. This change makes our build
      process slightly more maintainable, and improves parallelism for
      building with make -j. Original patch by Stewart Smith; various
      fixes by Jim Meyering.
    - Where available, we now use automake's "silent" make rules by
      default, so that warnings are easier to spot. You can get the old
      behavior with "make V=1". Patch by Stewart Smith for ticket 6522.
    - Resume building correctly with MSVC and Makefile.nmake. This patch
      resolves numerous bugs and fixes reported by ultramage, including
      7305, 7308, 7309, 7310, 7312, 7313, 7315, 7316, and 7669.

  o Security features:
    - Switch to a completely time-invariant approach for picking nodes
      weighted by bandwidth. Our old approach would run through the
      part of the loop after it had made its choice slightly slower
      than it ran through the part of the loop before it had made its
      choice. Addresses ticket 6538.
    - Disable the use of Guard nodes when in Tor2WebMode. Guard usage
      by tor2web clients allows hidden services to identify tor2web
      clients through their repeated selection of the same rendezvous
      and introduction point circuit endpoints (their guards). Resolves
      ticket 6888.

  o Major bugfixes (relay denial of service):
    - When we have too much memory queued in circuits (according to a new
      MaxMemInCellQueues option), close the circuits that have the oldest
      queued cells, on the theory that those are most responsible for
      us running low on memory. This prevents us from running out of
      memory as a relay if circuits fill up faster than they can be
      drained. Fixes bugs 9063 and 9093; bugfix on the 54th commit of
      Tor. This bug is a further fix beyond bug 6252, whose fix was
      merged into 0.2.3.21-rc.
    - Reject bogus create and relay cells with 0 circuit ID or 0 stream
      ID: these could be used to create unexpected streams and circuits
      which would count as "present" to some parts of Tor but "absent"
      to others, leading to zombie circuits and streams or to a bandwidth
      denial-of-service. Fixes bug 7889; bugfix on every released version
      of Tor. Reported by "oftc_must_be_destroyed".
    - Avoid a bug where our response to TLS renegotiation under certain
      network conditions could lead to a busy-loop, with 100% CPU
      consumption. Fixes bug 5650; bugfix on 0.2.0.16-alpha.

  o Major bugfixes (asserts, crashes, leaks):
    - Prevent the get_freelists() function from running off the end of
      the list of freelists if it somehow gets an unrecognized
      allocation. Fixes bug 8844; bugfix on 0.2.0.16-alpha. Reported by
      eugenis.
    - Avoid a memory leak where we would leak a consensus body when we
      find that a consensus which we couldn't previously verify due to
      missing certificates is now verifiable. Fixes bug 8719; bugfix
      on 0.2.0.10-alpha.
    - If we are unable to save a microdescriptor to the journal, do not
      drop it from memory and then reattempt downloading it. Fixes bug
      9645; bugfix on 0.2.2.6-alpha.
    - Fix an assertion failure that would occur when disabling the
      ORPort setting on a running Tor process while accounting was
      enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
    - Avoid an assertion failure on OpenBSD (and perhaps other BSDs)
      when an exit connection with optimistic data succeeds immediately
      rather than returning EINPROGRESS. Fixes bug 9017; bugfix on
      0.2.3.1-alpha.
    - Fix a memory leak that would occur whenever a configuration
      option changed. Fixes bug 8718; bugfix on 0.2.3.3-alpha.

  o Major bugfixes (relay rate limiting):
    - When a TLS write is partially successful but incomplete, remember
      that the flushed part has been flushed, and notice that bytes were
      actually written. Reported and fixed pseudonymously. Fixes bug 7708;
      bugfix on Tor 0.1.0.5-rc.
    - Raise the default BandwidthRate/BandwidthBurst values from 5MB/10MB
      to 1GB/1GB. The previous defaults were intended to be "basically
      infinite", but it turns out they're now limiting our 100mbit+
      relays and bridges. Fixes bug 6605; bugfix on 0.2.0.10-alpha (the
      last time we raised it).
    - No longer stop reading or writing on cpuworker connections when
      our rate limiting buckets go empty. Now we should handle circuit
      handshake requests more promptly. Resolves bug 9731.

  o Major bugfixes (client-side privacy):
    - When we mark a circuit as unusable for new circuits, have it
      continue to be unusable for new circuits even if MaxCircuitDirtiness
      is increased too much at the wrong time, or the system clock jumps
      backwards. Fixes bug 6174; bugfix on 0.0.2pre26.
    - If ClientDNSRejectInternalAddresses ("do not believe DNS queries
      which have resolved to internal addresses") is set, apply that
      rule to IPv6 as well. Fixes bug 8475; bugfix on 0.2.0.7-alpha.
    - When an exit relay rejects a stream with reason "exit policy", but
      we only know an exit policy summary (e.g. from the microdesc
      consensus) for it, do not mark the relay as useless for all exiting.
      Instead, mark just the circuit as unsuitable for that particular
      address. Fixes part of bug 7582; bugfix on 0.2.3.2-alpha.

  o Major bugfixes (stream isolation):
    - Allow applications to get proper stream isolation with
      IsolateSOCKSAuth. Many SOCKS5 clients that want to offer
      username/password authentication also offer "no authentication". Tor
      had previously preferred "no authentication", so the applications
      never actually sent Tor their auth details. Now Tor selects
      username/password authentication if it's offered. You can disable
      this behavior on a per-SOCKSPort basis via PreferSOCKSNoAuth. Fixes
      bug 8117; bugfix on 0.2.3.3-alpha.
    - Follow the socks5 protocol when offering username/password
      authentication. The fix for bug 8117 exposed this bug, and it
      turns out real-world applications like Pidgin do care. Bugfix on
      0.2.3.2-alpha; fixes bug 8879.

  o Major bugfixes (client circuit building):
    - Alter circuit build timeout measurement to start at the point
      where we begin the CREATE/CREATE_FAST step (as opposed to circuit
      initialization). This should make our timeout measurements more
      uniform. Previously, we were sometimes including ORconn setup time
      in our circuit build time measurements. Should resolve bug 3443.
    - If the circuit build timeout logic is disabled (via the consensus,
      or because we are an authority), then don't build testing circuits.
      Fixes bug 9657; bugfix on 0.2.2.14-alpha.

  o Major bugfixes (client-side DNS):
    - Turn off the client-side DNS cache by default. Updating and using
      the DNS cache is now configurable on a per-client-port
      level. SOCKSPort, DNSPort, etc lines may now contain
      {No,}Cache{IPv4,IPv6,}DNS lines to indicate that we shouldn't
      cache these types of DNS answers when we receive them from an
      exit node in response to an application request on this port, and
      {No,}UseCached{IPv4,IPv6,DNS} lines to indicate that if we have
      cached DNS answers of these types, we shouldn't use them. It's
      potentially risky to use cached DNS answers at the client, since
      doing so can indicate to one exit what answers we've gotten
      for DNS lookups in the past. With IPv6, this becomes especially
      problematic. Using cached DNS answers for requests on the same
      circuit would present less linkability risk, since all traffic
      on a circuit is already linkable, but it would also provide
      little performance benefit: the exit node caches DNS replies
      too. Implements a simplified version of Proposal 205. Implements
      ticket 7570.

  o Major bugfixes (hidden service privacy):
    - Limit hidden service descriptors to at most ten introduction
      points, to slow one kind of guard enumeration. Fixes bug 9002;
      bugfix on 0.1.1.11-alpha.

  o Major bugfixes (directory fetching):
    - If the time to download the next old-style networkstatus is in
      the future, do not decline to consider whether to download the
      next microdescriptor networkstatus. Fixes bug 9564; bugfix on
      0.2.3.14-alpha.
    - We used to always request authority certificates by identity digest,
      meaning we'd get the newest one even when we wanted one with a
      different signing key. Then we would complain about being given
      a certificate we already had, and never get the one we really
      wanted. Now we use the "fp-sk/" resource as well as the "fp/"
      resource to request the one we want. Fixes bug 5595; bugfix on
      0.2.0.8-alpha.

  o Major bugfixes (bridge reachability):
    - Bridges now send AUTH_CHALLENGE cells during their v3 handshakes;
      previously they did not, which prevented them from receiving
      successful connections from relays for self-test or bandwidth
      testing. Also, when a relay is extending a circuit to a bridge,
      it needs to send a NETINFO cell, even when the bridge hasn't sent
      an AUTH_CHALLENGE cell. Fixes bug 9546; bugfix on 0.2.3.6-alpha.

  o Major bugfixes (control interface):
    - When receiving a new configuration file via the control port's
      LOADCONF command, do not treat the defaults file as absent.
      Fixes bug 9122; bugfix on 0.2.3.9-alpha.

  o Major bugfixes (directory authorities):
    - Stop marking every relay as having been down for one hour every
      time we restart a directory authority. These artificial downtimes
      were messing with our Stable and Guard flag calculations. Fixes
      bug 8218 (introduced by the fix for 1035). Bugfix on 0.2.2.23-alpha.
    - When computing directory thresholds, ignore any rejected-as-sybil
      nodes during the computation so that they can't influence Fast,
      Guard, etc. (We should have done this for proposal 109.) Fixes
      bug 8146.
    - When marking a node as a likely sybil, reset its uptime metrics
      to zero, so that it cannot time towards getting marked as Guard,
      Stable, or HSDir. (We should have done this for proposal 109.) Fixes
      bug 8147.
    - Fix a bug in the voting algorithm that could yield incorrect results
      when a non-naming authority declared too many flags. Fixes bug 9200;
      bugfix on 0.2.0.3-alpha.

  o Internal abstraction features:
    - Introduce new channel_t abstraction between circuits and
      or_connection_t to allow for implementing alternate OR-to-OR
      transports. A channel_t is an abstract object which can either be a
      cell-bearing channel, which is responsible for authenticating and
      handshaking with the remote OR and transmitting cells to and from
      it, or a listening channel, which spawns new cell-bearing channels
      at the request of remote ORs. Implements part of ticket 6465.
    - Make a channel_tls_t subclass of channel_t, adapting it to the
      existing or_connection_t code. The V2/V3 protocol handshaking
      code which formerly resided in command.c has been moved below the
      channel_t abstraction layer and may be found in channeltls.c now.
      Implements the rest of ticket 6465.
    - Introduce new circuitmux_t storing the queue of circuits for
      a channel; this encapsulates and abstracts the queue logic and
      circuit selection policy, and allows the latter to be overridden
      easily by switching out a policy object. The existing EWMA behavior
      is now implemented as a circuitmux_policy_t. Resolves ticket 6816.

  o New build requirements:
    - Tor now requires OpenSSL 0.9.8 or later. OpenSSL 1.0.0 or later is
      strongly recommended.
    - Tor maintainers now require Automake version 1.9 or later to build
      Tor from the Git repository. (Automake is not required when building
      from a source distribution.)

  o Minor features (protocol):
    - No longer include the "opt" prefix when generating routerinfos
      or v2 directories: it has been needless since Tor 0.1.2. Closes
      ticket 5124.
    - Reject EXTEND cells sent to nonexistent streams. According to the
      spec, an EXTEND cell sent to _any_ nonzero stream ID is invalid, but
      we were only checking for stream IDs that were currently in use.
      Found while hunting for more instances of bug 6271. Bugfix on
      0.0.2pre8, which introduced incremental circuit construction.
    - Tor relays and clients now support a better CREATE/EXTEND cell
      format, allowing the sender to specify multiple address, identity,
      and handshake types. Implements Robert Ransom's proposal 200;
      closes ticket 7199.
    - Reject as invalid most directory objects containing a NUL.
      Belt-and-suspender fix for bug 8037.

  o Minor features (security):
    - Clear keys and key-derived material left on the stack in
      rendservice.c and rendclient.c. Check return value of
      crypto_pk_write_private_key_to_string() in rend_service_load_keys().
      These fixes should make us more forward-secure against cold-boot
      attacks and the like. Fixes bug 2385.
    - Use our own weak RNG when we need a weak RNG. Windows's rand() and
      Irix's random() only return 15 bits; Solaris's random() returns more
      bits but its RAND_MAX says it only returns 15, and so on. Motivated
      by the fix for bug 7801; bugfix on 0.2.2.20-alpha.

  o Minor features (control protocol):
    - Add a "GETINFO signal/names" control port command. Implements
      ticket 3842.
    - Provide default values for all options via "GETINFO config/defaults".
      Implements ticket 4971.
    - Allow an optional $ before the node identity digest in the
      controller command GETINFO ns/id/, for consistency with
      md/id/ and desc/id/. Resolves ticket 7059.
    - Add CACHED keyword to ADDRMAP events in the control protocol
      to indicate whether a DNS result will be cached or not. Resolves
      ticket 8596.
    - Generate bootstrapping status update events correctly when fetching
      microdescriptors. Fixes bug 9927.

  o Minor features (path selection):
    - When deciding whether we have enough descriptors to build circuits,
      instead of looking at raw relay counts, look at which fraction
      of (bandwidth-weighted) paths we're able to build. This approach
      keeps clients from building circuits if their paths are likely to
      stand out statistically. The default fraction of paths needed is
      taken from the consensus directory; you can override it with the
      new PathsNeededToBuildCircuits option. Fixes ticket 5956.
    - When any country code is listed in ExcludeNodes or ExcludeExitNodes,
      and we have GeoIP information, also exclude all nodes with unknown
      countries "??" and "A1". This behavior is controlled by the
      new GeoIPExcludeUnknown option: you can make such nodes always
      excluded with "GeoIPExcludeUnknown 1", and disable the feature
      with "GeoIPExcludeUnknown 0". Setting "GeoIPExcludeUnknown auto"
      gets you the default behavior. Implements feature 7706.

  o Minor features (hidden services):
    - Improve circuit build timeout handling for hidden services.
      In particular: adjust build timeouts more accurately depending
      upon the number of hop-RTTs that a particular circuit type
      undergoes. Additionally, launch intro circuits in parallel
      if they timeout, and take the first one to reply as valid.
    - The Tor client now ignores sub-domain components of a .onion
      address. This change makes HTTP "virtual" hosting
      possible: http://foo.aaaaaaaaaaaaaaaa.onion/ and
      http://bar.aaaaaaaaaaaaaaaa.onion/ can be two different websites
      hosted on the same hidden service. Implements proposal 204.
    - Enable Tor to read configuration, state, and key information from
      a FIFO. Previously Tor would only read from files with a positive
      stat.st_size. Code from meejah; fixes bug 6044.

  o Minor features (clients):
    - Teach bridge-using clients to avoid 0.2.2.x bridges when making
      microdescriptor-related dir requests, and only fall back to normal
      descriptors if none of their bridges can handle microdescriptors
      (as opposed to the fix in ticket 4013, which caused them to fall
      back to normal descriptors if *any* of their bridges preferred
      them). Resolves ticket 4994.
    - Tweak tor-fw-helper to accept an arbitrary amount of arbitrary
      TCP ports to forward. In the past it only accepted two ports:
      the ORPort and the DirPort.

  o Minor features (protecting client timestamps):
    - Clients no longer send timestamps in their NETINFO cells. These were
      not used for anything, and they provided one small way for clients
      to be distinguished from each other as they moved from network to
      network or behind NAT. Implements part of proposal 222.
    - Clients now round timestamps in INTRODUCE cells down to the nearest
      10 minutes. If a new Support022HiddenServices option is set to 0, or
      if it's set to "auto" and the feature is disabled in the consensus,
      the timestamp is sent as 0 instead. Implements part of proposal 222.
    - Stop sending timestamps in AUTHENTICATE cells. This is not such
      a big deal from a security point of view, but it achieves no actual
      good purpose, and isn't needed. Implements part of proposal 222.
    - Reduce down accuracy of timestamps in hidden service descriptors.
      Implements part of proposal 222.

  o Minor features (bridges):
    - Make bridge relays check once a minute for whether their IP
      address has changed, rather than only every 15 minutes. Resolves
      bugs 1913 and 1992.
    - Bridge statistics now count bridge clients connecting over IPv6:
      bridge statistics files now list "bridge-ip-versions" and
      extra-info documents list "geoip6-db-digest". The control protocol
      "CLIENTS_SEEN" and "ip-to-country" queries now support IPv6. Initial
      implementation by "shkoo", addressing ticket 5055.
    - Add a new torrc option "ServerTransportListenAddr" to let bridge
      operators select the address where their pluggable transports will
      listen for connections. Resolves ticket 7013.
    - Randomize the lifetime of our SSL link certificate, so censors can't
      use the static value for filtering Tor flows. Resolves ticket 8443;
      related to ticket 4014 which was included in 0.2.2.33.

  o Minor features (relays):
    - Option OutboundBindAddress can be specified multiple times an