Mike Perry [Wed, 5 Jun 2019 18:50:44 +0000 (11:50 -0700)]
Bug 29034: Cleanup hs circuitmap when purpose changes.
Leave the other rend and hs_ident data around until circuit free, since code
may still try to inspect it after marking the circuit for close. The
circuitmap is the important thing to clean up, since repurposed
intropoints must be removed from this map to ensure validity.
David Goulet [Mon, 3 Jun 2019 18:31:51 +0000 (14:31 -0400)]
sendme: Do not decrement window in a log_debug()
If "Log debug ..." is not set, the decrement never happens. This lead to the
package/deliver window to be out of sync at the stream level and thus breaking
the connection after 50+ cells.
Fixes #30628
Signed-off-by: David Goulet <dgoulet@torproject.org>
Nick Mathewson [Fri, 31 May 2019 16:19:29 +0000 (12:19 -0400)]
num_bridges_usable(): only count configured bridges.
When this function was implemented, it counted all the entry guards
in the bridge set. But this included previously configured bridges,
as well as currently configured ones! Instead, only count the
_filtered_ bridges (ones that are configured and possibly reachable)
as maybe usable.
Nick Mathewson [Wed, 29 May 2019 15:25:47 +0000 (11:25 -0400)]
Shutdown libevent _after_ the subsystems.
This is necessary since shutting down libevent frees some pointer
that the subsystems want to free themselves. A longer term solution
will be to turn the evloop module into a subsystem itself, but for
now it is best to do the minimal fix.
Nick Mathewson [Wed, 29 May 2019 15:00:09 +0000 (11:00 -0400)]
Make get_proxy_type() connection-specific
Previously, we were looking at our global settings to see what kind
of proxy we had. But doing this would sometimes give us the wrong
results when we had ClientTransportPlugin configured but we weren't
using it for a particular connection. In several places in the
code, we had added checks to see if we were _really_ using a PT or
whether we were using a socks proxy, but we had forgotten to do so
in at least once case. Instead, since every time we call this
function we are asking about a single connection, it is probably
best just to make this function connection-specific.
If tor is compiled on a system with neither vasprintf nor _vscprintf,
the fallback implementation exposes a logic flaw which prevents
proper usage of strings longer than 127 characters:
* tor_vsnprintf returns -1 if supplied buffer is not large enough,
but tor_vasprintf uses this function to retrieve required length
* the result of tor_vsnprintf is not properly checked for negative
return values
Both aspects together could in theory lead to exposure of uninitialized
stack memory in the resulting string. This requires an invalid format
string or data that exceeds integer limitations.
Fortunately tor is not even able to run with this implementation because
it runs into asserts early on during startup. Also the unit tests fail
during a "make check" run.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
[backported to 0.2.9 by nickm]
Use MAP_INHERIT_ZERO or MAP_INHERIT_NONE if available.
Fixes assertion failure in tests on NetBSD:
slow/prob_distr/stochastic_log_logistic: [forking] May 25 03:56:58.091 [err] tor_assertion_failed_(): Bug: src/lib/crypt_ops/crypto_rand_fast.c:184: crypto_fast_rng_new_from_seed: Assertion inherit != INHERIT_RES_KEEP failed; aborting. (on Tor 0.4.1.1-alpha-dev 29955f13e5bc8e61)
May 25 03:56:58.091 [err] Bug: Assertion inherit != INHERIT_RES_KEEP failed in crypto_fast_rng_new_from_seed at src/lib/crypt_ops/crypto_rand_fast.c:184: . (Stack trace not available) (on Tor 0.4.1.1-alpha-dev 29955f13e5bc8e61)
[Lost connection!]
Nick Mathewson [Fri, 17 May 2019 15:03:16 +0000 (11:03 -0400)]
Make sure that we send at least some random data in RELAY_DATA cells
Proposal 289 prevents SENDME-flooding by requiring the other side to
authenticate the data it has received. But this data won't actually
be random if they are downloading a known resource. "No problem",
we said, "let's fell the empty parts of our cells with some
randomness!" and we did that in #26871.
Unfortunately, if the relay data payloads are all completely full,
there won't be any empty parts for us to randomize.
Therefore, we now pick random "randomness windows" between
CIRCWINDOW_INCREMENT/2 and CIRCWINDOW_INCREMENT. We remember whether we have
sent a cell containing at least 16 bytes of randomness in that window. If we
haven't, then when the window is exhausted, we send one. (This window approach
is designed to lower the number of rng checks we have to do. The number 16 is
pulled out of a hat to change the attacker's guessing difficulty to
"impossible".)