daemon: Catch POST requests that try to send out messages.

Synapse seems to accept a POST requests on the
_matrix/client/r0/rooms/$ROOM/send/m.room.message path.

While this is not specced in any way people might shoot themselves in
the foot by sending unencrypted messages to a room if they, by accident,
use the wrong HTTP method.

This fixes: #56

pantalaimon/daemon.py

@@ -19,6 +19,7 @@ import urllib.parse
 import concurrent.futures
 from json import JSONDecodeError
 from typing import Any, Dict
+from uuid import uuid4
 
 import aiohttp
 import attr
@@ -817,7 +818,7 @@ class ProxyDaemon:
             return await self.forward_to_web(request, token=client.access_token)
 
         msgtype = request.match_info["event_type"]
-        txnid = request.match_info["txnid"]
+        txnid = request.match_info.get("txnid", uuid4())
 
         try:
             content = await request.json()

pantalaimon/main.py

@@ -69,6 +69,10 @@ async def init(data_dir, server_conf, send_queue, recv_queue):
                 r"/_matrix/client/r0/rooms/{room_id}/send/{event_type}/{txnid}",
                 proxy.send_message,
             ),
+            web.post(
+                r"/_matrix/client/r0/rooms/{room_id}/send/{event_type}",
+                proxy.send_message,
+            ),
             web.post("/_matrix/client/r0/user/{user_id}/filter", proxy.filter),
             web.post("/.well-known/matrix/client", proxy.well_known),
             web.get("/.well-known/matrix/client", proxy.well_known),