Improve validation of field size limits in events.

synapse/api/errors.py

@@ -426,7 +426,7 @@ def error_dict(self, config: Optional["HomeServerConfig"]) -> "JsonDict":
 class EventSizeError(SynapseError):
     """An error raised when an event is too big."""
 
-    def __init__(self, msg: str, strict: bool):
+    def __init__(self, msg: str, unpersistable: bool):
         """
         strict:
             if True, the PDU must not be persisted, not even as a rejected PDU
@@ -436,7 +436,7 @@ def __init__(self, msg: str, strict: bool):
         """
 
         super().__init__(413, msg, Codes.TOO_LARGE)
-        self.strict = strict
+        self.unpersistable = unpersistable
 
 
 class LoginError(SynapseError):

synapse/event_auth.py

@@ -385,36 +385,36 @@ def _check_size_limits(event: "EventBase") -> None:
 
     # Whole PDU check
     if len(encode_canonical_json(event.get_pdu_json())) > MAX_PDU_SIZE:
-        raise EventSizeError("event too large", strict=True)
+        raise EventSizeError("event too large", unpersistable=True)
 
     # Codepoint size check: Synapse always enforced these limits, so apply
     # them strictly.
     if len(event.user_id) > 255:
-        raise EventSizeError("'user_id' too large", strict=True)
+        raise EventSizeError("'user_id' too large", unpersistable=True)
     if len(event.room_id) > 255:
-        raise EventSizeError("'room_id' too large", strict=True)
+        raise EventSizeError("'room_id' too large", unpersistable=True)
     if event.is_state() and len(event.state_key) > 255:
-        raise EventSizeError("'state_key' too large", strict=True)
+        raise EventSizeError("'state_key' too large", unpersistable=True)
     if len(event.type) > 255:
-        raise EventSizeError("'type' too large", strict=True)
+        raise EventSizeError("'type' too large", unpersistable=True)
     if len(event.event_id) > 255:
-        raise EventSizeError("'event_id' too large", strict=True)
+        raise EventSizeError("'event_id' too large", unpersistable=True)
 
     strict_byte_limits = (
         event.room_version not in LENIENT_EVENT_BYTE_LIMITS_ROOM_VERSIONS
     )
 
     # Byte size check: if these fail, then be lenient to avoid breaking rooms.
     if len(event.user_id.encode("utf-8")) > 255:
-        raise EventSizeError("'user_id' too large", strict=strict_byte_limits)
+        raise EventSizeError("'user_id' too large", unpersistable=strict_byte_limits)
     if len(event.room_id.encode("utf-8")) > 255:
-        raise EventSizeError("'room_id' too large", strict=strict_byte_limits)
+        raise EventSizeError("'room_id' too large", unpersistable=strict_byte_limits)
     if event.is_state() and len(event.state_key.encode("utf-8")) > 255:
-        raise EventSizeError("'state_key' too large", strict=strict_byte_limits)
+        raise EventSizeError("'state_key' too large", unpersistable=strict_byte_limits)
     if len(event.type.encode("utf-8")) > 255:
-        raise EventSizeError("'type' too large", strict=strict_byte_limits)
+        raise EventSizeError("'type' too large", unpersistable=strict_byte_limits)
     if len(event.event_id.encode("utf-8")) > 255:
-        raise EventSizeError("'event_id' too large", strict=strict_byte_limits)
+        raise EventSizeError("'event_id' too large", unpersistable=strict_byte_limits)
 
 
 def _check_create(event: "EventBase") -> None:

synapse/handlers/federation_event.py

@@ -1739,7 +1739,7 @@ async def prep(event: EventBase) -> None:
                     logger.warning("Rejecting %r because %s", event, e)
                     context.rejected = RejectedReason.AUTH_ERROR
                 except EventSizeError as e:
-                    if e.strict:
+                    if e.unpersistable:
                         # A strict event size error means the event is completely
                         # unpersistable.
                         raise e
@@ -1794,7 +1794,7 @@ async def _check_event_auth(
             context.rejected = RejectedReason.AUTH_ERROR
             return
         except EventSizeError as e:
-            if e.strict:
+            if e.unpersistable:
                 # A strict event size error means the event is completely
                 # unpersistable.
                 raise e