diff options
Diffstat (limited to 'synapse/federation')
| -rw-r--r-- | synapse/federation/federation_base.py | 28 | ||||
| -rw-r--r-- | synapse/federation/federation_client.py | 61 | ||||
| -rw-r--r-- | synapse/federation/federation_server.py | 41 | ||||
| -rw-r--r-- | synapse/federation/transport/client.py | 30 |
4 files changed, 141 insertions, 19 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py index 2bfe6a3d37..024e440ff4 100644 --- a/synapse/federation/federation_base.py +++ b/synapse/federation/federation_base.py @@ -178,6 +178,34 @@ async def _check_sigs_on_pdu( ) raise SynapseError(403, errmsg, Codes.FORBIDDEN) + # If this is a join event for a restricted room it may have been authorised + # via a different server from the sending server. Check those signatures. + if ( + room_version.msc3083_join_rules + and pdu.type == EventTypes.Member + and pdu.membership == Membership.JOIN + and "join_authorised_via_users_server" in pdu.content + ): + authorising_server = get_domain_from_id( + pdu.content["join_authorised_via_users_server"] + ) + try: + await keyring.verify_event_for_server( + authorising_server, + pdu, + pdu.origin_server_ts if room_version.enforce_key_validity else 0, + ) + except Exception as e: + errmsg = ( + "event id %s: unable to verify signature for authorising server %s: %s" + % ( + pdu.event_id, + authorising_server, + e, + ) + ) + raise SynapseError(403, errmsg, Codes.FORBIDDEN) + def _is_invite_via_3pid(event: EventBase) -> bool: return ( diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index c767d30627..dbadf102f2 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -19,7 +19,6 @@ import itertools import logging from typing import ( TYPE_CHECKING, - Any, Awaitable, Callable, Collection, @@ -79,7 +78,15 @@ class InvalidResponseError(RuntimeError): we couldn't parse """ - pass + +@attr.s(slots=True, frozen=True, auto_attribs=True) +class SendJoinResult: + # The event to persist. + event: EventBase + # A string giving the server the event was sent to. + origin: str + state: List[EventBase] + auth_chain: List[EventBase] class FederationClient(FederationBase): @@ -677,7 +684,7 @@ class FederationClient(FederationBase): async def send_join( self, destinations: Iterable[str], pdu: EventBase, room_version: RoomVersion - ) -> Dict[str, Any]: + ) -> SendJoinResult: """Sends a join event to one of a list of homeservers. Doing so will cause the remote server to add the event to the graph, @@ -691,18 +698,38 @@ class FederationClient(FederationBase): did the make_join) Returns: - a dict with members ``origin`` (a string - giving the server the event was sent to, ``state`` (?) and - ``auth_chain``. + The result of the send join request. Raises: SynapseError: if the chosen remote server returns a 300/400 code, or no servers successfully handle the request. """ - async def send_request(destination) -> Dict[str, Any]: + async def send_request(destination) -> SendJoinResult: response = await self._do_send_join(room_version, destination, pdu) + # If an event was returned (and expected to be returned): + # + # * Ensure it has the same event ID (note that the event ID is a hash + # of the event fields for versions which support MSC3083). + # * Ensure the signatures are good. + # + # Otherwise, fallback to the provided event. + if room_version.msc3083_join_rules and response.event: + event = response.event + + valid_pdu = await self._check_sigs_and_hash_and_fetch_one( + pdu=event, + origin=destination, + outlier=True, + room_version=room_version, + ) + + if valid_pdu is None or event.event_id != pdu.event_id: + raise InvalidResponseError("Returned an invalid join event") + else: + event = pdu + state = response.state auth_chain = response.auth_events @@ -784,11 +811,21 @@ class FederationClient(FederationBase): % (auth_chain_create_events,) ) - return { - "state": signed_state, - "auth_chain": signed_auth, - "origin": destination, - } + return SendJoinResult( + event=event, + state=signed_state, + auth_chain=signed_auth, + origin=destination, + ) + + if room_version.msc3083_join_rules: + # If the join is being authorised via allow rules, we need to send + # the /send_join back to the same server that was originally used + # with /make_join. + if "join_authorised_via_users_server" in pdu.content: + destinations = [ + get_domain_from_id(pdu.content["join_authorised_via_users_server"]) + ] return await self._try_destination_list("send_join", destinations, send_request) diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 29619aeeb8..2892a11d7d 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -45,6 +45,7 @@ from synapse.api.errors import ( UnsupportedRoomVersionError, ) from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion +from synapse.crypto.event_signing import compute_event_signature from synapse.events import EventBase from synapse.events.snapshot import EventContext from synapse.federation.federation_base import FederationBase, event_from_pdu_json @@ -64,7 +65,7 @@ from synapse.replication.http.federation import ( ReplicationGetQueryRestServlet, ) from synapse.storage.databases.main.lock import Lock -from synapse.types import JsonDict +from synapse.types import JsonDict, get_domain_from_id from synapse.util import glob_to_regex, json_decoder, unwrapFirstError from synapse.util.async_helpers import Linearizer, concurrently_execute from synapse.util.caches.response_cache import ResponseCache @@ -586,7 +587,7 @@ class FederationServer(FederationBase): async def on_send_join_request( self, origin: str, content: JsonDict, room_id: str ) -> Dict[str, Any]: - context = await self._on_send_membership_event( + event, context = await self._on_send_membership_event( origin, content, Membership.JOIN, room_id ) @@ -597,6 +598,7 @@ class FederationServer(FederationBase): time_now = self._clock.time_msec() return { + "org.matrix.msc3083.v2.event": event.get_pdu_json(), "state": [p.get_pdu_json(time_now) for p in state.values()], "auth_chain": [p.get_pdu_json(time_now) for p in auth_chain], } @@ -681,7 +683,7 @@ class FederationServer(FederationBase): Returns: The stripped room state. """ - event_context = await self._on_send_membership_event( + _, context = await self._on_send_membership_event( origin, content, Membership.KNOCK, room_id ) @@ -690,14 +692,14 @@ class FederationServer(FederationBase): # related to the room while the knock request is pending. stripped_room_state = ( await self.store.get_stripped_room_state_from_event_context( - event_context, self._room_prejoin_state_types + context, self._room_prejoin_state_types ) ) return {"knock_state_events": stripped_room_state} async def _on_send_membership_event( self, origin: str, content: JsonDict, membership_type: str, room_id: str - ) -> EventContext: + ) -> Tuple[EventBase, EventContext]: """Handle an on_send_{join,leave,knock} request Does some preliminary validation before passing the request on to the @@ -712,7 +714,7 @@ class FederationServer(FederationBase): in the event Returns: - The context of the event after inserting it into the room graph. + The event and context of the event after inserting it into the room graph. Raises: SynapseError if there is a problem with the request, including things like @@ -748,6 +750,33 @@ class FederationServer(FederationBase): logger.debug("_on_send_membership_event: pdu sigs: %s", event.signatures) + # Sign the event since we're vouching on behalf of the remote server that + # the event is valid to be sent into the room. Currently this is only done + # if the user is being joined via restricted join rules. + if ( + room_version.msc3083_join_rules + and event.membership == Membership.JOIN + and "join_authorised_via_users_server" in event.content + ): + # We can only authorise our own users. + authorising_server = get_domain_from_id( + event.content["join_authorised_via_users_server"] + ) + if authorising_server != self.server_name: + raise SynapseError( + 400, + f"Cannot authorise request from resident server: {authorising_server}", + ) + + event.signatures.update( + compute_event_signature( + room_version, + event.get_pdu_json(), + self.hs.hostname, + self.hs.signing_key, + ) + ) + event = await self._check_sigs_and_hash(room_version, event) return await self.handler.on_send_membership_event(origin, event) diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py index e73bdb52b3..6a8d3ad4fe 100644 --- a/synapse/federation/transport/client.py +++ b/synapse/federation/transport/client.py @@ -1219,8 +1219,26 @@ def _create_v2_path(path: str, *args: str) -> str: class SendJoinResponse: """The parsed response of a `/send_join` request.""" + # The list of auth events from the /send_join response. auth_events: List[EventBase] + # The list of state from the /send_join response. state: List[EventBase] + # The raw join event from the /send_join response. + event_dict: JsonDict + # The parsed join event from the /send_join response. This will be None if + # "event" is not included in the response. + event: Optional[EventBase] = None + + +@ijson.coroutine +def _event_parser(event_dict: JsonDict): + """Helper function for use with `ijson.kvitems_coro` to parse key-value pairs + to add them to a given dictionary. + """ + + while True: + key, value = yield + event_dict[key] = value @ijson.coroutine @@ -1246,7 +1264,8 @@ class SendJoinParser(ByteParser[SendJoinResponse]): CONTENT_TYPE = "application/json" def __init__(self, room_version: RoomVersion, v1_api: bool): - self._response = SendJoinResponse([], []) + self._response = SendJoinResponse([], [], {}) + self._room_version = room_version # The V1 API has the shape of `[200, {...}]`, which we handle by # prefixing with `item.*`. @@ -1260,12 +1279,21 @@ class SendJoinParser(ByteParser[SendJoinResponse]): _event_list_parser(room_version, self._response.auth_events), prefix + "auth_chain.item", ) + self._coro_event = ijson.kvitems_coro( + _event_parser(self._response.event_dict), + prefix + "org.matrix.msc3083.v2.event", + ) def write(self, data: bytes) -> int: self._coro_state.send(data) self._coro_auth.send(data) + self._coro_event.send(data) return len(data) def finish(self) -> SendJoinResponse: + if self._response.event_dict: + self._response.event = make_event_from_dict( + self._response.event_dict, self._room_version + ) return self._response |