Add support for MSC3823 - Account Suspension (#17051)

9 files changed, 173 insertions, 7 deletions

diff --git a/changelog.d/17051.feature b/changelog.d/17051.feature
new file mode 100644
index 0000000000..1c41f49f7d
--- /dev/null
+++ b/changelog.d/17051.feature
@@ -0,0 +1 @@
+Add preliminary support for [MSC3823](https://github.com/matrix-org/matrix-spec-proposals/pull/3823) - Account Suspension.
\ No newline at end of file
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index 15507372a4..1e56f46911 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -127,7 +127,7 @@ BOOLEAN_COLUMNS = {
     "redactions": ["have_censored"],
     "room_stats_state": ["is_federatable"],
     "rooms": ["is_public", "has_auth_chain_index"],
-    "users": ["shadow_banned", "approved", "locked"],
+    "users": ["shadow_banned", "approved", "locked", "suspended"],
     "un_partial_stated_event_stream": ["rejection_status_changed"],
     "users_who_share_rooms": ["share_private"],
     "per_user_experimental_features": ["enabled"],
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 601d37341b..655c78e150 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -752,6 +752,36 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
             and requester.user.to_string() == self._server_notices_mxid
         )
 
+        requester_suspended = await self.store.get_user_suspended_status(
+            requester.user.to_string()
+        )
+        if action == Membership.INVITE and requester_suspended:
+            raise SynapseError(
+                403,
+                "Sending invites while account is suspended is not allowed.",
+                Codes.USER_ACCOUNT_SUSPENDED,
+            )
+
+        if target.to_string() != requester.user.to_string():
+            target_suspended = await self.store.get_user_suspended_status(
+                target.to_string()
+            )
+        else:
+            target_suspended = requester_suspended
+
+        if action == Membership.JOIN and target_suspended:
+            raise SynapseError(
+                403,
+                "Joining rooms while account is suspended is not allowed.",
+                Codes.USER_ACCOUNT_SUSPENDED,
+            )
+        if action == Membership.KNOCK and target_suspended:
+            raise SynapseError(
+                403,
+                "Knocking on rooms while account is suspended is not allowed.",
+                Codes.USER_ACCOUNT_SUSPENDED,
+            )
+
         if (
             not self.allow_per_room_profiles and not is_requester_server_notices_user
         ) or requester.shadow_banned:
diff --git a/synapse/storage/databases/main/registration.py b/synapse/storage/databases/main/registration.py
index 29bf47befc..df7f8a43b7 100644
--- a/synapse/storage/databases/main/registration.py
+++ b/synapse/storage/databases/main/registration.py
@@ -236,7 +236,8 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
                     consent_server_notice_sent, appservice_id, creation_ts, user_type,
                     deactivated, COALESCE(shadow_banned, FALSE) AS shadow_banned,
                     COALESCE(approved, TRUE) AS approved,
-                    COALESCE(locked, FALSE) AS locked
+                    COALESCE(locked, FALSE) AS locked,
+                    suspended
                 FROM users
                 WHERE name = ?
                 """,
@@ -261,6 +262,7 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
                 shadow_banned,
                 approved,
                 locked,
+                suspended,
             ) = row
 
             return UserInfo(
@@ -277,6 +279,7 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
                 user_type=user_type,
                 approved=bool(approved),
                 locked=bool(locked),
+                suspended=bool(suspended),
             )
 
         return await self.db_pool.runInteraction(
@@ -1180,6 +1183,27 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
         # Convert the potential integer into a boolean.
         return bool(res)
 
+    @cached()
+    async def get_user_suspended_status(self, user_id: str) -> bool:
+        """
+        Determine whether the user's account is suspended.
+            Args:
+                user_id: The user ID of the user in question
+            Returns:
+                True if the user's account is suspended, false if it is not suspended or
+                if the user ID cannot be found.
+        """
+
+        res = await self.db_pool.simple_select_one_onecol(
+            table="users",
+            keyvalues={"name": user_id},
+            retcol="suspended",
+            allow_none=True,
+            desc="get_user_suspended",
+        )
+
+        return bool(res)
+
     async def get_threepid_validation_session(
         self,
         medium: Optional[str],
@@ -2213,6 +2237,35 @@ class RegistrationBackgroundUpdateStore(RegistrationWorkerStore):
         self._invalidate_cache_and_stream(txn, self.get_user_by_id, (user_id,))
         txn.call_after(self.is_guest.invalidate, (user_id,))
 
+    async def set_user_suspended_status(self, user_id: str, suspended: bool) -> None:
+        """
+        Set whether the user's account is suspended in the `users` table.
+
+        Args:
+            user_id: The user ID of the user in question
+            suspended: True if the user is suspended, false if not
+        """
+        await self.db_pool.runInteraction(
+            "set_user_suspended_status",
+            self.set_user_suspended_status_txn,
+            user_id,
+            suspended,
+        )
+
+    def set_user_suspended_status_txn(
+        self, txn: LoggingTransaction, user_id: str, suspended: bool
+    ) -> None:
+        self.db_pool.simple_update_one_txn(
+            txn=txn,
+            table="users",
+            keyvalues={"name": user_id},
+            updatevalues={"suspended": suspended},
+        )
+        self._invalidate_cache_and_stream(
+            txn, self.get_user_suspended_status, (user_id,)
+        )
+        self._invalidate_cache_and_stream(txn, self.get_user_by_id, (user_id,))
+
     async def set_user_locked_status(self, user_id: str, locked: bool) -> None:
         """Set the `locked` property for the provided user to the provided value.
 
diff --git a/synapse/storage/schema/__init__.py b/synapse/storage/schema/__init__.py
index 039aa91b92..0dc5d24249 100644
--- a/synapse/storage/schema/__init__.py
+++ b/synapse/storage/schema/__init__.py
@@ -19,7 +19,7 @@
 #
 #
 
-SCHEMA_VERSION = 84  # remember to update the list below when updating
+SCHEMA_VERSION = 85  # remember to update the list below when updating
 """Represents the expectations made by the codebase about the database schema
 
 This should be incremented whenever the codebase changes its requirements on the
@@ -136,6 +136,9 @@ Changes in SCHEMA_VERSION = 83
 Changes in SCHEMA_VERSION = 84
     - No longer assumes that `event_auth_chain_links` holds transitive links, and
       so read operations must do graph traversal.
+
+Changes in SCHEMA_VERSION = 85
+    - Add a column `suspended` to the `users` table
 """
 
 
diff --git a/synapse/storage/schema/main/delta/85/01_add_suspended.sql b/synapse/storage/schema/main/delta/85/01_add_suspended.sql
new file mode 100644
index 0000000000..807aad374f
--- /dev/null
+++ b/synapse/storage/schema/main/delta/85/01_add_suspended.sql
@@ -0,0 +1,14 @@
+--
+-- This file is licensed under the Affero General Public License (AGPL) version 3.
+--
+-- Copyright (C) 2024 New Vector, Ltd
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- See the GNU Affero General Public License for more details:
+-- <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+ALTER TABLE users ADD COLUMN suspended BOOLEAN DEFAULT FALSE NOT NULL;
\ No newline at end of file
diff --git a/synapse/types/__init__.py b/synapse/types/__init__.py
index a88982a04c..509a2d3a0f 100644
--- a/synapse/types/__init__.py
+++ b/synapse/types/__init__.py
@@ -1156,6 +1156,7 @@ class UserInfo:
         user_type:  User type (None for normal user, 'support' and 'bot' other options).
         approved: If the user has been "approved" to register on the server.
         locked: Whether the user's account has been locked
+        suspended: Whether the user's account is currently suspended
     """
 
     user_id: UserID
@@ -1171,6 +1172,7 @@ class UserInfo:
     is_shadow_banned: bool
     approved: bool
     locked: bool
+    suspended: bool
 
 
 class UserProfile(TypedDict):
diff --git a/tests/rest/client/test_rooms.py b/tests/rest/client/test_rooms.py
index b796163dcb..d398cead1c 100644
--- a/tests/rest/client/test_rooms.py
+++ b/tests/rest/client/test_rooms.py
@@ -48,7 +48,16 @@ from synapse.appservice import ApplicationService
 from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.rest import admin
-from synapse.rest.client import account, directory, login, profile, register, room, sync
+from synapse.rest.client import (
+    account,
+    directory,
+    knock,
+    login,
+    profile,
+    register,
+    room,
+    sync,
+)
 from synapse.server import HomeServer
 from synapse.types import JsonDict, RoomAlias, UserID, create_requester
 from synapse.util import Clock
@@ -733,7 +742,7 @@ class RoomsCreateTestCase(RoomBase):
         self.assertEqual(HTTPStatus.OK, channel.code, channel.result)
         self.assertTrue("room_id" in channel.json_body)
         assert channel.resource_usage is not None
-        self.assertEqual(32, channel.resource_usage.db_txn_count)
+        self.assertEqual(33, channel.resource_usage.db_txn_count)
 
     def test_post_room_initial_state(self) -> None:
         # POST with initial_state config key, expect new room id
@@ -746,7 +755,7 @@ class RoomsCreateTestCase(RoomBase):
         self.assertEqual(HTTPStatus.OK, channel.code, channel.result)
         self.assertTrue("room_id" in channel.json_body)
         assert channel.resource_usage is not None
-        self.assertEqual(34, channel.resource_usage.db_txn_count)
+        self.assertEqual(35, channel.resource_usage.db_txn_count)
 
     def test_post_room_visibility_key(self) -> None:
         # POST with visibility config key, expect new room id
@@ -1154,6 +1163,7 @@ class RoomJoinTestCase(RoomBase):
         admin.register_servlets,
         login.register_servlets,
         room.register_servlets,
+        knock.register_servlets,
     ]
 
     def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
@@ -1167,6 +1177,8 @@ class RoomJoinTestCase(RoomBase):
         self.room2 = self.helper.create_room_as(room_creator=self.user1, tok=self.tok1)
         self.room3 = self.helper.create_room_as(room_creator=self.user1, tok=self.tok1)
 
+        self.store = hs.get_datastores().main
+
     def test_spam_checker_may_join_room_deprecated(self) -> None:
         """Tests that the user_may_join_room spam checker callback is correctly called
         and blocks room joins when needed.
@@ -1317,6 +1329,57 @@ class RoomJoinTestCase(RoomBase):
             expect_additional_fields=return_value[1],
         )
 
+    def test_suspended_user_cannot_join_room(self) -> None:
+        # set the user as suspended
+        self.get_success(self.store.set_user_suspended_status(self.user2, True))
+
+        channel = self.make_request(
+            "POST", f"/join/{self.room1}", access_token=self.tok2
+        )
+        self.assertEqual(channel.code, 403)
+        self.assertEqual(
+            channel.json_body["errcode"], "ORG.MATRIX.MSC3823.USER_ACCOUNT_SUSPENDED"
+        )
+
+        channel = self.make_request(
+            "POST", f"/rooms/{self.room1}/join", access_token=self.tok2
+        )
+        self.assertEqual(channel.code, 403)
+        self.assertEqual(
+            channel.json_body["errcode"], "ORG.MATRIX.MSC3823.USER_ACCOUNT_SUSPENDED"
+        )
+
+    def test_suspended_user_cannot_knock_on_room(self) -> None:
+        # set the user as suspended
+        self.get_success(self.store.set_user_suspended_status(self.user2, True))
+
+        channel = self.make_request(
+            "POST",
+            f"/_matrix/client/v3/knock/{self.room1}",
+            access_token=self.tok2,
+            content={},
+            shorthand=False,
+        )
+        self.assertEqual(channel.code, 403)
+        self.assertEqual(
+            channel.json_body["errcode"], "ORG.MATRIX.MSC3823.USER_ACCOUNT_SUSPENDED"
+        )
+
+    def test_suspended_user_cannot_invite_to_room(self) -> None:
+        # set the user as suspended
+        self.get_success(self.store.set_user_suspended_status(self.user1, True))
+
+        # first user invites second user
+        channel = self.make_request(
+            "POST",
+            f"/rooms/{self.room1}/invite",
+            access_token=self.tok1,
+            content={"user_id": self.user2},
+        )
+        self.assertEqual(
+            channel.json_body["errcode"], "ORG.MATRIX.MSC3823.USER_ACCOUNT_SUSPENDED"
+        )
+
 
 class RoomAppserviceTsParamTestCase(unittest.HomeserverTestCase):
     servlets = [
diff --git a/tests/storage/test_registration.py b/tests/storage/test_registration.py
index 505465d529..14e3871dc1 100644
--- a/tests/storage/test_registration.py
+++ b/tests/storage/test_registration.py
@@ -43,7 +43,6 @@ class RegistrationStoreTestCase(HomeserverTestCase):
 
         self.assertEqual(
             UserInfo(
-                # TODO(paul): Surely this field should be 'user_id', not 'name'
                 user_id=UserID.from_string(self.user_id),
                 is_admin=False,
                 is_guest=False,
@@ -57,6 +56,7 @@ class RegistrationStoreTestCase(HomeserverTestCase):
                 locked=False,
                 is_shadow_banned=False,
                 approved=True,
+                suspended=False,
             ),
             (self.get_success(self.store.get_user_by_id(self.user_id))),
         )