Improved validation for received requests (#9817)

* Simplify `start_listening` callpath

* Correctly check the size of uploaded files

1 files changed, 2 insertions, 2 deletions

diff --git a/synapse/event_auth.py b/synapse/event_auth.py

index afc2bc8267..70c556566e 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -21,7 +21,7 @@ from signedjson.key import decode_verify_key_bytes
 from signedjson.sign import SignatureVerifyException, verify_signed_json
 from unpaddedbase64 import decode_base64
 
-from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.api.constants import MAX_PDU_SIZE, EventTypes, JoinRules, Membership
 from synapse.api.errors import AuthError, EventSizeError, SynapseError
 from synapse.api.room_versions import (
     KNOWN_ROOM_VERSIONS,
@@ -205,7 +205,7 @@ def _check_size_limits(event: EventBase) -> None:
         too_big("type")
     if len(event.event_id) > 255:
         too_big("event_id")
-    if len(encode_canonical_json(event.get_pdu_json())) > 65536:
+    if len(encode_canonical_json(event.get_pdu_json())) > MAX_PDU_SIZE:
         too_big("event")