Be stricter about JSON that is accepted by Synapse (#8106)

1 files changed, 4 insertions, 4 deletions

diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 84169c1022..d8def45e38 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -19,7 +19,7 @@ import logging
 from typing import Dict, List, Optional, Tuple
 
 import attr
-from canonicaljson import encode_canonical_json, json
+from canonicaljson import encode_canonical_json
 from signedjson.key import VerifyKey, decode_verify_key_bytes
 from signedjson.sign import SignatureVerifyException, verify_signed_json
 from unpaddedbase64 import decode_base64
@@ -35,7 +35,7 @@ from synapse.types import (
     get_domain_from_id,
     get_verify_key_from_cross_signing_key,
 )
-from synapse.util import unwrapFirstError
+from synapse.util import json_decoder, unwrapFirstError
 from synapse.util.async_helpers import Linearizer
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.retryutils import NotRetryingDestination
@@ -404,7 +404,7 @@ class E2eKeysHandler(object):
             for device_id, keys in device_keys.items():
                 for key_id, json_bytes in keys.items():
                     json_result.setdefault(user_id, {})[device_id] = {
-                        key_id: json.loads(json_bytes)
+                        key_id: json_decoder.decode(json_bytes)
                     }
 
         @trace
@@ -1186,7 +1186,7 @@ def _exception_to_failure(e):
 
 
 def _one_time_keys_match(old_key_json, new_key):
-    old_key = json.loads(old_key_json)
+    old_key = json_decoder.decode(old_key_json)
 
     # if either is a string rather than an object, they must match exactly
     if not isinstance(old_key, dict) or not isinstance(new_key, dict):