Merge branch 'develop' of github.com:matrix-org/synapse into anoa/public_rooms_federate

1 files changed, 163 insertions, 182 deletions

diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index cd5b9bbb19..083f2e0ac3 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -34,6 +34,7 @@ from synapse.api.constants import (
     EventTypes,
     Membership,
     RejectedReason,
+    RoomVersions,
 )
 from synapse.api.errors import (
     AuthError,
@@ -43,10 +44,7 @@ from synapse.api.errors import (
     StoreError,
     SynapseError,
 )
-from synapse.crypto.event_signing import (
-    add_hashes_and_signatures,
-    compute_event_signature,
-)
+from synapse.crypto.event_signing import compute_event_signature
 from synapse.events.validator import EventValidator
 from synapse.replication.http.federation import (
     ReplicationCleanRoomRestServlet,
@@ -58,7 +56,6 @@ from synapse.types import UserID, get_domain_from_id
 from synapse.util import logcontext, unwrapFirstError
 from synapse.util.async_helpers import Linearizer
 from synapse.util.distributor import user_joined_room
-from synapse.util.frozenutils import unfreeze
 from synapse.util.logutils import log_function
 from synapse.util.retryutils import NotRetryingDestination
 from synapse.visibility import filter_events_for_server
@@ -105,7 +102,7 @@ class FederationHandler(BaseHandler):
 
         self.hs = hs
 
-        self.store = hs.get_datastore()  # type: synapse.storage.DataStore
+        self.store = hs.get_datastore()
         self.federation_client = hs.get_federation_client()
         self.state_handler = hs.get_state_handler()
         self.server_name = hs.hostname
@@ -202,27 +199,22 @@ class FederationHandler(BaseHandler):
             self.room_queues[room_id].append((pdu, origin))
             return
 
-        # If we're no longer in the room just ditch the event entirely. This
-        # is probably an old server that has come back and thinks we're still
-        # in the room (or we've been rejoined to the room by a state reset).
+        # If we're not in the room just ditch the event entirely. This is
+        # probably an old server that has come back and thinks we're still in
+        # the room (or we've been rejoined to the room by a state reset).
         #
-        # If we were never in the room then maybe our database got vaped and
-        # we should check if we *are* in fact in the room. If we are then we
-        # can magically rejoin the room.
+        # Note that if we were never in the room then we would have already
+        # dropped the event, since we wouldn't know the room version.
         is_in_room = yield self.auth.check_host_in_room(
             room_id,
             self.server_name
         )
         if not is_in_room:
-            was_in_room = yield self.store.was_host_joined(
-                pdu.room_id, self.server_name,
+            logger.info(
+                "[%s %s] Ignoring PDU from %s as we're not in the room",
+                room_id, event_id, origin,
             )
-            if was_in_room:
-                logger.info(
-                    "[%s %s] Ignoring PDU from %s as we've left the room",
-                    room_id, event_id, origin,
-                )
-                defer.returnValue(None)
+            defer.returnValue(None)
 
         state = None
         auth_chain = []
@@ -239,7 +231,7 @@ class FederationHandler(BaseHandler):
                 room_id, event_id, min_depth,
             )
 
-            prevs = {e_id for e_id, _ in pdu.prev_events}
+            prevs = set(pdu.prev_event_ids())
             seen = yield self.store.have_seen_events(prevs)
 
             if min_depth and pdu.depth < min_depth:
@@ -347,6 +339,8 @@ class FederationHandler(BaseHandler):
                             room_id, event_id, p,
                         )
 
+                        room_version = yield self.store.get_room_version(room_id)
+
                         with logcontext.nested_logging_context(p):
                             # note that if any of the missing prevs share missing state or
                             # auth events, the requests to fetch those events are deduped
@@ -360,7 +354,7 @@ class FederationHandler(BaseHandler):
                             # we want the state *after* p; get_state_for_room returns the
                             # state *before* p.
                             remote_event = yield self.federation_client.get_pdu(
-                                [origin], p, outlier=True,
+                                [origin], p, room_version, outlier=True,
                             )
 
                             if remote_event is None:
@@ -384,7 +378,6 @@ class FederationHandler(BaseHandler):
                             for x in remote_state:
                                 event_map[x.event_id] = x
 
-                    room_version = yield self.store.get_room_version(room_id)
                     state_map = yield resolve_events_with_store(
                         room_version, state_maps, event_map,
                         state_res_store=StateResolutionStore(self.store),
@@ -557,86 +550,54 @@ class FederationHandler(BaseHandler):
             room_id, event_id, event,
         )
 
-        # FIXME (erikj): Awful hack to make the case where we are not currently
-        # in the room work
-        # If state and auth_chain are None, then we don't need to do this check
-        # as we already know we have enough state in the DB to handle this
-        # event.
-        if state and auth_chain and not event.internal_metadata.is_outlier():
-            is_in_room = yield self.auth.check_host_in_room(
-                room_id,
-                self.server_name
-            )
-        else:
-            is_in_room = True
-
-        if not is_in_room:
-            logger.info(
-                "[%s %s] Got event for room we're not in",
-                room_id, event_id,
-            )
-
-            try:
-                yield self._persist_auth_tree(
-                    origin, auth_chain, state, event
-                )
-            except AuthError as e:
-                raise FederationError(
-                    "ERROR",
-                    e.code,
-                    e.msg,
-                    affected=event_id,
-                )
-
-        else:
-            event_ids = set()
-            if state:
-                event_ids |= {e.event_id for e in state}
-            if auth_chain:
-                event_ids |= {e.event_id for e in auth_chain}
+        event_ids = set()
+        if state:
+            event_ids |= {e.event_id for e in state}
+        if auth_chain:
+            event_ids |= {e.event_id for e in auth_chain}
 
-            seen_ids = yield self.store.have_seen_events(event_ids)
+        seen_ids = yield self.store.have_seen_events(event_ids)
 
-            if state and auth_chain is not None:
-                # If we have any state or auth_chain given to us by the replication
-                # layer, then we should handle them (if we haven't before.)
+        if state and auth_chain is not None:
+            # If we have any state or auth_chain given to us by the replication
+            # layer, then we should handle them (if we haven't before.)
 
-                event_infos = []
+            event_infos = []
 
-                for e in itertools.chain(auth_chain, state):
-                    if e.event_id in seen_ids:
-                        continue
-                    e.internal_metadata.outlier = True
-                    auth_ids = [e_id for e_id, _ in e.auth_events]
-                    auth = {
-                        (e.type, e.state_key): e for e in auth_chain
-                        if e.event_id in auth_ids or e.type == EventTypes.Create
-                    }
-                    event_infos.append({
-                        "event": e,
-                        "auth_events": auth,
-                    })
-                    seen_ids.add(e.event_id)
+            for e in itertools.chain(auth_chain, state):
+                if e.event_id in seen_ids:
+                    continue
+                e.internal_metadata.outlier = True
+                auth_ids = e.auth_event_ids()
+                auth = {
+                    (e.type, e.state_key): e for e in auth_chain
+                    if e.event_id in auth_ids or e.type == EventTypes.Create
+                }
+                event_infos.append({
+                    "event": e,
+                    "auth_events": auth,
+                })
+                seen_ids.add(e.event_id)
 
-                logger.info(
-                    "[%s %s] persisting newly-received auth/state events %s",
-                    room_id, event_id, [e["event"].event_id for e in event_infos]
-                )
-                yield self._handle_new_events(origin, event_infos)
+            logger.info(
+                "[%s %s] persisting newly-received auth/state events %s",
+                room_id, event_id, [e["event"].event_id for e in event_infos]
+            )
+            yield self._handle_new_events(origin, event_infos)
 
-            try:
-                context = yield self._handle_new_event(
-                    origin,
-                    event,
-                    state=state,
-                )
-            except AuthError as e:
-                raise FederationError(
-                    "ERROR",
-                    e.code,
-                    e.msg,
-                    affected=event.event_id,
-                )
+        try:
+            context = yield self._handle_new_event(
+                origin,
+                event,
+                state=state,
+            )
+        except AuthError as e:
+            raise FederationError(
+                "ERROR",
+                e.code,
+                e.msg,
+                affected=event.event_id,
+            )
 
         room = yield self.store.get_room(room_id)
 
@@ -692,6 +653,8 @@ class FederationHandler(BaseHandler):
         if dest == self.server_name:
             raise SynapseError(400, "Can't backfill from self.")
 
+        room_version = yield self.store.get_room_version(room_id)
+
         events = yield self.federation_client.backfill(
             dest,
             room_id,
@@ -726,7 +689,7 @@ class FederationHandler(BaseHandler):
         edges = [
             ev.event_id
             for ev in events
-            if set(e_id for e_id, _ in ev.prev_events) - event_ids
+            if set(ev.prev_event_ids()) - event_ids
         ]
 
         logger.info(
@@ -753,7 +716,7 @@ class FederationHandler(BaseHandler):
         required_auth = set(
             a_id
             for event in events + list(state_events.values()) + list(auth_events.values())
-            for a_id, _ in event.auth_events
+            for a_id in event.auth_event_ids()
         )
         auth_events.update({
             e_id: event_map[e_id] for e_id in required_auth if e_id in event_map
@@ -769,7 +732,7 @@ class FederationHandler(BaseHandler):
             auth_events.update(ret_events)
 
             required_auth.update(
-                a_id for event in ret_events.values() for a_id, _ in event.auth_events
+                a_id for event in ret_events.values() for a_id in event.auth_event_ids()
             )
             missing_auth = required_auth - set(auth_events)
 
@@ -785,6 +748,7 @@ class FederationHandler(BaseHandler):
                             self.federation_client.get_pdu,
                             [dest],
                             event_id,
+                            room_version=room_version,
                             outlier=True,
                             timeout=10000,
                         )
@@ -796,7 +760,7 @@ class FederationHandler(BaseHandler):
                 required_auth.update(
                     a_id
                     for event in results if event
-                    for a_id, _ in event.auth_events
+                    for a_id in event.auth_event_ids()
                 )
                 missing_auth = required_auth - set(auth_events)
 
@@ -816,7 +780,7 @@ class FederationHandler(BaseHandler):
                 "auth_events": {
                     (auth_events[a_id].type, auth_events[a_id].state_key):
                     auth_events[a_id]
-                    for a_id, _ in a.auth_events
+                    for a_id in a.auth_event_ids()
                     if a_id in auth_events
                 }
             })
@@ -828,7 +792,7 @@ class FederationHandler(BaseHandler):
                 "auth_events": {
                     (auth_events[a_id].type, auth_events[a_id].state_key):
                     auth_events[a_id]
-                    for a_id, _ in event_map[e_id].auth_events
+                    for a_id in event_map[e_id].auth_event_ids()
                     if a_id in auth_events
                 }
             })
@@ -1041,17 +1005,17 @@ class FederationHandler(BaseHandler):
         Raises:
             SynapseError if the event does not pass muster
         """
-        if len(ev.prev_events) > 20:
+        if len(ev.prev_event_ids()) > 20:
             logger.warn("Rejecting event %s which has %i prev_events",
-                        ev.event_id, len(ev.prev_events))
+                        ev.event_id, len(ev.prev_event_ids()))
             raise SynapseError(
                 http_client.BAD_REQUEST,
                 "Too many prev_events",
             )
 
-        if len(ev.auth_events) > 10:
+        if len(ev.auth_event_ids()) > 10:
             logger.warn("Rejecting event %s which has %i auth_events",
-                        ev.event_id, len(ev.auth_events))
+                        ev.event_id, len(ev.auth_event_ids()))
             raise SynapseError(
                 http_client.BAD_REQUEST,
                 "Too many auth_events",
@@ -1076,7 +1040,7 @@ class FederationHandler(BaseHandler):
     def on_event_auth(self, event_id):
         event = yield self.store.get_event(event_id)
         auth = yield self.store.get_auth_chain(
-            [auth_id for auth_id, _ in event.auth_events],
+            [auth_id for auth_id in event.auth_event_ids()],
             include_given=True
         )
         defer.returnValue([e for e in auth])
@@ -1097,7 +1061,7 @@ class FederationHandler(BaseHandler):
         """
         logger.debug("Joining %s to %s", joinee, room_id)
 
-        origin, event = yield self._make_and_verify_event(
+        origin, event, event_format_version = yield self._make_and_verify_event(
             target_hosts,
             room_id,
             joinee,
@@ -1120,7 +1084,6 @@ class FederationHandler(BaseHandler):
         handled_events = set()
 
         try:
-            event = self._sign_event(event)
             # Try the host we successfully got a response to /make_join/
             # request first.
             try:
@@ -1128,7 +1091,9 @@ class FederationHandler(BaseHandler):
                 target_hosts.insert(0, origin)
             except ValueError:
                 pass
-            ret = yield self.federation_client.send_join(target_hosts, event)
+            ret = yield self.federation_client.send_join(
+                target_hosts, event, event_format_version,
+            )
 
             origin = ret["origin"]
             state = ret["state"]
@@ -1201,13 +1166,18 @@ class FederationHandler(BaseHandler):
         """
         event_content = {"membership": Membership.JOIN}
 
-        builder = self.event_builder_factory.new({
-            "type": EventTypes.Member,
-            "content": event_content,
-            "room_id": room_id,
-            "sender": user_id,
-            "state_key": user_id,
-        })
+        room_version = yield self.store.get_room_version(room_id)
+
+        builder = self.event_builder_factory.new(
+            room_version,
+            {
+                "type": EventTypes.Member,
+                "content": event_content,
+                "room_id": room_id,
+                "sender": user_id,
+                "state_key": user_id,
+            }
+        )
 
         try:
             event, context = yield self.event_creation_handler.create_new_client_event(
@@ -1219,7 +1189,9 @@ class FederationHandler(BaseHandler):
 
         # The remote hasn't signed it yet, obviously. We'll do the full checks
         # when we get the event back in `on_send_join_request`
-        yield self.auth.check_from_context(event, context, do_sig_check=False)
+        yield self.auth.check_from_context(
+            room_version, event, context, do_sig_check=False,
+        )
 
         defer.returnValue(event)
 
@@ -1324,11 +1296,11 @@ class FederationHandler(BaseHandler):
             )
 
         event.internal_metadata.outlier = True
-        event.internal_metadata.invite_from_remote = True
+        event.internal_metadata.out_of_band_membership = True
 
         event.signatures.update(
             compute_event_signature(
-                event,
+                event.get_pdu_json(),
                 self.hs.hostname,
                 self.hs.config.signing_key[0]
             )
@@ -1341,7 +1313,7 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def do_remotely_reject_invite(self, target_hosts, room_id, user_id):
-        origin, event = yield self._make_and_verify_event(
+        origin, event, event_format_version = yield self._make_and_verify_event(
             target_hosts,
             room_id,
             user_id,
@@ -1350,7 +1322,7 @@ class FederationHandler(BaseHandler):
         # Mark as outlier as we don't have any state for this event; we're not
         # even in the room.
         event.internal_metadata.outlier = True
-        event = self._sign_event(event)
+        event.internal_metadata.out_of_band_membership = True
 
         # Try the host that we succesfully called /make_leave/ on first for
         # the /send_leave/ request.
@@ -1373,7 +1345,7 @@ class FederationHandler(BaseHandler):
     @defer.inlineCallbacks
     def _make_and_verify_event(self, target_hosts, room_id, user_id, membership,
                                content={}, params=None):
-        origin, pdu = yield self.federation_client.make_membership_event(
+        origin, event, format_ver = yield self.federation_client.make_membership_event(
             target_hosts,
             room_id,
             user_id,
@@ -1382,9 +1354,7 @@ class FederationHandler(BaseHandler):
             params=params,
         )
 
-        logger.debug("Got response to make_%s: %s", membership, pdu)
-
-        event = pdu
+        logger.debug("Got response to make_%s: %s", membership, event)
 
         # We should assert some things.
         # FIXME: Do this in a nicer way
@@ -1392,28 +1362,7 @@ class FederationHandler(BaseHandler):
         assert(event.user_id == user_id)
         assert(event.state_key == user_id)
         assert(event.room_id == room_id)
-        defer.returnValue((origin, event))
-
-    def _sign_event(self, event):
-        event.internal_metadata.outlier = False
-
-        builder = self.event_builder_factory.new(
-            unfreeze(event.get_pdu_json())
-        )
-
-        builder.event_id = self.event_builder_factory.create_event_id()
-        builder.origin = self.hs.hostname
-
-        if not hasattr(event, "signatures"):
-            builder.signatures = {}
-
-        add_hashes_and_signatures(
-            builder,
-            self.hs.hostname,
-            self.hs.config.signing_key[0],
-        )
-
-        return builder.build()
+        defer.returnValue((origin, event, format_ver))
 
     @defer.inlineCallbacks
     @log_function
@@ -1422,13 +1371,17 @@ class FederationHandler(BaseHandler):
         leave event for the room and return that. We do *not* persist or
         process it until the other server has signed it and sent it back.
         """
-        builder = self.event_builder_factory.new({
-            "type": EventTypes.Member,
-            "content": {"membership": Membership.LEAVE},
-            "room_id": room_id,
-            "sender": user_id,
-            "state_key": user_id,
-        })
+        room_version = yield self.store.get_room_version(room_id)
+        builder = self.event_builder_factory.new(
+            room_version,
+            {
+                "type": EventTypes.Member,
+                "content": {"membership": Membership.LEAVE},
+                "room_id": room_id,
+                "sender": user_id,
+                "state_key": user_id,
+            }
+        )
 
         event, context = yield self.event_creation_handler.create_new_client_event(
             builder=builder,
@@ -1437,7 +1390,9 @@ class FederationHandler(BaseHandler):
         try:
             # The remote hasn't signed it yet, obviously. We'll do the full checks
             # when we get the event back in `on_send_leave_request`
-            yield self.auth.check_from_context(event, context, do_sig_check=False)
+            yield self.auth.check_from_context(
+                room_version, event, context, do_sig_check=False,
+            )
         except AuthError as e:
             logger.warn("Failed to create new leave %r because %s", event, e)
             raise e
@@ -1696,9 +1651,16 @@ class FederationHandler(BaseHandler):
                 create_event = e
                 break
 
+        if create_event is None:
+            # If the state doesn't have a create event then the room is
+            # invalid, and it would fail auth checks anyway.
+            raise SynapseError(400, "No create event in state")
+
+        room_version = create_event.content.get("room_version", RoomVersions.V1)
+
         missing_auth_events = set()
         for e in itertools.chain(auth_events, state, [event]):
-            for e_id, _ in e.auth_events:
+            for e_id in e.auth_event_ids():
                 if e_id not in event_map:
                     missing_auth_events.add(e_id)
 
@@ -1706,6 +1668,7 @@ class FederationHandler(BaseHandler):
             m_ev = yield self.federation_client.get_pdu(
                 [origin],
                 e_id,
+                room_version=room_version,
                 outlier=True,
                 timeout=10000,
             )
@@ -1717,14 +1680,14 @@ class FederationHandler(BaseHandler):
         for e in itertools.chain(auth_events, state, [event]):
             auth_for_e = {
                 (event_map[e_id].type, event_map[e_id].state_key): event_map[e_id]
-                for e_id, _ in e.auth_events
+                for e_id in e.auth_event_ids()
                 if e_id in event_map
             }
             if create_event:
                 auth_for_e[(EventTypes.Create, "")] = create_event
 
             try:
-                self.auth.check(e, auth_events=auth_for_e)
+                self.auth.check(room_version, e, auth_events=auth_for_e)
             except SynapseError as err:
                 # we may get SynapseErrors here as well as AuthErrors. For
                 # instance, there are a couple of (ancient) events in some
@@ -1785,10 +1748,10 @@ class FederationHandler(BaseHandler):
 
         # This is a hack to fix some old rooms where the initial join event
         # didn't reference the create event in its auth events.
-        if event.type == EventTypes.Member and not event.auth_events:
-            if len(event.prev_events) == 1 and event.depth < 5:
+        if event.type == EventTypes.Member and not event.auth_event_ids():
+            if len(event.prev_event_ids()) == 1 and event.depth < 5:
                 c = yield self.store.get_event(
-                    event.prev_events[0][0],
+                    event.prev_event_ids()[0],
                     allow_none=True,
                 )
                 if c and c.type == EventTypes.Create:
@@ -1835,7 +1798,7 @@ class FederationHandler(BaseHandler):
 
         # Now get the current auth_chain for the event.
         local_auth_chain = yield self.store.get_auth_chain(
-            [auth_id for auth_id, _ in event.auth_events],
+            [auth_id for auth_id in event.auth_event_ids()],
             include_given=True
         )
 
@@ -1891,7 +1854,7 @@ class FederationHandler(BaseHandler):
         """
         # Check if we have all the auth events.
         current_state = set(e.event_id for e in auth_events.values())
-        event_auth_events = set(e_id for e_id, _ in event.auth_events)
+        event_auth_events = set(event.auth_event_ids())
 
         if event.is_state():
             event_key = (event.type, event.state_key)
@@ -1935,7 +1898,7 @@ class FederationHandler(BaseHandler):
                         continue
 
                     try:
-                        auth_ids = [e_id for e_id, _ in e.auth_events]
+                        auth_ids = e.auth_event_ids()
                         auth = {
                             (e.type, e.state_key): e for e in remote_auth_chain
                             if e.event_id in auth_ids or e.type == EventTypes.Create
@@ -1956,7 +1919,7 @@ class FederationHandler(BaseHandler):
                         pass
 
                 have_events = yield self.store.get_seen_events_with_rejections(
-                    [e_id for e_id, _ in event.auth_events]
+                    event.auth_event_ids()
                 )
                 seen_events = set(have_events.keys())
             except Exception:
@@ -1968,6 +1931,8 @@ class FederationHandler(BaseHandler):
         current_state = set(e.event_id for e in auth_events.values())
         different_auth = event_auth_events - current_state
 
+        room_version = yield self.store.get_room_version(event.room_id)
+
         if different_auth and not event.internal_metadata.is_outlier():
             # Do auth conflict res.
             logger.info("Different auth: %s", different_auth)
@@ -1992,8 +1957,6 @@ class FederationHandler(BaseHandler):
                     (d.type, d.state_key): d for d in different_events if d
                 })
 
-                room_version = yield self.store.get_room_version(event.room_id)
-
                 new_state = yield self.state_handler.resolve_events(
                     room_version,
                     [list(local_view.values()), list(remote_view.values())],
@@ -2058,7 +2021,7 @@ class FederationHandler(BaseHandler):
                             continue
 
                         try:
-                            auth_ids = [e_id for e_id, _ in ev.auth_events]
+                            auth_ids = ev.auth_event_ids()
                             auth = {
                                 (e.type, e.state_key): e
                                 for e in result["auth_chain"]
@@ -2093,7 +2056,7 @@ class FederationHandler(BaseHandler):
                 )
 
         try:
-            self.auth.check(event, auth_events=auth_events)
+            self.auth.check(room_version, event, auth_events=auth_events)
         except AuthError as e:
             logger.warn("Failed auth resolution for %r because %s", event, e)
             raise e
@@ -2250,7 +2213,7 @@ class FederationHandler(BaseHandler):
         missing_remote_ids = [e.event_id for e in missing_remotes]
         base_remote_rejected = list(missing_remotes)
         for e in missing_remotes:
-            for e_id, _ in e.auth_events:
+            for e_id in e.auth_event_ids():
                 if e_id in missing_remote_ids:
                     try:
                         base_remote_rejected.remove(e)
@@ -2316,18 +2279,26 @@ class FederationHandler(BaseHandler):
         }
 
         if (yield self.auth.check_host_in_room(room_id, self.hs.hostname)):
-            builder = self.event_builder_factory.new(event_dict)
-            EventValidator().validate_new(builder)
+            room_version = yield self.store.get_room_version(room_id)
+            builder = self.event_builder_factory.new(room_version, event_dict)
+
+            EventValidator().validate_builder(builder)
             event, context = yield self.event_creation_handler.create_new_client_event(
                 builder=builder
             )
 
             event, context = yield self.add_display_name_to_third_party_invite(
-                event_dict, event, context
+                room_version, event_dict, event, context
             )
 
+            EventValidator().validate_new(event)
+
+            # We need to tell the transaction queue to send this out, even
+            # though the sender isn't a local user.
+            event.internal_metadata.send_on_behalf_of = self.hs.hostname
+
             try:
-                yield self.auth.check_from_context(event, context)
+                yield self.auth.check_from_context(room_version, event, context)
             except AuthError as e:
                 logger.warn("Denying new third party invite %r because %s", event, e)
                 raise e
@@ -2354,23 +2325,31 @@ class FederationHandler(BaseHandler):
         Returns:
             Deferred: resolves (to None)
         """
-        builder = self.event_builder_factory.new(event_dict)
+        room_version = yield self.store.get_room_version(room_id)
+
+        # NB: event_dict has a particular specced format we might need to fudge
+        # if we change event formats too much.
+        builder = self.event_builder_factory.new(room_version, event_dict)
 
         event, context = yield self.event_creation_handler.create_new_client_event(
             builder=builder,
         )
 
         event, context = yield self.add_display_name_to_third_party_invite(
-            event_dict, event, context
+            room_version, event_dict, event, context
         )
 
         try:
-            self.auth.check_from_context(event, context)
+            self.auth.check_from_context(room_version, event, context)
         except AuthError as e:
             logger.warn("Denying third party invite %r because %s", event, e)
             raise e
         yield self._check_signature(event, context)
 
+        # We need to tell the transaction queue to send this out, even
+        # though the sender isn't a local user.
+        event.internal_metadata.send_on_behalf_of = get_domain_from_id(event.sender)
+
         # XXX we send the invite here, but send_membership_event also sends it,
         # so we end up making two requests. I think this is redundant.
         returned_invite = yield self.send_invite(origin, event)
@@ -2381,7 +2360,8 @@ class FederationHandler(BaseHandler):
         yield member_handler.send_membership_event(None, event, context)
 
     @defer.inlineCallbacks
-    def add_display_name_to_third_party_invite(self, event_dict, event, context):
+    def add_display_name_to_third_party_invite(self, room_version, event_dict,
+                                               event, context):
         key = (
             EventTypes.ThirdPartyInvite,
             event.content["third_party_invite"]["signed"]["token"]
@@ -2405,11 +2385,12 @@ class FederationHandler(BaseHandler):
             # auth checks. If we need the invite and don't have it then the
             # auth check code will explode appropriately.
 
-        builder = self.event_builder_factory.new(event_dict)
-        EventValidator().validate_new(builder)
+        builder = self.event_builder_factory.new(room_version, event_dict)
+        EventValidator().validate_builder(builder)
         event, context = yield self.event_creation_handler.create_new_client_event(
             builder=builder,
         )
+        EventValidator().validate_new(event)
         defer.returnValue((event, context))
 
     @defer.inlineCallbacks