When looking up an entry in the rend_cache, stop asserting that it exists but
rather confirm it exists and if not, return that no entry was found.
The reason for that is because the hs_circ_cleanup_on_free() function (which
can end up looking at the rend_cache) can be called from the
circuit_free_all() function that is called _after_ the rend cache is cleaned
up in tor_free_all().
We could fix the free all ordering but then it will just hide a future bug.
Instead, handle a missing rend_cache as a valid use case as in while we are in
the cleanup process.
As Tor becomes more modular, it is getting more and more difficult to ensure
subsystem callstack ordering thus this fix aims at making the HSv2 subsystem
more robust at being called while tor is pretty much in any kind of state.
Fixes#32847.
Signed-off-by: David Goulet <dgoulet@torproject.org>
When picking an intro point from the service descriptor, the client failed to
lookup the failure cache.
It made an HS v2 client re-pick bad intro points for which we already know it
won't work in the first place.
Based on Neel Chauhan original patch.
Fixes#25568
Signed-off-by: David Goulet <dgoulet@torproject.org>
I don't believe any of these represent a real timing vulnerability
(remote timing against memcmp() on a modern CPU is not easy), but
these are the ones where I believe we should be more careful.
Also, when we log about a failure from base32_decode(), we now
say that the length is wrong or that the characters were invalid:
previously we would just say that there were invalid characters.
Follow-up on 28913 work.
This commit won't build yet -- it just puts everything in a slightly
more logical place.
The reasoning here is that "src/core" will hold the stuff that every (or
nearly every) tor instance will need in order to do onion routing.
Other features (including some necessary ones) will live in
"src/feature". The "src/app" directory will hold the stuff needed
to have Tor be an application you can actually run.
This commit DOES NOT refactor the former contents of src/or into a
logical set of acyclic libraries, or change any code at all. That
will have to come in the future.
We will continue to move things around and split them in the future,
but I hope this lays a reasonable groundwork for doing so.
