Some functions that use digest maps did not mention that the digests are
expected to have DIGEST_LEN bytes. This lead to buffer over-reads in the
past.
When validating a new descriptor against our rend cache failure, we were
added the failure entry to the new cache entry without duplicating. It was
then freed just after the validation ending up in a very bad memory state
that was making tor abort(). To fix this, a dup function has been added and
used just before adding the failure entry.
Fixes#17041
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Performing lookups in both the client and service side descriptor
caches from the same rend_cache_lookup_entry() function increases the
risk of accidental API misuse.
I'm separating the lookup functions to keep the caches distinct.
Parameterize the rend_cache_clean() function to allow it clean
old rendezvous descriptors from the service-side cache as well as
the client descriptor cache.
Entries in the service-side descriptor cache are now cleaned when
rend_cache_free_all() is called. The call to tor_free(intro_content)
in rend_cache_store_v2_desc_as_service() is moved to prevent a
potential double-free when a service has a descriptor with a newer
timestamp already in it's service-side descriptor cache.
Adds an Enum which represents the different types of rendezvous
descriptor caches. This argument is passed in each call to
rend_cache_lookup_entry() to specify lookup in the client-side or
service-side descriptor caches.
Adds a service descriptor cache which is indexed by service ID. This
descriptor cache is used to store service descriptors generated by a
local rendevous service.
The service-side cach can be queried by calling rend_cache_lookup_entry()
with the 'service' argument set to 1.
When fetching a descriptor, we know test every introduction points in it
against our rend failure cache to know if we keep it or not. For this to
work, now everytime an introduction points is discareded (ex: receiving a
NACK), we note it down in our introduction cache.
See rendcache.c for a detailed explanation of the cache's behavior.
Fixes#16389
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Every functions and objects that are used for hidden service descriptor
caches are moved to rendcache.{c|h}.
This commit does NOT change anything, just moving code around.
Fixes#16399
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
For now, rend_cache_entry_t has been moved from or.h to rendcache.h and
those files have been added to the build system.
In the next commit, these will contain hidden service descriptor cache ABI
and API for both client and directory side. The goal is to consolidate the
descriptor caches in one location to ease development, maintenance, review
and improve documentation for each cache behavior and algorithm.
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
