The server-side clipping now clamps to one of two values, both
for what to report, and how long to cache.
Additionally, we move some defines to dns.h, and give them better
names.
It is no longer possible for the IPv6 preference options to differ from the
IPv6 usage: preferring IPv6 implies possibly using IPv6.
Also remove the corresponding unit test warning message checks.
(But keep the unit tests themselves - they now run without warnings.)
This commit adds 3 unit tests which validates a wrong signature length, a
wrong authentication key length and a wrong MAC in the cell.
Closes#20992
Signed-off-by: David Goulet <dgoulet@torproject.org>
Some DNS NXDOMAIN hijackers hijack truly ridiculous domains, like
"invalid-stuff!!" or "1.2.3.4.5". This would provoke unit test
failures where we used addresses like that to force
tor_addr_lookup() to fail. The fix, for testing, is to mock
tor_addr_lookup() with a variant that always fails when it gets
a name with a !.
Fixes bugs 20862 and 20863.
The abort handler masks the exit status of the backtrace generator by
capturing the abort signal from the backtrace handler and exiting with
zero. Because the output of the backtrace generator is meant to be piped
to `bt_test.py`, its exit status is unimportant and is currently
ignored.
The abort handler calls `exit(3)` which is not asynchronous-signal-safe
and calling it in this context is undefined behavior [0].
Closes ticket 21026.
[0] https://www.securecoding.cert.org/confluence/x/34At
Since both the client and service will use that data structure to store the
descriptor decoded data, only the public keys are common to both.
Fixes#20572.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is an important thing I hadn't considered when writing prop271:
sometimes you have to restrict what guard you use for a particular
circuit. Most frequently, that would be because you plan to use a
certain node as your exit, and so you can't choose that for your
guard.
This change means that the upgrade-waiting-circuits algorithm needs
a slight tweak too: circuit A cannot block circuit B from upgrading
if circuit B needs to follow a restriction that circuit A does not
follow.
George pointed out that (-1,0,1) for (never usable, maybe usable
later, usable right now) was a pretty rotten convention that made
the code harder to read.
This includes:
* making bridge_info_t exposed but opaque
* allowing guards where we don't know an identity
* making it possible to learn the identity of a guard
* creating a guard that lacks a node_t
* remembering a guard's address and port.
* Looking up a guard by address and port.
* Only enforcing the rule that we need a live consensus to update
the "listed" status for guards when we are not using bridges.
Currently, this code doesn't actually have the contexts behave
differently, (except for the legacy context), but it does switch
back and forth between them nicely.
Some of these will get torrc options to override them too; this
is just the mechanical conversion.
Also, add documentation for a couple of undocumented (but now used)
parameters.
Act I.
" But that I am forbid
To tell the secrets of my prison-house,
I could a tale unfold..."
Here's the bug: sometimes, rend_cache/store_v2_desc_as_client would
say:
"Dec 15 08:31:26.147 [warn] rend_cache_store_v2_desc_as_client():
Bug: Couldn't decode base32 [scrubbed] for descriptor id. (on Tor
0.3.0.0-alpha-dev 4098bfa260)"
When we merged ade5005853 back in 0.2.8.1-alpha, we added that
test: it mangles the hidden service ID for a hidden service, and
ensures that when the descriptor ID doesn't match the descriptor's
key, we don't store the descriptor.
How did it mangle the descriptor ID? By doing
desc_id_base32[0]++;
So, if the hidden service ID started with z or 7, we'd wind up with an
invalid base32 string, and get the warning. And if it started with
any other character, we wouldn't.
That there is part 1 of the bug: in 2/32 cases, we'd get a BUG
warning. But we wouldn't display it, since warnings weren't shown
from the unit tests.
Act II.
"Our indiscretion sometime serves us well,
When our deep plots do pall"
Part two: in 0.2.9.3-alpha, for part of #19999, we turned on BUG
warnings in the unit tests, so that we'd actually start seeing them.
At this point we also began to consider each BUG warning that made
it through the unit tests to be an actual bug. So before this
point, we wouldn't actually notice anything happening in those 2/32
cases.
So, at this point it was a nice random _visible_ bug.
Act III.
"Our thoughts are ours, their ends none of our own"
In acbb60cd63, which was part of my prop220 work, I
changed how RSA key generation worked in the unit tests. While
previously we'd use pre-made RSA keys in some cases, this change
made us use a set of pregenerated RSA keys for _all_ 1024 or 2048
keys, and to return them in a rotation when Tor tried to generate a
key.
And now we had the heisenbug: anything that affected the number of
pregenerated keys that we had yielded before reaching
rend_cache/store_v2_desc_as_client would make us return a different
key, which would give us a different base32 ID, which would make the
bug occur, or not. So as we added or removed test cases, the bug
might or might not happen.
So yeah. Don't mangle a base32 ID like that. Do it this way instead.
