ChangeLog

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 0.3.4.4-rc - 2018-07-09
  Tor 0.3.4.4-rc fixes several small compilation, portability, and
  correctness issues in previous versions of Tor. This version is a
  release candidate: if no serious bugs are found, we expect that the
  stable 0.3.4 release will be (almost) the same as this release.

  o Minor features (compilation):
    - 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 (Rust, portability):
    - Rust cross-compilation is now supported. Closes ticket 25895.

  o Minor bugfixes (compilation):
    - 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):
    - Report the port correctly when a port is configured to bind to
      "auto". Fixes bug 26568; bugfix on 0.3.4.1-alpha.
    - 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 (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 (memory, correctness):
    - Fix a number of small memory leaks identified by coverity. Fixes
      bug 26467; bugfix on numerous Tor versions.

  o Minor bugfixes (testing, compatibility):
    - 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 0.3.4.3-alpha - 2018-06-26
  Tor 0.3.4.3-alpha fixes several bugs in earlier versions, including
  one that was causing stability issues on directory authorities.

  o Major bugfixes (directory authority):
    - 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):
    - 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 feature (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

  o Minor features (relay, diagnostic):
    - 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 (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 (compilation):
    - 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.
    - When linking the libtor_testing.a library, only include the
      dirauth object files once. Previously, they were getting added
      twice. Fixes bug 26402; bugfix on 0.3.4.1-alpha.
    - The --enable-fatal-warnings flag now affects Rust code as well.
      Closes ticket 26245.

  o Minor bugfixes (onion services):
    - 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 (relay):
    - 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 (testing):
    - Fix compilation of the doctests in the Rust crypto crate. Fixes
      bug 26415; bugfix on 0.3.4.1-alpha.
    - Instead of trying to read the geoip configuration files from
      within the unit tests, instead create our own ersatz files with
      just enough geoip data in the format we expect. Trying to read
      from the source directory created problems on Windows with mingw,
      where the build system's paths are not the same as the platform's
      paths. Fixes bug 25787; bugfix on 0.3.4.1-alpha.
    - Refrain from trying to get an item from an empty smartlist in
      test_bridges_clear_bridge_list. Set DEBUG_SMARTLIST in unit tests
      to catch improper smartlist usage. Furthermore, enable
      DEBUG_SMARTLIST globally when build is configured with fragile
      hardening. Fixes bug 26196; bugfix on 0.3.4.1-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 0.3.4.2-alpha - 2018-06-12
  Tor 0.3.4.2-alpha fixes several minor bugs in the previous alpha
  release, and forward-ports an authority-only security fix from 0.3.3.6.

  o Directory authority changes:
    - Add an IPv6 address for the "dannenberg" directory authority.
      Closes ticket 26343.

  o Major bugfixes (security, directory authority, denial-of-service, also in 0.3.3.6):
    - 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 Minor features (continuous integration):
    - 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 (geoip):
    - Update geoip and geoip6 to the June 7 2018 Maxmind GeoLite2
      Country database. Closes ticket 26351.

  o Minor bugfixes (compatibility, openssl):
    - 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):
    - Silence unused-const-variable warnings in zstd.h with some GCC
      versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha.
    - Fix compilation when using OpenSSL 1.1.0 with the "no-deprecated"
      flag enabled. Fixes bug 26156; bugfix on 0.3.4.1-alpha.
    - 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 (control port):
    - Do not count 0-length RELAY_COMMAND_DATA cells as valid data in
      CIRC_BW events. Previously, such cells were counted entirely in
      the OVERHEAD field. Now they are not. Fixes bug 26259; bugfix
      on 0.3.4.1-alpha.

  o Minor bugfixes (controller):
    - 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):
    - 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 (onion services):
    - Fix a bug that blocked the creation of ephemeral v3 onion
      services. Fixes bug 25939; bugfix on 0.3.4.1-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.


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 0.3.3.5-rc. For a list of all changes
  since 0.3.2.10, see the ReleaseNotes file.

  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 (directory authorities, backport from 0.3.4.1-alpha):
    - Avoid a crash when testing router reachability on a router that
      could have an ed25519 ID, but which does not. Fixes bug 25415;
      bugfix on 0.3.3.2-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 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 (compatibility, backport from 0.3.4.1-alpha):
    - Avoid some compilation warnings with recent versions of LibreSSL.
      Closes ticket 26006.

  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 (geoip):
    - Update geoip and geoip6 to the May 1 2018 Maxmind GeoLite2 Country
      database. Closes ticket 26104.

  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 (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 (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 (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 (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, crash, backport from 0.3.4.1-alpha):
    - Avoid a crash when running with DirPort set but ORPort tuned off.
      Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.

  o Documentation (backport from 0.3.4.1-alpha):
    - Correct an IPv6 error in the documentation for ExitPolicy. Closes
      ticket 25857. Patch from "CTassisF".


Changes in version 0.3.4.1-alpha - 2018-05-17
  Tor 0.3.4.1-alpha is the first release in the 0.3.4.x series. It
  includes refactoring to begin reducing Tor's binary size and idle CPU
  usage on mobile, along with prep work for new bandwidth scanners,
  improvements to the experimental "vanguards" feature, and numerous
  other small features and bugfixes.

  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 feature (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 with 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 ticket
      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 Major bugfixes (directory authorities, security):
    - 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 (crash):
    - 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 (directory authority):
    - Avoid a crash when testing router reachability on a router that
      could have an ed25519 ID, but which does not. Fixes bug 25415;
      bugfix on 0.3.3.2-alpha.

  o Major bugfixes (onion service):
    - Correctly detect when onion services get disabled after HUP. Fixes
      bug 25761; bugfix on 0.3.2.1.

  o Major bugfixes (protover, voting):
    - Revise Rust implementation of protover to use a more memory-
      efficient voting algorithm and corresponding data structures, thus
      avoiding a potential (but small impact) DoS attack where specially
      crafted protocol strings would expand to several potential
      megabytes in memory. In the process, several portions of code were
      revised to be methods on new, custom types, rather than functions
      taking interchangeable types, thus increasing type safety of the
      module. Custom error types and handling were added as well, in
      order to facilitate better error dismissal/handling in outside
      crates and avoid mistakenly passing an internal error string to C
      over the FFI boundary. Many tests were added, and some previous
      differences between the C and Rust implementations have been
      remedied. Fixes bug 24031; bugfix on 0.3.3.1-alpha.

  o Major bugfixes (relay, denial of service):
    - 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 (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 (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):
    - 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.
    - Avoid some compilation warnings with recent versions of LibreSSL.
      Closes ticket 26006.

  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):
    - 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 (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 (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 May 1 2018 Maxmind GeoLite2 Country
      database. Closes ticket 26104.

  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 (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 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 (circuit path selection):
    - 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 (client):
    - 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 (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 (control interface):
    - 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.

  o Minor bugfixes (controller):
    - 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, client):
    - 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 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 (documentation):
    - 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 (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 (Linux seccomp2 sandbox):
    - 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 (onion service):
    - 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 (path selection):
    - 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.

  o Minor bugfixes (portability):
    - 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 (relay, crash):
    - Avoid a crash when running with DirPort set but ORPort tuned off.
      Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.

  o Minor bugfixes (restart-in-process):
    - 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):
    - 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 (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 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 PortForwsrding 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 the want to downgrade to an older version of tor without
      ed25519. Closes ticket 20522.

  o Documentation:
    - Correct an IPv6 error in the documentation for ExitPolicy. Closes
      ticket 25857. Patch from "CTassisF".

  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 0.3.3.5-rc - 2018-04-15
  Tor 0.3.3.5-rc fixes various bugs in earlier versions of Tor,
  including some that could affect reliability or correctness.

  This is the first release candidate in the 0.3.3 series. If we find no
  new bugs or regression here, then the first stable 0.3.3 release will
  be nearly identical to this one.

  o Major bugfixes (security, protover, voting):
    - Revise Rust implementation of protover to use a more memory-
      efficient voting algorithm and corresponding data structures, thus
      avoiding a potential memory-based DoS attack where specially
      crafted protocol strings would expand to fill available memory.
      Fixes bug 24031; bugfix on 0.3.3.1-alpha.

  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 Minor feature (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 (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 (geoip):
    - Update geoip and geoip6 to the April 3 2018 Maxmind GeoLite2
      Country database. Closes ticket 25718.

  o Minor bugfixes (client):
    - When using a listed relay as a bridge, and also using
      microdescriptors, and considering that relay as a non-bridge in a
      circuit, treat its microdescriptor as a valid source of
      information about that relay. This change should prevent a non-
      fatal assertion error. Fixes bug 25691; bugfix on 0.3.3.4-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.

  o Minor bugfixes (distribution, compilation, rust):
    - Build correctly when the rust dependencies submodule is loaded,
      but the TOR_RUST_DEPENDENCIES environment variable is not set.
      Fixes bug 25679; bugfix on 0.3.3.1-alpha.
    - Actually include all of our Rust source in our source
      distributions. (Previously, a few of the files were accidentally
      omitted.) Fixes bug 25732; bugfix on 0.3.3.2-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.
    - Revert a misformatting issue in the ExitPolicy documentation.
      Fixes bug 25582; bugfix on 0.3.3.1-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 (onion services):
    - Re-instate counting the client HSDir fetch circuits against the
      MaxClientCircuitsPending rate limit. Fixes bug 24989; bugfix
      on 0.3.3.1-alpha.
    - Remove underscores from the _HSLayer{2,3}Nodes options. This
      expert-user configuration can now be enabled as HSLayer{2,3}Nodes.
      Fixes bug 25581; bugfix on 0.3.3.1-alpha

  o Code simplification and refactoring:
    - Move the list of default directory authorities to its own file.
      Closes ticket 24854. Patch by "beastr0".

  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 0.3.3.4-alpha - 2018-03-29
  Tor 0.3.3.4-alpha includes various bugfixes for issues found during
  the alpha testing of earlier releases in its series. We are
  approaching a stable 0.3.3.4-alpha release: more testing is welcome!

  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 bugfixes (relay, connection):
    - 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 Minor features (geoip):
    - Update geoip and geoip6 to the March 8 2018 Maxmind GeoLite2
      Country database. Closes ticket 25469.

  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.

  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 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 (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, reliability):
    - 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 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 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 (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.
    - Rust crates are now automatically detected and tested. Previously,
      some crates were not tested by `make test-rust` due to a static
      string in the `src/test/test_rust.sh` script specifying which
      crates to test. Fixes bug 25560; bugfix on 0.3.3.3-alpha.

  o Minor bugfixes (testing, benchmarks):
    - Fix a crash when running benchmark tests on win32 systems. The
      crash was due to a mutex that wasn't initialized before logging
      and options were initialized. Fixes bug 25479; bugfix
      on 0.3.3.3-alpha.

  o Minor bugfixes (warnings, ipv6):
    - Avoid a bug warning that could occur when trying to connect to a
      relay over IPv6. This warning would occur on a Tor instance that
      downloads router descriptors, but prefers to use microdescriptors.
      Fixes bug 25213; bugfix on 0.3.3.1-alpha.

  o Code simplification and refactoring:
    - Remove the old (deterministic) directory retry logic entirely:
      We've used exponential backoff exclusively for some time. Closes
      ticket 23814.

  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.


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 0.3.3.3-alpha - 2018-03-03
  Tor 0.3.3.3-alpha is the third alpha release for the 0.3.3.x series.
  It includes an important security fix for a remote crash attack
  against directory authorities tracked as TROVE-2018-001.

  Additionally, with this release, we are upgrading the severity of a
  bug fixed in 0.3.3.2-alpha. 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. This bug affected versions
  0.3.2.1-alpha through 0.3.2.9, as well as 0.3.3.1-alpha.

  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):
    - 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 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 (logging):
    - Clarify the log messages produced when getrandom() or a related
      entropy-generation mechanism gives an error. Closes ticket 25120.

  o Minor features (testing):
    - Add a "make test-rust" target to run the rust tests only. Closes
      ticket 25071.

  o Minor bugfixes (denial-of-service):
    - 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 (DoS mitigation):
    - Add extra safety checks when refilling the circuit creation bucket
      to ensure we never set a value above the allowed maximum burst.
      Fixes bug 25202; bugfix on 0.3.3.2-alpha.
    - When a new consensus arrives, don't update our DoS-mitigation
      parameters if we aren't a public relay. Fixes bug 25223; bugfix
      on 0.3.3.2-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 (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.

  o Minor bugfixes (spec conformance):
    - 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 (spec conformance, rust):
    - Resolve a denial-of-service issue caused by an infinite loop in
      the rust protover code. Fixes bug 25250, bugfix on 0.3.3.1-alpha.
      Also tracked as TROVE-2018-003.

  o Code simplification and refactoring:
    - Update the "rust dependencies" submodule to be a project-level
      repository, rather than a user repository. Closes ticket 25323.


Changes in version 0.3.3.2-alpha - 2018-02-10
  Tor 0.3.3.2-alpha is the second alpha in the 0.3.3.x series. It
  introduces a mechanism to handle the high loads that many relay
  operators have been reporting recently. It also fixes several bugs in
  older releases. If this new code proves reliable, we plan to backport
  it to older supported release series.

  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 (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 (protocol versions):
    - Add Link protocol version 5 to the supported protocols list. Fixes
      bug 25070; bugfix on 0.3.1.1-alpha.

  o Major bugfixes (scheduler, consensus):
    - 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):
    - 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 (directory authority):
    - When directory authorities are unable to add signatures to a
      pending consensus, log the reason why. Closes ticket 24849.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2
      Country database.

  o Minor features (logging, diagnostic):
    - 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):
    - 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 (all versions of Tor):
    - 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 (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 (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 (logging):
    - 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.
    - 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 (onion services):
    - 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.
    - 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):
    - 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 (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 (scheduler, KIST):
    - Avoid adding the same channel twice in the KIST scheduler pending
      list, which would waste CPU cycles. Fixes bug 24700; bugfix
      on 0.3.2.1-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 Minor bugfixes (v3 onion services):
    - 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:
    - 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.

  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.


Changes in version 0.3.3.1-alpha - 2018-01-25
  Tor 0.3.3.1-alpha is the first release in the 0.3.3.x series. It adds
  several new features to Tor, including several improvements to
  bootstrapping, and support for an experimental "vanguards" feature to
  resist guard discovery attacks. This series also includes better
  support for applications that need to embed Tor or manage v3
  onion services.

  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.