Start implementing auth conflict res

synapse/federation/federation_client.py

@@ -331,6 +331,45 @@ class FederationClient(object):
 
         defer.returnValue(pdu)
 
+    @defer.inlineCallbacks
+    def query_auth(self, destination, room_id, event_id, local_auth):
+        """
+        Params:
+            destination (str)
+            event_it (str)
+            local_auth (list)
+        """
+        time_now = self._clock.time_msec()
+
+        send_content = {
+            "auth_chain": [e.get_pdu_json(time_now) for e in local_auth],
+        }
+
+        code, content = yield self.transport_layer.send_invite(
+            destination=destination,
+            room_id=room_id,
+            event_id=event_id,
+            content=send_content,
+        )
+
+        auth_chain = [
+            (yield self._check_sigs_and_hash(self.event_from_pdu_json(e)))
+            for e in content["auth_chain"]
+        ]
+
+        missing = [
+            (yield self._check_sigs_and_hash(self.event_from_pdu_json(e)))
+            for e in content.get("missing", [])
+        ]
+
+        ret = {
+            "auth_chain": auth_chain,
+            "rejects": content.get("rejects", []),
+            "missing": missing,
+        }
+
+        defer.returnValue(ret)
+
     def event_from_pdu_json(self, pdu_json, outlier=False):
         event = FrozenEvent(
             pdu_json