diff options
| -rw-r--r-- | changelog.d/8095.feature | 1 | ||||
| -rw-r--r-- | synapse/api/errors.py | 8 | ||||
| -rw-r--r-- | synapse/handlers/room.py | 16 | ||||
| -rw-r--r-- | synapse/handlers/room_member.py | 62 | ||||
| -rw-r--r-- | synapse/rest/admin/rooms.py | 3 | ||||
| -rw-r--r-- | synapse/rest/client/v1/room.py | 67 | ||||
| -rw-r--r-- | tests/rest/client/v1/test_rooms.py | 100 |
7 files changed, 226 insertions, 31 deletions
diff --git a/changelog.d/8095.feature b/changelog.d/8095.feature new file mode 100644 index 0000000000..813e6d0903 --- /dev/null +++ b/changelog.d/8095.feature @@ -0,0 +1 @@ +Add support for shadow-banning users (ignoring any message send requests). diff --git a/synapse/api/errors.py b/synapse/api/errors.py index a3f314118a..4888c0ec4d 100644 --- a/synapse/api/errors.py +++ b/synapse/api/errors.py @@ -604,3 +604,11 @@ class HttpResponseException(CodeMessageException): errmsg = j.pop("error", self.msg) return ProxiedRequestError(self.code, errmsg, errcode, j) + + +class ShadowBanError(Exception): + """ + Raised when a shadow-banned user attempts to perform an action. + + This should be caught and a proper "fake" success response sent to the user. + """ diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py index 442cca28e6..0fc71475c3 100644 --- a/synapse/handlers/room.py +++ b/synapse/handlers/room.py @@ -20,6 +20,7 @@ import itertools import logging import math +import random import string from collections import OrderedDict from typing import TYPE_CHECKING, Any, Awaitable, Dict, List, Optional, Tuple @@ -626,6 +627,7 @@ class RoomCreationHandler(BaseHandler): if mapping: raise SynapseError(400, "Room alias already taken", Codes.ROOM_IN_USE) + invite_3pid_list = config.get("invite_3pid", []) invite_list = config.get("invite", []) for i in invite_list: try: @@ -634,6 +636,14 @@ class RoomCreationHandler(BaseHandler): except Exception: raise SynapseError(400, "Invalid user_id: %s" % (i,)) + if (invite_list or invite_3pid_list) and requester.shadow_banned: + # We randomly sleep a bit just to annoy the requester. + await self.clock.sleep(random.randint(1, 10)) + + # Allow the request to go through, but remove any associated invites. + invite_3pid_list = [] + invite_list = [] + await self.event_creation_handler.assert_accepted_privacy_policy(requester) power_level_content_override = config.get("power_level_content_override") @@ -648,8 +658,6 @@ class RoomCreationHandler(BaseHandler): % (user_id,), ) - invite_3pid_list = config.get("invite_3pid", []) - visibility = config.get("visibility", None) is_public = visibility == "public" @@ -744,6 +752,8 @@ class RoomCreationHandler(BaseHandler): if is_direct: content["is_direct"] = is_direct + # Note that update_membership with an action of "invite" can raise a + # ShadowBanError, but this was handled above by emptying invite_list. _, last_stream_id = await self.room_member_handler.update_membership( requester, UserID.from_string(invitee), @@ -758,6 +768,8 @@ class RoomCreationHandler(BaseHandler): id_access_token = invite_3pid.get("id_access_token") # optional address = invite_3pid["address"] medium = invite_3pid["medium"] + # Note that do_3pid_invite can raise a ShadowBanError, but this was + # handled above by emptying invite_3pid_list. last_stream_id = await self.hs.get_room_member_handler().do_3pid_invite( room_id, requester.user, diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index aa1ccde211..3a6ee6378d 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -15,6 +15,7 @@ import abc import logging +import random from http import HTTPStatus from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Tuple, Union @@ -22,7 +23,13 @@ from unpaddedbase64 import encode_base64 from synapse import types from synapse.api.constants import MAX_DEPTH, EventTypes, Membership -from synapse.api.errors import AuthError, Codes, LimitExceededError, SynapseError +from synapse.api.errors import ( + AuthError, + Codes, + LimitExceededError, + ShadowBanError, + SynapseError, +) from synapse.api.ratelimiting import Ratelimiter from synapse.api.room_versions import EventFormatVersions from synapse.crypto.event_signing import compute_event_reference_hash @@ -285,6 +292,31 @@ class RoomMemberHandler(object): content: Optional[dict] = None, require_consent: bool = True, ) -> Tuple[str, int]: + """Update a user's membership in a room. + + Params: + requester: The user who is performing the update. + target: The user whose membership is being updated. + room_id: The room ID whose membership is being updated. + action: The membership change, see synapse.api.constants.Membership. + txn_id: The transaction ID, if given. + remote_room_hosts: Remote servers to send the update to. + third_party_signed: Information from a 3PID invite. + ratelimit: Whether to rate limit the request. + content: The content of the created event. + require_consent: Whether consent is required. + + Returns: + A tuple of the new event ID and stream ID. + + Raises: + ShadowBanError if a shadow-banned requester attempts to send an invite. + """ + if action == Membership.INVITE and requester.shadow_banned: + # We randomly sleep a bit just to annoy the requester. + await self.clock.sleep(random.randint(1, 10)) + raise ShadowBanError() + key = (room_id,) with (await self.member_linearizer.queue(key)): @@ -773,6 +805,25 @@ class RoomMemberHandler(object): txn_id: Optional[str], id_access_token: Optional[str] = None, ) -> int: + """Invite a 3PID to a room. + + Args: + room_id: The room to invite the 3PID to. + inviter: The user sending the invite. + medium: The 3PID's medium. + address: The 3PID's address. + id_server: The identity server to use. + requester: The user making the request. + txn_id: The transaction ID this is part of, or None if this is not + part of a transaction. + id_access_token: The optional identity server access token. + + Returns: + The new stream ID. + + Raises: + ShadowBanError if the requester has been shadow-banned. + """ if self.config.block_non_admin_invites: is_requester_admin = await self.auth.is_server_admin(requester.user) if not is_requester_admin: @@ -780,6 +831,11 @@ class RoomMemberHandler(object): 403, "Invites have been disabled on this server", Codes.FORBIDDEN ) + if requester.shadow_banned: + # We randomly sleep a bit just to annoy the requester. + await self.clock.sleep(random.randint(1, 10)) + raise ShadowBanError() + # We need to rate limit *before* we send out any 3PID invites, so we # can't just rely on the standard ratelimiting of events. await self.base_handler.ratelimit(requester) @@ -804,6 +860,8 @@ class RoomMemberHandler(object): ) if invitee: + # Note that update_membership with an action of "invite" can raise + # a ShadowBanError, but this was done above already. _, stream_id = await self.update_membership( requester, UserID.from_string(invitee), room_id, "invite", txn_id=txn_id ) @@ -1042,7 +1100,7 @@ class RoomMemberMasterHandler(RoomMemberHandler): return event_id, stream_id # The room is too large. Leave. - requester = types.create_requester(user, None, False, None) + requester = types.create_requester(user, None, False, False, None) await self.update_membership( requester=requester, target=user, room_id=room_id, action="leave" ) diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py index 7c292ef3f9..09726d52d6 100644 --- a/synapse/rest/admin/rooms.py +++ b/synapse/rest/admin/rooms.py @@ -316,6 +316,9 @@ class JoinRoomAliasServlet(RestServlet): join_rules_event = room_state.get((EventTypes.JoinRules, "")) if join_rules_event: if not (join_rules_event.content.get("join_rule") == JoinRules.PUBLIC): + # update_membership with an action of "invite" can raise a + # ShadowBanError. This is not handled since it is assumed that + # an admin isn't going to call this API with a shadow-banned user. await self.room_member_handler.update_membership( requester=requester, target=fake_requester.user, diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py index f216382636..a9dd3a6aec 100644 --- a/synapse/rest/client/v1/room.py +++ b/synapse/rest/client/v1/room.py @@ -27,6 +27,7 @@ from synapse.api.errors import ( Codes, HttpResponseException, InvalidClientCredentialsError, + ShadowBanError, SynapseError, ) from synapse.api.filtering import Filter @@ -45,6 +46,7 @@ from synapse.storage.state import StateFilter from synapse.streams.config import PaginationConfig from synapse.types import RoomAlias, RoomID, StreamToken, ThirdPartyInstanceID, UserID from synapse.util import json_decoder +from synapse.util.stringutils import random_string MYPY = False if MYPY: @@ -200,14 +202,17 @@ class RoomStateEventRestServlet(TransactionRestServlet): event_dict["state_key"] = state_key if event_type == EventTypes.Member: - membership = content.get("membership", None) - event_id, _ = await self.room_member_handler.update_membership( - requester, - target=UserID.from_string(state_key), - room_id=room_id, - action=membership, - content=content, - ) + try: + membership = content.get("membership", None) + event_id, _ = await self.room_member_handler.update_membership( + requester, + target=UserID.from_string(state_key), + room_id=room_id, + action=membership, + content=content, + ) + except ShadowBanError: + event_id = "$" + random_string(43) else: ( event, @@ -719,16 +724,20 @@ class RoomMembershipRestServlet(TransactionRestServlet): content = {} if membership_action == "invite" and self._has_3pid_invite_keys(content): - await self.room_member_handler.do_3pid_invite( - room_id, - requester.user, - content["medium"], - content["address"], - content["id_server"], - requester, - txn_id, - content.get("id_access_token"), - ) + try: + await self.room_member_handler.do_3pid_invite( + room_id, + requester.user, + content["medium"], + content["address"], + content["id_server"], + requester, + txn_id, + content.get("id_access_token"), + ) + except ShadowBanError: + # Pretend the request succeeded. + pass return 200, {} target = requester.user @@ -740,15 +749,19 @@ class RoomMembershipRestServlet(TransactionRestServlet): if "reason" in content: event_content = {"reason": content["reason"]} - await self.room_member_handler.update_membership( - requester=requester, - target=target, - room_id=room_id, - action=membership_action, - txn_id=txn_id, - third_party_signed=content.get("third_party_signed", None), - content=event_content, - ) + try: + await self.room_member_handler.update_membership( + requester=requester, + target=target, + room_id=room_id, + action=membership_action, + txn_id=txn_id, + third_party_signed=content.get("third_party_signed", None), + content=event_content, + ) + except ShadowBanError: + # Pretend the request succeeded. + pass return_value = {} diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py index ef6b775ed2..e674eb90d7 100644 --- a/tests/rest/client/v1/test_rooms.py +++ b/tests/rest/client/v1/test_rooms.py @@ -1974,3 +1974,103 @@ class RoomCanonicalAliasTestCase(unittest.HomeserverTestCase): """An alias which does not point to the room raises a SynapseError.""" self._set_canonical_alias({"alias": "@unknown:test"}, expected_code=400) self._set_canonical_alias({"alt_aliases": ["@unknown:test"]}, expected_code=400) + + +class ShadowBannedTestCase(unittest.HomeserverTestCase): + servlets = [ + synapse.rest.admin.register_servlets_for_client_rest_resource, + directory.register_servlets, + login.register_servlets, + room.register_servlets, + ] + + def prepare(self, reactor, clock, homeserver): + self.banned_user_id = self.register_user("banned", "test") + self.banned_access_token = self.login("banned", "test") + + self.store = self.hs.get_datastore() + + self.get_success( + self.store.db_pool.simple_update( + table="users", + keyvalues={"name": self.banned_user_id}, + updatevalues={"shadow_banned": True}, + desc="shadow_ban", + ) + ) + + self.other_user_id = self.register_user("otheruser", "pass") + self.other_access_token = self.login("otheruser", "pass") + + def test_invite(self): + """Invites from shadow-banned users don't actually get sent.""" + + # The create works fine. + room_id = self.helper.create_room_as( + self.banned_user_id, tok=self.banned_access_token + ) + + # Inviting the user completes successfully. + self.helper.invite( + room=room_id, + src=self.banned_user_id, + tok=self.banned_access_token, + targ=self.other_user_id, + ) + + # But the user wasn't actually invited. + invited_rooms = self.get_success( + self.store.get_invited_rooms_for_local_user(self.other_user_id) + ) + self.assertEqual(invited_rooms, []) + + def test_invite_3pid(self): + """Ensure that a 3PID invite does not attempt to contact the identity server.""" + identity_handler = self.hs.get_handlers().identity_handler + identity_handler.lookup_3pid = Mock( + side_effect=AssertionError("This should not get called") + ) + + # The create works fine. + room_id = self.helper.create_room_as( + self.banned_user_id, tok=self.banned_access_token + ) + + # Inviting the user completes successfully. + request, channel = self.make_request( + "POST", + "/rooms/%s/invite" % (room_id,), + {"id_server": "test", "medium": "email", "address": "test@test.test"}, + access_token=self.banned_access_token, + ) + self.render(request) + self.assertEquals(200, channel.code, channel.result) + + # This should have raised an error earlier, but double check this wasn't called. + identity_handler.lookup_3pid.assert_not_called() + + def test_create_room(self): + """Invitations during a room creation should be discarded, but the room still gets created.""" + # The room creation is successful. + request, channel = self.make_request( + "POST", + "/_matrix/client/r0/createRoom", + {"visibility": "public", "invite": [self.other_user_id]}, + access_token=self.banned_access_token, + ) + self.render(request) + self.assertEquals(200, channel.code, channel.result) + room_id = channel.json_body["room_id"] + + # But the user wasn't actually invited. + invited_rooms = self.get_success( + self.store.get_invited_rooms_for_local_user(self.other_user_id) + ) + self.assertEqual(invited_rooms, []) + + # Since a real room was created, the other user should be able to join it. + self.helper.join(room_id, self.other_user_id, tok=self.other_access_token) + + # Both users should be in the room. + users = self.get_success(self.store.get_users_in_room(room_id)) + self.assertCountEqual(users, ["@banned:test", "@otheruser:test"]) |