Tor Browser Bundle (2.2.32-3)

Update Firefox to 6.0.2
New Firefox patches:
Improve cache APIs to enable better isolation (closes: #3666)
Provide auth headers to on-modify-request (closes: #3907)
Randomize HTTP pipelining as an experimental website traffic fingerprinting defense (closes: #3914)
Enable HTTP pipelining in TBB prefs.js (closes: #3913)
Update Torbutton to 1.4.2
bug 3879: Fix broken framed sites (yopmail, gmane, gmaps, etc)
bug 3337: Fetch check.tp.o page to check versions (TBB only)
Bug 3754: Fix SafeCache OCSP errors (fix for TBB only)
Update NoScript to 2.1.2.7

Windows fixes

Add missing C runtime libraries so WinXP users can use TBB again. Fix found by velope.

Linux fixes

Update libpng to 1.4.8 (closes: #3906)
Make the TBB launch script work when using a relative symlink (closes: #2525)

The Tor Browser Bundles have been updated with a bunch of bug fixes.

Important note to Windows users: in the last release we enabled automatic port selection for Tor and this had very unexpected side effects on many Windows machines. It turns out that there are a number of consumer firewalls that don't like things connecting on high ports, which was the default. We're looking into smarter ways to handle this failure mode, but until we find one, we have reverted the behavior to using the previous static port. We're very sorry for the huge inconvenience this caused and hope you will find these bundles more bug-free! As ever, if you don't, please let us know.
https://www.torproject.org/download

Tor Browser Bundle (2.2.32-4)
Windows fixes

Disable automatic port selection to accommodate Windows users with
firewalls that don't allow connections or traffic on high ports (closes: #3952, #3945)

Linux fixes
Fix Makefile to allow for automatic retrieval of Qt and libpng (closes: #2255)
Remove symlinks from tarball (closes: #2312)

General fixes and updates
New Firefox patches
Prevent Firefox from loading all system plugins besides Flash (closes: #2826, #3547)
Prevent content-preferences service from writing website urls and their settings to disk (closes: #3229)
Update Torbutton to 1.4.3
Don't let Torbutton inadvertently enable automatic updating in Firefox (closes: #3933)
Fix auto-scroll on Twitter (closes: #3960)
Allow site zoom information to be stored (closes: #3928)
Make permissions and disk errors human-readable (closes: #3649)

Iran blocks Tor; Tor releases same-day fix

The short version: Tor relays and bridges should upgrade to Tor 0.2.2.33 or Tor 0.2.3.4-alpha so users in Iran can reach them again.

Yesterday morning (in our timezones — that evening, in Iran), Iran added a filter rule to their border routers that recognized Tor traffic and blocked it. Thanks to help from a variety of friends around the world, we quickly discovered how they were blocking it and released a new version of Tor that isn't blocked. Fortunately, the fix is on the relay side: that means once enough relays and bridges upgrade, the many tens of thousands of Tor users in Iran will resume being able to reach the Tor network, without needing to change their software.

How did the filter work technically? Tor tries to make its traffic look like a web browser talking to an https web server, but if you look carefully enough you can tell some differences. In this case, the characteristic of Tor's SSL handshake they looked at was the expiry time for our SSL session certificates: we rotate the session certificates every two hours, whereas normal SSL certificates you get from a certificate authority typically last a year or more. The fix was to simply write a larger expiration time on the certificates, so our certs have more plausible expiry times.

There are plenty of interesting discussion points from the research angle around how this arms race should be played. We're working on medium term and longer term solutions, but in the short term, there are other ways to filter Tor traffic like the one Iran used. Should we fix them all preemptively, meaning the next time they block us it will be through some more complex mechanism that's harder to figure out? Or should we leave things as they are, knowing there will be more blocking events but also knowing that we can solve them easily? Given that their last blocking attempt was in January 2011, I think it's smartest to collect some more data points first.

It's too early to have cool graphs showing a drop in users and then the users coming back a day or so later. I'll plan to add these graphs once things play out more.

The Tor Browser Bundles have been updated to Firefox 7.0.1 and Tor 0.2.2.33. The bundles were originally uploaded with Firefox 7.0, but a fix was quickly released, so the two changelogs have been merged in this post.

Windows fixes

Begin building Vidalia with DEP/ASLR

OS X fixes

Stop TBB from logging so much information to the system by only allowing dyld log library loads to syslog when it is in debug mode (closes: #4093)

General fixes and updates

Update Firefox to 7.0.1
Update OpenSSL to 1.0.0e (closes: #3996) (except for OS X)
Update Tor to 0.2.2.33
Update NoScript to 2.1.2.8
Downgrade HTTPS Everywhere to 1.0.3, because we don't want stable TBBs to use development versions of extensions (closes: #4050)

Tor 0.2.3.5-alpha fixes two bugs that make it possible to enumerate
bridge relays; fixes an assertion error that many users started hitting
today; and adds the ability to refill token buckets more often than
once per second, allowing significant performance improvements.

Security fixes:

Bridge relays now do their directory fetches inside Tor TLS
connections, like all the other clients do, rather than connecting
directly to the DirPort like public relays do. Removes another
avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
Bridges relays now build circuits for themselves in a more similar
way to how clients build them. Removes another avenue for
enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
when bridges were introduced.

Major bugfixes:

Fix an "Assertion md->held_by_node == 1 failed" error that could
occur when the same microdescriptor was referenced by two node_t
objects at once. Fix for bug 4118; bugfix on Tor 0.2.3.1-alpha.

Major features (networking):

Add a new TokenBucketRefillInterval option to refill token buckets
more frequently than once per second. This should improve network
performance, alleviate queueing problems, and make traffic less
bursty. Implements proposal 183; closes ticket 3630. Design by
Florian Tschorsch and Björn Scheuermann; implementation by
Florian Tschorsch.

Minor bugfixes:

Change an integer overflow check in the OpenBSD_Malloc code so
that GCC is less likely to eliminate it as impossible. Patch
from Mansour Moufid. Fixes bug 4059.

Minor bugfixes (usability):

Downgrade log messages about circuit timeout calibration from
"notice" to "info": they don't require or suggest any human
intervention. Patch from Tom Lowenthal. Fixes bug 4063;
bugfix on 0.2.2.14-alpha.

Minor features (diagnostics):

When the system call to create a listener socket fails, log the
error message explaining why. This may help diagnose bug 4027.

Changes in version 0.2.3.5-alpha - 2011-09-28

Tor 0.2.3.5-alpha fixes two bugs that make it possible to enumerate
bridge relays; fixes an assertion error that many users started hitting
today; and adds the ability to refill token buckets more often than
once per second, allowing significant performance improvements.

o Security fixes:
- Bridge relays now do their directory fetches inside Tor TLS
connections, like all the other clients do, rather than connecting
directly to the DirPort like public relays do. Removes another
avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
- Bridges relays now build circuits for themselves in a more similar
way to how clients build them. Removes another avenue for
enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
when bridges were introduced.

o Major bugfixes:
- Fix an "Assertion md->held_by_node == 1 failed" error that could
occur when the same microdescriptor was referenced by two node_t
objects at once. Fix for bug 4118; bugfix on Tor 0.2.3.1-alpha.

o Major features (networking):
- Add a new TokenBucketRefillInterval option to refill token buckets
more frequently than once per second. This should improve network
performance, alleviate queueing problems, and make traffic less
bursty. Implements proposal 183; closes ticket 3630. Design by
Florian Tschorsch and Björn Scheuermann; implementation by
Florian Tschorsch.

o Minor bugfixes:
- Change an integer overflow check in the OpenBSD_Malloc code so
that GCC is less likely to eliminate it as impossible. Patch
from Mansour Moufid. Fixes bug 4059.

o Minor bugfixes (usability):
- Downgrade log messages about circuit timeout calibration from
"notice" to "info": they don't require or suggest any human
intervention. Patch from Tom Lowenthal. Fixes bug 4063;
bugfix on 0.2.2.14-alpha.

o Minor features (diagnostics):
- When the system call to create a listener socket fails, log the
error message explaining why. This may help diagnose bug 4027.

o Draw the bandwidth graph curves based on the local maximum, not
the global maximum. Fixes bug 2188.
o Add an option for setting up a non-exit relay to the Sharing
configuration panel. This is meant to clarify what an exit policy
and an exit relay are. Resolves bug 2644.
o Display time statistics for bridges in UTC time, rather than local
time. Fixes bug 3342.
o Change the parameter for ordering the entries in the Basic Log
list from currentTime to currentDateTime to avoid missplacing
entries from different days.
o Check the tor version and that settings are sanitized before
trying to use the port autoconfiguration feature. Fixes bug 3843.
o Provide a way to hide Dock or System Tray icons in OSX. Resolves
ticket 2163.
o Make new processes appear at front when they are started (OSX
specific).

Tor 0.2.2.34 fixes a critical anonymity vulnerability where an attacker
can deanonymize Tor users. Everybody should upgrade.

The attack relies on four components:
1) Clients reuse their TLS cert when talking to different relays, so relays can recognize a user by the identity key in her cert.
2) An attacker who knows the client's identity key can probe each guard relay to see if that identity key is connected to that guard relay right now.
3) A variety of active attacks in the literature (starting from "Low-Cost Traffic Analysis of Tor" by Murdoch and Danezis in 2005) allow a malicious website to discover the guard relays that a Tor user visiting the website is using.
4) Clients typically pick three guards at random, so the set of guards for a given user could well be a unique fingerprint for her. This release fixes components #1 and #2, which is enough to block the attack; the other two remain as open research problems.

Special thanks to "frosty_un" for reporting the issue to us! (As far as we know, this has nothing to do with any claimed attack currently getting attention in the media.)

Clients should upgrade so they are no longer recognizable by the TLS certs they present. Relays should upgrade so they no longer allow a remote attacker to probe them to test whether unpatched clients are currently connected to them.

This release also fixes several vulnerabilities that allow an attacker to enumerate bridge relays. Some bridge enumeration attacks still remain; see for example proposal 188.

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

Changes in version 0.2.2.34 - 2011-10-26

Privacy/anonymity fixes (clients):
Clients and bridges no longer send TLS certificate chains on outgoing OR
connections. Previously, each client or bridge would use the same cert chain
for all outgoing OR connections until its IP address changes, which allowed any
relay that the client or bridge contacted to determine which entry guards it is
using. Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
If a relay receives a CREATE_FAST cell on a TLS connection, it no longer
considers that connection as suitable for satisfying a circuit EXTEND request.
Now relays can protect clients from the CVE-2011-2768 issue even if the clients
haven't upgraded yet.
Directory authorities no longer assign the Guard flag to relays that
haven't upgraded to the above "refuse EXTEND requests to client connections"
fix. Now directory authorities can protect clients from the CVE-2011-2768 issue
even if neither the clients nor the relays have upgraded yet. There's a new
"GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays" config option to let us
transition smoothly, else tomorrow there would be no guard relays.

Privacy/anonymity fixes (bridge enumeration):
Bridge relays now do their directory fetches inside Tor TLS connections,
like all the other clients do, rather than connecting directly to the DirPort
like public relays do. Removes another avenue for enumerating bridges. Fixes
bug 4115; bugfix on 0.2.0.35.
Bridges relays now build circuits for themselves in a more similar way to
how clients build them. Removes another avenue for enumerating bridges. Fixes
bug 4124; bugfix on 0.2.0.3-alpha, when bridges were introduced.
Bridges now refuse CREATE or CREATE_FAST cells on OR connections that they
initiated. Relays could distinguish incoming bridge connections from client
connections, creating another avenue for enumerating bridges. Fixes
CVE-2011-2769. Bugfix on 0.2.0.3-alpha. Found by "frosty_un".

Major bugfixes:
Fix a crash bug when changing node restrictions while a DNS lookup is
in-progress. Fixes bug 4259; bugfix on 0.2.2.25-alpha. Bugfix by "Tey'".
Don't launch a useless circuit after failing to use one of a hidden
service's introduction points. Previously, we would launch a new introduction
circuit, but not set the hidden service which that circuit was intended to
connect to, so it would never actually be used. A different piece of code would
then create a new introduction circuit correctly. Bug reported by katmagic and
found by Sebastian Hahn. Bugfix on 0.2.1.13-alpha; fixes bug 4212.

Minor bugfixes:
Change an integer overflow check in the OpenBSD_Malloc code so that GCC is
less likely to eliminate it as impossible. Patch from Mansour Moufid. Fixes bug
4059.
When a hidden service turns an extra service-side introduction circuit into
a general-purpose circuit, free the rend_data and intro_key fields first, so we
won't leak memory if the circuit is cannibalized for use as another
service-side introduction circuit. Bugfix on 0.2.1.7-alpha; fixes bug
4251.
Bridges now skip DNS self-tests, to act a little more stealthily. Fixes
bug 4201; bugfix on 0.2.0.3-alpha, which first introduced bridges. Patch by
"warms0x".
Fix internal bug-checking logic that was supposed to catch failures in
digest generation so that it will fail more robustly if we ask for a
nonexistent algorithm. Found by Coverity Scan. Bugfix on 0.2.2.1-alpha; fixes
Coverity CID 479.
Report any failure in init_keys() calls launched because our IP address has
changed. Spotted by Coverity Scan. Bugfix on 0.1.1.4-alpha; fixes CID 484.

Minor bugfixes (log messages and documentation):
Remove a confusing dollar sign from the example fingerprint in the man
page, and also make the example fingerprint a valid one. Fixes bug 4309; bugfix
on 0.2.1.3-alpha.
The next version of Windows will be called Windows 8, and it has a major
version of 6, minor version of 2. Correctly identify that version instead of
calling it "Very recent version". Resolves ticket 4153; reported by
funkstar.
Downgrade log messages about circuit timeout calibration from "notice" to
"info": they don't require or suggest any human intervention. Patch from Tom
Lowenthal. Fixes bug 4063; bugfix on 0.2.2.14-alpha.

Minor features:
Turn on directory request statistics by default and include them in
extra-info descriptors. Don't break if we have no GeoIP database. Backported
from 0.2.3.1-alpha; implements ticket 3951.
Update to the October 4 2011 Maxmind GeoLite Country database.

Tor 0.2.3.7-alpha fixes a crash bug in 0.2.3.6-alpha introduced by the new v3 handshake. It also resolves yet another bridge address enumeration issue.

All packages are updated, with the exception of the OS X PPC packages. The build machine is down and packages will be built as soon as it is back online.

https://www.torproject.org/download

Changes in version 0.2.3.7-alpha - 2011-10-30
Major bugfixes:
If we mark an OR connection for close based on a cell we process,
don't process any further cells on it. We already avoid further
reads on marked-for-close connections, but now we also discard the
cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
which was the first version where we might mark a connection for
close based on processing a cell on it.
Fix a double-free bug that would occur when we received an invalid
certificate in a CERT cell in the new v3 handshake. Fixes bug 4343;
bugfix on 0.2.3.6-alpha.
Bridges no longer include their address in NETINFO cells on outgoing
OR connections, to allow them to blend in better with clients.
Removes another avenue for enumerating bridges. Reported by
"troll_un". Fixes bug 4348; bugfix on 0.2.0.10-alpha, when NETINFO
cells were introduced.

Trivial fixes:
Fixed a typo in a hibernation-related log message. Fixes bug 4331;
bugfix on 0.2.2.23-alpha; found by "tmpname0901".

Changes in version 0.2.3.8-alpha - 2011-11-22
Tor 0.2.3.8-alpha fixes some crash and assert bugs, including a
socketpair-related bug that has been bothering Windows users. It adds
support to serve microdescriptors to controllers, so Vidalia's network
map can resume listing relays (once Vidalia implements its side),
and adds better support for hardware AES acceleration. Finally, it
starts the process of adjusting the bandwidth cutoff for getting the
"Fast" flag from 20KB to (currently) 32KB -- preliminary results show
that tiny relays harm performance more than they help network capacity.

o Major bugfixes:
- Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
that it doesn't attempt to allocate a socketpair. This could cause
some problems on Windows systems with overzealous firewalls. Fix for
bug 4457; workaround for Libevent versions 2.0.1-alpha through
2.0.15-stable.
- Correctly sanity-check that we don't underflow on a memory
allocation (and then assert) for hidden service introduction
point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
bugfix on 0.2.1.5-alpha.
- Remove the artificially low cutoff of 20KB to guarantee the Fast
flag. In the past few years the average relay speed has picked
up, and while the "top 7/8 of the network get the Fast flag" and
"all relays with 20KB or more of capacity get the Fast flag" rules
used to have the same result, now the top 7/8 of the network has
a capacity more like 32KB. Bugfix on 0.2.1.14-rc. Fixes bug 4489.
- Fix a rare assertion failure when checking whether a v0 hidden
service descriptor has any usable introduction points left, and
we don't have enough information to build a circuit to the first
intro point named in the descriptor. The HS client code in
0.2.3.x no longer uses v0 HS descriptors, but this assertion can
trigger on (and crash) v0 HS authorities. Fixes bug 4411.
Bugfix on 0.2.3.1-alpha; diagnosed by frosty_un.
- Make bridge authorities not crash when they are asked for their own
descriptor. Bugfix on 0.2.3.7-alpha, reported by Lucky Green.
- When running as a client, do not print a misleading (and plain
wrong) log message that we're collecting "directory request"
statistics: clients don't collect statistics. Also don't create a
useless (because empty) stats file in the stats/ directory. Fixes
bug 4353; bugfix on 0.2.2.34 and 0.2.3.7-alpha.

o Major features:
- Allow Tor controllers like Vidalia to obtain the microdescriptor
for a relay by identity digest or nickname. Previously,
microdescriptors were only available by their own digests, so a
controller would have to ask for and parse the whole microdescriptor
consensus in order to look up a single relay's microdesc. Fixes
bug 3832; bugfix on 0.2.3.1-alpha.
- Use OpenSSL's EVP interface for AES encryption, so that all AES
operations can use hardware acceleration (if present). Resolves
ticket 4442.

o Minor bugfixes (on 0.2.2.x and earlier):
- Detect failure to initialize Libevent. This fix provides better
detection for future instances of bug 4457.
- Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
function. This was eating up hideously large amounts of time on some
busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
- Don't warn about unused log_mutex in log.c when building with
--disable-threads using a recent GCC. Fixes bug 4437; bugfix on
0.1.0.6-rc which introduced --disable-threads.
- Allow manual 'authenticate' commands to the controller interface
from netcat (nc) as well as telnet. We were rejecting them because
they didn't come with the expected whitespace at the end of the
command. Bugfix on 0.1.1.1-alpha; fixes bug 2893.
- Fix some (not actually triggerable) buffer size checks in usage of
tor_inet_ntop. Fixes bug 4434; bugfix on Tor 0.2.0.1-alpha. Patch
by Anders Sundman.
- Fix parsing of some corner-cases with tor_inet_pton(). Fixes
bug 4515; bugfix on 0.2.0.1-alpha; fix by Anders Sundman.
- When configuring, starting, or stopping an NT service, stop
immediately after the service configuration attempt has succeeded
or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
- When sending a NETINFO cell, include the original address
received for the other side, not its canonical address. Found
by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
- Rename the bench_{aes,dmap} functions to test_*, so that tinytest
can pick them up when the tests aren't disabled. Bugfix on
0.2.2.4-alpha which introduced tinytest.
- Fix a memory leak when we check whether a hidden service
descriptor has any usable introduction points left. Fixes bug
4424. Bugfix on 0.2.2.25-alpha.
- Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
occurred when a client tried to fetch a descriptor for a bridge
in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.

o Minor bugfixes (on 0.2.3.x):
- Make util unit tests build correctly with MSVC. Bugfix on
0.2.3.3-alpha. Patch by Gisle Vanem.
- Successfully detect AUTH_CHALLENGE cells with no recognized
authentication type listed. Fixes bug 4367; bugfix on 0.2.3.6-alpha.
Found by frosty_un.
- If a relay receives an AUTH_CHALLENGE cell it can't answer,
it should still send a NETINFO cell to allow the connection to
become open. Fixes bug 4368; fix on 0.2.3.6-alpha; bug found by
"frosty".
- Log less loudly when we get an invalid authentication certificate
from a source other than a directory authority: it's not unusual
to see invalid certs because of clock skew. Fixes bug 4370; bugfix
on 0.2.3.6-alpha.
- Tolerate servers with more clock skew in their authentication
certificates than previously. Fixes bug 4371; bugfix on
0.2.3.6-alpha.
- Fix a couple of compile warnings on Windows. Fixes bug 4469; bugfix
on 0.2.3.4-alpha and 0.2.3.6-alpha.

o Minor features:
- Add two new config options for directory authorities:
AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
that is always sufficient to satisfy the bandwidth requirement for
the Guard flag. Now it will be easier for researchers to simulate
Tor networks with different values. Resolves ticket 4484.
- When Tor ignores a hidden service specified in its configuration,
include the hidden service's directory in the warning message.
Previously, we would only tell the user that some hidden service
was ignored. Bugfix on 0.0.6; fixes bug 4426.
- When we fail to initialize Libevent, retry with IOCP disabled so we
don't need to turn on multi-threading support in Libevent, which in
turn requires a working socketpair(). This is a workaround for bug
4457, which affects Libevent versions from 2.0.1-alpha through
2.0.15-stable.
- Detect when we try to build on a platform that doesn't define
AF_UNSPEC to 0. We don't work there, so refuse to compile.
- Update to the November 1 2011 Maxmind GeoLite Country database.

o Packaging changes:
- Make it easier to automate expert package builds on Windows,
by removing an absolute path from makensis.exe command.

o Code simplifications and refactoring:
- Remove some redundant #include directives throughout the code.
Patch from Andrea Gelmini.
- Unconditionally use OpenSSL's AES implementation instead of our
old built-in one. OpenSSL's AES has been better for a while, and
relatively few servers should still be on any version of OpenSSL
that doesn't have good optimized assembly AES.
- Use the name "CERTS" consistently to refer to the new cell type;
we were calling it CERT in some places and CERTS in others.

o Testing:
- Numerous new unit tests for functions in util.c and address.c by
Anders Sundman.
- The long-disabled benchmark tests are now split into their own
./src/test/bench binary.
- The benchmark tests can now use more accurate timers than
gettimeofday() when such timers are available.

Changes in version 0.2.3.9-alpha - 2011-12-08
Tor 0.2.3.9-alpha introduces initial IPv6 support for bridges, adds
a "DisableNetwork" security feature that bundles can use to avoid
touching the network until bridges are configured, moves forward on
the pluggable transport design, fixes a flaw in the hidden service
design that unnecessarily prevented clients with wrong clocks from
reaching hidden services, and fixes a wide variety of other issues.

o Major features:
- Clients can now connect to private bridges over IPv6. Bridges
still need at least one IPv4 address in order to connect to
other relays. Note that we don't yet handle the case where the
user has two bridge lines for the same bridge (one IPv4, one
IPv6). Implements parts of proposal 186.
- New "DisableNetwork" config option to prevent Tor from launching any
connections or accepting any connections except on a control port.
Bundles and controllers can set this option before letting Tor talk
to the rest of the network, for example to prevent any connections
to a non-bridge address. Packages like Orbot can also use this
option to instruct Tor to save power when the network is off.
- Clients and bridges can now be configured to use a separate
"transport" proxy. This approach makes the censorship arms race
easier by allowing bridges to use protocol obfuscation plugins. It
implements the "managed proxy" part of proposal 180 (ticket 3472).
- When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode
implementation. It makes AES_CTR about 7% faster than our old one
(which was about 10% faster than the one OpenSSL used to provide).
Resolves ticket 4526.
- Add a "tor2web mode" for clients that want to connect to hidden
services non-anonymously (and possibly more quickly). As a safety
measure to try to keep users from turning this on without knowing
what they are doing, tor2web mode must be explicitly enabled at
compile time, and a copy of Tor compiled to run in tor2web mode
cannot be used as a normal Tor client. Implements feature 2553.
- Add experimental support for running on Windows with IOCP and no
kernel-space socket buffers. This feature is controlled by a new
"UserspaceIOCPBuffers" config option (off by default), which has
no effect unless Tor has been built with support for bufferevents,
is running on Windows, and has enabled IOCP. This may, in the long
run, help solve or mitigate bug 98.
- Use a more secure consensus parameter voting algorithm. Now at
least three directory authorities or a majority of them must
vote on a given parameter before it will be included in the
consensus. Implements proposal 178.

o Major bugfixes:
- Hidden services now ignore the timestamps on INTRODUCE2 cells.
They used to check that the timestamp was within 30 minutes
of their system clock, so they could cap the size of their
replay-detection cache, but that approach unnecessarily refused
service to clients with wrong clocks. Bugfix on 0.2.1.6-alpha, when
the v3 intro-point protocol (the first one which sent a timestamp
field in the INTRODUCE2 cell) was introduced; fixes bug 3460.
- Only use the EVP interface when AES acceleration is enabled,
to avoid a 5-7% performance regression. Resolves issue 4525;
bugfix on 0.2.3.8-alpha.

o Privacy/anonymity features (bridge detection):
- Make bridge SSL certificates a bit more stealthy by using random
serial numbers, in the same fashion as OpenSSL when generating
self-signed certificates. Implements ticket 4584.
- Introduce a new config option "DynamicDHGroups", enabled by
default, which provides each bridge with a unique prime DH modulus
to be used during SSL handshakes. This option attempts to help
against censors who might use the Apache DH modulus as a static
identifier for bridges. Addresses ticket 4548.

o Minor features (new/different config options):
- New configuration option "DisableDebuggerAttachment" (on by default)
to prevent basic debugging attachment attempts by other processes.
Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
- Allow MapAddress directives to specify matches against super-domains,
as in "MapAddress *.torproject.org *.torproject.org.torserver.exit".
Implements issue 933.
- Slightly change behavior of "list" options (that is, config
options that can appear more than once) when they appear both in
torrc and on the command line. Previously, the command-line options
would be appended to the ones from torrc. Now, the command-line
options override the torrc options entirely. This new behavior
allows the user to override list options (like exit policies and
ports to listen on) from the command line, rather than simply
appending to the list.
- You can get the old (appending) command-line behavior for "list"
options by prefixing the option name with a "+".
- You can remove all the values for a "list" option from the command
line without adding any new ones by prefixing the option name
with a "/".
- Add experimental support for a "defaults" torrc file to be parsed
before the regular torrc. Torrc options override the defaults file's
options in the same way that the command line overrides the torrc.
The SAVECONF controller command saves only those options which
differ between the current configuration and the defaults file. HUP
reloads both files. (Note: This is an experimental feature; its
behavior will probably be refined in future 0.2.3.x-alpha versions
to better meet packagers' needs.)

o Minor features:
- Try to make the introductory warning message that Tor prints on
startup more useful for actually finding help and information.
Resolves ticket 2474.
- Running "make version" now displays the version of Tor that
we're about to build. Idea from katmagic; resolves issue 4400.
- Expire old or over-used hidden service introduction points.
Required by fix for bug 3460.
- Move the replay-detection cache for the RSA-encrypted parts of
INTRODUCE2 cells to the introduction point data structures.
Previously, we would use one replay-detection cache per hidden
service. Required by fix for bug 3460.
- Reduce the lifetime of elements of hidden services' Diffie-Hellman
public key replay-detection cache from 60 minutes to 5 minutes. This
replay-detection cache is now used only to detect multiple
INTRODUCE2 cells specifying the same rendezvous point, so we can
avoid launching multiple simultaneous attempts to connect to it.

o Minor bugfixes (on Tor 0.2.2.x and earlier):
- Resolve an integer overflow bug in smartlist_ensure_capacity().
Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
Mansour Moufid.
- Fix a minor formatting issue in one of tor-gencert's error messages.
Fixes bug 4574.
- Prevent a false positive from the check-spaces script, by disabling
the "whitespace between function name and (" check for functions
named 'op()'.
- Fix a log message suggesting that people contact a non-existent
email address. Fixes bug 3448.
- Fix null-pointer access that could occur if TLS allocation failed.
Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
- Report a real bootstrap problem to the controller on router
identity mismatch. Previously we just said "foo", which probably
made a lot of sense at the time. Fixes bug 4169; bugfix on
0.2.1.1-alpha.
- If we had ever tried to call tor_addr_to_str() on an address of
unknown type, we would have done a strdup() on an uninitialized
buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
Reported by "troll_un".
- Correctly detect and handle transient lookup failures from
tor_addr_lookup(). Fixes bug 4530; bugfix on 0.2.1.5-alpha.
Reported by "troll_un".
- Use tor_socket_t type for listener argument to accept(). Fixes bug
4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
- Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes
bug 4532; found by "troll_un".

o Minor bugfixes (on Tor 0.2.3.x):
- Fix a compile warning in tor_inet_pton(). Bugfix on 0.2.3.8-alpha;
fixes bug 4554.
- Don't send two ESTABLISH_RENDEZVOUS cells when opening a new
circuit for use as a hidden service client's rendezvous point.
Fixes bugs 4641 and 4171; bugfix on 0.2.3.3-alpha. Diagnosed
with help from wanoskarnet.
- Restore behavior of overriding SocksPort, ORPort, and similar
options from the command line. Bugfix on 0.2.3.3-alpha.

o Build fixes:
- Properly handle the case where the build-tree is not the same
as the source tree when generating src/common/common_sha1.i,
src/or/micro-revision.i, and src/or/or_sha1.i. Fixes bug 3953;
bugfix on 0.2.0.1-alpha.

o Code simplifications, cleanups, and refactorings:
- Remove the pure attribute from all functions that used it
previously. In many cases we assigned it incorrectly, because the
functions might assert or call impure functions, and we don't have
evidence that keeping the pure attribute is worthwhile. Implements
changes suggested in ticket 4421.
- Remove some dead code spotted by coverity. Fixes cid 432.
Bugfix on 0.2.3.1-alpha, closes bug 4637.

Tor 0.2.2.35 fixes a critical heap-overflow security issue in Tor's
buffers code. Absolutely everybody should upgrade.

The bug relied on an incorrect calculation when making data continuous
in one of our IO buffers, if the first chunk of the buffer was
misaligned by just the wrong amount. The miscalculation would allow an
attacker to overflow a piece of heap-allocated memory. To mount this
attack, the attacker would need to either open a SOCKS connection to
Tor's SocksPort (usually restricted to localhost), or target a Tor
instance configured to make its connections through a SOCKS proxy
(which Tor does not do by default).

Good security practice requires that all heap-overflow bugs should be
presumed to be exploitable until proven otherwise, so we are treating
this as a potential code execution attack. Please upgrade immediately!
This bug does not affect bufferevents-based builds of Tor. Special
thanks to "Vektor" for reporting this issue to us!

Tor 0.2.2.35 also fixes several bugs in previous versions, including
crash bugs for unusual configurations, and a long-term bug that
would prevent Tor from starting on Windows machines with draconian
AV software.

With this release, we remind everyone that 0.2.0.x has reached its
formal end-of-life. Those Tor versions have many known flaws, and
nobody should be using them. You should upgrade -- ideally to the
0.2.2.x series. If you're using a Linux or BSD and its packages are
obsolete, stop using those packages and upgrade anyway.

The Tor 0.2.1.x series is also approaching its end-of-life: it will no
longer receive support after some time in early 2012.

https://www.torproject.org/download

Changes in version 0.2.2.35 - 2011-12-16

Major bugfixes:
Fix a heap overflow bug that could occur when trying to pull
data into the first chunk of a buffer, when that chunk had
already had some data drained from it. Fixes CVE-2011-2778;
bugfix on 0.2.0.16-alpha. Reported by "Vektor".
Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
that it doesn't attempt to allocate a socketpair. This could cause
some problems on Windows systems with overzealous firewalls. Fix for
bug 4457; workaround for Libevent versions 2.0.1-alpha through
2.0.15-stable.
If we mark an OR connection for close based on a cell we process,
don't process any further cells on it. We already avoid further
reads on marked-for-close connections, but now we also discard the
cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
which was the first version where we might mark a connection for
close based on processing a cell on it.
Correctly sanity-check that we don't underflow on a memory
allocation (and then assert) for hidden service introduction
point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
bugfix on 0.2.1.5-alpha.
Fix a memory leak when we check whether a hidden service
descriptor has any usable introduction points left. Fixes bug
4424. Bugfix on 0.2.2.25-alpha.
Don't crash when we're running as a relay and don't have a GeoIP
file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix
we've had in the 0.2.3.x branch already.
When running as a client, do not print a misleading (and plain
wrong) log message that we're collecting "directory request"
statistics: clients don't collect statistics. Also don't create a
useless (because empty) stats file in the stats/ directory. Fixes
bug 4353; bugfix on 0.2.2.34.

Minor bugfixes:
Detect failure to initialize Libevent. This fix provides better
detection for future instances of bug 4457.
Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
function. This was eating up hideously large amounts of time on some
busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
Resolve an integer overflow bug in smartlist_ensure_capacity().
Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
Mansour Moufid.
Don't warn about unused log_mutex in log.c when building with
--disable-threads using a recent GCC. Fixes bug 4437; bugfix on
0.1.0.6-rc which introduced --disable-threads.
When configuring, starting, or stopping an NT service, stop
immediately after the service configuration attempt has succeeded
or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
When sending a NETINFO cell, include the original address
received for the other side, not its canonical address. Found
by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
Fix a typo in a hibernation-related log message. Fixes bug 4331;
bugfix on 0.2.2.23-alpha; found by "tmpname0901".
Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
occurred when a client tried to fetch a descriptor for a bridge
in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
Backport fixes for a pair of compilation warnings on Windows.
Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
If we had ever tried to call tor_addr_to_str on an address of
unknown type, we would have done a strdup on an uninitialized
buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
Reported by "troll_un".
Correctly detect and handle transient lookup failures from
tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha.
Reported by "troll_un".
Fix null-pointer access that could occur if TLS allocation failed.
Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
Use tor_socket_t type for listener argument to accept(). Fixes bug
4535; bugfix on 0.2.2.28-beta. Found by "troll_un".

Minor features:
Add two new config options for directory authorities:
AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
that is always sufficient to satisfy the bandwidth requirement for
the Guard flag. Now it will be easier for researchers to simulate
Tor networks with different values. Resolves ticket 4484.
When Tor ignores a hidden service specified in its configuration,
include the hidden service's directory in the warning message.
Previously, we would only tell the user that some hidden service
was ignored. Bugfix on 0.0.6; fixes bug 4426.
Update to the December 6 2011 Maxmind GeoLite Country database.

Packaging changes:
Make it easier to automate expert package builds on Windows,
by removing an absolute path from makensis.exe command.

Tor 0.2.3.10-alpha fixes a critical heap-overflow security issue in
Tor's buffers code. Absolutely everybody should upgrade.

The bug relied on an incorrect calculation when making data continuous
in one of our IO buffers, if the first chunk of the buffer was
misaligned by just the wrong amount. The miscalculation would allow an
attacker to overflow a piece of heap-allocated memory. To mount this
attack, the attacker would need to either open a SOCKS connection to
Tor's SocksPort (usually restricted to localhost), or target a Tor
instance configured to make its connections through a SOCKS proxy
(which Tor does not do by default).

Good security practice requires that all heap-overflow bugs should be
presumed to be exploitable until proven otherwise, so we are treating
this as a potential code execution attack. Please upgrade immediately!
This bug does not affect bufferevents-based builds of Tor. Special
thanks to "Vektor" for reporting this issue to us!

This release also contains a few minor bugfixes for issues discovered
in 0.2.3.9-alpha.

https://www.torproject.org/download

Changes in version 0.2.3.10-alpha - 2011-12-16

Major bugfixes
Fix a heap overflow bug that could occur when trying to pull
data into the first chunk of a buffer, when that chunk had
already had some data drained from it. Fixes CVE-2011-2778;
bugfix on 0.2.0.16-alpha. Reported by "Vektor".

Minor bugfixes
If we can't attach streams to a rendezvous circuit when we
finish connecting to a hidden service, clear the rendezvous
circuit's stream-isolation state and try to attach streams
again. Previously, we cleared rendezvous circuits' isolation
state either too early (if they were freshly built) or not at all
(if they had been built earlier and were cannibalized). Bugfix on
0.2.3.3-alpha; fixes bug 4655.
Fix compilation of the libnatpmp helper on non-Windows. Bugfix on
0.2.3.9-alpha; fixes bug 4691. Reported by Anthony G. Basile.
Fix an assertion failure when a relay with accounting enabled
starts up while dormant. Fixes bug 4702; bugfix on 0.2.3.9-alpha.

Minor features
Update to the December 6 2011 Maxmind GeoLite Country database.

The Tor Browser Bundles have been updated to Tor 0.2.2.35 which has a fix for a security critical bug. Please see the release announcement for further details. All users should update immediately.

This Tor Browser Bundle release also contains new Firefox patches which improve privacy and unlinkability.

https://www.torproject.org/download

Tor Browser Bundle (2.2.35-1)
Update Tor to 0.2.2.35
Update NoScript to 2.2.3
Update Torbutton to 1.4.5
New Firefox patches
Disable SSL Session ID tracking
Provide an observer event to close persistent connections

Tor Browser Bundle (2.2.35-2); suite=windows

* Update Firefox to 9.0
* Update Torbutton to 1.4.5.1
* Update Noscript to 2.2.4
* New Firefox patches
- Provide client values only to CSS Media Queries and disable several
Mozilla extensions that seem fingerprintable