We need to make sure that the worst thing that a weird consensus param
can do to us is to break our Tor (and only if the other Tors are
reliably broken in the same way) so that the majority of directory
authorities can't pull any attacks that are worse than the DoS that
they can trigger by simply shutting down.
One of these worse things was the cbtnummodes parameter, which could
lead to heap corruption on some systems if the value was sufficiently
large.
This commit fixes this particular issue and also introduces sanity
checking for all consensus parameters.
Our public key functions assumed that they were always writing into a
large enough buffer. In one case, they weren't.
(Incorporates fixes from sebastian)
In dnsserv_resolved(), we carefully made a nul-terminated copy of the
answer in a PTR RESOLVED cell... then never used that nul-terminated
copy. Ouch.
Surprisingly this one isn't as huge a security problem as it could be.
The only place where the input to dnsserv_resolved wasn't necessarily
nul-terminated was when it was called indirectly from relay.c with the
contents of a relay cell's payload. If the end of the payload was
filled with junk, eventdns.c would take the strdup() of the name [This
part is bad; we might crash there if the cell is in a bad part of the
stack or the heap] and get a name of at least length
495[*]. eventdns.c then rejects any name of length over 255, so the
bogus data would be neither transmitted nor altered.
[*] If the name was less than 495 bytes long, the client wouldn't
actually be reading off the end of the cell.
Nonetheless this is a reasonably annoying bug. Better fix it.
Found while looking at bug 2332, reported by doorss. Bugfix on
0.2.0.1-alpha.
Previously, we only looked at up to 128 bytes. This is a bad idea
since socks messages can be at least 256+x bytes long. Now we look at
up to 512 bytes; this should be enough for 0.2.2.x to handle all valid
SOCKS messages. For 0.2.3.x, we can think about handling trickier
cases.
Fixes 2330. Bugfix on 0.2.0.16-alpha.
Right now, Tor routers don't save the maxima values from the
bw_history_t between sessions. That's no good, since we use those
values to determine bandwidth. This code adds a new BWHist.*Maximum
set of values to the state file. If they're not present, we estimate
them by taking the observed total bandwidth and dividing it by the
period length, which provides a lower bound.
This should fix bug 1863. I'm calling it a feature.
Previously, our state parsing code would fail to parse a bwhist
correctly if the Interval was anything other than the default
hardcoded 15 minutes. This change makes the parsing less incorrect,
though the resulting history array might get strange values in it if
the intervals don't match the one we're using. (That is, if stuff was
generated in 15 minute intervals, and we read it into an array that
expects 30 minute intervals, we're fine, since values can be combined
pairwise. But if we generate data at 30 minute intervals and read it
into 15 minute intervals, alternating buckets will be empty.)
Bugfix on 0.1.1.11-alpha.
An object, you'll recall, is something between -----BEGIN----- and
-----END----- tags in a directory document. Some of our code, as
doorss has noted in bug 2352, could assert if one of these ever
overflowed SIZE_T_CEILING but not INT_MAX. As a solution, I'm setting
a maximum size on a single object such that neither of these limits
will ever be hit. I'm also fixing the INT_MAX checks, just to be sure.
When using libevent 2, we use evdns_base_resolve_*(). When not, we
fake evdns_base_resolve_*() using evdns_resolve_*().
Our old check was looking for negative values (like libevent 2
returns), but our eventdns.c code returns 1. This code makes the
check just test for nonzero.
Note that this broken check was not for _resolve_ failures or even for
failures to _launch_ a resolve: it was for failures to _create_ or
_encode_ a resolve request.
Bug introduced in 81eee0ecfff3dac1e9438719d2f7dc0ba7e84a71; found by
lodger; uploaded to trac by rransom. Bug 2363. Fix on 0.2.2.6-alpha.
We were decrementing "available" twice for each in-use address we ran
across. This would make us declare that we ran out of virtual
addresses when the address space was only half full.
On Windows, we never use pthreads, since it doesn't usually exist,
and when it does it tends to be a little weirdly-behaved. But some
mingw installations have a pthreads installed, so autoconf detects
pthread.h and tells us about it. This would make us include
pthread.h, which could make for trouble when the iffy pthread.h
tried to include config.h.
This patch changes compat.h so that we never include pthread.h on
Windows. Fixes bug 2313; bugfix on 0.1.0.1-rc.
If you had TIME_MAX > INT_MAX, and your "time_to_exhaust_bw =
accountingmax/expected_bandwidth_usage * 60" calculation managed to
overflow INT_MAX, then your time_to_consider value could underflow and
wind up being rediculously low or high. "Low" was no problem;
negative values got caught by the (time_to_consider <= 0) check.
"High", however, would get you a wakeup time somewhere in the distant
future.
The fix is to check for time_to_exhaust_bw overflowing INT_MAX, not
TIME_MAX: We don't allow any accounting interval longer than a month,
so if time_to_exhaust_bw is significantly larger than 31*24*60*60, we
can just clip it.
This is a bugfix on 0.0.9pre6, when accounting was first introduced.
It fixes bug 2146, unless there are other causes there too. The fix
is from boboper. (I tweaked it slightly by removing an assignment
that boboper marked as dead, and lowering a variable that no longer
needed to be function-scoped.)
The old logic would have us fetch from authorities if we were refusing
unknown exits and our exit policy was reject*. Instead, we want to
fetch from authorities if we're refusing unknown exits and our exit
policy is _NOT_ reject*.
Fixed by boboper. Fixes more of 2097. Bugfix on 0.2.2.16-alpha.
We use a hash of the identity key to seed a prng to tell when an
accounting period should end. But thanks to the bug998 changes,
clients no longer have server-identity keys to use as a long-term seed
in accounting calculations. In any case, their identity keys (as used
in TLS) were never never fixed. So we can just set the wakeup time
from a random seed instead there. Still open is whether everybody
should be random.
This patch fixes bug 2235, which was introduced in 0.2.2.18-alpha.
Diagnosed with help from boboper on irc.
Doing so could make Libevent call Libevent from inside a Libevent
logging call, which is a recipe for reentrant confusion and
hard-to-debug crashes. This would especially hurt if Libevent
debug-level logging is enabled AND the user has a controller
watching for low-severity log messages.
Fix bug 2190; fix on 0.1.0.2-rc.
Doing so could make Libevent call Libevent from inside a Libevent
logging call, which is a recipe for reentrant confusion and
hard-to-debug crashes. This would especially hurt if Libevent
debug-level logging is enabled AND the user has a controller
watching for low-severity log messages.
Fix bug 2190; fix on 0.1.0.2-rc.
Pick 5 seconds as the limit. 5 seconds is a compromise here between
making sure the user notices that the bad behaviour is (still) happening
and not spamming their log too much needlessly (the log message is
pretty long). We also keep warning every time if safesocks is
specified, because then the user presumably wants to hear about every
blocked instance.
(This is based on the original patch by Sebastian, then backported to
0.2.2 and with warnings split into their own function.)
Our checks that we don't exceed the 50 KB size limit of extra-info
descriptors apparently failed. This patch fixes these checks and reserves
another 250 bytes for appending the signature. Fixes bug 2183.
We would never actually enforce multiplicity rules when parsing
annotations, since the counts array never got entries added to it for
annotations in the token list that got added by earlier calls to
tokenize_string.
Found by piebeer.
We had a spelling discrepancy between the manpage and the source code
for some option. Resolve these in favor of the manpage, because it
makes more sense (for example, HTTP should be capitalized).
We decided to no longer ship expert packages for OS X because they're a
lot of trouble to keep maintained and confuse users. For those who want
a tor on OS X without Vidalia, macports is a fine option. Alternatively,
building from source is easy, too.
The polipo stuff that is still required for the Vidalia bundle build can
now be found in the torbrowser repository,
git://git.torproject.org/torbrowser.git.
In the case where old_router == NULL but sdmap has an entry for the
router, we can currently safely infer that the old_router was not a
bridge. Add an assert to ensure that this remains true, and fix the
logic not to die with the tor_assert(old_router) call.
We used to enable ssp-buffer-size=1 only when building with
--enable-gcc-warnings. That would result in warnings (and no
protection for small arrays) when building with
--enable-gcc-hardening without enabling warnings, too. Fixes bug
2031.
Also remove an XXX: We now allow to build with -fstack-protector
by using --enable-gcc-hardening.
Do not double-report signatures from unrecognized authorities both as
"from unknown authority" and "not present". Fixes bug 1956, bugfix on
0.2.2.16-alpha.
Our attempt to make compilation work on old versions of Windows
again while keeping wince compatibility broke the build for Win2k+.
helix reports this patch fixes the issue for WinXP. Bugfix on
0.2.2.15-alpha; related to bug 1797.
Karsten says: "the ChangeLog should say it's a bugfix on
0.2.2.15-alpha, because enabling stats while Tor is running (which
leads to this false log message) is only possible since then."
Sounds right enough to me. Tell me if I'm wrong.
When the CellStatistics option is off, we don't store cell insertion
times. Doing so would also not be very smart, because there seem to
still be some performance issues with this type of statistics. Nothing
harmful happens when we don't have insertion times, so we don't need to
alarm the user.
Previously[*], the function would start with the first stream on the
circuit, and let it package as many cells as it wanted before
proceeding to the next stream in turn. If a circuit had many live
streams that all wanted to package data, the oldest would get
preference, and the newest would get ignored.
Now, we figure out how many cells we're willing to send per stream,
and try to allocate them fairly.
Roger diagnosed this in the comments for bug 1298.
[*] This bug has existed since before the first-ever public release
of Tor. It was added by r152 of Tor on 26 Jan 2003, which was
the first commit to implement streams (then called "topics").
This is not the oldest bug to be fixed in 0.2.2.x: that honor
goes to the windowing bug in r54, which got fixed in e50b7768 by
Roger with diagnosis by Karsten. This is, however, the most
long-lived bug to be fixed in 0.2.2.x: the r54 bug was fixed
2580 days after it was introduced, whereas I am writing this
commit message 2787 days after r152.
Bridges and other relays not included in the consensus don't
necessarily have a non-zero bandwidth capacity. If all our
configured bridges had a zero bw capacity we would warn the
user. Change that.
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.
This patch also makes us store a few more fields in the state file,
including the time at which we entered soft hibernation.
Fixes bug 1789. Bugfix on 0.0.9pre5.
This will make changes for DST still work, and avoid double-spending
bytes when there are slight changes to configurations.
Fixes bug 1511; the DST issue is a bugfix on 0.0.9pre5.
When we introduced the code to close non-open OR connections after
KeepalivePeriod had passed, we replaced some code that said
if (!connection_is_open(conn)) {
/* let it keep handshaking forever */
} else if (do other tests here) {
...
with new code that said
if (!connection_is_open(conn) && past_keepalive) {
/* let it keep handshaking forever */
} else if (do other tests here) {
...
This was a mistake, since it made all the other tests start applying
to non-open connections, thus causing bug 1840, where non-open
connections get closed way early.
Fixes bug 1840. Bugfix on 0.2.1.26 (commit 67b38d50).
It's normal when bootstrapping to have a lot of different certs
missing, so we don't want missing certs to make us warn... unless
the certs we're missing are ones that we've tried to fetch a couple
of times and failed at.
May fix bug 1145.
This should keep WinCE working (unicode always-on) and get Win98
working again (unicode never-on).
There are two places where we explicitly use ASCII-only APIs, still:
in ntmain.c and in the unit tests.
This patch also fixes a bug in windoes tor_listdir that would cause
the first file to be listed an arbitrary number of times that was
also introduced with WinCE support.
Should fix bug 1797.
Setting CookieAuthFileGroupReadable but without setting CookieAuthFile makes
no sense, because unix directory permissions for the data directory prevent
the group from accessing the file anyways.
When this happens, run through the streams on the circuit and make
sure they're all blocked. If some aren't, that's a bug: block them
all and log it! If they all are, where did the cell come from? Log
it!
(I suspect that this actually happens pretty frequently, so I'm making
these log messages appear at INFO.)
If the voting interval was short enough, the two-minutes delay
of CONSENSUS_MIN_SECONDS_BEFORE_CACHING would confuse bridges
to the point where they would assert before downloading a consensus.
It it was even shorter (<4 minutes, I think), caches would
assert too. This patch fixes that by having replacing the
two-minutes value with MIN(2 minutes, interval/16).
Bugfix for 1141; the cache bug could occur since 0.2.0.8-alpha, so
I'm calling this a bugfix on that. Robert Hogan diagnosed this.
Done as a patch against maint-0.2.1, since it makes it hard to
run some kinds of testing networks.
