3 files changed, 14 insertions, 3 deletions
diff --git a/src/feature/hs/hs_client.c b/src/feature/hs/hs_client.c
index f7294447b2..4140dee8d2 100644
--- a/src/feature/hs/hs_client.c
+++ b/src/feature/hs/hs_client.c
@@ -2248,6 +2248,13 @@ parse_auth_file_content(const char *client_key_str)
                       "can't be decoded: %s", seckey_b32);
     goto err;
   }
+
+  if (fast_mem_is_zero((const char*)auth->enc_seckey.secret_key,
+                       sizeof(auth->enc_seckey.secret_key))) {
+    log_warn(LD_REND, "Client authorization private key can't be all-zeroes");
+    goto err;
+  }
+
   strncpy(auth->onion_address, onion_address, HS_SERVICE_ADDR_LEN_BASE32);
 
   /* We are reading this from the disk, so set the permanent flag anyway. */
diff --git a/src/feature/hs/hs_client.h b/src/feature/hs/hs_client.h
index 685b10f955..a11caa309f 100644
--- a/src/feature/hs/hs_client.h
+++ b/src/feature/hs/hs_client.h
@@ -45,7 +45,7 @@ typedef enum {
   REGISTER_SUCCESS_AND_DECRYPTED,
   /* We failed to register these credentials, because of a bad HS address. */
   REGISTER_FAIL_BAD_ADDRESS,
-  /* We failed to register these credentials, because of a bad HS address. */
+  /* We failed to store these credentials in a persistent file on disk. */
   REGISTER_FAIL_PERMANENT_STORAGE,
 } hs_client_register_auth_status_t;
 
diff --git a/src/feature/hs/hs_descriptor.c b/src/feature/hs/hs_descriptor.c
index a39a4a09c9..50a46fb40f 100644
--- a/src/feature/hs/hs_descriptor.c
+++ b/src/feature/hs/hs_descriptor.c
@@ -1429,11 +1429,15 @@ decrypt_descriptor_cookie(const hs_descriptor_t *desc,
   tor_assert(!fast_mem_is_zero(
         (char *) &desc->superencrypted_data.auth_ephemeral_pubkey,
         sizeof(desc->superencrypted_data.auth_ephemeral_pubkey)));
-  tor_assert(!fast_mem_is_zero((char *) client_auth_sk,
-                              sizeof(*client_auth_sk)));
   tor_assert(!fast_mem_is_zero((char *) desc->subcredential.subcred,
                                DIGEST256_LEN));
 
+  /* Catch potential code-flow cases of an unitialized private key sneaking
+   * into this function. */
+  if (BUG(fast_mem_is_zero((char *)client_auth_sk, sizeof(*client_auth_sk)))) {
+    goto done;
+  }
+
   /* Get the KEYS component to derive the CLIENT-ID and COOKIE-KEY. */
   keystream_length =
     build_descriptor_cookie_keys(&desc->subcredential,