hs-v3: Function to re-parse unencrypted descriptor

We now keep descriptor that we can't decode due to missing client
authorization in the cache.

This new function is used when new client authorization are added and to tell
the client cache to retry decoding.

Part of #30382

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/feature/hs/hs_cache.c b/src/feature/hs/hs_cache.c
index 59b05d8f0a..49d5ade419 100644
--- a/src/feature/hs/hs_cache.c
+++ b/src/feature/hs/hs_cache.c
@@ -942,6 +942,34 @@ hs_cache_client_intro_state_purge(void)
                     "cache purged.");
 }
 
+/* This is called when new client authorization was added to the global state.
+ * It attemps to decode the descriptor of the given service identity key.
+ *
+ * Return true if decoding was successful else false. */
+bool
+hs_cache_client_new_auth_parse(const ed25519_public_key_t *service_pk)
+{
+  bool ret = false;
+  hs_cache_client_descriptor_t *cached_desc = NULL;
+
+  tor_assert(service_pk);
+
+  cached_desc = lookup_v3_desc_as_client(service_pk->pubkey);
+  if (cached_desc == NULL || cached_desc->desc != NULL) {
+    /* No entry for that service or the descriptor is already decoded. */
+    goto end;
+  }
+
+  /* Attempt a decode. If we are successful, inform the caller. */
+  if (hs_client_decode_descriptor(cached_desc->encoded_desc, service_pk,
+                                  &cached_desc->desc) == HS_DESC_DECODE_OK) {
+    ret = true;
+  }
+
+ end:
+  return ret;
+}
+
 /**************** Generics *********************************/
 
 /** Do a round of OOM cleanup on all directory caches. Return the amount of