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
diff --git a/src/feature/hs/hs_cache.h b/src/feature/hs/hs_cache.h
index e7729f2041..4fd9ac5445 100644
--- a/src/feature/hs/hs_cache.h
+++ b/src/feature/hs/hs_cache.h
@@ -99,6 +99,8 @@ const hs_cache_intro_state_t *hs_cache_client_intro_state_find(
 void hs_cache_client_intro_state_clean(time_t now);
 void hs_cache_client_intro_state_purge(void);
 
+bool hs_cache_client_new_auth_parse(const ed25519_public_key_t *service_pk);
+
 #ifdef HS_CACHE_PRIVATE
 #include "lib/crypt_ops/crypto_ed25519.h"