diff --git a/synapse/handlers/event_auth.py b/synapse/handlers/event_auth.py
new file mode 100644
index 0000000000..eff639f407
--- /dev/null
+++ b/synapse/handlers/event_auth.py
@@ -0,0 +1,86 @@
+# Copyright 2021 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from typing import TYPE_CHECKING
+
+from synapse.api.constants import EventTypes, JoinRules
+from synapse.api.room_versions import RoomVersion
+from synapse.types import StateMap
+
+if TYPE_CHECKING:
+ from synapse.server import HomeServer
+
+
+class EventAuthHandler:
+ """
+ This class contains methods for authenticating events added to room graphs.
+ """
+
+ def __init__(self, hs: "HomeServer"):
+ self._store = hs.get_datastore()
+
+ async def can_join_without_invite(
+ self, state_ids: StateMap[str], room_version: RoomVersion, user_id: str
+ ) -> bool:
+ """
+ Check whether a user can join a room without an invite.
+
+ When joining a room with restricted joined rules (as defined in MSC3083),
+ the membership of spaces must be checked during join.
+
+ Args:
+ state_ids: The state of the room as it currently is.
+ room_version: The room version of the room being joined.
+ user_id: The user joining the room.
+
+ Returns:
+ True if the user can join the room, false otherwise.
+ """
+ # This only applies to room versions which support the new join rule.
+ if not room_version.msc3083_join_rules:
+ return True
+
+ # If there's no join rule, then it defaults to invite (so this doesn't apply).
+ join_rules_event_id = state_ids.get((EventTypes.JoinRules, ""), None)
+ if not join_rules_event_id:
+ return True
+
+ # If the join rule is not restricted, this doesn't apply.
+ join_rules_event = await self._store.get_event(join_rules_event_id)
+ if join_rules_event.content.get("join_rule") != JoinRules.MSC3083_RESTRICTED:
+ return True
+
+ # If allowed is of the wrong form, then only allow invited users.
+ allowed_spaces = join_rules_event.content.get("allow", [])
+ if not isinstance(allowed_spaces, list):
+ return False
+
+ # Get the list of joined rooms and see if there's an overlap.
+ joined_rooms = await self._store.get_rooms_for_user(user_id)
+
+ # Pull out the other room IDs, invalid data gets filtered.
+ for space in allowed_spaces:
+ if not isinstance(space, dict):
+ continue
+
+ space_id = space.get("space")
+ if not isinstance(space_id, str):
+ continue
+
+ # The user was joined to one of the spaces specified, they can join
+ # this room!
+ if space_id in joined_rooms:
+ return True
+
+ # The user was not in any of the required spaces.
+ return False
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index dbdd7d2db3..9d867aaf4d 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -146,6 +146,7 @@ class FederationHandler(BaseHandler):
self.is_mine_id = hs.is_mine_id
self.spam_checker = hs.get_spam_checker()
self.event_creation_handler = hs.get_event_creation_handler()
+ self._event_auth_handler = hs.get_event_auth_handler()
self._message_handler = hs.get_message_handler()
self._server_notices_mxid = hs.config.server_notices_mxid
self.config = hs.config
@@ -1673,8 +1674,40 @@ class FederationHandler(BaseHandler):
# would introduce the danger of backwards-compatibility problems.
event.internal_metadata.send_on_behalf_of = origin
+ # Calculate the event context.
context = await self.state_handler.compute_event_context(event)
- context = await self._auth_and_persist_event(origin, event, context)
+
+ # Get the state before the new event.
+ prev_state_ids = await context.get_prev_state_ids()
+
+ # Check if the user is already in the room or invited to the room.
+ user_id = event.state_key
+ prev_member_event_id = prev_state_ids.get((EventTypes.Member, user_id), None)
+ newly_joined = True
+ user_is_invited = False
+ if prev_member_event_id:
+ prev_member_event = await self.store.get_event(prev_member_event_id)
+ newly_joined = prev_member_event.membership != Membership.JOIN
+ user_is_invited = prev_member_event.membership == Membership.INVITE
+
+ # If the member is not already in the room, and not invited, check if
+ # they should be allowed access via membership in a space.
+ if (
+ newly_joined
+ and not user_is_invited
+ and not await self._event_auth_handler.can_join_without_invite(
+ prev_state_ids,
+ event.room_version,
+ user_id,
+ )
+ ):
+ raise AuthError(
+ 403,
+ "You do not belong to any of the required spaces to join this room.",
+ )
+
+ # Persist the event.
+ await self._auth_and_persist_event(origin, event, context)
logger.debug(
"on_send_join_request: After _auth_and_persist_event: %s, sigs: %s",
@@ -1682,8 +1715,6 @@ class FederationHandler(BaseHandler):
event.signatures,
)
- prev_state_ids = await context.get_prev_state_ids()
-
state_ids = list(prev_state_ids.values())
auth_chain = await self.store.get_auth_chain(event.room_id, state_ids)
@@ -2006,7 +2037,7 @@ class FederationHandler(BaseHandler):
state: Optional[Iterable[EventBase]] = None,
auth_events: Optional[MutableStateMap[EventBase]] = None,
backfilled: bool = False,
- ) -> EventContext:
+ ) -> None:
"""
Process an event by performing auth checks and then persisting to the database.
@@ -2028,9 +2059,6 @@ class FederationHandler(BaseHandler):
event is an outlier), may be the auth events claimed by the remote
server.
backfilled: True if the event was backfilled.
-
- Returns:
- The event context.
"""
context = await self._check_event_auth(
origin,
@@ -2060,8 +2088,6 @@ class FederationHandler(BaseHandler):
)
raise
- return context
-
async def _auth_and_persist_events(
self,
origin: str,
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 2bbfac6471..2c5bada1d8 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -19,7 +19,7 @@ from http import HTTPStatus
from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple
from synapse import types
-from synapse.api.constants import AccountDataTypes, EventTypes, JoinRules, Membership
+from synapse.api.constants import AccountDataTypes, EventTypes, Membership
from synapse.api.errors import (
AuthError,
Codes,
@@ -28,7 +28,6 @@ from synapse.api.errors import (
SynapseError,
)
from synapse.api.ratelimiting import Ratelimiter
-from synapse.api.room_versions import RoomVersion
from synapse.events import EventBase
from synapse.events.snapshot import EventContext
from synapse.types import JsonDict, Requester, RoomAlias, RoomID, StateMap, UserID
@@ -64,6 +63,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
self.profile_handler = hs.get_profile_handler()
self.event_creation_handler = hs.get_event_creation_handler()
self.account_data_handler = hs.get_account_data_handler()
+ self.event_auth_handler = hs.get_event_auth_handler()
self.member_linearizer = Linearizer(name="member")
@@ -178,62 +178,6 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
await self._invites_per_user_limiter.ratelimit(requester, invitee_user_id)
- async def _can_join_without_invite(
- self, state_ids: StateMap[str], room_version: RoomVersion, user_id: str
- ) -> bool:
- """
- Check whether a user can join a room without an invite.
-
- When joining a room with restricted joined rules (as defined in MSC3083),
- the membership of spaces must be checked during join.
-
- Args:
- state_ids: The state of the room as it currently is.
- room_version: The room version of the room being joined.
- user_id: The user joining the room.
-
- Returns:
- True if the user can join the room, false otherwise.
- """
- # This only applies to room versions which support the new join rule.
- if not room_version.msc3083_join_rules:
- return True
-
- # If there's no join rule, then it defaults to public (so this doesn't apply).
- join_rules_event_id = state_ids.get((EventTypes.JoinRules, ""), None)
- if not join_rules_event_id:
- return True
-
- # If the join rule is not restricted, this doesn't apply.
- join_rules_event = await self.store.get_event(join_rules_event_id)
- if join_rules_event.content.get("join_rule") != JoinRules.MSC3083_RESTRICTED:
- return True
-
- # If allowed is of the wrong form, then only allow invited users.
- allowed_spaces = join_rules_event.content.get("allow", [])
- if not isinstance(allowed_spaces, list):
- return False
-
- # Get the list of joined rooms and see if there's an overlap.
- joined_rooms = await self.store.get_rooms_for_user(user_id)
-
- # Pull out the other room IDs, invalid data gets filtered.
- for space in allowed_spaces:
- if not isinstance(space, dict):
- continue
-
- space_id = space.get("space")
- if not isinstance(space_id, str):
- continue
-
- # The user was joined to one of the spaces specified, they can join
- # this room!
- if space_id in joined_rooms:
- return True
-
- # The user was not in any of the required spaces.
- return False
-
async def _local_membership_update(
self,
requester: Requester,
@@ -302,7 +246,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
if (
newly_joined
and not user_is_invited
- and not await self._can_join_without_invite(
+ and not await self.event_auth_handler.can_join_without_invite(
prev_state_ids, event.room_version, user_id
)
):
|
