diff options
| -rw-r--r-- | changelog.d/12943.misc | 1 | ||||
| -rw-r--r-- | synapse/handlers/federation_event.py | 277 | ||||
| -rw-r--r-- | synapse/state/__init__.py | 26 | ||||
| -rw-r--r-- | tests/handlers/test_federation.py | 140 | ||||
| -rw-r--r-- | tests/rest/client/test_third_party_rules.py | 11 | ||||
| -rw-r--r-- | tests/test_federation.py | 8 |
6 files changed, 88 insertions, 375 deletions
diff --git a/changelog.d/12943.misc b/changelog.d/12943.misc new file mode 100644 index 0000000000..f66bb3ec32 --- /dev/null +++ b/changelog.d/12943.misc @@ -0,0 +1 @@ +Remove code which incorrectly attempted to reconcile state with remote servers when processing incoming events. diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py index c74117c19a..b1dab57447 100644 --- a/synapse/handlers/federation_event.py +++ b/synapse/handlers/federation_event.py @@ -12,6 +12,7 @@ # See the License for the specific language governing permissions and # limitations under the License. +import collections import itertools import logging from http import HTTPStatus @@ -347,7 +348,7 @@ class FederationEventHandler: event.internal_metadata.send_on_behalf_of = origin context = await self._state_handler.compute_event_context(event) - context = await self._check_event_auth(origin, event, context) + await self._check_event_auth(origin, event, context) if context.rejected: raise SynapseError( 403, f"{event.membership} event was rejected", Codes.FORBIDDEN @@ -485,7 +486,7 @@ class FederationEventHandler: partial_state=partial_state, ) - context = await self._check_event_auth(origin, event, context) + await self._check_event_auth(origin, event, context) if context.rejected: raise SynapseError(400, "Join event was rejected") @@ -1116,11 +1117,7 @@ class FederationEventHandler: state_ids_before_event=state_ids, ) try: - context = await self._check_event_auth( - origin, - event, - context, - ) + await self._check_event_auth(origin, event, context) except AuthError as e: # This happens only if we couldn't find the auth events. We'll already have # logged a warning, so now we just convert to a FederationError. @@ -1495,11 +1492,8 @@ class FederationEventHandler: ) async def _check_event_auth( - self, - origin: str, - event: EventBase, - context: EventContext, - ) -> EventContext: + self, origin: str, event: EventBase, context: EventContext + ) -> None: """ Checks whether an event should be rejected (for failing auth checks). @@ -1509,9 +1503,6 @@ class FederationEventHandler: context: The event context. - Returns: - The updated context object. - Raises: AuthError if we were unable to find copies of the event's auth events. (Most other failures just cause us to set `context.rejected`.) @@ -1526,7 +1517,7 @@ class FederationEventHandler: logger.warning("While validating received event %r: %s", event, e) # TODO: use a different rejected reason here? context.rejected = RejectedReason.AUTH_ERROR - return context + return # next, check that we have all of the event's auth events. # @@ -1538,6 +1529,9 @@ class FederationEventHandler: ) # ... and check that the event passes auth at those auth events. + # https://spec.matrix.org/v1.3/server-server-api/#checks-performed-on-receipt-of-a-pdu: + # 4. Passes authorization rules based on the event’s auth events, + # otherwise it is rejected. try: await check_state_independent_auth_rules(self._store, event) check_state_dependent_auth_rules(event, claimed_auth_events) @@ -1546,55 +1540,90 @@ class FederationEventHandler: "While checking auth of %r against auth_events: %s", event, e ) context.rejected = RejectedReason.AUTH_ERROR - return context + return + + # now check the auth rules pass against the room state before the event + # https://spec.matrix.org/v1.3/server-server-api/#checks-performed-on-receipt-of-a-pdu: + # 5. Passes authorization rules based on the state before the event, + # otherwise it is rejected. + # + # ... however, if we only have partial state for the room, then there is a good + # chance that we'll be missing some of the state needed to auth the new event. + # So, we state-resolve the auth events that we are given against the state that + # we know about, which ensures things like bans are applied. (Note that we'll + # already have checked we have all the auth events, in + # _load_or_fetch_auth_events_for_event above) + if context.partial_state: + room_version = await self._store.get_room_version_id(event.room_id) + + local_state_id_map = await context.get_prev_state_ids() + claimed_auth_events_id_map = { + (ev.type, ev.state_key): ev.event_id for ev in claimed_auth_events + } + + state_for_auth_id_map = ( + await self._state_resolution_handler.resolve_events_with_store( + event.room_id, + room_version, + [local_state_id_map, claimed_auth_events_id_map], + event_map=None, + state_res_store=StateResolutionStore(self._store), + ) + ) + else: + event_types = event_auth.auth_types_for_event(event.room_version, event) + state_for_auth_id_map = await context.get_prev_state_ids( + StateFilter.from_types(event_types) + ) - # now check auth against what we think the auth events *should* be. - event_types = event_auth.auth_types_for_event(event.room_version, event) - prev_state_ids = await context.get_prev_state_ids( - StateFilter.from_types(event_types) + calculated_auth_event_ids = self._event_auth_handler.compute_auth_events( + event, state_for_auth_id_map, for_verification=True ) - auth_events_ids = self._event_auth_handler.compute_auth_events( - event, prev_state_ids, for_verification=True + # if those are the same, we're done here. + if collections.Counter(event.auth_event_ids()) == collections.Counter( + calculated_auth_event_ids + ): + return + + # otherwise, re-run the auth checks based on what we calculated. + calculated_auth_events = await self._store.get_events_as_list( + calculated_auth_event_ids ) - auth_events_x = await self._store.get_events(auth_events_ids) + + # log the differences + + claimed_auth_event_map = {(e.type, e.state_key): e for e in claimed_auth_events} calculated_auth_event_map = { - (e.type, e.state_key): e for e in auth_events_x.values() + (e.type, e.state_key): e for e in calculated_auth_events } + logger.info( + "event's auth_events are different to our calculated auth_events. " + "Claimed but not calculated: %s. Calculated but not claimed: %s", + [ + ev + for k, ev in claimed_auth_event_map.items() + if k not in calculated_auth_event_map + or calculated_auth_event_map[k].event_id != ev.event_id + ], + [ + ev + for k, ev in calculated_auth_event_map.items() + if k not in claimed_auth_event_map + or claimed_auth_event_map[k].event_id != ev.event_id + ], + ) try: - updated_auth_events = await self._update_auth_events_for_auth( + check_state_dependent_auth_rules(event, calculated_auth_events) + except AuthError as e: + logger.warning( + "While checking auth of %r against room state before the event: %s", event, - calculated_auth_event_map=calculated_auth_event_map, - ) - except Exception: - # We don't really mind if the above fails, so lets not fail - # processing if it does. However, it really shouldn't fail so - # let's still log as an exception since we'll still want to fix - # any bugs. - logger.exception( - "Failed to double check auth events for %s with remote. " - "Ignoring failure and continuing processing of event.", - event.event_id, - ) - updated_auth_events = None - - if updated_auth_events: - context = await self._update_context_for_auth_events( - event, context, updated_auth_events + e, ) - auth_events_for_auth = updated_auth_events - else: - auth_events_for_auth = calculated_auth_event_map - - try: - check_state_dependent_auth_rules(event, auth_events_for_auth.values()) - except AuthError as e: - logger.warning("Failed auth resolution for %r because %s", event, e) context.rejected = RejectedReason.AUTH_ERROR - return context - async def _maybe_kick_guest_users(self, event: EventBase) -> None: if event.type != EventTypes.GuestAccess: return @@ -1704,93 +1733,6 @@ class FederationEventHandler: soft_failed_event_counter.inc() event.internal_metadata.soft_failed = True - async def _update_auth_events_for_auth( - self, - event: EventBase, - calculated_auth_event_map: StateMap[EventBase], - ) -> Optional[StateMap[EventBase]]: - """Helper for _check_event_auth. See there for docs. - - Checks whether a given event has the expected auth events. If it - doesn't then we talk to the remote server to compare state to see if - we can come to a consensus (e.g. if one server missed some valid - state). - - This attempts to resolve any potential divergence of state between - servers, but is not essential and so failures should not block further - processing of the event. - - Args: - event: - - calculated_auth_event_map: - Our calculated auth_events based on the state of the room - at the event's position in the DAG. - - Returns: - updated auth event map, or None if no changes are needed. - - """ - assert not event.internal_metadata.outlier - - # check for events which are in the event's claimed auth_events, but not - # in our calculated event map. - event_auth_events = set(event.auth_event_ids()) - different_auth = event_auth_events.difference( - e.event_id for e in calculated_auth_event_map.values() - ) - - if not different_auth: - return None - - logger.info( - "auth_events refers to events which are not in our calculated auth " - "chain: %s", - different_auth, - ) - - # XXX: currently this checks for redactions but I'm not convinced that is - # necessary? - different_events = await self._store.get_events_as_list(different_auth) - - # double-check they're all in the same room - we should already have checked - # this but it doesn't hurt to check again. - for d in different_events: - assert ( - d.room_id == event.room_id - ), f"Event {event.event_id} refers to auth_event {d.event_id} which is in a different room" - - # now we state-resolve between our own idea of the auth events, and the remote's - # idea of them. - - local_state = calculated_auth_event_map.values() - remote_auth_events = dict(calculated_auth_event_map) - remote_auth_events.update({(d.type, d.state_key): d for d in different_events}) - remote_state = remote_auth_events.values() - - room_version = await self._store.get_room_version_id(event.room_id) - new_state = await self._state_handler.resolve_events( - room_version, (local_state, remote_state), event - ) - different_state = { - (d.type, d.state_key): d - for d in new_state.values() - if calculated_auth_event_map.get((d.type, d.state_key)) != d - } - if not different_state: - logger.info("State res returned no new state") - return None - - logger.info( - "After state res: updating auth_events with new state %s", - different_state.values(), - ) - - # take a copy of calculated_auth_event_map before we modify it. - auth_events = dict(calculated_auth_event_map) - auth_events.update(different_state) - return auth_events - async def _load_or_fetch_auth_events_for_event( self, destination: str, event: EventBase ) -> Collection[EventBase]: @@ -1888,61 +1830,6 @@ class FederationEventHandler: await self._auth_and_persist_outliers(room_id, remote_auth_events) - async def _update_context_for_auth_events( - self, event: EventBase, context: EventContext, auth_events: StateMap[EventBase] - ) -> EventContext: - """Update the state_ids in an event context after auth event resolution, - storing the changes as a new state group. - - Args: - event: The event we're handling the context for - - context: initial event context - - auth_events: Events to update in the event context. - - Returns: - new event context - """ - # exclude the state key of the new event from the current_state in the context. - if event.is_state(): - event_key: Optional[Tuple[str, str]] = (event.type, event.state_key) - else: - event_key = None - state_updates = { - k: a.event_id for k, a in auth_events.items() if k != event_key - } - - current_state_ids = await context.get_current_state_ids() - current_state_ids = dict(current_state_ids) # type: ignore - - current_state_ids.update(state_updates) - - prev_state_ids = await context.get_prev_state_ids() - prev_state_ids = dict(prev_state_ids) - - prev_state_ids.update({k: a.event_id for k, a in auth_events.items()}) - - # create a new state group as a delta from the existing one. - prev_group = context.state_group - state_group = await self._state_storage_controller.store_state_group( - event.event_id, - event.room_id, - prev_group=prev_group, - delta_ids=state_updates, - current_state_ids=current_state_ids, - ) - - return EventContext.with_state( - storage=self._storage_controllers, - state_group=state_group, - state_group_before_event=context.state_group_before_event, - state_delta_due_to_event=state_updates, - prev_group=prev_group, - delta_ids=state_updates, - partial_state=context.partial_state, - ) - async def _run_push_actions_and_persist_event( self, event: EventBase, context: EventContext, backfilled: bool = False ) -> None: diff --git a/synapse/state/__init__.py b/synapse/state/__init__.py index 9f0a36652c..dcd272034d 100644 --- a/synapse/state/__init__.py +++ b/synapse/state/__init__.py @@ -24,7 +24,6 @@ from typing import ( DefaultDict, Dict, FrozenSet, - Iterable, List, Mapping, Optional, @@ -422,31 +421,6 @@ class StateHandler: ) return result - async def resolve_events( - self, - room_version: str, - state_sets: Collection[Iterable[EventBase]], - event: EventBase, - ) -> StateMap[EventBase]: - logger.info( - "Resolving state for %s with %d groups", event.room_id, len(state_sets) - ) - state_set_ids = [ - {(ev.type, ev.state_key): ev.event_id for ev in st} for st in state_sets - ] - - state_map = {ev.event_id: ev for st in state_sets for ev in st} - - new_state = await self._state_resolution_handler.resolve_events_with_store( - event.room_id, - room_version, - state_set_ids, - event_map=state_map, - state_res_store=StateResolutionStore(self.store), - ) - - return {key: state_map[ev_id] for key, ev_id in new_state.items()} - async def update_current_state(self, room_id: str) -> None: """Recalculates the current state for a room, and persists it. diff --git a/tests/handlers/test_federation.py b/tests/handlers/test_federation.py index 712933f9ca..8a0bb91f40 100644 --- a/tests/handlers/test_federation.py +++ b/tests/handlers/test_federation.py @@ -12,7 +12,7 @@ # See the License for the specific language governing permissions and # limitations under the License. import logging -from typing import List, cast +from typing import cast from unittest import TestCase from twisted.test.proto_helpers import MemoryReactor @@ -50,8 +50,6 @@ class FederationTestCase(unittest.FederatingHomeserverTestCase): hs = self.setup_test_homeserver(federation_http_client=None) self.handler = hs.get_federation_handler() self.store = hs.get_datastores().main - self.state_storage_controller = hs.get_storage_controllers().state - self._event_auth_handler = hs.get_event_auth_handler() return hs def test_exchange_revoked_invite(self) -> None: @@ -314,142 +312,6 @@ class FederationTestCase(unittest.FederatingHomeserverTestCase): ) self.get_success(d) - def test_backfill_floating_outlier_membership_auth(self) -> None: - """ - As the local homeserver, check that we can properly process a federated - event from the OTHER_SERVER with auth_events that include a floating - membership event from the OTHER_SERVER. - - Regression test, see #10439. - """ - OTHER_SERVER = "otherserver" - OTHER_USER = "@otheruser:" + OTHER_SERVER - - # create the room - user_id = self.register_user("kermit", "test") - tok = self.login("kermit", "test") - room_id = self.helper.create_room_as( - room_creator=user_id, - is_public=True, - tok=tok, - extra_content={ - "preset": "public_chat", - }, - ) - room_version = self.get_success(self.store.get_room_version(room_id)) - - prev_event_ids = self.get_success(self.store.get_prev_events_for_room(room_id)) - ( - most_recent_prev_event_id, - most_recent_prev_event_depth, - ) = self.get_success(self.store.get_max_depth_of(prev_event_ids)) - # mapping from (type, state_key) -> state_event_id - assert most_recent_prev_event_id is not None - prev_state_map = self.get_success( - self.state_storage_controller.get_state_ids_for_event( - most_recent_prev_event_id - ) - ) - # List of state event ID's - prev_state_ids = list(prev_state_map.values()) - auth_event_ids = prev_state_ids - auth_events = list( - self.get_success(self.store.get_events(auth_event_ids)).values() - ) - - # build a floating outlier member state event - fake_prev_event_id = "$" + random_string(43) - member_event_dict = { - "type": EventTypes.Member, - "content": { - "membership": "join", - }, - "state_key": OTHER_USER, - "room_id": room_id, - "sender": OTHER_USER, - "depth": most_recent_prev_event_depth, - "prev_events": [fake_prev_event_id], - "origin_server_ts": self.clock.time_msec(), - "signatures": {OTHER_SERVER: {"ed25519:key_version": "SomeSignatureHere"}}, - } - builder = self.hs.get_event_builder_factory().for_room_version( - room_version, member_event_dict - ) - member_event = self.get_success( - builder.build( - prev_event_ids=member_event_dict["prev_events"], - auth_event_ids=self._event_auth_handler.compute_auth_events( - builder, - prev_state_map, - for_verification=False, - ), - depth=member_event_dict["depth"], - ) - ) - # Override the signature added from "test" homeserver that we created the event with - member_event.signatures = member_event_dict["signatures"] - - # Add the new member_event to the StateMap - updated_state_map = dict(prev_state_map) - updated_state_map[ - (member_event.type, member_event.state_key) - ] = member_event.event_id - auth_events.append(member_event) - - # build and send an event authed based on the member event - message_event_dict = { - "type": EventTypes.Message, - "content": {}, - "room_id": room_id, - "sender": OTHER_USER, - "depth": most_recent_prev_event_depth, - "prev_events": prev_event_ids.copy(), - "origin_server_ts": self.clock.time_msec(), - "signatures": {OTHER_SERVER: {"ed25519:key_version": "SomeSignatureHere"}}, - } - builder = self.hs.get_event_builder_factory().for_room_version( - room_version, message_event_dict - ) - message_event = self.get_success( - builder.build( - prev_event_ids=message_event_dict["prev_events"], - auth_event_ids=self._event_auth_handler.compute_auth_events( - builder, - updated_state_map, - for_verification=False, - ), - depth=message_event_dict["depth"], - ) - ) - # Override the signature added from "test" homeserver that we created the event with - message_event.signatures = message_event_dict["signatures"] - - # Stub the /event_auth response from the OTHER_SERVER - async def get_event_auth( - destination: str, room_id: str, event_id: str - ) -> List[EventBase]: - return [ - event_from_pdu_json(ae.get_pdu_json(), room_version=room_version) - for ae in auth_events - ] - - self.handler.federation_client.get_event_auth = get_event_auth # type: ignore[assignment] - - with LoggingContext("receive_pdu"): - # Fake the OTHER_SERVER federating the message event over to our local homeserver - d = run_in_background( - self.hs.get_federation_event_handler().on_receive_pdu, - OTHER_SERVER, - message_event, - ) - self.get_success(d) - - # Now try and get the events on our local homeserver - stored_event = self.get_success( - self.store.get_event(message_event.event_id, allow_none=True) - ) - self.assertTrue(stored_event is not None) - @unittest.override_config( {"rc_invites": {"per_user": {"per_second": 0.5, "burst_count": 3}}} ) diff --git a/tests/rest/client/test_third_party_rules.py b/tests/rest/client/test_third_party_rules.py index 5eb0f243f7..9a48e9286f 100644 --- a/tests/rest/client/test_third_party_rules.py +++ b/tests/rest/client/test_third_party_rules.py @@ -21,7 +21,6 @@ from synapse.api.constants import EventTypes, LoginType, Membership from synapse.api.errors import SynapseError from synapse.api.room_versions import RoomVersion from synapse.events import EventBase -from synapse.events.snapshot import EventContext from synapse.events.third_party_rules import load_legacy_third_party_event_rules from synapse.rest import admin from synapse.rest.client import account, login, profile, room @@ -113,14 +112,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase): # Have this homeserver skip event auth checks. This is necessary due to # event auth checks ensuring that events were signed by the sender's homeserver. - async def _check_event_auth( - origin: str, - event: EventBase, - context: EventContext, - *args: Any, - **kwargs: Any, - ) -> EventContext: - return context + async def _check_event_auth(origin: Any, event: Any, context: Any) -> None: + pass hs.get_federation_event_handler()._check_event_auth = _check_event_auth # type: ignore[assignment] diff --git a/tests/test_federation.py b/tests/test_federation.py index 0cbef70bfa..779fad1f63 100644 --- a/tests/test_federation.py +++ b/tests/test_federation.py @@ -81,12 +81,8 @@ class MessageAcceptTests(unittest.HomeserverTestCase): self.handler = self.homeserver.get_federation_handler() federation_event_handler = self.homeserver.get_federation_event_handler() - async def _check_event_auth( - origin, - event, - context, - ): - return context + async def _check_event_auth(origin, event, context): + pass federation_event_handler._check_event_auth = _check_event_auth self.client = self.homeserver.get_federation_client() |