decryption_error_message: add logging when it happens

Signed-off-by: Sumner Evans <sumner@beeper.com>

mausignald/types.py

@@ -475,6 +475,13 @@ class ReceiptMessage(SerializableAttrs):
     when: int
 
 
+@dataclass
+class DecryptionErrorMessage(SerializableAttrs):
+    timestamp: int
+    device_id: int
+    ratchet_key: Optional[str] = None
+
+
 @dataclass
 class ContactSyncMeta(SerializableAttrs):
     id: Optional[str] = None
@@ -612,6 +619,7 @@ class IncomingMessage(SerializableAttrs):
     sync_message: Optional[SyncMessage] = field(default=None)
     typing_message: Optional[TypingMessage] = None
     receipt_message: Optional[ReceiptMessage] = None
+    decryption_error_message: Optional[DecryptionErrorMessage] = None
 
 
 @dataclass(kw_only=True)

mautrix_signal/signal.py

@@ -83,6 +83,8 @@ class SignalHandler(SignaldClient):
             await self.handle_receipt(sender, evt.receipt_message)
         if evt.call_message:
             await self.handle_call_message(user, sender, evt)
+        if evt.decryption_error_message:
+            await self.handle_decryption_error(user, sender, evt)
         if evt.sync_message:
             if evt.sync_message.read_messages:
                 await self.handle_own_receipts(sender, evt.sync_message.read_messages)
@@ -347,6 +349,24 @@ class SignalHandler(SignaldClient):
             portal = await po.Portal.get_by_mxid(message.mx_room)
             await sender.intent_for(portal).mark_read(portal.mxid, message.mxid)
 
+    async def handle_decryption_error(
+        self, user: u.User, sender: pu.Puppet, msg: IncomingMessage
+    ) -> None:
+        # These messages mean that a message resend was requested. Signald will handle it, but we
+        # need to update the checkpoints.
+        assert msg.decryption_error_message
+        my_uuid = user.address.uuid
+        timestamp = msg.decryption_error_message.timestamp
+        self.log.debug(f"Got decryption error message for {my_uuid}/{timestamp}")
+        message = await DBMessage.find_by_sender_timestamp(my_uuid, timestamp)
+        if not message:
+            self.log.warning("couldn't find message to referenced in decryption error")
+            return
+        portal = await po.Portal.get_by_mxid(message.mx_room)
+        self.log.debug(
+            f"Got decryption error message for {message.mxid} from {sender} in {portal.mxid}"
+        )
+
     async def start(self) -> None:
         await self.connect()
         known_usernames = set()