3 files changed, 48 insertions, 5 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index cffa831d80..4b38f7c759 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -265,7 +265,7 @@ def _check_sigs_on_pdus(keyring, room_version, pdus):
     ]
 
     more_deferreds = keyring.verify_json_objects_for_server([
-        (p.sender_domain, p.redacted_pdu_json)
+        (p.sender_domain, p.redacted_pdu_json, 0)
         for p in pdus_to_check_sender
     ])
 
@@ -298,7 +298,7 @@ def _check_sigs_on_pdus(keyring, room_version, pdus):
         ]
 
         more_deferreds = keyring.verify_json_objects_for_server([
-            (get_domain_from_id(p.pdu.event_id), p.redacted_pdu_json)
+            (get_domain_from_id(p.pdu.event_id), p.redacted_pdu_json, 0)
             for p in pdus_to_check_event_id
         ])
 
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index df60828dba..4c28c1dc3c 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -33,6 +33,7 @@ from synapse.api.errors import (
     IncompatibleRoomVersionError,
     NotFoundError,
     SynapseError,
+    UnsupportedRoomVersionError,
 )
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.crypto.event_signing import compute_event_signature
@@ -198,11 +199,22 @@ class FederationServer(FederationBase):
 
             try:
                 room_version = yield self.store.get_room_version(room_id)
-                format_ver = room_version_to_event_format(room_version)
             except NotFoundError:
                 logger.info("Ignoring PDU for unknown room_id: %s", room_id)
                 continue
 
+            try:
+                format_ver = room_version_to_event_format(room_version)
+            except UnsupportedRoomVersionError:
+                # this can happen if support for a given room version is withdrawn,
+                # so that we still get events for said room.
+                logger.info(
+                    "Ignoring PDU for room %s with unknown version %s",
+                    room_id,
+                    room_version,
+                )
+                continue
+
             event = event_from_pdu_json(p, format_ver)
             pdus_by_room.setdefault(room_id, []).append(event)
 
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 385eda2dca..0db8858cf1 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -23,7 +23,11 @@ from twisted.internet import defer
 import synapse
 from synapse.api.errors import Codes, FederationDeniedError, SynapseError
 from synapse.api.room_versions import RoomVersions
-from synapse.api.urls import FEDERATION_V1_PREFIX, FEDERATION_V2_PREFIX
+from synapse.api.urls import (
+    FEDERATION_UNSTABLE_PREFIX,
+    FEDERATION_V1_PREFIX,
+    FEDERATION_V2_PREFIX,
+)
 from synapse.http.endpoint import parse_and_validate_server_name
 from synapse.http.server import JsonResource
 from synapse.http.servlet import (
@@ -90,6 +94,7 @@ class NoAuthenticationError(AuthenticationError):
 
 class Authenticator(object):
     def __init__(self, hs):
+        self._clock = hs.get_clock()
         self.keyring = hs.get_keyring()
         self.server_name = hs.hostname
         self.store = hs.get_datastore()
@@ -98,6 +103,7 @@ class Authenticator(object):
     # A method just so we can pass 'self' as the authenticator to the Servlets
     @defer.inlineCallbacks
     def authenticate_request(self, request, content):
+        now = self._clock.time_msec()
         json_request = {
             "method": request.method.decode('ascii'),
             "uri": request.uri.decode('ascii'),
@@ -134,7 +140,7 @@ class Authenticator(object):
                 401, "Missing Authorization headers", Codes.UNAUTHORIZED,
             )
 
-        yield self.keyring.verify_json_for_server(origin, json_request)
+        yield self.keyring.verify_json_for_server(origin, json_request, now)
 
         logger.info("Request from %s", origin)
         request.authenticated_entity = origin
@@ -1304,6 +1310,30 @@ class FederationGroupsSettingJoinPolicyServlet(BaseFederationServlet):
         defer.returnValue((200, new_content))
 
 
+class RoomComplexityServlet(BaseFederationServlet):
+    """
+    Indicates to other servers how complex (and therefore likely
+    resource-intensive) a public room this server knows about is.
+    """
+    PATH = "/rooms/(?P<room_id>[^/]*)/complexity"
+    PREFIX = FEDERATION_UNSTABLE_PREFIX
+
+    @defer.inlineCallbacks
+    def on_GET(self, origin, content, query, room_id):
+
+        store = self.handler.hs.get_datastore()
+
+        is_public = yield store.is_room_world_readable_or_publicly_joinable(
+            room_id
+        )
+
+        if not is_public:
+            raise SynapseError(404, "Room not found", errcode=Codes.INVALID_PARAM)
+
+        complexity = yield store.get_room_complexity(room_id)
+        defer.returnValue((200, complexity))
+
+
 FEDERATION_SERVLET_CLASSES = (
     FederationSendServlet,
     FederationEventServlet,
@@ -1327,6 +1357,7 @@ FEDERATION_SERVLET_CLASSES = (
     FederationThirdPartyInviteExchangeServlet,
     On3pidBindServlet,
     FederationVersionServlet,
+    RoomComplexityServlet,
 )
 
 OPENID_SERVLET_CLASSES = (