Update MSC3083 support per changes in the MSC. (#10189)

Adds a "type" field and generalize "space" to "room_id".

4 files changed, 47 insertions, 31 deletions

diff --git a/changelog.d/10189.misc b/changelog.d/10189.misc
new file mode 100644
index 0000000000..df0e636c7d
--- /dev/null
+++ b/changelog.d/10189.misc
@@ -0,0 +1 @@
+Update MSC3083 support for modifications in the MSC.
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index ca13843680..6c3958f7ab 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -65,6 +65,12 @@ class JoinRules:
     MSC3083_RESTRICTED = "restricted"
 
 
+class RestrictedJoinRuleTypes:
+    """Understood types for the allow rules in restricted join rules."""
+
+    ROOM_MEMBERSHIP = "m.room_membership"
+
+
 class LoginType:
     PASSWORD = "m.login.password"
     EMAIL_IDENTITY = "m.login.email.identity"
diff --git a/synapse/handlers/event_auth.py b/synapse/handlers/event_auth.py
index a0df16a32f..989996b628 100644
--- a/synapse/handlers/event_auth.py
+++ b/synapse/handlers/event_auth.py
@@ -13,7 +13,12 @@
 # limitations under the License.
 from typing import TYPE_CHECKING, Collection, Optional
 
-from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.api.constants import (
+    EventTypes,
+    JoinRules,
+    Membership,
+    RestrictedJoinRuleTypes,
+)
 from synapse.api.errors import AuthError
 from synapse.api.room_versions import RoomVersion
 from synapse.events import EventBase
@@ -42,7 +47,7 @@ class EventAuthHandler:
         Check whether a user can join a room without an invite due to restricted join rules.
 
         When joining a room with restricted joined rules (as defined in MSC3083),
-        the membership of spaces must be checked during a room join.
+        the membership of rooms must be checked during a room join.
 
         Args:
             state_ids: The state of the room as it currently is.
@@ -67,20 +72,20 @@ class EventAuthHandler:
         if not await self.has_restricted_join_rules(state_ids, room_version):
             return
 
-        # Get the spaces which allow access to this room and check if the user is
+        # Get the rooms which allow access to this room and check if the user is
         # in any of them.
-        allowed_spaces = await self.get_spaces_that_allow_join(state_ids)
-        if not await self.is_user_in_rooms(allowed_spaces, user_id):
+        allowed_rooms = await self.get_rooms_that_allow_join(state_ids)
+        if not await self.is_user_in_rooms(allowed_rooms, user_id):
             raise AuthError(
                 403,
-                "You do not belong to any of the required spaces to join this room.",
+                "You do not belong to any of the required rooms to join this room.",
             )
 
     async def has_restricted_join_rules(
         self, state_ids: StateMap[str], room_version: RoomVersion
     ) -> bool:
         """
-        Return if the room has the proper join rules set for access via spaces.
+        Return if the room has the proper join rules set for access via rooms.
 
         Args:
             state_ids: The state of the room as it currently is.
@@ -102,17 +107,17 @@ class EventAuthHandler:
         join_rules_event = await self._store.get_event(join_rules_event_id)
         return join_rules_event.content.get("join_rule") == JoinRules.MSC3083_RESTRICTED
 
-    async def get_spaces_that_allow_join(
+    async def get_rooms_that_allow_join(
         self, state_ids: StateMap[str]
     ) -> Collection[str]:
         """
-        Generate a list of spaces which allow access to a room.
+        Generate a list of rooms in which membership allows access to a room.
 
         Args:
-            state_ids: The state of the room as it currently is.
+            state_ids: The current state of the room the user wishes to join
 
         Returns:
-            A collection of spaces which provide membership to the room.
+            A collection of room IDs. Membership in any of the rooms in the list grants the ability to join the target room.
         """
         # 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)
@@ -123,21 +128,25 @@ class EventAuthHandler:
         join_rules_event = await self._store.get_event(join_rules_event_id)
 
         # 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):
+        allow_list = join_rules_event.content.get("allow", [])
+        if not isinstance(allow_list, list):
             return ()
 
         # Pull out the other room IDs, invalid data gets filtered.
         result = []
-        for space in allowed_spaces:
-            if not isinstance(space, dict):
+        for allow in allow_list:
+            if not isinstance(allow, dict):
+                continue
+
+            # If the type is unexpected, skip it.
+            if allow.get("type") != RestrictedJoinRuleTypes.ROOM_MEMBERSHIP:
                 continue
 
-            space_id = space.get("space")
-            if not isinstance(space_id, str):
+            room_id = allow.get("room_id")
+            if not isinstance(room_id, str):
                 continue
 
-            result.append(space_id)
+            result.append(room_id)
 
         return result
 
diff --git a/synapse/handlers/space_summary.py b/synapse/handlers/space_summary.py
index 73d2aab15c..e953a8afe6 100644
--- a/synapse/handlers/space_summary.py
+++ b/synapse/handlers/space_summary.py
@@ -160,14 +160,14 @@ class SpaceSummaryHandler:
 
                     # Check if the user is a member of any of the allowed spaces
                     # from the response.
-                    allowed_spaces = room.get("allowed_spaces")
+                    allowed_rooms = room.get("allowed_spaces")
                     if (
                         not include_room
-                        and allowed_spaces
-                        and isinstance(allowed_spaces, list)
+                        and allowed_rooms
+                        and isinstance(allowed_rooms, list)
                     ):
                         include_room = await self._event_auth_handler.is_user_in_rooms(
-                            allowed_spaces, requester
+                            allowed_rooms, requester
                         )
 
                     # Finally, if this isn't the requested room, check ourselves
@@ -455,11 +455,11 @@ class SpaceSummaryHandler:
             if self._event_auth_handler.has_restricted_join_rules(
                 state_ids, room_version
             ):
-                allowed_spaces = (
-                    await self._event_auth_handler.get_spaces_that_allow_join(state_ids)
+                allowed_rooms = (
+                    await self._event_auth_handler.get_rooms_that_allow_join(state_ids)
                 )
                 if await self._event_auth_handler.is_user_in_rooms(
-                    allowed_spaces, requester
+                    allowed_rooms, requester
                 ):
                     return True
 
@@ -475,10 +475,10 @@ class SpaceSummaryHandler:
             if await self._event_auth_handler.has_restricted_join_rules(
                 state_ids, room_version
             ):
-                allowed_spaces = (
-                    await self._event_auth_handler.get_spaces_that_allow_join(state_ids)
+                allowed_rooms = (
+                    await self._event_auth_handler.get_rooms_that_allow_join(state_ids)
                 )
-                for space_id in allowed_spaces:
+                for space_id in allowed_rooms:
                     if await self._auth.check_host_in_room(space_id, origin):
                         return True
 
@@ -512,11 +512,11 @@ class SpaceSummaryHandler:
         )
 
         room_version = await self._store.get_room_version(room_id)
-        allowed_spaces = None
+        allowed_rooms = None
         if await self._event_auth_handler.has_restricted_join_rules(
             current_state_ids, room_version
         ):
-            allowed_spaces = await self._event_auth_handler.get_spaces_that_allow_join(
+            allowed_rooms = await self._event_auth_handler.get_rooms_that_allow_join(
                 current_state_ids
             )
 
@@ -533,7 +533,7 @@ class SpaceSummaryHandler:
             "guest_can_join": stats["guest_access"] == "can_join",
             "creation_ts": create_event.origin_server_ts,
             "room_type": create_event.content.get(EventContentFields.ROOM_TYPE),
-            "allowed_spaces": allowed_spaces,
+            "allowed_spaces": allowed_rooms,
         }
 
         # Filter out Nones – rather omit the field altogether