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Tor released

6. Jun 2012

Tor has been updated to (stable). You should upgrade when you run the stable branch.

Expect another update to work around an bug regarding TLS renegotiation.

That has been changed:

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 (for controller-purpose descriptors)
and (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
– Avoid a client-side assertion failure when receiving an INTRODUCE2
cell on a general purpose circuit. Fixes bug 5644; bugfix on
– Fix builds when the path to sed, openssl, or sha1sum contains
spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
– 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
– 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 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 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 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
– 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
– Fix a compile warning when using the –enable-openbsd-malloc
configure option. Fixes bug 5340; bugfix on
– 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
– Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE
command. Found by mikeyc. Fixes bug 5796; bugfix on
– 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

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
– 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
– Correctly spell “connect” in a log message on failure to create a
controlsocket. Fixes bug 4803; bugfix on
– Clarify the behavior of MaxCircuitDirtiness with hidden service
circuits. Fixes issue 5259.

o Minor features:
– Directory authorities now reject versions of Tor older than, and Tor versions between and
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.

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