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Changes in version 0.2.5.3-alpha - 2014-03-??

  Tor 0.2.5.3-alpha includes all the fixes from 0.2.4.21. It contains

  two new anti-DoS features for Tor nodes, resolves a bug that was

  keeping SOCKS5 support for IPv6 from working, fixes several annoying

  usability issues for bridge users, and removes more old

  code for unused directory formats.

  two new anti-DoS features for Tor nodes, resolves a bug that kept

  SOCKS5 support for IPv6 from working, fixes several annoying usability

  issues for bridge users, and removes more old code for unused

  directory formats.

  The Tor 0.2.5.x release series is now in patch-freeze: no feature

  patches not already written will be considered for inclusion in

  0.2.5.x.

  o Major features (server security, DoS-resistance):

    - When we run out of memory and we need to close circuits, also

      consider how much memory is allocated in buffers for streams

      attached to each circuit.

    - When deciding whether we have run out of memory and we need to

      close circuits, also consider memory allocated in buffers for

      streams attached to each circuit.

      This change, which extends an anti-DoS feature introduced in

      0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit nodes

      better resist more memory-based DoS attacks than before. Since the

      MaxMemInCellQueues option now applies to all queues, not only cell

      queues, it is now renamed to MaxMemInQueues. This feature fixes

      bug 10169.

      MaxMemInCellQueues option now applies to all queues, it is renamed

      to MaxMemInQueues. This feature fixes bug 10169.

    - Avoid hash-flooding denial-of-service attacks by using the secure

      SipHash-2-4 hash function for our hashtables. Without this

      feature, an attacker could degrade performance of a targeted

      client or server by flooding their data structures with a large

      number of data entries all calculated to be stored at the same

      hash table position, thereby slowing down hash table operations.

      With this feature, hash table positions are derived from a

      randomized cryptographic key, and an attacker cannot predict which

      entries will collide. Closes ticket 4900.

      number of entries to be stored at the same hash table position,

      thereby slowing down the Tor instance. With this feature, hash

      table positions are derived from a randomized cryptographic key,

      and an attacker cannot predict which entries will collide. Closes

      ticket 4900.

    - Decrease the lower limit of MaxMemInQueues to 256 MBytes, to

      better support Raspberry Pi users. Fixes bug 9686; bugfix on

      0.2.4.14-alpha.

  o Minor features (bridges, pluggable transports):

    - Bridges now write the SHA1 digest of their identity key

      fingerprint (that is, a hash of a hash of their public key) to

      notice-level logs and to a new hashed-fingerprint file. This will

      help bridge operatorslook up their bridge in Globe and similar

      tools. Resolves ticket 10884.

    - Improve the message that gets displayed when Tor as a bridge is

      using pluggable transports but doesn't have an Extended ORPort

      notice-level logs, and to a new hashed-fingerprint file. This

      information will help bridge operators look up their bridge in

      Globe and similar tools. Resolves ticket 10884.

    - Improve the message that Tor displays when running as a bridge

      using pluggable transports without an Extended ORPort

      listener. Also, log the message in the log file too. Resolves

      ticket 11043.

    - Stop giving annoying warning messages when we decide not to launch

  o Minor features (other):

    - Add a new option, PredictedPortsRelevanceTime, to control how long

      after having received a request to connect to a given port Tor

      will try to keep circuits ready in anticipation of future request

      will try to keep circuits ready in anticipation of future requests

      for that port. Patch from "unixninja92"; implements ticket 9176.

    - Generate a warning if any ports are listed in the SocksPolicy,

      DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or

      bugfix on 0.2.5.1-alpha. Patch from Dana Koch.

  o Minor bugfixes (client):

    - Fix connections to IPv6 addresses over SOCKS5; previously, we were

    - Fix connections to IPv6 addresses over SOCKS5. Previously, we were

      generating incorrect SOCKS5 responses, and confusing client

      applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.

    - Raises a control port warning when we fail to connect to all of

      our bridges. Previously, we didn't let the controller know, which

      would make the bootstrap process stall. Fixes bug 11069; bugfix on

    - Raise a control port warning when we fail to connect to all of

      our bridges. Previously, we didn't inform the controller, and

      the bootstrap process would stall. Fixes bug 11069; bugfix on

      tor-0.2.1.2-alpha.

    - Exit immediately when a process-owning controller exits.

      Previously, tor relays would wait for a little while after their

      controller exited, as if they had gotten an INT signal--but this

      was problematic, since there was no feedback for the

      user. Controllers that want to do a clean shutdown should send an

      INT signal to let the user know what's going on. Fix for bug

      10449; bugfix on 0.2.2.28-beta.

      was problematic, since there was no feedback for the user. To do a

      clean shutdown, controllers should send an INT signal and give Tor

      a chance to clean up. Fix for bug 10449; bugfix on 0.2.2.28-beta.

    - Improve the log message when we can't connect to a hidden service

      because we have excluded all of the hidden service directory nodes

      hosting its descriptor. Improves on our fix for bug 10722, which

      because all of the hidden service directory nodes hosting its

      descriptor are excluded. Improves on our fix for bug 10722, which

      was a bugfix on 0.2.0.10-alpha.

    - Fix a bug where we would attempt to connect to bridges before our

      pluggable transports were configured, which resulted in some

      bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.

    - Avoid crashing on a malformed resolv.conf file when running a

      server using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.

    - Give the correct URL in the warning message that we present when

      trying to run a Tor relay on an ancient version of Windows. Fixes

      bug 9393.

    - Give the correct URL in the warning message when trying to run a

      Tor relay on an ancient version of Windows. Fixes bug 9393.

    - Bridges now never collect statistics that were designed for

      relays. Fix for bug 5824; bugfix on 0.2.3.8-alpha.

    - Bridges now report complete directory request statistics. Related

      -fasynchronous-unwind-tables compiler option. This option is

      needed for platforms like 32-bit Intel where -fomit-frame-pointer

      is on by default and table generation is not. This doesn't yet

      add Windows support yet; only Linux, OSX, and some BSD are

      add Windows support yet; only Linux, OSX, and some BSDs are

      affected. Reported by 'cypherpunks'; fixes bug 11047; bugfix on

      0.2.5.2-alpha.

    - Avoid strange behavior if two threads hit failed assertions at the

      intermediate results in the same buffer, and generated junk

      outputs.) Reported by "cypherpunks". Fixes bug 11048; bugfix on

      0.2.5.2-alpha.

    - Fix a 64-to-32-conversion compiler warning in

      format_number_sigsafe(). Bugfix on 0.2.5.2-alpha; patch from Nick

      Hopper.

    - Fix a compiler warning in format_number_sigsafe(). Bugfix on

      0.2.5.2-alpha; patch from Nick Hopper.

  o Removed code:

    - Remove all remaining code related to version-0 hidden service

      the rest of bug 10841.

  o Documentation:

    - Explain that SocksPolicy, DirPolicy, and their allies don't take

      port arguments. Fixes ticket 11108.

    - Fix the max client name length in the manpage's description of

      HiddenServiceAuthorizeClient description: it should have been 16,

      not 19. Fixes bug 11118; bugfix on 0.2.1.6-alpha.

    - Document in the manpage that "KBytes" may also be written as

      "kilobytes" or "KB", that "Kbits" may also be written as

      "kilobits", and so forth. Closes ticket 9222.

    - Explain that SocksPolicy, DirPolicy, and similar options don't

      take port arguments. Fixes ticket 11108.

    - Fix the manpage's description of HiddenServiceAuthorizeClient

      description: it should have given the maximum client name length

      as 16, not 19. Fixes bug 11118; bugfix on 0.2.1.6-alpha.

    - Fix a comment about the rend_server_descriptor_t.protocols field

      to more accurately describe its range. Also, make that field

      unsigned, to more accurately reflect its usage. Fixes bug 9099;

      bugfix on 0.2.1.5-alpha.

    - Document in the manpage that "KBytes" may also be written as

      "kilobytes" or "KB", that "Kbits" may also be written as

      "kilobits", and so forth. Closes ticket 9222.

  o Code simplifications and refactoring:

    - Get rid of router->address, since in all cases it was just the