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SUMMARY:
This is a critical security announcement.
An attack that exploits a Firefox vulnerability in JavaScript [1]
has been observed in the wild. Specifically, Windows users using the
Tor Browser Bundle (which includes Firefox plus privacy patches [2])
appear to have been targeted.
This vulnerability was fixed in Firefox 17.0.7 ESR [3]. The following
versions of the Tor Browser Bundle include this fixed version:
2.3.25-10 (released June 26 2013) [4]
2.4.15-alpha-1 (released June 26 2013) [4]
2.4.15-beta-1 (released July 8 2013) [5]
3.0alpha2 (released June 30 2013) [6]
Tor Browser Bundle users should ensure they're running a recent enough
bundle version, and consider taking further security precautions as
described below.
WHO IS AFFECTED:
In principle, all users of all Tor Browser Bundles earlier than
the above versions are vulnerable. But in practice, it appears that
only Windows users with vulnerable Firefox versions were actually
exploitable by this attack.
(If you're not sure what version you have, click on "Help -> About
Torbrowser" and make sure it says Firefox 17.0.7. Here's a video: [7])
To be clear, while the Firefox vulnerability is cross-platform, the
attack code is Windows-specific. It appears that TBB users on Linux
and OS X, as well as users of LiveCD systems like Tails, were not
exploited by this attack.
IMPACT:
The vulnerability allows arbitrary code execution, so an attacker
could in principle take over the victim's computer. However, the
observed version of the attack appears to collect the hostname and MAC
address of the victim computer, send that to a remote webserver over
a non-Tor connection, and then crash or exit [8]. The attack appears
to have been injected into (or by) various Tor hidden services [9],
and it's reasonable to conclude that the attacker now has a list of
vulnerable Tor users who visited those hidden services.
We don't currently believe that the attack modifies anything on the
victim computer.
WHAT TO DO:
First, be sure you're running a recent enough Tor Browser Bundle. That
should keep you safe from this attack.
Second, be sure to keep up-to-date in the future. Tor Browser Bundle
automatically checks whether it's out of date, and notifies you on its
homepage when you need to upgrade. Recent versions also add a flashing
exclamation point over the Tor onion icon. We also post about new
versions on the Tor blog: https://blog.torproject.org/
Third, realize that this wasn't the first Firefox vulnerability, nor
will it be the last [10]. Consider disabling JavaScript (click the blue
"S" beside the green onion, and select "Forbid Scripts Globally").
Disabling JavaScript will reduce your vulnerability to other attacks
like this one, but disabling JavaScript will make some websites not work
like you expect. A future version of Tor Browser Bundle will have an
easier interface for letting you configure your JavaScript settings [11].
You might also like Request Policy [12]. And you might want to randomize
your MAC address, install various firewalls, etc.
Fourth, consider switching to a "live system" approach like Tails [13].
Really, switching away from Windows is probably a good security move
for many reasons.
And finally, be aware that many other vectors remain for vulnerabilities
in Firefox. JavaScript is one big vector for attack, but many other
big vectors exist, like css, svg, xml, the renderer, etc. We need
help improving usability of (and doing more security analysis of)
better sandboxing approaches [14] as well as VM-based approaches like
Whonix [15] and WiNoN [16]. Please help!
[1] https://www.mozilla.org/security/announce/2013/mfsa2013-53.html
[2] https://www.torproject.org/projects/torbrowser/design/
[3] https://blog.mozilla.org/security/2013/08/04/investigating-security-vulnera…
[4] https://blog.torproject.org/blog/new-tor-browser-bundles-and-tor-02414-alph…
[5] https://blog.torproject.org/blog/tor-02415-rc-packages-available
[6] https://blog.torproject.org/blog/tor-browser-bundle-30alpha2-released
[7] https://media.torproject.org/video/2013-08-05-TBBversion.mp4
[8] http://tsyrklevich.net/tbb_payload.txt
[9] https://blog.torproject.org/blog/hidden-services-current-events-and-freedom…
[10] https://www.mozilla.org/security/known-vulnerabilities/firefoxESR.html
[11] https://trac.torproject.org/projects/tor/ticket/9387
[12] https://www.requestpolicy.com/
[13] https://tails.boum.org/
[14] https://trac.torproject.org/projects/tor/ticket/7680
[15] http://sourceforge.net/projects/whonix/
[16] http://dedis.cs.yale.edu/2010/anon/papers/osdi12.pdf
https://trac.torproject.org/projects/tor/ticket/7681
1
0
The Tor 0.2.3 release series is dedicated to the memory of Len "rabbi"
Sassaman (1980-2011), a long-time cypherpunk, anonymity researcher,
Mixmaster maintainer, Pynchon Gate co-designer, CodeCon organizer,
programmer, and friend. Unstinting in his dedication to the cause of
freedom, he inspired and helped many of us as we began our work on
anonymity, and inspires us still. Please honor his memory by writing
software to protect people's freedoms, and by helping others to do so.
Tor 0.2.3.25, the first stable release in the 0.2.3 branch, features
significantly reduced directory overhead (via microdescriptors),
enormous crypto performance improvements for fast relays on new
enough hardware, a new v3 TLS handshake protocol that can better
resist fingerprinting, support for protocol obfuscation plugins (aka
pluggable transports), better scalability for hidden services, IPv6
support for bridges, performance improvements like allowing clients
to skip the first round-trip on the circuit ("optimistic data") and
refilling token buckets more often, a new "stream isolation" design
to isolate different applications on different circuits, and many
stability, security, and privacy fixes.
(I apologize for the delay in announcing the release to this list:
I was waiting for the Tor Browser Bundles with it to stabilize a bit,
but with the new integration to Firefox 17, it's become clear that TBB
will be in flux a while more.)
https://www.torproject.org/download/download
Changes in version 0.2.3.25 - 2012-11-19
Major features (v3 directory protocol):
- Clients now use microdescriptors instead of regular descriptors
to build circuits. Microdescriptors are authority-generated
summaries of regular descriptors' contents, designed to change very
rarely (see proposal 158 for details). This feature is designed
to save bandwidth, especially for clients on slow internet
connections. Use "UseMicrodescriptors 0" to disable it.
- Caches now download, cache, and serve microdescriptors, as well
as multiple "flavors" of the consensus, including a flavor that
describes microdescriptors.
o Major features (build hardening):
- Enable gcc and ld hardening by default. Resolves ticket 5210.
o Major features (relay scaling):
- When built to use OpenSSL 1.0.1, and built for an x86 or x86_64
instruction set, take advantage of OpenSSL's AESNI, bitsliced, or
vectorized AES implementations as appropriate. These can be much,
much faster than other AES implementations.
- 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.
- Use OpenSSL's EVP interface for AES encryption, so that all AES
operations can use hardware acceleration (if present). Resolves
ticket 4442.
- 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.
o Major features (blocking resistance):
- Update TLS cipher list to match Firefox 8 and later. Resolves
ticket 4744.
- Remove support for clients falsely claiming to support standard
ciphersuites that they can actually provide. As of modern OpenSSL
versions, it's not necessary to fake any standard ciphersuite,
and doing so prevents us from using better ciphersuites in the
future, since servers can't know whether an advertised ciphersuite
is really supported or not. Some hosts -- notably, ones with very
old versions of OpenSSL or where OpenSSL has been built with ECC
disabled -- will stand out because of this change; TBB users should
not be affected. Implements the client side of proposal 198.
- Implement a new handshake protocol (v3) for authenticating Tors to
each other over TLS. It should be more resistant to fingerprinting
than previous protocols, and should require less TLS hacking for
future Tor implementations. Implements proposal 176.
- Allow variable-length padding cells, to disguise the length of
Tor's TLS records. Implements part of proposal 184.
- While we're trying to bootstrap, record how many TLS connections
fail in each state, and report which states saw the most failures
in response to any bootstrap failures. This feature may speed up
diagnosis of censorship events. Implements ticket 3116.
o Major features (pluggable transports):
- 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.
Implements proposal 180 (tickets 2841 and 3472).
o Major features (DoS resistance):
- Now that Tor 0.2.0.x is completely deprecated, enable the final
part of "Proposal 110: Avoiding infinite length circuits" by
refusing all circuit-extend requests that do not use a relay_early
cell. This change helps Tor resist a class of denial-of-service
attacks by limiting the maximum circuit length.
- Tear down the circuit if we get an unexpected SENDME cell. Clients
could use this trick to make their circuits receive cells faster
than our flow control would have allowed, or to gum up the network,
or possibly to do targeted memory denial-of-service attacks on
entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor --
from July 2002, before the release of Tor 0.0.0.
o Major features (hidden services):
- Adjust the number of introduction points that a hidden service
will try to maintain based on how long its introduction points
remain in use and how many introductions they handle. Fixes
part of bug 3825.
- 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.
o Major features (IPv6):
- 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.
o Major features (directory authorities):
- 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.
- 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.
o Major features (performance):
- Exit nodes now accept and queue data on not-yet-connected streams.
Previously, the client wasn't allowed to send data until the
stream was connected, which slowed down all connections. This
change will enable clients to perform a "fast-start" on streams
and send data without having to wait for a confirmation that the
stream has opened. Patch from Ian Goldberg; implements the server
side of Proposal 174.
- When using an exit relay running 0.2.3.x, clients can now
"optimistically" send data before the exit relay reports that
the stream has opened. This saves a round trip when starting
connections where the client speaks first (such as web browsing).
This behavior is controlled by a consensus parameter (currently
disabled). To turn it on or off manually, use the "OptimisticData"
torrc option. Implements proposal 181; code by Ian Goldberg.
- 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.
- Raise the threshold of server descriptors needed (75%) and exit
server descriptors needed (50%) before we will declare ourselves
bootstrapped. This will make clients start building circuits a
little later, but makes the initially constructed circuits less
skewed and less in conflict with further directory fetches. Fixes
ticket 3196.
o Major features (relays):
- Relays now try regenerating and uploading their descriptor more
frequently if they are not listed in the consensus, or if the
version of their descriptor listed in the consensus is too
old. This fix should prevent situations where a server declines
to re-publish itself because it has done so too recently, even
though the authorities decided not to list its recent-enough
descriptor. Fix for bug 3327.
o Major features (stream isolation):
- You can now configure Tor so that streams from different
applications are isolated on different circuits, to prevent an
attacker who sees your streams as they leave an exit node from
linking your sessions to one another. To do this, choose some way
to distinguish the applications: have them connect to different
SocksPorts, or have one of them use SOCKS4 while the other uses
SOCKS5, or have them pass different authentication strings to the
SOCKS proxy. Then, use the new SocksPort syntax to configure the
degree of isolation you need. This implements Proposal 171.
- There's a new syntax for specifying multiple client ports (such as
SOCKSPort, TransPort, DNSPort, NATDPort): you can now just declare
multiple *Port entries with full addr:port syntax on each.
The old *ListenAddress format is still supported, but you can't
mix it with the new *Port syntax.
o Major features (bufferevents):
- Tor can now optionally build with the "bufferevents" buffered IO
backend provided by Libevent 2. To use this feature, make sure you
have the latest possible version of Libevent, and pass the
--enable-bufferevents flag to configure when building Tor from
source. This feature will make our networking code more flexible,
let us stack layers on each other, and let us use more efficient
zero-copy transports where available.
- 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 bufferevents enabled,
you're running on Windows, and you've set "DisableIOCP 0". In the
long run, this may help solve or mitigate bug 98.
o Major features (path selection):
- The EntryNodes option can now include country codes like {de} or IP
addresses or network masks. Previously we had disallowed these
options because we didn't have an efficient way to keep the list up
to date. Addresses ticket 1982, but see bug 2798 for an unresolved
issue here.
o Major features (port forwarding):
- Add support for automatic port mapping on the many home routers
that support NAT-PMP or UPnP. To build the support code, you'll
need to have the libnatpnp library and/or the libminiupnpc library,
and you'll need to enable the feature specifically by passing
"--enable-upnp" and/or "--enable-natpnp" to ./configure. To turn
it on, use the new PortForwarding option.
o Major features (logging):
- Add a new 'Heartbeat' log message type to periodically log a message
describing Tor's status at level Notice. This feature is meant for
operators who log at notice, and want to make sure that their Tor
server is still working. Implementation by George Kadianakis.
- Make logging resolution configurable with a new LogTimeGranularity
option, and change the default from 1 millisecond to 1 second.
Implements enhancement 1668.
o Major features (other):
- 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.
- Try to use system facilities for enumerating local interface
addresses, before falling back to our old approach (which was
binding a UDP socket, and calling getsockname() on it). That
approach was scaring OS X users whose draconian firewall
software warned about binding to UDP sockets regardless of
whether packets were sent. Now we try to use getifaddrs(),
SIOCGIFCONF, or GetAdaptersAddresses(), depending on what the
system supports. Resolves ticket 1827.
- 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. Implements task 4552.
o New directory authorities:
- Add Faravahar (run by Sina Rabbani) as the ninth v3 directory
authority. Closes ticket 5749.
o Security/privacy fixes:
- Avoid read-from-freed-memory and double-free bugs that could occur
when a DNS request fails while launching it. Fixes bug 6480;
bugfix on 0.2.0.1-alpha.
- Reject any attempt to extend to an internal address. Without
this fix, a router could be used to probe addresses on an internal
network to see whether they were accepting connections. Fixes bug
6710; bugfix on 0.0.8pre1.
- Close any connection that sends unrecognized junk before the TLS
handshake. Solves an issue noted in bug 4369.
- The advertised platform of a relay now includes only its operating
system's name (e.g., "Linux", "Darwin", "Windows 7"), and not
its service pack level (for Windows) or its CPU architecture
(for Unix). Also drop the "git-XYZ" tag in the version. Packagers
can insert an extra string in the platform line by setting the
preprocessor variable TOR_BUILD_TAG. Resolves bug 2988.
- Disable TLS session tickets. OpenSSL's implementation was giving
our TLS session keys the lifetime of our TLS context objects, when
perfect forward secrecy would want us to discard anything that
could decrypt a link connection as soon as the link connection
was closed. Fixes bug 7139; bugfix on all versions of Tor linked
against OpenSSL 1.0.0 or later. Found by Florent Daignière.
- Tor tries to wipe potentially sensitive data after using it, so
that if some subsequent security failure exposes Tor's memory,
the damage will be limited. But we had a bug where the compiler
was eliminating these wipe operations when it decided that the
memory was no longer visible to a (correctly running) program,
hence defeating our attempt at defense in depth. We fix that
by using OpenSSL's OPENSSL_cleanse() operation, which a compiler
is unlikely to optimize away. Future versions of Tor may use
a less ridiculously heavy approach for this. Fixes bug 7352.
Reported in an article by Andrey Karpov.
o Major bugfixes (crashes and asserts):
- Avoid a pair of double-free and use-after-mark bugs that can
occur with certain timings in canceled and re-received DNS
requests. Fixes bug 6472; bugfix on 0.0.7rc1.
- Fix a denial of service attack by which any directory authority
could crash all the others, or by which a single v2 directory
authority could crash everybody downloading v2 directory
information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.
- Fix an assert that directory authorities could trigger on sighup
during some configuration state transitions. We now don't treat
it as a fatal error when the new descriptor we just generated in
init_keys() isn't accepted. Fixes bug 4438; bugfix on 0.2.1.9-alpha.
- Avoid segfault when starting up having run with an extremely old
version of Tor and parsing its state file. Fixes bug 6801; bugfix
on 0.2.2.23-alpha.
o Major bugfixes (clients):
- If we are unable to find any exit that supports our predicted ports,
stop calling them predicted, so that we don't loop and build
hopeless circuits indefinitely. Fixes bug 3296; bugfix on 0.0.9pre6,
which introduced predicted ports.
- Check at each new consensus whether our entry guards were picked
long enough ago that we should rotate them. Previously, we only
did this check at startup, which could lead to us holding a guard
indefinitely. Fixes bug 5380; bugfix on 0.2.1.14-rc.
- When fetching a bridge descriptor from a bridge authority,
always do so anonymously, whether we have been able to open
circuits or not. Partial fix for bug 1938; bugfix on 0.2.0.7-alpha.
This behavior makes it *safer* to use UpdateBridgesFromAuthority,
but we'll need to wait for bug 6010 before it's actually usable.
o Major bugfixes (directory voting):
- Check more thoroughly to prevent a rogue authority from
double-voting on any consensus directory parameter. Previously,
authorities would crash in this case if the total number of
votes for any parameter exceeded the number of active voters,
but would let it pass otherwise. Partially fixes bug 5786; bugfix
on 0.2.2.2-alpha.
- When computing weight parameters, behave more robustly in the
presence of a bad bwweightscale value. Previously, the authorities
would crash if they agreed on a sufficiently broken weight_scale
value; now, they use a reasonable default and carry on. Fixes the
rest of bug 5786; bugfix on 0.2.2.17-alpha.
- If authorities are unable to get a v2 consensus document from other
directory authorities, they no longer fall back to fetching
them from regular directory caches. Fixes bug 5635; bugfix on
0.2.2.26-beta, where routers stopped downloading v2 consensus
documents entirely.
o Major bugfixes (relays):
- Fix a bug handling SENDME cells on nonexistent streams that could
result in bizarre window values. Report and patch contributed
pseudonymously. Fixes part of bug 6271. This bug was introduced
before the first Tor release, in svn commit r152.
- Don't update the AccountingSoftLimitHitAt state file entry whenever
tor gets started. This prevents a wrong average bandwidth
estimate, which would cause relays to always start a new accounting
interval at the earliest possible moment. Fixes bug 2003; bugfix
on 0.2.2.7-alpha. Reported by Bryon Eldridge, who also helped
immensely in tracking this bug down.
- Fix a possible crash bug when checking for deactivated circuits
in connection_or_flush_from_first_active_circuit(). Fixes bug 6341;
bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.
- Set the SO_REUSEADDR socket option before we call bind() on outgoing
connections. This change should allow busy exit relays to stop
running out of available sockets as quickly. Fixes bug 4950;
bugfix on 0.2.2.26-beta.
o Major bugfixes (blocking resistance):
- 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.
- Warn the user when HTTPProxy, but no other proxy type, is
configured. This can cause surprising behavior: it doesn't send
all of Tor's traffic over the HTTPProxy -- it sends unencrypted
directory traffic only. Resolves ticket 4663.
o Major bugfixes (hidden services):
- Improve hidden service robustness: when an attempt to connect to
a hidden service ends, be willing to refetch its hidden service
descriptors from each of the HSDir relays responsible for them
immediately. Previously, we would not consider refetching the
service's descriptors from each HSDir for 15 minutes after the last
fetch, which was inconvenient if the hidden service was not running
during the first attempt. Bugfix on 0.2.0.18-alpha; fixes bug 3335.
- 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.
- When one of a hidden service's introduction points appears to be
unreachable, stop trying it. Previously, we would keep trying
to build circuits to the introduction point until we lost the
descriptor, usually because the user gave up and restarted Tor.
Fixes part of bug 3825.
o Changes to default torrc file:
- Stop listing "socksport 9050" in torrc.sample. We open a socks
port on 9050 by default anyway, so this should not change anything
in practice.
- Stop mentioning the deprecated *ListenAddress options in
torrc.sample. Fixes bug 5438.
- Document unit of bandwidth-related options in sample torrc.
Fixes bug 5621.
- Fix broken URLs in the sample torrc file, and tell readers about
the OutboundBindAddress, ExitPolicyRejectPrivate, and
PublishServerDescriptor options. Addresses bug 4652.
o Minor features (directory authorities):
- Consider new, removed or changed IPv6 OR ports a non-cosmetic
change when the authority is deciding whether to accept a newly
uploaded descriptor. Implements ticket 6423.
- Directory authorities are now a little more lenient at accepting
older router descriptors, or newer router descriptors that don't
make big changes. This should help ameliorate past and future
issues where routers think they have uploaded valid descriptors,
but the authorities don't think so. Fix for ticket 2479.
- Authority operators can now vote for all relays in a given
set of countries to be BadDir/BadExit/Invalid/Rejected.
- Provide two consensus parameters (FastFlagMinThreshold and
FastFlagMaxThreshold) to control the range of allowable bandwidths
for the Fast directory flag. These allow authorities to run
experiments on appropriate requirements for being a "Fast" node.
The AuthDirFastGuarantee config value still applies. Implements
ticket 3946.
o Minor features (bridges / bridge authorities):
- 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.
- Tag a bridge's descriptor as "never to be sent unencrypted".
This shouldn't matter, since bridges don't open non-anonymous
connections to the bridge authority and don't allow unencrypted
directory connections from clients, but we might as well make
sure. Closes bug 5139.
- The Bridge Authority now writes statistics on how many bridge
descriptors it gave out in total, and how many unique descriptors
it gave out. It also lists how often the most and least commonly
fetched descriptors were given out, as well as the median and
25th/75th percentile. Implements tickets 4200 and 4294.
o Minor features (IPv6):
- Make the code that clients use to detect an address change be
IPv6-aware, so that it won't fill clients' logs with error
messages when trying to get the IPv4 address of an IPv6
connection. Implements ticket 5537.
- Relays now understand an IPv6 address when they get one from a
directory server. Resolves ticket 4875.
o Minor features (hidden services):
- Expire old or over-used hidden service introduction points.
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.
- When a hidden service's introduction point times out, consider
trying it again during the next attempt to connect to the
HS. Previously, we would not try it again unless a newly fetched
descriptor contained it. Required by fixes for bugs 1297 and 3825.
o Minor features (relays):
- Relays now include a reason for regenerating their descriptors
in an HTTP header when uploading to the authorities. This will
make it easier to debug descriptor-upload issues in the future.
- Turn on directory request statistics by default and include them in
extra-info descriptors. Don't break if we have no GeoIP database.
- Replace files in stats/ rather than appending to them. Now that we
include statistics in extra-info descriptors, it makes no sense to
keep old statistics forever. Implements ticket 2930.
- Relays that set "ConnDirectionStatistics 1" write statistics on the
bidirectional use of connections to disk every 24 hours.
- Add a GeoIP file digest to the extra-info descriptor. Implements
ticket 1883.
o Minor features (new config options):
- New config option "DynamicDHGroups" (disabled by default) 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.
- New config option "DisableDebuggerAttachment" (on by default)
to prevent basic debugging attachment attempts by other processes.
Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
- Ordinarily, Tor does not count traffic from private addresses (like
127.0.0.1 or 10.0.0.1) when calculating rate limits or accounting.
There is now a new option, CountPrivateBandwidth, to disable this
behavior. Patch from Daniel Cagara.
o Minor features (different behavior for old config options):
- Allow MapAddress directives to specify matches against super-domains,
as in "MapAddress *.torproject.org *.torproject.org.torserver.exit".
Implements issue 933.
- Don't disable the DirPort when we cannot exceed our AccountingMax
limit during this interval because the effective bandwidthrate is
low enough. This is useful in a situation where AccountMax is only
used as an additional safeguard or to provide statistics.
- Add port 6523 (Gobby) to LongLivedPorts. Patch by intrigeri;
implements ticket 3439.
- When configuring a large set of nodes in EntryNodes, and there are
enough of them listed as Guard so that we don't need to consider
the non-guard entries, prefer the ones listed with the Guard flag.
- If you set the NumCPUs option to 0, Tor will now try to detect how
many CPUs you have. This is the new default behavior.
- The NodeFamily option -- which let you declare that you want to
consider nodes to be part of a family whether they list themselves
that way or not -- now allows IP address ranges and country codes.
o Minor features (new command-line config behavior):
- 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 "/".
o Minor features (controller, new events):
- Extend the control protocol to report flags that control a circuit's
path selection in CIRC events and in replies to 'GETINFO
circuit-status'. Implements part of ticket 2411.
- Extend the control protocol to report the hidden service address
and current state of a hidden-service-related circuit in CIRC
events and in replies to 'GETINFO circuit-status'. Implements part
of ticket 2411.
- Include the creation time of a circuit in CIRC and CIRC2
control-port events and the list produced by the 'GETINFO
circuit-status' control-port command.
- Add a new CONF_CHANGED event so that controllers can be notified
of any configuration changes made by other controllers, or by the
user. Implements ticket 1692.
- Add a new SIGNAL event to the controller interface so that
controllers can be notified when Tor handles a signal. Resolves
issue 1955. Patch by John Brooks.
o Minor features (controller, new getinfo options):
- Expose our view of whether we have gone dormant to the controller,
via a new "GETINFO dormant" value. Torbutton and other controllers
can use this to avoid doing periodic requests through Tor while
it's dormant (bug 4718). Resolves ticket 5954.
- Add a new GETINFO option to get total bytes read and written. Patch
from pipe, revised by atagar. Resolves ticket 2345.
- Implement new GETINFO controller fields to provide information about
the Tor process's pid, euid, username, and resource limits.
o Minor features (controller, other):
- Allow controllers to request an event notification whenever a
circuit is cannibalized or its purpose is changed. Implements
part of ticket 3457.
- Use absolute path names when reporting the torrc filename in the
control protocol, so a controller can more easily find the torrc
file. Resolves bug 1101.
- When reporting the path to the cookie file to the controller,
give an absolute path. Resolves ticket 4881.
o Minor features (log messages):
- Add more information to a log statement that might help track down
bug 4091. If you're seeing "Bug: tor_addr_is_internal() called with a
non-IP address" messages (or any Bug messages, for that matter!),
please let us know about it.
- If EntryNodes are given, but UseEntryGuards is set to 0, warn that
EntryNodes will have no effect. Resolves issue 2571.
- Try to make the introductory warning message that Tor prints on
startup more useful for actually finding help and information.
Resolves ticket 2474.
- When the system call to create a listener socket fails, log the
error message explaining why. This may help diagnose bug 4027.
o Minor features (other):
- 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.
- When starting as root and then changing our UID via the User
control option, and we have a ControlSocket configured, make sure
that the ControlSocket is owned by the same account that Tor will
run under. Implements ticket 3421; fix by Jérémy Bobbio.
- Accept attempts to include a password authenticator in the
handshake, as supported by SOCKS5. This handles SOCKS clients that
don't know how to omit a password when authenticating. Resolves
bug 1666.
- Check for and recover from inconsistency in the microdescriptor
cache. This will make it harder for us to accidentally free a
microdescriptor without removing it from the appropriate data
structures. Fixes issue 3135; issue noted by "wanoskarnet".
- Shorten links in the tor-exit-notice file. Patch by Christian Kujau.
o Minor bugfixes (code security):
- Prevent a null-pointer dereference when receiving a data cell
for a nonexistent stream when the circuit in question has an
empty deliver window. We don't believe this is triggerable,
since we don't currently allow deliver windows to become empty,
but the logic is tricky enough that it's better to make the code
robust. Fixes bug 5541; bugfix on 0.0.2pre14.
- Fix a (harmless) integer overflow in cell statistics reported by
some fast relays. Fixes bug 5849; bugfix on 0.2.2.1-alpha.
- Fix our implementation of crypto_random_hostname() so it can't
overflow on ridiculously large inputs. (No Tor version has ever
provided this kind of bad inputs, but let's be correct in depth.)
Fixes bug 4413; bugfix on 0.2.2.9-alpha. Fix by Stephen Palmateer.
- Add a (probably redundant) memory clear between iterations of
the router status voting loop, to prevent future coding errors
where data might leak between iterations of the loop. Resolves
ticket 6514.
o Minor bugfixes (wrapper functions):
- Abort if tor_vasprintf() fails in connection_printf_to_buf() (a
utility function used in the control-port code). This shouldn't
ever happen unless Tor is completely out of memory, but if it did
happen and Tor somehow recovered from it, Tor could have sent a log
message to a control port in the middle of a reply to a controller
command. Fixes part of bug 3428; bugfix on 0.1.2.3-alpha.
- 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.
- Enforce correct return behavior of tor_vsscanf() when the '%%'
pattern is used. Fixes bug 5558. Bugfix on 0.2.1.13.
- Make our replacement implementation of strtok_r() compatible with
the standard behavior of strtok_r(). Patch by nils. Fixes bug 5091;
bugfix on 0.2.2.1-alpha.
- Find more places in the code that should have been testing for
invalid sockets using the SOCKET_OK macro. Required for a fix
for bug 4533. Bugfix on 0.2.2.28-beta.
o Minor bugfixes (code correctness):
- Check return value of fputs() when writing authority certificate
file. Fixes Coverity issue 709056; bugfix on 0.2.0.1-alpha.
- When building Tor on Windows with -DUNICODE (not default), ensure
that error messages, filenames, and DNS server names are always
NUL-terminated when we convert them to a single-byte encoding.
Fixes bug 5909; bugfix on 0.2.2.16-alpha.
- Fix a memory leak when trying to launch a DNS request when the
nameservers are unconfigurable. Fixes bug 5916; bugfix on Tor
0.1.2.1-alpha.
- Correct file sizes when reading binary files on Cygwin, to avoid
a bug where Tor would fail to read its state file. Fixes bug 6844;
bugfix on 0.1.2.7-alpha.
- Make sure to set *socket_error in all error cases in
connection_connect(), so it can't produce a warning about
errno being zero from errno_to_orconn_end_reason(). Bugfix on
0.2.1.1-alpha; resolves ticket 6028.
- Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes
bug 4532; found by "troll_un".
o Minor bugfixes (clients):
- Allow one-hop directory-fetching circuits the full "circuit build
timeout" period, rather than just half of it, before failing them
and marking the relay down. This fix should help reduce cases where
clients declare relays (or worse, bridges) unreachable because
the TLS handshake takes a few seconds to complete. Fixes bug 6743;
bugfix on 0.2.2.2-alpha, where we changed the timeout from a static
30 seconds.
- Ensure we don't cannibalize circuits that are longer than three hops
already, so we don't end up making circuits with 5 or more
hops. Patch contributed by wanoskarnet. Fixes bug 5231; bugfix on
0.1.0.1-rc which introduced cannibalization.
o Minor bugfixes (relays):
- Don't publish a new relay descriptor when we reload our onion key,
unless the onion key has actually changed. Fixes bug 3263 and
resolves another cause of bug 1810. Bugfix on 0.1.1.11-alpha.
- When relays refuse a "create" cell because their queue of pending
create cells is too big (typically because their cpu can't keep up
with the arrival rate), send back reason "resource limit" rather
than reason "internal", so network measurement scripts can get a
more accurate picture. Bugfix on 0.1.1.11-alpha; fixes bug 7037.
- Exit nodes don't need to fetch certificates for authorities that
they don't recognize; only directory authorities, bridges,
and caches need to do that. Fixes part of bug 2297; bugfix on
0.2.2.11-alpha.
o Minor bugfixes (directory authority / mirrors):
- Avoid O(n^2) performance characteristics when parsing a large
extrainfo cache. Fixes bug 5828; bugfix on 0.2.0.1-alpha.
- Authorities no longer include any router in their microdescriptor
consensuses for which they couldn't generate or agree on a
microdescriptor. Fixes the second piece of bug 6404; fix on
0.2.2.6-alpha.
- When checking for requested signatures on the latest consensus
before serving it to a client, make sure to check the right
consensus flavor. Bugfix on 0.2.2.6-alpha.
- Fix an edge case where TestingTorNetwork is set but the authorities
and relays all have an uptime of zero, so the private Tor network
could briefly lack support for hidden services. Fixes bug 3886;
bugfix on 0.2.2.18-alpha.
- Directory caches no longer refuse to clean out descriptors because
of missing v2 networkstatus documents, unless they're configured
to retrieve v2 networkstatus documents. Fixes bug 4838; bugfix on
0.2.2.26-beta. Patch by Daniel Bryg.
- Don't serve or accept v2 hidden service descriptors over a relay's
DirPort. It's never correct to do so, and disabling it might
make it more annoying to exploit any bugs that turn up in the
descriptor-parsing code. Fixes bug 7149.
o Minor bugfixes (hidden services, client-side):
- Assert that hidden-service-related operations are not performed
using single-hop circuits. Previously, Tor would assert that
client-side streams are not attached to single-hop circuits,
but not that other sensitive operations on the client and service
side are not performed using single-hop circuits. Fixes bug 3332;
bugfix on 0.0.6.
- Avoid undefined behaviour when parsing the list of supported
rendezvous/introduction protocols in a hidden service descriptor.
Previously, Tor would have confused (as-yet-unused) protocol version
numbers greater than 32 with lower ones on many platforms. Fixes
bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.
- Don't close hidden service client circuits which have almost
finished connecting to their destination when they reach
the normal circuit-build timeout. Previously, we would close
introduction circuits which are waiting for an acknowledgement
from the introduction point, and rendezvous circuits which have
been specified in an INTRODUCE1 cell sent to a hidden service,
after the normal CBT. Now, we mark them as 'timed out', and launch
another rendezvous attempt in parallel. This behavior change can
be disabled using the new CloseHSClientCircuitsImmediatelyOnTimeout
option. Fixes part of bug 1297; bugfix on 0.2.2.2-alpha.
o Minor bugfixes (hidden services, service-side):
- Don't close hidden-service-side rendezvous circuits when they
reach the normal circuit-build timeout. This behaviour change can
be disabled using the new
CloseHSServiceRendCircuitsImmediatelyOnTimeout option. Fixes the
remaining part of bug 1297; bugfix on 0.2.2.2-alpha.
- Don't launch more than 10 service-side introduction-point circuits
for a hidden service in five minutes. Previously, we would consider
launching more introduction-point circuits if at least one second
had passed without any introduction-point circuits failing. Fixes
bug 4607; bugfix on 0.0.7pre1.
o Minor bugfixes (config option behavior):
- If the user tries to set MyFamily on a bridge, refuse to
do so, and warn about the security implications. Fixes bug 4657;
bugfix on 0.2.0.3-alpha.
- The "--quiet" and "--hush" options now apply not only to Tor's
behavior before logs are configured, but also to Tor's behavior in
the absense of configured logs. Fixes bug 3550; bugfix on
0.2.0.10-alpha.
- Change the AllowDotExit rules so they should actually work.
We now enforce AllowDotExit only immediately after receiving an
address via SOCKS or DNSPort: other sources are free to provide
.exit addresses after the resolution occurs. Fixes bug 3940;
bugfix on 0.2.2.1-alpha.
- Make "LearnCircuitBuildTimeout 0" work more reliably. Specifically,
don't depend on the consensus parameters or compute adaptive
timeouts when it is disabled. Fixes bug 5049; bugfix on
0.2.2.14-alpha.
- After we pick a directory mirror, we would refuse to use it if
it's in our ExcludeExitNodes list, resulting in mysterious failures
to bootstrap for people who just wanted to avoid exiting from
certain locations. Fixes bug 5623; bugfix on 0.2.2.25-alpha.
- When told to add a bridge with the same digest as a preexisting
bridge but a different addr:port, change the addr:port as
requested. Previously we would not notice the change. Fixes half
of bug 5603; fix on 0.2.2.26-beta.
o Minor bugfixes (controller):
- 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.
- 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.
- When we receive a SIGHUP and the controller __ReloadTorrcOnSIGHUP
option is set to 0 (which Vidalia version 0.2.16 now does when
a SAVECONF attempt fails), perform other actions that SIGHUP
usually causes (like reopening the logs). Fixes bug 5095; bugfix
on 0.2.1.9-alpha.
- Correctly handle checking the permissions on the parent
directory of a control socket in the root directory. Bug found
by Esteban Manchado Velázquez. Fixes bug 5089; bugfix on Tor
0.2.2.26-beta.
- End AUTHCHALLENGE error messages (in the control protocol) with
a CRLF. Fixes bug 5760; bugfix on 0.2.2.36.
o Minor bugfixes (network reading/writing):
- Disable writing on marked-for-close connections when they are
blocked on bandwidth, to prevent busy-looping in Libevent. Fixes
bug 5263; bugfix on 0.0.2pre13, where we first added a special
case for flushing marked connections.
- Make sure that there are no unhandled pending TLS errors before
reading from a TLS stream. We had checks in 0.1.0.3-rc, but
lost them in 0.1.0.5-rc when we refactored read_to_buf_tls().
Bugfix on 0.1.0.5-rc; fixes bug 4528.
- Detect SSL handshake even when the initial attempt to write the
server hello fails. Fixes bug 4592; bugfix on 0.2.0.13-alpha.
- If the client fails to set a reasonable set of ciphersuites
during its v2 handshake renegotiation, allow the renegotiation to
continue nevertheless (i.e. send all the required certificates).
Fixes bug 4591; bugfix on 0.2.0.20-rc.
o Minor bugfixes (other):
- Exit nodes now correctly report EADDRINUSE and EADDRNOTAVAIL as
resource exhaustion, so that clients can adjust their load to
try other exits. Fixes bug 4710; bugfix on 0.1.0.1-rc, which
started using END_STREAM_REASON_RESOURCELIMIT.
- Don't check for whether the address we're using for outbound
connections has changed until after the outbound connection has
completed. On Windows, getsockname() doesn't succeed until the
connection is finished. Fixes bug 5374; bugfix on 0.1.1.14-alpha.
- Don't hold a Windows file handle open for every file mapping;
the file mapping handle is sufficient. Fixes bug 5951; bugfix on
0.1.2.1-alpha.
- Fix wrong TCP port range in parse_port_range(). Fixes bug 6218;
bugfix on 0.2.1.10-alpha.
- If we fail to write a microdescriptor to the disk cache, do not
continue replacing the old microdescriptor file. Fixes bug 2954;
bugfix on 0.2.2.6-alpha.
o Minor bugfixes (log messages, path selection):
- Downgrade "set buildtimeout to low value" messages to "info"
severity; they were never an actual problem, there was never
anything reasonable to do about them, and they tended to spam logs
from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
- Rate-limit the "Weighted bandwidth is 0.000000" message, and add
more information to it, so that we can track it down in case it
returns again. Mitigates bug 5235.
- Check CircuitBuildTimeout and LearnCircuitBuildTimeout in
options_validate(); warn if LearnCircuitBuildTimeout is disabled and
CircuitBuildTimeout is set unreasonably low. Resolves ticket 5452.
- Issue a log message if a guard completes less than 40% of your
circuits. Threshold is configurable by torrc option
PathBiasNoticeRate and consensus parameter pb_noticepct. There is
additional, off-by-default code to disable guards which fail too
many circuits. Addresses ticket 5458.
o Minor bugfixes (log messages, client):
- Downgrade "Got a certificate, but we already have it" log messages
from warning to info, except when we're a dirauth. Fixes bug 5238;
bugfix on 0.2.1.7-alpha.
- Fix the log message describing how we work around discovering
that our version is the ill-fated OpenSSL 0.9.8l. Fixes bug
4837; bugfix on 0.2.2.9-alpha.
- When logging about a disallowed .exit name, do not also call it
an "invalid onion address". Fixes bug 3325; bugfix on 0.2.2.9-alpha.
- Fix a log message suggesting that people contact a non-existent
email address. Fixes bug 3448.
- Rephrase the log message emitted if the TestSocks check is
successful. Patch from Fabian Keil; fixes bug 4094.
- Log (at debug level) whenever a circuit's purpose is changed.
- Log SSL state transitions at log level DEBUG, log domain
HANDSHAKE. This can be useful for debugging censorship events.
Implements ticket 3264.
- We now log which torrc file we're using on startup. Implements
ticket 2444.
- Rate-limit log messages when asked to connect anonymously to
a private address. When these hit, they tended to hit fast and
often. Also, don't bother trying to connect to addresses that we
are sure will resolve to 127.0.0.1: getting 127.0.0.1 in a directory
reply makes us think we have been lied to, even when the address the
client tried to connect to was "localhost." Resolves ticket 2822.
o Minor bugfixes (log messages, non-client):
- Downgrade "eventdns rejected address" message to LOG_PROTOCOL_WARN.
Fixes bug 5932; bugfix on 0.2.2.7-alpha.
- Don't log that we have "decided to publish new relay descriptor"
unless we are actually publishing a descriptor. Fixes bug 3942;
bugfix on 0.2.2.28-beta.
- Log which authority we're missing votes from when we go to fetch
them from the other auths.
- Replace "Sending publish request" log messages with "Launching
upload", so that they no longer confusingly imply that we're
sending something to a directory we might not even be connected
to yet. Fixes bug 3311; bugfix on 0.2.0.10-alpha.
- Warn when Tor is configured to use accounting in a way that can
link a hidden service to some other hidden service or public
address. Resolves ticket 6490.
- Fix a minor formatting issue in one of tor-gencert's error messages.
Fixes bug 4574.
o Testing:
- Update to the latest version of the tinytest unit testing framework.
This includes a couple of bugfixes that can be relevant for
running forked unit tests on Windows, and removes all reserved
identifiers.
- Avoid a false positive in the util/threads unit test by increasing
the maximum timeout time. Fixes bug 6227; bugfix on 0.2.0.4-alpha.
- Make it possible to set the TestingTorNetwork configuration
option using AlternateDirAuthority and AlternateBridgeAuthority
as an alternative to setting DirServer. Addresses ticket 6377.
- Add a unit test for the environment_variable_names_equal() function.
- A wide variety of new unit tests by Esteban Manchado Velázquez.
- 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.
- Use tt_assert(), not tor_assert(), for checking for test failures.
This makes the unit tests more able to go on in the event that
one of them fails.
o Build improvements:
- Use the dead_strip option when building Tor on OS X. This reduces
binary size by almost 19% when linking openssl and libevent
statically, which we do for Tor Browser Bundle.
- Provide a better error message about possible OSX Asciidoc failure
reasons. Fixes bug 6436.
- Detect attempts to build Tor on (as yet hypothetical) versions
of Windows where sizeof(intptr_t) != sizeof(SOCKET). Partial
fix for bug 4533. Bugfix on 0.2.2.28-beta.
- On Windows, we now define the _WIN32_WINNT macros only if they
are not already defined. This lets the person building Tor decide,
if they want, to require a later version of Windows.
- Our autogen.sh script now uses autoreconf to launch autoconf,
automake, and so on. This is more robust against some of the failure
modes associated with running the autotools pieces on their own.
- Running "make version" now displays the version of Tor that
we're about to build. Idea from katmagic; resolves issue 4400.
- Make 'tor --digests' list hashes of all Tor source files. Bugfix
on 0.2.2.4-alpha; fixes bug 3427.
- New --enable-static-tor configure option for building Tor as
statically as possible. Idea, general hackery and thoughts from
Alexei Czeskis, John Gilmore, Jacob Appelbaum. Implements ticket
2702.
- Limited, experimental support for building with nmake and MSVC.
o Build requirements:
- Building Tor with bufferevent support now requires Libevent
2.0.13-stable or later. Previous versions of Libevent had bugs in
SSL-related bufferevents and related issues that would make Tor
work badly with bufferevents. Requiring 2.0.13-stable also allows
Tor with bufferevents to take advantage of Libevent APIs
introduced after 2.0.8-rc.
- Our build system requires automake 1.6 or later to create the
Makefile.in files. Previously, you could have used 1.4.
This only affects developers and people building Tor from git;
people who build Tor from the source distribution without changing
the Makefile.am files should be fine.
- 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.
o Build fixes (compile/link):
- Format more doubles with %f, not %lf. Patch from grarpamp to make
Tor build correctly on older BSDs again. Fixes bug 3894; bugfix on
Tor 0.2.0.8-alpha.
- When building with --enable-static-tor on OpenBSD, do not
erroneously attempt to link -lrt. Fixes bug 5103.
- Set _WIN32_WINNT to 0x0501 consistently throughout the code, so
that IPv6 stuff will compile on MSVC, and compilation issues
will be easier to track down. Fixes bug 5861.
- Fix build and 64-bit compile warnings from --enable-openbsd-malloc.
Fixes bug 6379. Bugfix on 0.2.0.20-rc.
- Make Tor build correctly again with -DUNICODE -D_UNICODE defined.
Fixes bug 6097; bugfix on 0.2.2.16-alpha.
o Build fixes (other):
- Use the _WIN32 macro throughout our code to detect Windows.
(Previously we had used the obsolete 'WIN32' and the idiosyncratic
'MS_WINDOWS'.)
- 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.
- During configure, search for library containing cos function as
libm lives in libcore on some platforms (BeOS/Haiku). Linking
against libm was hard-coded before. Fixes the first part of bug
4727; bugfix on 0.2.2.2-alpha. Patch and analysis by Martin Hebnes
Pedersen.
- Prevent a false positive from the check-spaces script, by disabling
the "whitespace between function name and (" check for functions
named 'op()'.
o Packaging (RPM) changes:
- Update our default RPM spec files to work with mock and rpmbuild
on RHEL/Fedora. They have an updated set of dependencies and
conflicts, a fix for an ancient typo when creating the "_tor"
user, and better instructions. Thanks to Ondrej Mikle for the
patch series. Fixes bug 6043.
- On OpenSUSE, create the /var/run/tor directory on startup if it
is not already created. Patch from Andreas Stieger. Fixes bug 2573.
o Code refactoring (safety):
- Do not use SMARTLIST_FOREACH for any loop whose body exceeds
10 lines. Also, don't nest them. Doing so in the past has
led to hard-to-debug code. The new style is to use the
SMARTLIST_FOREACH_{BEGIN,END} pair. Addresses issue 6400.
- Use macros to indicate OpenSSL versions, so we don't need to worry
about accidental hexadecimal bit shifts.
- Use tor_sscanf() in place of scanf() in more places through the
code. This makes us a little more locale-independent, and
should help shut up code-analysis tools that can't tell
a safe sscanf string from a dangerous one.
- Convert more instances of tor_snprintf+tor_strdup into tor_asprintf.
- Use the smartlist_add_asprintf() alias more consistently.
o Code refactoring (consolidate):
- A major revision to our internal node-selecting and listing logic.
Tor already had at least two major ways to look at the question of
"which Tor servers do we know about": a list of router descriptors,
and a list of entries in the current consensus. With
microdescriptors, we're adding a third. Having so many systems
without an abstraction layer over them was hurting the codebase.
Now, we have a new "node_t" abstraction that presents a consistent
interface to a client's view of a Tor node, and holds (nearly) all
of the mutable state formerly in routerinfo_t and routerstatus_t.
- Move tor_gettimeofday_cached() into compat_libevent.c, and use
Libevent's notion of cached time when possible.
- Remove duplicate code for invoking getrlimit() from control.c.
- Use OpenSSL's built-in SSL_state_string_long() instead of our
own homebrewed ssl_state_to_string() replacement. Patch from
Emile Snyder. Fixes bug 4653.
- Change the symmetric cipher interface so that creating and
initializing a stream cipher are no longer separate functions.
o Code refactoring (separate):
- Make a new "entry connection" struct as an internal subtype of "edge
connection", to simplify the code and make exit connections smaller.
- Split connection_about_to_close() into separate functions for each
connection type.
- Rewrite the listener-selection logic so that parsing which ports
we want to listen on is now separate from binding to the ports
we want.
o Code refactoring (name changes):
- Rename a handful of old identifiers, mostly related to crypto
structures and crypto functions. By convention, our "create an
object" functions are called "type_new()", our "free an object"
functions are called "type_free()", and our types indicate that
they are types only with a final "_t". But a handful of older
types and functions broke these rules, with function names like
"type_create" or "subsystem_op_type", or with type names like
type_env_t.
- Rename Tor functions that turn strings into addresses, so that
"parse" indicates that no hostname resolution occurs, and
"lookup" indicates that hostname resolution may occur. This
should help prevent mistakes in the future. Fixes bug 3512.
- Use the name "CERTS" consistently to refer to the new cell type;
we were calling it CERT in some places and CERTS in others.
- Use a TOR_INVALID_SOCKET macro when initializing a socket to an
invalid value, rather than just -1.
- 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.
o Code refactoring (other):
- Defensively refactor rend_mid_rendezvous() so that protocol
violations and length checks happen in the beginning. Fixes
bug 5645.
- 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.
- 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.
- The helper programs tor-gencert, tor-resolve, and tor-checkkey
no longer link against Libevent: they never used it, but
our library structure used to force them to link it.
o Removed features and files:
- Remove all internal support for unpadded RSA. We never used it, and
it would be a bad idea to start.
- Remove some workaround code for OpenSSL 0.9.6 (which is no longer
supported).
- Remove some redundant #include directives throughout the code.
Patch from Andrea Gelmini.
- Remove some old code to remember statistics about which descriptors
we've served as a directory mirror. The feature wasn't used and
is outdated now that microdescriptors are around.
- Remove some old code to work around even older versions of Tor that
used forked processes to handle DNS requests. Such versions of Tor
are no longer in use as relays.
- The "torify" script no longer supports the "tsocks" socksifier
tool, since tsocks doesn't support DNS and UDP right for Tor.
Everyone should be using torsocks instead. Fixes bugs 3530 and
5180. Based on a patch by "ugh".
- Remove the torrc.bridge file: we don't use it for anything, and
it had become badly desynchronized from torrc.sample. Resolves
bug 5622.
o Documentation:
- Begin a doc/state-contents.txt file to explain the contents of
the Tor state file. Fixes bug 2987.
- Clarify the documentation for the Alternate*Authority options.
Fixes bug 6387.
- Document the --defaults-torrc option, and the new semantics for
overriding, extending, and clearing lists of options. Closes
bug 4748.
- Add missing man page documentation for consensus and microdesc
files. Resolves ticket 6732.
- Fix some typos in the manpages. Patch from A. Costa. Fixes bug 6500.
o Documentation fixes:
- Improve the manual's documentation for the NT Service command-line
options. Addresses ticket 3964.
- Clarify SessionGroup documentation slightly; resolves ticket 5437.
- Document the changes to the ORPort and DirPort options, and the
fact that {OR/Dir}ListenAddress is now unnecessary (and
therefore deprecated). Resolves ticket 5597.
- Correct a broken faq link in the INSTALL file. Fixes bug 2307.
- Clarify that hidden services are TCP only. Fixes bug 6024.
1
0
Tor 0.2.2.39 fixes two more opportunities for remotely triggerable
assertions.
https://www.torproject.org/download/download
Changes in version 0.2.2.39 - 2012-09-11
o Security fixes:
- Fix an assertion failure in tor_timegm() that could be triggered
by a badly formatted directory object. Bug found by fuzzing with
Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.
- Do not crash when comparing an address with port value 0 to an
address policy. This bug could have been used to cause a remote
assertion failure by or against directory authorities, or to
allow some applications to crash clients. Fixes bug 6690; bugfix
on 0.2.1.10-alpha.
1
0
Tor 0.2.2.38 fixes a rare race condition that can crash exit relays;
fixes a remotely triggerable crash bug; and fixes a timing attack that
could in theory leak path information.
https://www.torproject.org/download/download
Changes in version 0.2.2.38 - 2012-08-12
o Security fixes:
- Avoid read-from-freed-memory and double-free bugs that could occur
when a DNS request fails while launching it. Fixes bug 6480;
bugfix on 0.2.0.1-alpha.
- Avoid an uninitialized memory read when reading a vote or consensus
document that has an unrecognized flavor name. This read could
lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
- Try to leak less information about what relays a client is
choosing to a side-channel attacker. Previously, a Tor client would
stop iterating through the list of available relays as soon as it
had chosen one, thus finishing a little earlier when it picked
a router earlier in the list. If an attacker can recover this
timing information (nontrivial but not proven to be impossible),
they could learn some coarse-grained information about which relays
a client was picking (middle nodes in particular are likelier to
be affected than exits). The timing attack might be mitigated by
other factors (see bug 6537 for some discussion), but it's best
not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.
1
0
Tor 0.2.2.37 introduces a workaround for a critical renegotiation
bug in OpenSSL 1.0.1 (where 20% of the Tor network can't talk to itself
currently).
https://www.torproject.org/download/download
Changes in version 0.2.2.37 - 2012-06-06
o Major bugfixes:
- Work around a bug in OpenSSL that broke renegotiation with TLS
1.1 and TLS 1.2. Without this workaround, all attempts to speak
the v2 Tor connection protocol when both sides were using OpenSSL
1.0.1 would fail. Resolves ticket 6033.
- When waiting for a client to renegotiate, don't allow it to add
any bytes to the input buffer. This fixes a potential DoS issue.
Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
- Fix an edge case where if we fetch or publish a hidden service
descriptor, we might build a 4-hop circuit and then use that circuit
for exiting afterwards -- even if the new last hop doesn't obey our
ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.
o Minor bugfixes:
- Fix a build warning with Clang 3.1 related to our use of vasprintf.
Fixes bug 5969. Bugfix on 0.2.2.11-alpha.
o Minor features:
- Tell GCC and Clang to check for any errors in format strings passed
to the tor_v*(print|scan)f functions.
1
0
Tor 0.2.2.36 updates the addresses for two of the eight directory
authorities, fixes some potential anonymity and security issues,
and fixes several crash bugs.
We're going to be following it soon with 0.2.2.37, which works around
a bug in OpenSSL's TLS renegotiation (currently being tested in the Tor
0.2.3.16-alpha release). Stay tuned.
Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many
known flaws, and nobody should be using them. You should upgrade. If
you're using a Linux or BSD and its packages are obsolete, stop using
those packages and upgrade anyway.
https://www.torproject.org/download/download
Changes in version 0.2.2.36 - 2012-05-24
o Directory authority changes:
- Change IP address for maatuska (v3 directory authority).
- Change IP address for ides (v3 directory authority), and rename
it to turtles.
o Security fixes:
- When building or running with any version of OpenSSL earlier
than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL
versions have a bug (CVE-2011-4576) in which their block cipher
padding includes uninitialized data, potentially leaking sensitive
information to any peer with whom they make a SSLv3 connection. Tor
does not use SSL v3 by default, but a hostile client or server
could force an SSLv3 connection in order to gain information that
they shouldn't have been able to get. The best solution here is to
upgrade to OpenSSL 0.9.8s or 1.0.0f (or later). But when building
or running with a non-upgraded OpenSSL, we disable SSLv3 entirely
to make sure that the bug can't happen.
- Never use a bridge or a controller-supplied node as an exit, even
if its exit policy allows it. Found by wanoskarnet. Fixes bug
5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors)
and 0.2.0.3-alpha (for bridge-purpose descriptors).
- Only build circuits if we have a sufficient threshold of the total
descriptors that are marked in the consensus with the "Exit"
flag. This mitigates an attack proposed by wanoskarnet, in which
all of a client's bridges collude to restrict the exit nodes that
the client knows about. Fixes bug 5343.
- Provide controllers with a safer way to implement the cookie
authentication mechanism. With the old method, if another locally
running program could convince a controller that it was the Tor
process, then that program could trick the controller into telling
it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE"
authentication method uses a challenge-response approach to prevent
this attack. Fixes bug 5185; implements proposal 193.
o Major bugfixes:
- Avoid logging uninitialized data when unable to decode a hidden
service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
- Avoid a client-side assertion failure when receiving an INTRODUCE2
cell on a general purpose circuit. Fixes bug 5644; bugfix on
0.2.1.6-alpha.
- Fix builds when the path to sed, openssl, or sha1sum contains
spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
on 0.2.2.1-alpha.
- Correct our replacements for the timeradd() and timersub() functions
on platforms that lack them (for example, Windows). The timersub()
function is used when expiring circuits, while timeradd() is
currently unused. Bug report and patch by Vektor. Fixes bug 4778;
bugfix on 0.2.2.24-alpha.
- Fix the SOCKET_OK test that we use to tell when socket
creation fails so that it works on Win64. Fixes part of bug 4533;
bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.
o Minor bugfixes:
- Reject out-of-range times like 23:59:61 in parse_rfc1123_time().
Fixes bug 5346; bugfix on 0.0.8pre3.
- Make our number-parsing functions always treat too-large values
as an error, even when those values exceed the width of the
underlying type. Previously, if the caller provided these
functions with minima or maxima set to the extreme values of the
underlying integer type, these functions would return those
values on overflow rather than treating overflow as an error.
Fixes part of bug 5786; bugfix on 0.0.9.
- Older Linux kernels erroneously respond to strange nmap behavior
by having accept() return successfully with a zero-length
socket. When this happens, just close the connection. Previously,
we would try harder to learn the remote address: but there was
no such remote address to learn, and our method for trying to
learn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix
on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
- Correct parsing of certain date types in parse_http_time().
Without this patch, If-Modified-Since would behave
incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from
Esteban Manchado Velázques.
- Change the BridgePassword feature (part of the "bridge community"
design, which is not yet implemented) to use a time-independent
comparison. The old behavior might have allowed an adversary
to use timing to guess the BridgePassword value. Fixes bug 5543;
bugfix on 0.2.0.14-alpha.
- Detect and reject certain misformed escape sequences in
configuration values. Previously, these values would cause us
to crash if received in a torrc file or over an authenticated
control port. Bug found by Esteban Manchado Velázquez, and
independently by Robert Connolly from Matta Consulting who further
noted that it allows a post-authentication heap overflow. Patch
by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668);
bugfix on 0.2.0.16-alpha.
- Fix a compile warning when using the --enable-openbsd-malloc
configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
- During configure, detect when we're building with clang version
3.0 or lower and disable the -Wnormalized=id and -Woverride-init
CFLAGS. clang doesn't support them yet.
- When sending an HTTP/1.1 proxy request, include a Host header.
Fixes bug 5593; bugfix on 0.2.2.1-alpha.
- Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE
command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
- If we hit the error case where routerlist_insert() replaces an
existing (old) server descriptor, make sure to remove that
server descriptor from the old_routers list. Fix related to bug
1776. Bugfix on 0.2.2.18-alpha.
o Minor bugfixes (documentation and log messages):
- Fix a typo in a log message in rend_service_rendezvous_has_opened().
Fixes bug 4856; bugfix on Tor 0.0.6.
- Update "ClientOnly" man page entry to explain that there isn't
really any point to messing with it. Resolves ticket 5005.
- Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays
directory authority option (introduced in Tor 0.2.2.34).
- Downgrade the "We're missing a certificate" message from notice
to info: people kept mistaking it for a real problem, whereas it
is seldom the problem even when we are failing to bootstrap. Fixes
bug 5067; bugfix on 0.2.0.10-alpha.
- Correctly spell "connect" in a log message on failure to create a
controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta.
- Clarify the behavior of MaxCircuitDirtiness with hidden service
circuits. Fixes issue 5259.
o Minor features:
- Directory authorities now reject versions of Tor older than
0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha
inclusive. These versions accounted for only a small fraction of
the Tor network, and have numerous known security issues. Resolves
issue 4788.
- Update to the May 1 2012 Maxmind GeoLite Country database.
- Feature removal:
- When sending or relaying a RELAY_EARLY cell, we used to convert
it to a RELAY cell if the connection was using the v1 link
protocol. This was a workaround for older versions of Tor, which
didn't handle RELAY_EARLY cells properly. Now that all supported
versions can handle RELAY_EARLY cells, and now that we're enforcing
the "no RELAY_EXTEND commands except in RELAY_EARLY cells" rule,
remove this workaround. Addresses bug 4786.
1
0
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/download
Note that the tarball and git tags are signed by Nick Mathewson (gpg
key 165733EA) this time around.
Changes in version 0.2.2.35 - 2011-12-16
o 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.
o 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".
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.
- Update to the December 6 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.
1
0
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
o 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.
o 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".
o 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.
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.
- 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.
o 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.
o 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.
1
0
Tor 0.2.2.33 fixes several bugs, and includes a slight tweak to Tor's
TLS handshake that makes relays and bridges that run this new version
reachable from Iran again.
https://www.torproject.org/download/download
Relays and bridges should upgrade:
https://blog.torproject.org/blog/iran-blocks-tor-tor-releases-same-day-fix
Since there are no critical client-side fixes, we haven't built new Tor
Browser Bundle packages for this version yet. The latest Tor Browser
Bundle version remains 2.2.32-4:
https://blog.torproject.org/blog/new-tor-browser-bundles-6
Changes in version 0.2.2.33 - 2011-09-13
o Major bugfixes:
- Avoid an assertion failure when reloading a configuration with
TrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug
3923; bugfix on 0.2.2.25-alpha.
o Minor features (security):
- Check for replays of the public-key encrypted portion of an
INTRODUCE1 cell, in addition to the current check for replays of
the g^x value. This prevents a possible class of active attacks
by an attacker who controls both an introduction point and a
rendezvous point, and who uses the malleability of AES-CTR to
alter the encrypted g^x portion of the INTRODUCE1 cell. We think
that these attacks are infeasible (requiring the attacker to send
on the order of zettabytes of altered cells in a short interval),
but we'd rather block them off in case there are any classes of
this attack that we missed. Reported by Willem Pinckaers.
o Minor features:
- Adjust the expiration time on our SSL session certificates to
better match SSL certs seen in the wild. Resolves ticket 4014.
- Change the default required uptime for a relay to be accepted as
a HSDir (hidden service directory) from 24 hours to 25 hours.
Improves on 0.2.0.10-alpha; resolves ticket 2649.
- Add a VoteOnHidServDirectoriesV2 config option to allow directory
authorities to abstain from voting on assignment of the HSDir
consensus flag. Related to bug 2649.
- Update to the September 6 2011 Maxmind GeoLite Country database.
o Minor bugfixes (documentation and log messages):
- Correct the man page to explain that HashedControlPassword and
CookieAuthentication can both be set, in which case either method
is sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,
when we decided to allow these config options to both be set. Issue
raised by bug 3898.
- Demote the 'replay detected' log message emitted when a hidden
service receives the same Diffie-Hellman public key in two different
INTRODUCE2 cells to info level. A normal Tor client can cause that
log message during its normal operation. Bugfix on 0.2.1.6-alpha;
fixes part of bug 2442.
- Demote the 'INTRODUCE2 cell is too {old,new}' log message to info
level. There is nothing that a hidden service's operator can do
to fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes part
of bug 2442.
- Clarify a log message specifying the characters permitted in
HiddenServiceAuthorizeClient client names. Previously, the log
message said that "[A-Za-z0-9+-_]" were permitted; that could have
given the impression that every ASCII character between "+" and "_"
was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.
o Build fixes:
- Provide a substitute implementation of lround() for MSVC, which
apparently lacks it. Patch from Gisle Vanem.
- Clean up some code issues that prevented Tor from building on older
BSDs. Fixes bug 3894; reported by "grarpamp".
- Search for a platform-specific version of "ar" when cross-compiling.
Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.
1
0
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
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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).
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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".
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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".
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
o 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.
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