It is possible in normal circumstances that a client fetches a descriptor
that has a lower revision counter than the one in its cache. This can happen
due to HSDir desync.
Fixes#24976
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit adds hs_cache_lookup_encoded_as_client() function that returns the
encoded descriptor for a given service public key. This will be needed by the
"GETINFO hs/client/desc/id/<ADDR>" control port command.
Signed-off-by: David Goulet <dgoulet@torproject.org>
In #23466 we discovered that cached descriptors can stay around on the
client-side for up to 72 hours. In reality we only want those descs to
get cached for the duration of the current time period, since after that
TP is gone the client needs to compute a new blinded key to use for the HS.
In this commit we start using the consensus time (if available) when
cleaning up cached client descriptor entries. That makes sense because
the client uses consensus time anyway for connecting to hidden
services (e.g. computing blinded keys and time periods).
If no recent consensus is available, we consider descriptors to be
expired since we will want to fetch new ones when we get a live
consensus to avoid the Roger bug. If we didn't do that, when Roger
desuspends his laptop there would be a race between Tor fetching a new
consensus, and Tor connecting to the HS which would still cause
reachability issues.
We also turned a rev counter check into a BUG, since we should never
receive a descriptor with a strictly smaller rev counter than the one we
already have, except if there is a bug or if the HSDir wants to mess
with us. In any case, let's turn this into a BUG so that we can detect
and debug such cases easily.
This cache keeps track of the state of intro points which is needed when we
have failures when using them. It is similar to the failure cache of the
legacy system.
At this commit, it is unused but initialized, cleanup and freed.
Signed-off-by: David Goulet <dgoulet@torproject.org>
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 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>
