diff options
Diffstat (limited to 'synapse/crypto')
| -rw-r--r-- | synapse/crypto/keyring.py | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py index eaf41b983c..a64ba0752a 100644 --- a/synapse/crypto/keyring.py +++ b/synapse/crypto/keyring.py @@ -394,8 +394,7 @@ class BaseV2KeyFetcher(object): POST /_matrix/key/v2/query. Checks that each signature in the response that claims to come from the origin - server is valid. (Does not check that there actually is such a signature, for - some reason.) + server is valid, and that there is at least one such signature. Stores the json in server_keys_json so that it can be used for future responses to /_matrix/key/v2/query. @@ -430,16 +429,25 @@ class BaseV2KeyFetcher(object): verify_key=verify_key, valid_until_ts=ts_valid_until_ms ) - # TODO: improve this signature checking server_name = response_json["server_name"] + verified = False for key_id in response_json["signatures"].get(server_name, {}): - if key_id not in verify_keys: + # each of the keys used for the signature must be present in the response + # json. + key = verify_keys.get(key_id) + if not key: raise KeyLookupError( - "Key response must include verification keys for all signatures" + "Key response is signed by key id %s:%s but that key is not " + "present in the response" % (server_name, key_id) ) - verify_signed_json( - response_json, server_name, verify_keys[key_id].verify_key + verify_signed_json(response_json, server_name, key.verify_key) + verified = True + + if not verified: + raise KeyLookupError( + "Key response for %s is not signed by the origin server" + % (server_name,) ) for key_id, key_data in response_json["old_verify_keys"].items(): @@ -677,12 +685,6 @@ class ServerKeyFetcher(BaseV2KeyFetcher): except HttpResponseException as e: raise_from(KeyLookupError("Remote server returned an error"), e) - if ( - u"signatures" not in response - or server_name not in response[u"signatures"] - ): - raise KeyLookupError("Key response not signed by remote server") - if response["server_name"] != server_name: raise KeyLookupError( "Expected a response for server %r not %r" |