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.
This implements the proposal 224 directory descriptor cache store and lookup
functionalities. Furthermore, it merges the OOM call for the HSDir cache with
current protocol v2 and the new upcoming v3.
Add hs_cache.{c|h} with store/lookup API.
Closes#18572
Signed-off-by: David Goulet <dgoulet@torproject.org>
Signed-off-by: George Kadianakis <desnacked@riseup.net>
In order to implement proposal 224, we need the data structure rend_data_t to
be able to accomodate versionning that is the current version of hidden
service (2) and the new version (3) and future version.
For that, we implement a series of accessors and a downcast function to get
the v2 data structure. rend_data_t becomes a top level generic place holder.
The entire rend_data_t API has been moved to hs_common.{c|h} in order to
seperate code that is shared from between HS versions and unshared code (in
rendcommon.c).
Closes#19024
Signed-off-by: David Goulet <dgoulet@torproject.org>
Signed-off-by: George Kadianakis <desnacked@riseup.net>
Previously, you needed to store the previous log severity in a local
variable, and it wasn't clear if you were allowed to call these
functions more than once.
Slow system can sometime take more than 10 seconds to reach the test
callsite resulting in the unit test failing when using time in the future or
in the past.
Fixes#19465
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is a big-ish patch, but it's very straightforward. Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it. The cases where we
violated this rule fall into three roughly equal groups:
* Stuff that should have been static.
* Stuff that was global but where the extern was local to some
other C file.
* Stuff that was only global when built for the unit tests, that
needed a conditional extern in the headers.
The first two were IMO genuine problems; the last is a wart of how
we build tests.
When we made HidServDirectoryV2 always 1, we removed the situation
where a relay could choose not to be an HSDir. Now simplify the
rest of the code to reflect this decision.
(We have to remove two apparently unrelated free() calls in the unit
tests, since they used to free stuff that we created as a side effect
of calling router_get_my_routerinfo(), and now we no longer call that.)
This simplifies relay behavior, because the relay offers the hsdir
functionality independent of whether the directory authorities have
decided this relay is suitable for clients to use yet.
Implements ticket 18332.
The hidden service descriptor cache (rendcache) tests use digest maps
which expect keys to have a length of DIGEST_LEN.
Because the tests use key strings with a length lower than DIGEST_LEN,
the internal copy operation reads outside the key strings which leads to
buffer over-reads.
The issue is resolved by using character arrays with a size of
DIGEST_LEN.
Patch on ade5005853.
