ReleaseNotes

      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
      implemenation) 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 Major bugfixes (windows, startup):
    - When reading a consensus file from disk, detect whether it was
      written in text mode, and re-read it in text mode if so. Always
      write consensus files in binary mode so that we can map them into
      memory later. Previously, we had written in text mode, which
      confused us when we tried to map the file on windows. Fixes bug
      28614; bugfix on 0.4.0.1-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):
    - Fix compilation warnings in test_circuitpadding.c. Fixes bug
      29169; bugfix on 0.4.0.1-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.
    - 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 (linux seccomp sandbox):
    - Fix startup crash when experimental sandbox support is enabled.
      Fixes bug 29150; bugfix on 0.4.0.1-alpha. Patch by Peter Gerber.

  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 (shellcheck):
    - Look for scripts in their correct locations during "make
      shellcheck". Previously we had looked in the wrong place during
      out-of-tree builds. Fixes bug 30263; bugfix on 0.4.0.1-alpha.

  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.
    - Decrease the false positive rate of stochastic probability
      distribution tests. Fixes bug 29693; bugfix on 0.4.0.1-alpha.
    - Fix intermittent failures on an adaptive padding test. Fixes one
      case of bug 29122; bugfix on 0.4.0.1-alpha.
    - Disable an unstable circuit-padding test that was failing
      intermittently because of an ill-defined small histogram. Such
      histograms will be allowed again after 29298 is implemented. Fixes
      a second case of bug 29122; bugfix on 0.4.0.1-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.
    - Check the time in the "Expires" header using approx_time(). Fixes
      bug 30001; bugfix on 0.4.0.4-rc.

  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 (UI):
    - Lower log level of unlink() errors during bootstrap. Fixes bug
      29930; bugfix on 0.4.0.1-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().