Tor: defend against a form of network surveillance that threatens personal freedom and privacy>>Tor 0.2.2.32 is released

Tor 0.2.2.32 is released:

The Tor 0.2.2 release series is dedicated to the memory of Andreas

Pfitzmann (1958-2010), a pioneer in anonymity and privacy research,

a founder of the PETS community, a leader in our field, a mentor,

and a friend. He left us with these words: "I had the possibility

to contribute to this world that is not as it should be. I hope I

could help in some areas to make the world a better place, and that

I could also encourage other people to be engaged in improving the

world. Please, stay engaged. This world needs you, your love, your

initiative -- now I cannot be part of that anymore."

Tor 0.2.2.32, the first stable release in the 0.2.2 branch, is finally

ready. More than two years in the making, this release features improved

client performance and hidden service reliability, better compatibility

for Android, correct behavior for bridges that listen on more than

one address, more extensible and flexible directory object handling,

better reporting of network statistics, improved code security, and

many many other features and bugfixes.

https://www.torproject.org/download/download

Changes in version 0.2.2.32 - 2011-08-27

Major features (client performance):

• When choosing which cells to relay first, relays now favor circuits
  
  that have been quiet recently, to provide lower latency for
  
  low-volume circuits. By default, relays enable or disable this
  
  feature based on a setting in the consensus. They can override
  
  this default by using the new "CircuitPriorityHalflife" config
  
  option. Design and code by Ian Goldberg, Can Tang, and Chris
  
  Alexander.


• Directory authorities now compute consensus weightings that instruct
  
  clients how to weight relays flagged as Guard, Exit, Guard+Exit,
  
  and no flag. Clients use these weightings to distribute network load
  
  more evenly across these different relay types. The weightings are
  
  in the consensus so we can change them globally in the future. Extra
  
  thanks to "outofwords" for finding some nasty security bugs in
  
  the first implementation of this feature.

Major features (client performance, circuit build timeout):

• Tor now tracks how long it takes to build client-side circuits
  
  over time, and adapts its timeout to local network performance.
  
  Since a circuit that takes a long time to build will also provide
  
  bad performance, we get significant latency improvements by
  
  discarding the slowest 20% of circuits. Specifically, Tor creates
  
  circuits more aggressively than usual until it has enough data
  
  points for a good timeout estimate. Implements proposal 151.


• Circuit build timeout constants can be controlled by consensus
  
  parameters. We set good defaults for these parameters based on
  
  experimentation on broadband and simulated high-latency links.


• Circuit build time learning can be disabled via consensus parameter
  
  or by the client via a LearnCircuitBuildTimeout config option. We
  
  also automatically disable circuit build time calculation if either
  
  AuthoritativeDirectory is set, or if we fail to write our state
  
  file. Implements ticket 1296.

Major features (relays use their capacity better):

• Set SO_REUSEADDR socket option on all sockets, not just
  
  listeners. This should help busy exit nodes avoid running out of
  
  useable ports just because all the ports have been used in the
  
  near past. Resolves issue 2850.


• Relays now save observed peak bandwidth throughput rates to their
  
  state file (along with total usage, which was already saved),
  
  so that they can determine their correct estimated bandwidth on
  
  restart. Resolves bug 1863, where Tor relays would reset their
  
  estimated bandwidth to 0 after restarting.


• Lower the maximum weighted-fractional-uptime cutoff to 98%. This
  
  should give us approximately 40-50% more Guard-flagged nodes,
  
  improving the anonymity the Tor network can provide and also
  
  decreasing the dropoff in throughput that relays experience when
  
  they first get the Guard flag.


• Directory authorities now take changes in router IP address and
  
  ORPort into account when determining router stability. Previously,
  
  if a router changed its IP or ORPort, the authorities would not
  
  treat it as having any downtime for the purposes of stability
  
  calculation, whereas clients would experience downtime since the
  
  change would take a while to propagate to them. Resolves issue 1035.


• New AccelName and AccelDir options add support for dynamic OpenSSL
  
  hardware crypto acceleration engines.

Major features (relays control their load better):

• Exit relays now try harder to block exit attempts from unknown
  
  relays, to make it harder for people to use them as one-hop proxies
  
  a la tortunnel. Controlled by the refuseunknownexits consensus
  
  parameter (currently enabled), or you can override it on your
  
  relay with the RefuseUnknownExits torrc option. Resolves bug 1751;
  
  based on a variant of proposal 163.


• Add separate per-conn write limiting to go with the per-conn read
  
  limiting. We added a global write limit in Tor 0.1.2.5-alpha,
  
  but never per-conn write limits.


• New consensus params "bwconnrate" and "bwconnburst" to let us
  
  rate-limit client connections as they enter the network. It's
  
  controlled in the consensus so we can turn it on and off for
  
  experiments. It's starting out off. Based on proposal 163.

Major features (controllers):

• Export GeoIP information on bridge usage to controllers even if we
  
  have not yet been running for 24 hours. Now Vidalia bridge operators
  
  can get more accurate and immediate feedback about their
  
  contributions to the network.


• Add an __OwningControllerProcess configuration option and a
  
  TAKEOWNERSHIP control-port command. Now a Tor controller can ensure
  
  that when it exits, Tor will shut down. Implements feature 3049.

Major features (directory authorities):

• Directory authorities now create, vote on, and serve multiple
  
  parallel formats of directory data as part of their voting process.
  
  Partially implements Proposal 162: "Publish the consensus in
  
  multiple flavors".


• Directory authorities now agree on and publish small summaries
  
  of router information that clients can use in place of regular
  
  server descriptors. This transition will allow Tor 0.2.3 clients
  
  to use far less bandwidth for downloading information about the
  
  network. Begins the implementation of Proposal 158: "Clients
  
  download consensus + microdescriptors".


• The directory voting system is now extensible to use multiple hash
  
  algorithms for signatures and resource selection. Newer formats
  
  are signed with SHA256, with a possibility for moving to a better
  
  hash algorithm in the future.


• Directory authorities can now vote on arbitary integer values as
  
  part of the consensus process. This is designed to help set
  
  network-wide parameters. Implements proposal 167.

Major features and bugfixes (node selection):

• Revise and reconcile the meaning of the ExitNodes, EntryNodes,
  
  ExcludeEntryNodes, ExcludeExitNodes, ExcludeNodes, and Strict*Nodes
  
  options. Previously, we had been ambiguous in describing what
  
  counted as an "exit" node, and what operations exactly "StrictNodes
  
  0" would permit. This created confusion when people saw nodes built
  
  through unexpected circuits, and made it hard to tell real bugs from
  
  surprises. Now the intended behavior is:

• "Exit", in the context of ExitNodes and ExcludeExitNodes, means
  
  a node that delivers user traffic outside the Tor network.


• "Entry", in the context of EntryNodes, means a node used as the
  
  first hop of a multihop circuit. It doesn't include direct
  
  connections to directory servers.


• "ExcludeNodes" applies to all nodes.


• "StrictNodes" changes the behavior of ExcludeNodes only. When
  
  StrictNodes is set, Tor should avoid all nodes listed in
  
  ExcludeNodes, even when it will make user requests fail. When
  
  StrictNodes is *not* set, then Tor should follow ExcludeNodes
  
  whenever it can, except when it must use an excluded node to
  
  perform self-tests, connect to a hidden service, provide a
  
  hidden service, fulfill a .exit request, upload directory
  
  information, or fetch directory information.

Collectively, the changes to implement the behavior fix bug 1090.

If EntryNodes, ExitNodes, ExcludeNodes, or ExcludeExitNodes

change during a config reload, mark and discard all our origin

circuits. This fix should address edge cases where we change the

config options and but then choose a circuit that we created before

the change.

Make EntryNodes config option much more aggressive even when

StrictNodes is not set. Before it would prepend your requested

entrynodes to your list of guard nodes, but feel free to use others

after that. Now it chooses only from your EntryNodes if any of

those are available, and only falls back to others if a) they're

all down and b) StrictNodes is not set.

Now we refresh your entry guards from EntryNodes at each consensus

fetch -- rather than just at startup and then they slowly rot as

the network changes.

Add support for the country code "{??}" in torrc options like

ExcludeNodes, to indicate all routers of unknown country. Closes

bug 1094.

ExcludeNodes now takes precedence over EntryNodes and ExitNodes: if

a node is listed in both, it's treated as excluded.

ExcludeNodes now applies to directory nodes -- as a preference if

StrictNodes is 0, or an absolute requirement if StrictNodes is 1.

Don't exclude all the directory authorities and set StrictNodes to 1

unless you really want your Tor to break.

ExcludeNodes and ExcludeExitNodes now override exit enclaving.

ExcludeExitNodes now overrides .exit requests.

We don't use bridges listed in ExcludeNodes.

When StrictNodes is 1:

• We now apply ExcludeNodes to hidden service introduction points
  
  and to rendezvous points selected by hidden service users. This
  
  can make your hidden service less reliable: use it with caution!


• If we have used ExcludeNodes on ourself, do not try relay
  
  reachability self-tests.


• If we have excluded all the directory authorities, we will not
  
  even try to upload our descriptor if we're a relay.


• Do not honor .exit requests to an excluded node.

When the set of permitted nodes changes, we now remove any mappings

introduced via TrackExitHosts to now-excluded nodes. Bugfix on

0.1.0.1-rc.

We never cannibalize a circuit that had excluded nodes on it, even

if StrictNodes is 0. Bugfix on 0.1.0.1-rc.

Improve log messages related to excluded nodes.

Major features (misc):

• Numerous changes, bugfixes, and workarounds from Nathan Freitas
  
  to help Tor build correctly for Android phones.


• The options SocksPort, ControlPort, and so on now all accept a
  
  value "auto" that opens a socket on an OS-selected port. A
  
  new ControlPortWriteToFile option tells Tor to write its
  
  actual control port or ports to a chosen file. If the option
  
  ControlPortFileGroupReadable is set, the file is created as
  
  group-readable. Now users can run two Tor clients on the same
  
  system without needing to manually mess with parameters. Resolves
  
  part of ticket 3076.


• Tor now supports tunneling all of its outgoing connections over
  
  a SOCKS proxy, using the SOCKS4Proxy and/or SOCKS5Proxy
  
  configuration options. Code by Christopher Davis.

Code security improvements:

• Replace all potentially sensitive memory comparison operations
  
  with versions whose runtime does not depend on the data being
  
  compared. This will help resist a class of attacks where an
  
  adversary can use variations in timing information to learn
  
  sensitive data. Fix for one case of bug 3122. (Safe memcmp
  
  implementation by Robert Ransom based partially on code by DJB.)


• Enable Address Space Layout Randomization (ASLR) and Data Execution
  
  Prevention (DEP) by default on Windows to make it harder for
  
  attackers to exploit vulnerabilities. Patch from John Brooks.


• New "--enable-gcc-hardening" ./configure flag (off by default)
  
  to turn on gcc compile time hardening options. It ensures
  
  that signed ints have defined behavior (-fwrapv), enables
  
  -D_FORTIFY_SOURCE=2 (requiring -O2), adds stack smashing protection
  
  with canaries (-fstack-protector-all), turns on ASLR protection if
  
  supported by the kernel (-fPIE, -pie), and adds additional security
  
  related warnings. Verified to work on Mac OS X and Debian Lenny.


• New "--enable-linker-hardening" ./configure flag (off by default)
  
  to turn on ELF specific hardening features (relro, now). This does
  
  not work with Mac OS X or any other non-ELF binary format.


• Always search the Windows system directory for system DLLs, and
  
  nowhere else. Bugfix on 0.1.1.23; fixes bug 1954.


• New DisableAllSwap option. If set to 1, Tor will attempt to lock all
  
  current and future memory pages via mlockall(). On supported
  
  platforms (modern Linux and probably BSD but not Windows or OS X),
  
  this should effectively disable any and all attempts to page out
  
  memory. This option requires that you start your Tor as root --
  
  if you use DisableAllSwap, please consider using the User option
  
  to properly reduce the privileges of your Tor.

Major bugfixes (crashes):

• Fix crash bug on platforms where gmtime and localtime can return
  
  NULL. Windows 7 users were running into this one. Fixes part of bug
  
  2077. Bugfix on all versions of Tor. Found by boboper.


• Introduce minimum/maximum values that clients will believe
  
  from the consensus. Now we'll have a better chance to avoid crashes
  
  or worse when a consensus param has a weird value.


• Fix a rare crash bug that could occur when a client was configured
  
  with a large number of bridges. Fixes bug 2629; bugfix on
  
  0.2.1.2-alpha. Bugfix by trac user "shitlei".


• Do not crash when our configuration file becomes unreadable, for
  
  example due to a permissions change, between when we start up
  
  and when a controller calls SAVECONF. Fixes bug 3135; bugfix
  
  on 0.0.9pre6.


• If we're in the pathological case where there's no exit bandwidth
  
  but there is non-exit bandwidth, or no guard bandwidth but there
  
  is non-guard bandwidth, don't crash during path selection. Bugfix
  
  on 0.2.0.3-alpha.


• Fix a crash bug when trying to initialize the evdns module in
  
  Libevent 2. Bugfix on 0.2.1.16-rc.

Major bugfixes (stability):

• Fix an assert in parsing router descriptors containing IPv6
  
  addresses. This one took down the directory authorities when
  
  somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.


• Fix an uncommon assertion failure when running with DNSPort under
  
  heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.


• Treat an unset $HOME like an empty $HOME rather than triggering an
  
  assert. Bugfix on 0.0.8pre1; fixes bug 1522.


• More gracefully handle corrupt state files, removing asserts
  
  in favor of saving a backup and resetting state.


• Instead of giving an assertion failure on an internal mismatch
  
  on estimated freelist size, just log a BUG warning and try later.
  
  Mitigates but does not fix bug 1125.


• Fix an assert that got triggered when using the TestingTorNetwork
  
  configuration option and then issuing a GETINFO config-text control
  
  command. Fixes bug 2250; bugfix on 0.2.1.2-alpha.


• If the cached cert file is unparseable, warn but don't exit.

Privacy fixes (relays/bridges):

• Don't list Windows capabilities in relay descriptors. We never made
  
  use of them, and maybe it's a bad idea to publish them. Bugfix
  
  on 0.1.1.8-alpha.


• If the Nickname configuration option isn't given, Tor would pick a
  
  nickname based on the local hostname as the nickname for a relay.
  
  Because nicknames are not very important in today's Tor and the
  
  "Unnamed" nickname has been implemented, this is now problematic
  
  behavior: It leaks information about the hostname without being
  
  useful at all. Fixes bug 2979; bugfix on 0.1.2.2-alpha, which
  
  introduced the Unnamed nickname. Reported by tagnaq.


• Maintain separate TLS contexts and certificates for incoming and
  
  outgoing connections in bridge relays. Previously we would use the
  
  same TLS contexts and certs for incoming and outgoing connections.
  
  Bugfix on 0.2.0.3-alpha; addresses bug 988.


• Maintain separate identity keys for incoming and outgoing TLS
  
  contexts in bridge relays. Previously we would use the same
  
  identity keys for incoming and outgoing TLS contexts. Bugfix on
  
  0.2.0.3-alpha; addresses the other half of bug 988.


• Make the bridge directory authority refuse to answer directory
  
  requests for "all descriptors". It used to include bridge
  
  descriptors in its answer, which was a major information leak.
  
  Found by "piebeer". Bugfix on 0.2.0.3-alpha.

Privacy fixes (clients):

• When receiving a hidden service descriptor, check that it is for
  
  the hidden service we wanted. Previously, Tor would store any
  
  hidden service descriptors that a directory gave it, whether it
  
  wanted them or not. This wouldn't have let an attacker impersonate
  
  a hidden service, but it did let directories pre-seed a client
  
  with descriptors that it didn't want. Bugfix on 0.0.6.


• Start the process of disabling ".exit" address notation, since it
  
  can be used for a variety of esoteric application-level attacks
  
  on users. To reenable it, set "AllowDotExit 1" in your torrc. Fix
  
  on 0.0.9rc5.


• Reject attempts at the client side to open connections to private
  
  IP addresses (like 127.0.0.1, 10.0.0.1, and so on) with
  
  a randomly chosen exit node. Attempts to do so are always
  
  ill-defined, generally prevented by exit policies, and usually
  
  in error. This will also help to detect loops in transparent
  
  proxy configurations. You can disable this feature by setting
  
  "ClientRejectInternalAddresses 0" in your torrc.


• Log a notice when we get a new control connection. Now it's easier
  
  for security-conscious users to recognize when a local application
  
  is knocking on their controller door. Suggested by bug 1196.

Privacy fixes (newnym):

• Avoid linkability based on cached hidden service descriptors: forget
  
  all hidden service descriptors cached as a client when processing a
  
  SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.


• On SIGHUP, do not clear out all TrackHostExits mappings, client
  
  DNS cache entries, and virtual address mappings: that's what
  
  NEWNYM is for. Fixes bug 1345; bugfix on 0.1.0.1-rc.


• Don't attach new streams to old rendezvous circuits after SIGNAL
  
  NEWNYM. Previously, we would keep using an existing rendezvous
  
  circuit if it remained open (i.e. if it were kept open by a
  
  long-lived stream, or if a new stream were attached to it before
  
  Tor could notice that it was old and no longer in use). Bugfix on
  
  0.1.1.15-rc; fixes bug 3375.

Major bugfixes (relay bandwidth accounting):

• Fix a bug that could break accounting on 64-bit systems with large
  
  time_t values, making them hibernate for impossibly long intervals.
  
  Fixes bug 2146. Bugfix on 0.0.9pre6; fix by boboper.


• Fix a bug in bandwidth accounting that could make us use twice
  
  the intended bandwidth when our interval start changes due to
  
  daylight saving time. Now we tolerate skew in stored vs computed
  
  interval starts: if the start of the period changes by no more than
  
  50% of the period's duration, we remember bytes that we transferred
  
  in the old period. Fixes bug 1511; bugfix on 0.0.9pre5.

Major bugfixes (bridges):

• Bridges now use "reject *:*" as their default exit policy. Bugfix
  
  on 0.2.0.3-alpha. Fixes bug 1113.


• If you configure your bridge with a known identity fingerprint,
  
  and the bridge authority is unreachable (as it is in at least
  
  one country now), fall back to directly requesting the descriptor
  
  from the bridge. Finishes the feature started in 0.2.0.10-alpha;
  
  closes bug 1138.


• Fix a bug where bridge users who configure the non-canonical
  
  address of a bridge automatically switch to its canonical
  
  address. If a bridge listens at more than one address, it
  
  should be able to advertise those addresses independently and
  
  any non-blocked addresses should continue to work. Bugfix on Tor
  
  0.2.0.3-alpha. Fixes bug 2510.


• If you configure Tor to use bridge A, and then quit and
  
  configure Tor to use bridge B instead (or if you change Tor
  
  to use bridge B via the controller), it would happily continue
  
  to use bridge A if it's still reachable. While this behavior is
  
  a feature if your goal is connectivity, in some scenarios it's a
  
  dangerous bug. Bugfix on Tor 0.2.0.1-alpha; fixes bug 2511.


• When the controller configures a new bridge, don't wait 10 to 60
  
  seconds before trying to fetch its descriptor. Bugfix on
  
  0.2.0.3-alpha; fixes bug 3198 (suggested by 2355).

Major bugfixes (directory authorities):

• Many relays have been falling out of the consensus lately because
  
  not enough authorities know about their descriptor for them to get
  
  a majority of votes. When we deprecated the v2 directory protocol,
  
  we got rid of the only way that v3 authorities can hear from each
  
  other about other descriptors. Now authorities examine every v3
  
  vote for new descriptors, and fetch them from that authority. Bugfix
  
  on 0.2.1.23.


• Authorities could be tricked into giving out the Exit flag to relays
  
  that didn't allow exiting to any ports. This bug could screw
  
  with load balancing and stats. Bugfix on 0.1.1.6-alpha; fixes bug
  
  1238. Bug discovered by Martin Kowalczyk.


• If all authorities restart at once right before a consensus vote,
  
  nobody will vote about "Running", and clients will get a consensus
  
  with no usable relays. Instead, authorities refuse to build a
  
  consensus if this happens. Bugfix on 0.2.0.10-alpha; fixes bug 1066.

Major bugfixes (stream-level fairness):

• When receiving a circuit-level SENDME for a blocked circuit, try
  
  to package cells fairly from all the streams that had previously
  
  been blocked on that circuit. Previously, we had started with the
  
  oldest stream, and allowed each stream to potentially exhaust
  
  the circuit's package window. This gave older streams on any
  
  given circuit priority over newer ones. Fixes bug 1937. Detected
  
  originally by Camilo Viecco. This bug was introduced before the
  
  first Tor release, in svn commit r152: it is the new winner of
  
  the longest-lived bug prize.


• Fix a stream fairness bug that would cause newer streams on a given
  
  circuit to get preference when reading bytes from the origin or
  
  destination. Fixes bug 2210. Fix by Mashael AlSabah. This bug was
  
  introduced before the first Tor release, in svn revision r152.


• When the exit relay got a circuit-level sendme cell, it started
  
  reading on the exit streams, even if had 500 cells queued in the
  
  circuit queue already, so the circuit queue just grew and grew in
  
  some cases. We fix this by not re-enabling reading on receipt of a
  
  sendme cell when the cell queue is blocked. Fixes bug 1653. Bugfix
  
  on 0.2.0.1-alpha. Detected by Mashael AlSabah. Original patch by
  
  "yetonetime".


• Newly created streams were allowed to read cells onto circuits,
  
  even if the circuit's cell queue was blocked and waiting to drain.
  
  This created potential unfairness, as older streams would be
  
  blocked, but newer streams would gladly fill the queue completely.
  
  We add code to detect this situation and prevent any stream from
  
  getting more than one free cell. Bugfix on 0.2.0.1-alpha. Partially
  
  fixes bug 1298.

Major bugfixes (hidden services):

• Apply circuit timeouts to opened hidden-service-related circuits
  
  based on the correct start time. Previously, we would apply the
  
  circuit build timeout based on time since the circuit's creation;
  
  it was supposed to be applied based on time since the circuit
  
  entered its current state. Bugfix on 0.0.6; fixes part of bug 1297.


• Improve hidden service robustness: When we find that we have
  
  extended a hidden service's introduction circuit to a relay not
  
  listed as an introduction point in the HS descriptor we currently
  
  have, retry with an introduction point from the current
  
  descriptor. Previously we would just give up. Fixes bugs 1024 and
  
  1930; bugfix on 0.2.0.10-alpha.


• Directory authorities now use data collected from their own
  
  uptime observations when choosing whether to assign the HSDir flag
  
  to relays, instead of trusting the uptime value the relay reports in
  
  its descriptor. This change helps prevent an attack where a small
  
  set of nodes with frequently-changing identity keys can blackhole
  
  a hidden service. (Only authorities need upgrade; others will be
  
  fine once they do.) Bugfix on 0.2.0.10-alpha; fixes bug 2709.


• Stop assigning the HSDir flag to relays that disable their
  
  DirPort (and thus will refuse to answer directory requests). This
  
  fix should dramatically improve the reachability of hidden services:
  
  hidden services and hidden service clients pick six HSDir relays
  
  to store and retrieve the hidden service descriptor, and currently
  
  about half of the HSDir relays will refuse to work. Bugfix on
  
  0.2.0.10-alpha; fixes part of bug 1693.

Major bugfixes (misc):

• Clients now stop trying to use an exit node associated with a given
  
  destination by TrackHostExits if they fail to reach that exit node.
  
  Fixes bug 2999. Bugfix on 0.2.0.20-rc.


• Fix a regression that caused Tor to rebind its ports if it receives
  
  SIGHUP while hibernating. Bugfix in 0.1.1.6-alpha; closes bug 919.

Remove an extra pair of quotation marks around the error

message in control-port STATUS_GENERAL BUG events. Bugfix on

0.1.2.6-alpha; fixes bug 3732.

Minor features (relays):

• Ensure that no empty [dirreq-](read|write)-history lines are added
  
  to an extrainfo document. Implements ticket 2497.


• When bandwidth accounting is enabled, be more generous with how
  
  much bandwidth we'll use up before entering "soft hibernation".
  
  Previously, we'd refuse new connections and circuits once we'd
  
  used up 95% of our allotment. Now, we use up 95% of our allotment,
  
  AND make sure that we have no more than 500MB (or 3 hours of
  
  expected traffic, whichever is lower) remaining before we enter
  
  soft hibernation.


• Relays now log the reason for publishing a new relay descriptor,
  
  so we have a better chance of hunting down instances of bug 1810.
  
  Resolves ticket 3252.


• Log a little more clearly about the times at which we're no longer
  
  accepting new connections (e.g. due to hibernating). Resolves
  
  bug 2181.


• When AllowSingleHopExits is set, print a warning to explain to the
  
  relay operator why most clients are avoiding her relay.


• Send END_STREAM_REASON_NOROUTE in response to EHOSTUNREACH errors.
  
  Clients before 0.2.1.27 didn't handle NOROUTE correctly, but such
  
  clients are already deprecated because of security bugs.

Minor features (network statistics):

• Directory mirrors that set "DirReqStatistics 1" write statistics
  
  about directory requests to disk every 24 hours. As compared to the
  
  "--enable-geoip-stats" ./configure flag in 0.2.1.x, there are a few
  
  improvements: 1) stats are written to disk exactly every 24 hours;
  
  2) estimated shares of v2 and v3 requests are determined as mean
  
  values, not at the end of a measurement period; 3) unresolved
  
  requests are listed with country code '??'; 4) directories also
  
  measure download times.


• Exit nodes that set "ExitPortStatistics 1" write statistics on the
  
  number of exit streams and transferred bytes per port to disk every
  
  24 hours.


• Relays that set "CellStatistics 1" write statistics on how long
  
  cells spend in their circuit queues to disk every 24 hours.


• Entry nodes that set "EntryStatistics 1" write statistics on the
  
  rough number and origins of connecting clients to disk every 24
  
  hours.


• Relays that write any of the above statistics to disk and set
  
  "ExtraInfoStatistics 1" include the past 24 hours of statistics in
  
  their extra-info documents. Implements proposal 166.

Minor features (GeoIP and statistics):

• Provide a log message stating which geoip file we're parsing
  
  instead of just stating that we're parsing the geoip file.
  
  Implements ticket 2432.


• Make sure every relay writes a state file at least every 12 hours.
  
  Previously, a relay could go for weeks without writing its state
  
  file, and on a crash could lose its bandwidth history, capacity
  
  estimates, client country statistics, and so on. Addresses bug 3012.


• Relays report the number of bytes spent on answering directory
  
  requests in extra-info descriptors similar to {read,write}-history.
  
  Implements enhancement 1790.


• Report only the top 10 ports in exit-port stats in order not to
  
  exceed the maximum extra-info descriptor length of 50 KB. Implements
  
  task 2196.


• If writing the state file to disk fails, wait up to an hour before
  
  retrying again, rather than trying again each second. Fixes bug
  
  2346; bugfix on Tor 0.1.1.3-alpha.


• Delay geoip stats collection by bridges for 6 hours, not 2 hours,
  
  when we switch from being a public relay to a bridge. Otherwise
  
  there will still be clients that see the relay in their consensus,
  
  and the stats will end up wrong. Bugfix on 0.2.1.15-rc; fixes
  
  bug 932.


• Update to the August 2 2011 Maxmind GeoLite Country database.

Minor features (clients):

• When expiring circuits, use microsecond timers rather than
  
  one-second timers. This can avoid an unpleasant situation where a
  
  circuit is launched near the end of one second and expired right
  
  near the beginning of the next, and prevent fluctuations in circuit
  
  timeout values.


• If we've configured EntryNodes and our network goes away and/or all
  
  our entrynodes get marked down, optimistically retry them all when
  
  a new socks application request appears. Fixes bug 1882.


• Always perform router selections using weighted relay bandwidth,
  
  even if we don't need a high capacity circuit at the time. Non-fast
  
  circuits now only differ from fast ones in that they can use relays
  
  not marked with the Fast flag. This "feature" could turn out to
  
  be a horrible bug; we should investigate more before it goes into
  
  a stable release.


• When we run out of directory information such that we can't build
  
  circuits, but then get enough that we can build circuits, log when
  
  we actually construct a circuit, so the user has a better chance of
  
  knowing what's going on. Fixes bug 1362.


• Log SSL state transitions at debug level during handshake, and
  
  include SSL states in error messages. This may help debug future
  
  SSL handshake issues.

Minor features (directory authorities):

• When a router changes IP address or port, authorities now launch
  
  a new reachability test for it. Implements ticket 1899.


• Directory authorities now reject relays running any versions of
  
  Tor between 0.2.1.3-alpha and 0.2.1.18 inclusive; they have
  
  known bugs that keep RELAY_EARLY cells from working on rendezvous
  
  circuits. Followup to fix for bug 2081.


• Directory authorities now reject relays running any version of Tor
  
  older than 0.2.0.26-rc. That version is the earliest that fetches
  
  current directory information correctly. Fixes bug 2156.


• Directory authorities now do an immediate reachability check as soon
  
  as they hear about a new relay. This change should slightly reduce
  
  the time between setting up a relay and getting listed as running
  
  in the consensus. It should also improve the time between setting
  
  up a bridge and seeing use by bridge users.


• Directory authorities no longer launch a TLS connection to every
  
  relay as they startup. Now that we have 2k+ descriptors cached,
  
  the resulting network hiccup is becoming a burden. Besides,
  
  authorities already avoid voting about Running for the first half
  
  hour of their uptime.


• Directory authorities now log the source of a rejected POSTed v3
  
  networkstatus vote, so we can track failures better.


• Backport code from 0.2.3.x that allows directory authorities to
  
  clean their microdescriptor caches. Needed to resolve bug 2230.

Minor features (hidden services):

• Use computed circuit-build timeouts to decide when to launch
  
  parallel introduction circuits for hidden services. (Previously,
  
  we would retry after 15 seconds.)


• Don't allow v0 hidden service authorities to act as clients.
  
  Required by fix for bug 3000.


• Ignore SIGNAL NEWNYM commands on relay-only Tor instances. Required
  
  by fix for bug 3000.


• Make hidden services work better in private Tor networks by not
  
  requiring any uptime to join the hidden service descriptor
  
  DHT. Implements ticket 2088.


• Log (at info level) when purging pieces of hidden-service-client
  
  state because of SIGNAL NEWNYM.

Minor features (controller interface):

• New "GETINFO net/listeners/(type)" controller command to return
  
  a list of addresses and ports that are bound for listeners for a
  
  given connection type. This is useful when the user has configured
  
  "SocksPort auto" and the controller needs to know which port got
  
  chosen. Resolves another part of ticket 3076.


• Have the controller interface give a more useful message than
  
  "Internal Error" in response to failed GETINFO requests.


• Add a TIMEOUT_RATE keyword to the BUILDTIMEOUT_SET control port
  
  event, to give information on the current rate of circuit timeouts
  
  over our stored history.


• The 'EXTENDCIRCUIT' control port command can now be used with
  
  a circ id of 0 and no path. This feature will cause Tor to build
  
  a new 'fast' general purpose circuit using its own path selection
  
  algorithms.


• Added a BUILDTIMEOUT_SET controller event to describe changes
  
  to the circuit build timeout.


• New controller command "getinfo config-text". It returns the
  
  contents that Tor would write if you send it a SAVECONF command,
  
  so the controller can write the file to disk itself.

Minor features (controller protocol):

• Add a new ControlSocketsGroupWritable configuration option: when
  
  it is turned on, ControlSockets are group-writeable by the default
  
  group of the current user. Patch by Jérémy Bobbio; implements
  
  ticket 2972.


• Tor now refuses to create a ControlSocket in a directory that is
  
  world-readable (or group-readable if ControlSocketsGroupWritable
  
  is 0). This is necessary because some operating systems do not
  
  enforce permissions on an AF_UNIX sockets. Permissions on the
  
  directory holding the socket, however, seems to work everywhere.


• Warn when CookieAuthFileGroupReadable is set but CookieAuthFile is
  
  not. This would lead to a cookie that is still not group readable.
  
  Closes bug 1843. Suggested by katmagic.


• Future-proof the controller protocol a bit by ignoring keyword
  
  arguments we do not recognize.

Minor features (more useful logging):

• Revise most log messages that refer to nodes by nickname to
  
  instead use the "$key=nickname at address" format. This should be
  
  more useful, especially since nicknames are less and less likely
  
  to be unique. Resolves ticket 3045.


• When an HTTPS proxy reports "403 Forbidden", we now explain
  
  what it means rather than calling it an unexpected status code.
  
  Closes bug 2503. Patch from Michael Yakubovich.


• Rate-limit a warning about failures to download v2 networkstatus
  
  documents. Resolves part of bug 1352.


• Rate-limit the "your application is giving Tor only an IP address"
  
  warning. Addresses bug 2000; bugfix on 0.0.8pre2.


• Rate-limit "Failed to hand off onionskin" warnings.


• When logging a rate-limited warning, we now mention how many messages
  
  got suppressed since the last warning.


• Make the formerly ugly "2 unknown, 7 missing key, 0 good, 0 bad,
  
  2 no signature, 4 required" messages about consensus signatures
  
  easier to read, and make sure they get logged at the same severity
  
  as the messages explaining which keys are which. Fixes bug 1290.


• Don't warn when we have a consensus that we can't verify because
  
  of missing certificates, unless those certificates are ones
  
  that we have been trying and failing to download. Fixes bug 1145.

Minor features (log domains):

• Add documentation for configuring logging at different severities in
  
  different log domains. We've had this feature since 0.2.1.1-alpha,
  
  but for some reason it never made it into the manpage. Fixes
  
  bug 2215.


• Make it simpler to specify "All log domains except for A and B".
  
  Previously you needed to say "[*,~A,~B]". Now you can just say
  
  "[~A,~B]".


• Add a "LogMessageDomains 1" option to include the domains of log
  
  messages along with the messages. Without this, there's no way
  
  to use log domains without reading the source or doing a lot
  
  of guessing.


• Add a new "Handshake" log domain for activities that happen
  
  during the TLS handshake.

Minor features (build process):

• Make compilation with clang possible when using
  
  "--enable-gcc-warnings" by removing two warning options that clang
  
  hasn't implemented yet and by fixing a few warnings. Resolves
  
  ticket 2696.


• Detect platforms that brokenly use a signed size_t, and refuse to
  
  build there. Found and analyzed by doorss and rransom.


• Fix a bunch of compile warnings revealed by mingw with gcc 4.5.
  
  Resolves bug 2314.


• Add support for statically linking zlib by specifying
  
  "--enable-static-zlib", to go with our support for statically
  
  linking openssl and libevent. Resolves bug 1358.


• Instead of adding the svn revision to the Tor version string, report
  
  the git commit (when we're building from a git checkout).


• Rename the "log.h" header to "torlog.h" so as to conflict with fewer
  
  system headers.


• New --digests command-line switch to output the digests of the
  
  source files Tor was built with.


• Generate our manpage and HTML documentation using Asciidoc. This
  
  change should make it easier to maintain the documentation, and
  
  produce nicer HTML. The build process fails if asciidoc cannot
  
  be found and building with asciidoc isn't disabled (via the
  
  "--disable-asciidoc" argument to ./configure. Skipping the manpage
  
  speeds up the build considerably.

Minor features (options / torrc):

• Warn when the same option is provided more than once in a torrc
  
  file, on the command line, or in a single SETCONF statement, and
  
  the option is one that only accepts a single line. Closes bug 1384.


• Warn when the user configures two HiddenServiceDir lines that point
  
  to the same directory. Bugfix on 0.0.6 (the version introducing
  
  HiddenServiceDir); fixes bug 3289.


• Add new "perconnbwrate" and "perconnbwburst" consensus params to
  
  do individual connection-level rate limiting of clients. The torrc
  
  config options with the same names trump the consensus params, if
  
  both are present. Replaces the old "bwconnrate" and "bwconnburst"
  
  consensus params which were broken from 0.2.2.7-alpha through
  
  0.2.2.14-alpha. Closes bug 1947.


• New config option "WarnUnsafeSocks 0" disables the warning that
  
  occurs whenever Tor receives a socks handshake using a version of
  
  the socks protocol that can only provide an IP address (rather
  
  than a hostname). Setups that do DNS locally over Tor are fine,
  
  and we shouldn't spam the logs in that case.


• New config option "CircuitStreamTimeout" to override our internal
  
  timeout schedule for how many seconds until we detach a stream from
  
  a circuit and try a new circuit. If your network is particularly
  
  slow, you might want to set this to a number like 60.


• New options for SafeLogging to allow scrubbing only log messages
  
  generated while acting as a relay. Specify "SafeLogging relay" if
  
  you want to ensure that only messages known to originate from
  
  client use of the Tor process will be logged unsafely.


• Time and memory units in the configuration file can now be set to
  
  fractional units. For example, "2.5 GB" is now a valid value for
  
  AccountingMax.


• Support line continuations in the torrc config file. If a line
  
  ends with a single backslash character, the newline is ignored, and
  
  the configuration value is treated as continuing on the next line.
  
  Resolves bug 1929.

Minor features (unit tests):

• Revise our unit tests to use the "tinytest" framework, so we
  
  can run tests in their own processes, have smarter setup/teardown
  
  code, and so on. The unit test code has moved to its own
  
  subdirectory, and has been split into multiple modules.


• Add a unit test for cross-platform directory-listing code.


• Add some forgotten return value checks during unit tests. Found
  
  by coverity.


• Use GetTempDir to find the proper temporary directory location on
  
  Windows when generating temporary files for the unit tests. Patch
  
  by Gisle Vanem.

Minor features (misc):

• The "torify" script now uses torsocks where available.


• Make Libevent log messages get delivered to controllers later,
  
  and not from inside the Libevent log handler. This prevents unsafe
  
  reentrant Libevent calls while still letting the log messages
  
  get through.


• Certain Tor clients (such as those behind check.torproject.org) may
  
  want to fetch the consensus in an extra early manner. To enable this
  
  a user may now set FetchDirInfoExtraEarly to 1. This also depends on
  
  setting FetchDirInfoEarly to 1. Previous behavior will stay the same
  
  as only certain clients who must have this information sooner should
  
  set this option.


• Expand homedirs passed to tor-checkkey. This should silence a
  
  coverity complaint about passing a user-supplied string into
  
  open() without checking it.


• Make sure to disable DirPort if running as a bridge. DirPorts aren't
  
  used on bridges, and it makes bridge scanning somewhat easier.


• Create the /var/run/tor directory on startup on OpenSUSE if it is
  
  not already created. Patch from Andreas Stieger. Fixes bug 2573.

Minor bugfixes (relays):

• When a relay decides that its DNS is too broken for it to serve
  
  as an exit server, it advertised itself as a non-exit, but
  
  continued to act as an exit. This could create accidental
  
  partitioning opportunities for users. Instead, if a relay is
  
  going to advertise reject *:* as its exit policy, it should
  
  really act with exit policy "reject *:*". Fixes bug 2366.
  
  Bugfix on Tor 0.1.2.5-alpha. Bugfix by user "postman" on trac.


• Publish a router descriptor even if generating an extra-info
  
  descriptor fails. Previously we would not publish a router
  
  descriptor without an extra-info descriptor; this can cause fast
  
  exit relays collecting exit-port statistics to drop from the
  
  consensus. Bugfix on 0.1.2.9-rc; fixes bug 2195.


• When we're trying to guess whether we know our IP address as
  
  a relay, we would log various ways that we failed to guess
  
  our address, but never log that we ended up guessing it
  
  successfully. Now add a log line to help confused and anxious
  
  relay operators. Bugfix on 0.1.2.1-alpha; fixes bug 1534.


• For bandwidth accounting, calculate our expected bandwidth rate
  
  based on the time during which we were active and not in
  
  soft-hibernation during the last interval. Previously, we were
  
  also considering the time spent in soft-hibernation. If this
  
  was a long time, we would wind up underestimating our bandwidth
  
  by a lot, and skewing our wakeup time towards the start of the
  
  accounting interval. Fixes bug 1789. Bugfix on 0.0.9pre5.


• Demote a confusing TLS warning that relay operators might get when
  
  someone tries to talk to their ORPort. It is not the operator's
  
  fault, nor can they do anything about it. Fixes bug 1364; bugfix
  
  on 0.2.0.14-alpha.


• Change "Application request when we're believed to be offline."
  
  notice to "Application request when we haven't used client
  
  functionality lately.", to clarify that it's not an error. Bugfix
  
  on 0.0.9.3; fixes bug 1222.

Minor bugfixes (bridges):

• When a client starts or stops using bridges, never use a circuit
  
  that was built before the configuration change. This behavior could
  
  put at risk a user who uses bridges to ensure that her traffic
  
  only goes to the chosen addresses. Bugfix on 0.2.0.3-alpha; fixes
  
  bug 3200.


• Do not reset the bridge descriptor download status every time we
  
  re-parse our configuration or get a configuration change. Fixes
  
  bug 3019; bugfix on 0.2.0.3-alpha.


• Users couldn't configure a regular relay to be their bridge. It
  
  didn't work because when Tor fetched the bridge descriptor, it found
  
  that it already had it, and didn't realize that the purpose of the
  
  descriptor had changed. Now we replace routers with a purpose other
  
  than bridge with bridge descriptors when fetching them. Bugfix on
  
  0.1.1.9-alpha. Fixes bug 1776.


• In the special case where you configure a public exit relay as your
  
  bridge, Tor would be willing to use that exit relay as the last
  
  hop in your circuit as well. Now we fail that circuit instead.
  
  Bugfix on 0.2.0.12-alpha. Fixes bug 2403. Reported by "piebeer".

Minor bugfixes (clients):

• We now ask the other side of a stream (the client or the exit)
  
  for more data on that stream when the amount of queued data on
  
  that stream dips low enough. Previously, we wouldn't ask the
  
  other side for more data until either it sent us more data (which
  
  it wasn't supposed to do if it had exhausted its window!) or we
  
  had completely flushed all our queued data. This flow control fix
  
  should improve throughput. Fixes bug 2756; bugfix on the earliest
  
  released versions of Tor (svn commit r152).


• When a client finds that an origin circuit has run out of 16-bit
  
  stream IDs, we now mark it as unusable for new streams. Previously,
  
  we would try to close the entire circuit. Bugfix on 0.0.6.


• Make it explicit that we don't cannibalize one-hop circuits. This
  
  happens in the wild, but doesn't turn out to be a problem because
  
  we fortunately don't use those circuits. Many thanks to outofwords
  
  for the initial analysis and to swissknife who confirmed that
  
  two-hop circuits are actually created.


• Resolve an edge case in path weighting that could make us misweight
  
  our relay selection. Fixes bug 1203; bugfix on 0.0.8rc1.


• Make the DNSPort option work with libevent 2.x. Don't alter the
  
  behaviour for libevent 1.x. Fixes bug 1143. Found by SwissTorExit.

Minor bugfixes (directory authorities):

• Make directory authorities more accurate at recording when
  
  relays that have failed several reachability tests became
  
  unreachable, so we can provide more accuracy at assigning Stable,
  
  Guard, HSDir, etc flags. Bugfix on 0.2.0.6-alpha. Resolves bug 2716.


• Directory authorities are now more robust to hops back in time
  
  when calculating router stability. Previously, if a run of uptime
  
  or downtime appeared to be negative, the calculation could give
  
  incorrect results. Bugfix on 0.2.0.6-alpha; noticed when fixing
  
  bug 1035.


• Directory authorities will now attempt to download consensuses
  
  if their own efforts to make a live consensus have failed. This
  
  change means authorities that restart will fetch a valid
  
  consensus, and it means authorities that didn't agree with the
  
  current consensus will still fetch and serve it if it has enough
  
  signatures. Bugfix on 0.2.0.9-alpha; fixes bug 1300.


• Never vote for a server as "Running" if we have a descriptor for
  
  it claiming to be hibernating, and that descriptor was published
  
  more recently than our last contact with the server. Bugfix on
  
  0.2.0.3-alpha; fixes bug 911.


• Directory authorities no longer change their opinion of, or vote on,
  
  whether a router is Running, unless they have themselves been
  
  online long enough to have some idea. Bugfix on 0.2.0.6-alpha.
  
  Fixes bug 1023.

Minor bugfixes (hidden services):

• Log malformed requests for rendezvous descriptors as protocol
  
  warnings, not warnings. Also, use a more informative log message
  
  in case someone sees it at log level warning without prior
  
  info-level messages. Fixes bug 2748; bugfix on 0.2.0.10-alpha.


• Accept hidden service descriptors if we think we might be a hidden
  
  service directory, regardless of what our consensus says. This
  
  helps robustness, since clients and hidden services can sometimes
  
  have a more up-to-date view of the network consensus than we do,
  
  and if they think that the directory authorities list us a HSDir,
  
  we might actually be one. Related to bug 2732; bugfix on
  
  0.2.0.10-alpha.


• Correct the warning displayed when a rendezvous descriptor exceeds
  
  the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
  
  John Brooks.


• Clients and hidden services now use HSDir-flagged relays for hidden
  
  service descriptor downloads and uploads even if the relays have no
  
  DirPort set and the client has disabled TunnelDirConns. This will
  
  eventually allow us to give the HSDir flag to relays with no
  
  DirPort. Fixes bug 2722; bugfix on 0.2.1.6-alpha.


• Only limit the lengths of single HS descriptors, even when multiple
  
  HS descriptors are published to an HSDir relay in a single POST
  
  operation. Fixes bug 2948; bugfix on 0.2.1.5-alpha. Found by hsdir.

Minor bugfixes (controllers):

• Allow GETINFO fingerprint to return a fingerprint even when
  
  we have not yet built a router descriptor. Fixes bug 3577;
  
  bugfix on 0.2.0.1-alpha.


• Send a SUCCEEDED stream event to the controller when a reverse
  
  resolve succeeded. Fixes bug 3536; bugfix on 0.0.8pre1. Issue
  
  discovered by katmagic.


• Remove a trailing asterisk from "exit-policy/default" in the
  
  output of the control port command "GETINFO info/names". Bugfix
  
  on 0.1.2.5-alpha.


• Make the SIGNAL DUMP controller command work on FreeBSD. Fixes bug
  
  2917. Bugfix on 0.1.1.1-alpha.


• When we restart our relay, we might get a successful connection
  
  from the outside before we've started our reachability tests,
  
  triggering a warning: "ORPort found reachable, but I have no
  
  routerinfo yet. Failing to inform controller of success." This
  
  bug was harmless unless Tor is running under a controller
  
  like Vidalia, in which case the controller would never get a
  
  REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
  
  fixes bug 1172.


• When a controller changes TrackHostExits, remove mappings for
  
  hosts that should no longer have their exits tracked. Bugfix on
  
  0.1.0.1-rc.


• When a controller changes VirtualAddrNetwork, remove any mappings
  
  for hosts that were automapped to the old network. Bugfix on
  
  0.1.1.19-rc.


• When a controller changes one of the AutomapHosts* options, remove
  
  any mappings for hosts that should no longer be automapped. Bugfix
  
  on 0.2.0.1-alpha.


• Fix an off-by-one error in calculating some controller command
  
  argument lengths. Fortunately, this mistake is harmless since
  
  the controller code does redundant NUL termination too. Found by
  
  boboper. Bugfix on 0.1.1.1-alpha.


• Fix a bug in the controller interface where "GETINFO ns/asdaskljkl"
  
  would return "551 Internal error" rather than "552 Unrecognized key
  
  ns/asdaskljkl". Bugfix on 0.1.2.3-alpha.


• Don't spam the controller with events when we have no file
  
  descriptors available. Bugfix on 0.2.1.5-alpha. (Rate-limiting
  
  for log messages was already solved from bug 748.)


• Emit a GUARD DROPPED controller event for a case we missed.


• Ensure DNS requests launched by "RESOLVE" commands from the
  
  controller respect the __LeaveStreamsUnattached setconf options. The
  
  same goes for requests launched via DNSPort or transparent
  
  proxying. Bugfix on 0.2.0.1-alpha; fixes bug 1525.

Minor bugfixes (config options):

• Tor used to limit HttpProxyAuthenticator values to 48 characters.
  
  Change the limit to 512 characters by removing base64 newlines.
  
  Fixes bug 2752. Fix by Michael Yakubovich.


• Complain if PublishServerDescriptor is given multiple arguments that
  
  include 0 or 1. This configuration will be rejected in the future.
  
  Bugfix on 0.2.0.1-alpha; closes bug 1107.


• Disallow BridgeRelay 1 and ORPort 0 at once in the configuration.
  
  Bugfix on 0.2.0.13-alpha; closes bug 928.

Minor bugfixes (log subsystem fixes):

• When unable to format an address as a string, report its value
  
  as "???" rather than reusing the last formatted address. Bugfix
  
  on 0.2.1.5-alpha.


• Be more consistent in our treatment of file system paths. "~" should
  
  get expanded to the user's home directory in the Log config option.
  
  Fixes bug 2971; bugfix on 0.2.0.1-alpha, which introduced the
  
  feature for the -f and --DataDirectory options.

Minor bugfixes (memory management):

• Don't stack-allocate the list of supplementary GIDs when we're
  
  about to log them. Stack-allocating NGROUPS_MAX gid_t elements
  
  could take up to 256K, which is way too much stack. Found by
  
  Coverity; CID #450. Bugfix on 0.2.1.7-alpha.


• Save a couple bytes in memory allocation every time we escape
  
  certain characters in a string. Patch from Florian Zumbiehl.

Minor bugfixes (protocol correctness):

• When checking for 1024-bit keys, check for 1024 bits, not 128
  
  bytes. This allows Tor to correctly discard keys of length 1017
  
  through 1023. Bugfix on 0.0.9pre5.


• Require that introduction point keys and onion handshake keys
  
  have a public exponent of 65537. Starts to fix bug 3207; bugfix
  
  on 0.2.0.10-alpha.


• Handle SOCKS messages longer than 128 bytes long correctly, rather
  
  than waiting forever for them to finish. Fixes bug 2330; bugfix
  
  on 0.2.0.16-alpha. Found by doorss.


• Never relay a cell for a circuit we have already destroyed.
  
  Between marking a circuit as closeable and finally closing it,
  
  it may have been possible for a few queued cells to get relayed,
  
  even though they would have been immediately dropped by the next
  
  OR in the circuit. Fixes bug 1184; bugfix on 0.2.0.1-alpha.


• Never queue a cell for a circuit that's already been marked
  
  for close.


• Fix a spec conformance issue: the network-status-version token
  
  must be the first token in a v3 consensus or vote. Discovered by
  
  "parakeep". Bugfix on 0.2.0.3-alpha.


• A networkstatus vote must contain exactly one signature. Spec
  
  conformance issue. Bugfix on 0.2.0.3-alpha.


• When asked about a DNS record type we don't support via a
  
  client DNSPort, reply with NOTIMPL rather than an empty
  
  reply. Patch by intrigeri. Fixes bug 3369; bugfix on 2.0.1-alpha.


• Make more fields in the controller protocol case-insensitive, since
  
  control-spec.txt said they were.

Minor bugfixes (log messages):

• Fix a log message that said "bits" while displaying a value in
  
  bytes. Found by wanoskarnet. Fixes bug 3318; bugfix on
  
  0.2.0.1-alpha.


• Downgrade "no current certificates known for authority" message from
  
  Notice to Info. Fixes bug 2899; bugfix on 0.2.0.10-alpha.


• Correctly describe errors that occur when generating a TLS object.
  
  Previously we would attribute them to a failure while generating a
  
  TLS context. Patch by Robert Ransom. Bugfix on 0.1.0.4-rc; fixes
  
  bug 1994.


• Fix an instance where a Tor directory mirror might accidentally
  
  log the IP address of a misbehaving Tor client. Bugfix on
  
  0.1.0.1-rc.


• Stop logging at severity 'warn' when some other Tor client tries
  
  to establish a circuit with us using weak DH keys. It's a protocol
  
  violation, but that doesn't mean ordinary users need to hear about
  
  it. Fixes the bug part of bug 1114. Bugfix on 0.1.0.13.


• If your relay can't keep up with the number of incoming create
  
  cells, it would log one warning per failure into your logs. Limit
  
  warnings to 1 per minute. Bugfix on 0.0.2pre10; fixes bug 1042.

Minor bugfixes (build fixes):

• Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
  
• When warning about missing zlib development packages during compile,
  
  give the correct package names. Bugfix on 0.2.0.1-alpha.


• Fix warnings that newer versions of autoconf produce during
  
  ./autogen.sh. These warnings appear to be harmless in our case,
  
  but they were extremely verbose. Fixes bug 2020.


• Squash a compile warning on OpenBSD. Reported by Tas; fixes
  
  bug 1848.

Minor bugfixes (portability):

• Write several files in text mode, on OSes that distinguish text
  
  mode from binary mode (namely, Windows). These files are:
  
  'buffer-stats', 'dirreq-stats', and 'entry-stats' on relays
  
  that collect those statistics; 'client_keys' and 'hostname' for
  
  hidden services that use authentication; and (in the tor-gencert
  
  utility) newly generated identity and signing keys. Previously,
  
  we wouldn't specify text mode or binary mode, leading to an
  
  assertion failure. Fixes bug 3607. Bugfix on 0.2.1.1-alpha (when
  
  the DirRecordUsageByCountry option which would have triggered
  
  the assertion failure was added), although this assertion failure
  
  would have occurred in tor-gencert on Windows in 0.2.0.1-alpha.


• Selectively disable deprecation warnings on OS X because Lion
  
  started deprecating the shipped copy of openssl. Fixes bug 3643.


• Use a wide type to hold sockets when built for 64-bit Windows.
  
  Fixes bug 3270.


• Fix an issue that prevented static linking of libevent on
  
  some platforms (notably Linux). Fixes bug 2698; bugfix on 0.2.1.23,
  
  where we introduced the "--with-static-libevent" configure option.


• Fix a bug with our locking implementation on Windows that couldn't
  
  correctly detect when a file was already locked. Fixes bug 2504,
  
  bugfix on 0.2.1.6-alpha.


• Build correctly on OSX with zlib 1.2.4 and higher with all warnings
  
  enabled.


• Fix IPv6-related connect() failures on some platforms (BSD, OS X).
  
  Bugfix on 0.2.0.3-alpha; fixes first part of bug 2660. Patch by
  
  "piebeer".

Minor bugfixes (code correctness):

• Always NUL-terminate the sun_path field of a sockaddr_un before
  
  passing it to the kernel. (Not a security issue: kernels are
  
  smart enough to reject bad sockaddr_uns.) Found by Coverity;
  
  CID #428. Bugfix on Tor 0.2.0.3-alpha.


• Make connection_printf_to_buf()'s behaviour sane. Its callers
  
  expect it to emit a CRLF iff the format string ends with CRLF;
  
  it actually emitted a CRLF iff (a) the format string ended with
  
  CRLF or (b) the resulting string was over 1023 characters long or
  
  (c) the format string did not end with CRLF *and* the resulting
  
  string was 1021 characters long or longer. Bugfix on 0.1.1.9-alpha;
  
  fixes part of bug 3407.


• Make send_control_event_impl()'s behaviour sane. Its callers
  
  expect it to always emit a CRLF at the end of the string; it
  
  might have emitted extra control characters as well. Bugfix on
  
  0.1.1.9-alpha; fixes another part of bug 3407.


• Make crypto_rand_int() check the value of its input correctly.
  
  Previously, it accepted values up to UINT_MAX, but could return a
  
  negative number if given a value above INT_MAX+1. Found by George
  
  Kadianakis. Fixes bug 3306; bugfix on 0.2.2pre14.


• Fix a potential null-pointer dereference while computing a
  
  consensus. Bugfix on tor-0.2.0.3-alpha, found with the help of
  
  clang's analyzer.


• If we fail to compute the identity digest of a v3 legacy keypair,
  
  warn, and don't use a buffer-full of junk instead. Bugfix on
  
  0.2.1.1-alpha; fixes bug 3106.


• Resolve an untriggerable issue in smartlist_string_num_isin(),
  
  where if the function had ever in the future been used to check
  
  for the presence of a too-large number, it would have given an
  
  incorrect result. (Fortunately, we only used it for 16-bit
  
  values.) Fixes bug 3175; bugfix on 0.1.0.1-rc.


• Be more careful about reporting the correct error from a failed
  
  connect() system call. Under some circumstances, it was possible to
  
  look at an incorrect value for errno when sending the end reason.
  
  Bugfix on 0.1.0.1-rc.


• Correctly handle an "impossible" overflow cases in connection byte
  
  counting, where we write or read more than 4GB on an edge connection
  
  in a single second. Bugfix on 0.1.2.8-beta.


• Avoid a double mark-for-free warning when failing to attach a
  
  transparent proxy connection. Bugfix on 0.1.2.1-alpha. Fixes
  
  bug 2279.


• Correctly detect failure to allocate an OpenSSL BIO. Fixes bug 2378;
  
  found by "cypherpunks". This bug was introduced before the first
  
  Tor release, in svn commit r110.


• Fix a bug in bandwidth history state parsing that could have been
  
  triggered if a future version of Tor ever changed the timing
  
  granularity at which bandwidth history is measured. Bugfix on
  
  Tor 0.1.1.11-alpha.


• Add assertions to check for overflow in arguments to
  
  base32_encode() and base32_decode(); fix a signed-unsigned
  
  comparison there too. These bugs are not actually reachable in Tor,
  
  but it's good to prevent future errors too. Found by doorss.


• Avoid a bogus overlapped memcpy in tor_addr_copy(). Reported by
  
  "memcpyfail".


• Set target port in get_interface_address6() correctly. Bugfix
  
  on 0.1.1.4-alpha and 0.2.0.3-alpha; fixes second part of bug 2660.


• Fix an impossible-to-actually-trigger buffer overflow in relay
  
  descriptor generation. Bugfix on 0.1.0.15.


• Fix numerous small code-flaws found by Coverity Scan Rung 3.

Minor bugfixes (code improvements):

• After we free an internal connection structure, overwrite it
  
  with a different memory value than we use for overwriting a freed
  
  internal circuit structure. Should help with debugging. Suggested
  
  by bug 1055.


• If OpenSSL fails to make a duplicate of a private or public key, log
  
  an error message and try to exit cleanly. May help with debugging
  
  if bug 1209 ever remanifests.


• Some options used different conventions for uppercasing of acronyms
  
  when comparing manpage and source. Fix those in favor of the
  
  manpage, as it makes sense to capitalize acronyms.


• Take a first step towards making or.h smaller by splitting out
  
  function definitions for all source files in src/or/. Leave
  
  structures and defines in or.h for now.


• Remove a few dead assignments during router parsing. Found by
  
  coverity.


• Don't use 1-bit wide signed bit fields. Found by coverity.


• Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
  
  None of the cases where we did this before were wrong, but by making
  
  this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.


• The memarea code now uses a sentinel value at the end of each area
  
  to make sure nothing writes beyond the end of an area. This might
  
  help debug some conceivable causes of bug 930.


• Always treat failure to allocate an RSA key as an unrecoverable
  
  allocation error.


• Add some more defensive programming for architectures that can't
  
  handle unaligned integer accesses. We don't know of any actual bugs
  
  right now, but that's the best time to fix them. Fixes bug 1943.

Minor bugfixes (misc):

• Fix a rare bug in rend_fn unit tests: we would fail a test when
  
  a randomly generated port is 0. Diagnosed by Matt Edman. Bugfix
  
  on 0.2.0.10-alpha; fixes bug 1808.


• Where available, use Libevent 2.0's periodic timers so that our
  
  once-per-second cleanup code gets called even more closely to
  
  once per second than it would otherwise. Fixes bug 943.


• Ignore OutboundBindAddress when connecting to localhost.
  
  Connections to localhost need to come _from_ localhost, or else
  
  local servers (like DNS and outgoing HTTP/SOCKS proxies) will often
  
  refuse to listen.


• Update our OpenSSL 0.9.8l fix so that it works with OpenSSL 0.9.8m
  
  too.


• If any of the v3 certs we download are unparseable, we should
  
  actually notice the failure so we don't retry indefinitely. Bugfix
  
  on 0.2.0.x; reported by "rotator".


• When Tor fails to parse a descriptor of any kind, dump it to disk.
  
  Might help diagnosing bug 1051.


• Make our 'torify' script more portable; if we have only one of
  
  'torsocks' or 'tsocks' installed, don't complain to the user;
  
  and explain our warning about tsocks better.


• Fix some urls in the exit notice file and make it XHTML1.1 strict
  
  compliant. Based on a patch from Christian Kujau.

Documentation changes:

• Modernize the doxygen configuration file slightly. Fixes bug 2707.


• Resolve all doxygen warnings except those for missing documentation.
  
  Fixes bug 2705.


• Add doxygen documentation for more functions, fields, and types.


• Convert the HACKING file to asciidoc, and add a few new sections
  
  to it, explaining how we use Git, how we make changelogs, and
  
  what should go in a patch.


• Document the default socks host and port (127.0.0.1:9050) for
  
  tor-resolve.


• Removed some unnecessary files from the source distribution. The
  
  AUTHORS file has now been merged into the people page on the
  
  website. The roadmaps and design doc can now be found in the
  
  projects directory in svn.

Deprecated and removed features (config):

• Remove the torrc.complete file. It hasn't been kept up to date
  
  and users will have better luck checking out the manpage.


• Remove the HSAuthorityRecordStats option that version 0 hidden
  
  service authorities could use to track statistics of overall v0
  
  hidden service usage.


• Remove the obsolete "NoPublish" option; it has been flagged
  
  as obsolete and has produced a warning since 0.1.1.18-rc.


• Caches no longer download and serve v2 networkstatus documents
  
  unless FetchV2Networkstatus flag is set: these documents haven't
  
  haven't been used by clients or relays since 0.2.0.x. Resolves
  
  bug 3022.

Deprecated and removed features (controller):

• The controller no longer accepts the old obsolete "addr-mappings/"
  
  or "unregistered-servers-" GETINFO values.


• The EXTENDED_EVENTS and VERBOSE_NAMES controller features are now
  
  always on; using them is necessary for correct forward-compatible
  
  controllers.

Deprecated and removed features (misc):

• Hidden services no longer publish version 0 descriptors, and clients
  
  do not request or use version 0 descriptors. However, the old hidden
  
  service authorities still accept and serve version 0 descriptors
  
  when contacted by older hidden services/clients.


• Remove undocumented option "-F" from tor-resolve: it hasn't done
  
  anything since 0.2.1.16-rc.


• Remove everything related to building the expert bundle for OS X.
  
  It has confused many users, doesn't work right on OS X 10.6,
  
  and is hard to get rid of once installed. Resolves bug 1274.


• Remove support for .noconnect style addresses. Nobody was using
  
  them, and they provided another avenue for detecting Tor users
  
  via application-level web tricks.


• When we fixed bug 1038 we had to put in a restriction not to send
  
  RELAY_EARLY cells on rend circuits. This was necessary as long
  
  as relays using Tor 0.2.1.3-alpha through 0.2.1.18-alpha were
  
  active. Now remove this obsolete check. Resolves bug 2081.


• Remove workaround code to handle directory responses from servers
  
  that had bug 539 (they would send HTTP status 503 responses _and_
  
  send a body too). Since only server versions before
  
  0.2.0.16-alpha/0.1.2.19 were affected, there is no longer reason to
  
  keep the workaround in place.


• Remove the old 'fuzzy time' logic. It was supposed to be used for
  
  handling calculations where we have a known amount of clock skew and
  
  an allowed amount of unknown skew. But we only used it in three
  
  places, and we never adjusted the known/unknown skew values. This is
  
  still something we might want to do someday, but if we do, we'll
  
  want to do it differently.


• Remove the "--enable-iphone" option to ./configure. According to
  
  reports from Marco Bonetti, Tor builds fine without any special
  
  tweaking on recent iPhone SDK versions.