diff options
| -rw-r--r-- | changelog.d/5707.bugfix | 1 | ||||
| -rw-r--r-- | synapse/storage/events_worker.py | 64 | ||||
| -rw-r--r-- | tests/rest/client/test_redactions.py | 159 | ||||
| -rw-r--r-- | tests/unittest.py | 1 |
4 files changed, 198 insertions, 27 deletions
diff --git a/changelog.d/5707.bugfix b/changelog.d/5707.bugfix new file mode 100644 index 0000000000..aa3046c5e1 --- /dev/null +++ b/changelog.d/5707.bugfix @@ -0,0 +1 @@ +Fix some problems with authenticating redactions in recent room versions. diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py index e2fc7bc047..1d969d70be 100644 --- a/synapse/storage/events_worker.py +++ b/synapse/storage/events_worker.py @@ -236,38 +236,48 @@ class EventsWorkerStore(SQLBaseStore): "allow_rejected=False" ) - # Starting in room version v3, some redactions need to be rechecked if we - # didn't have the redacted event at the time, so we recheck on read - # instead. + # We may not have had the original event when we received a redaction, so + # we have to recheck auth now. + if not allow_rejected and entry.event.type == EventTypes.Redaction: - if entry.event.internal_metadata.need_to_check_redaction(): - # XXX: we should probably use _get_events_from_cache_or_db here, - # so that we can benefit from caching. - orig_sender = yield self._simple_select_one_onecol( - table="events", - keyvalues={"event_id": entry.event.redacts}, - retcol="sender", - allow_none=True, + redacted_event_id = entry.event.redacts + event_map = yield self._get_events_from_cache_or_db([redacted_event_id]) + original_event_entry = event_map.get(redacted_event_id) + if not original_event_entry: + # we don't have the redacted event (or it was rejected). + # + # We assume that the redaction isn't authorized for now; if the + # redacted event later turns up, the redaction will be re-checked, + # and if it is found valid, the original will get redacted before it + # is served to the client. + logger.debug( + "Withholding redaction event %s since we don't (yet) have the " + "original %s", + event_id, + redacted_event_id, ) + continue - expected_domain = get_domain_from_id(entry.event.sender) - if ( - orig_sender - and get_domain_from_id(orig_sender) == expected_domain - ): - # This redaction event is allowed. Mark as not needing a - # recheck. - entry.event.internal_metadata.recheck_redaction = False - else: - # We either don't have the event that is being redacted (so we - # assume that the event isn't authorised for now), or the - # senders don't match (so it will never be authorised). Either - # way, we shouldn't return it. - # - # (If we later receive the event, then we will redact it anyway, - # since we have this redaction) + original_event = original_event_entry.event + + if entry.event.internal_metadata.need_to_check_redaction(): + original_domain = get_domain_from_id(original_event.sender) + redaction_domain = get_domain_from_id(entry.event.sender) + if original_domain != redaction_domain: + # the senders don't match, so this is forbidden + logger.info( + "Withholding redaction %s whose sender domain %s doesn't " + "match that of redacted event %s %s", + event_id, + redaction_domain, + redacted_event_id, + original_domain, + ) continue + # Update the cache to save doing the checks again. + entry.event.internal_metadata.recheck_redaction = False + if check_redacted and entry.redacted_event: event = entry.redacted_event else: diff --git a/tests/rest/client/test_redactions.py b/tests/rest/client/test_redactions.py new file mode 100644 index 0000000000..7d5df95855 --- /dev/null +++ b/tests/rest/client/test_redactions.py @@ -0,0 +1,159 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 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 synapse.rest import admin +from synapse.rest.client.v1 import login, room +from synapse.rest.client.v2_alpha import sync + +from tests.unittest import HomeserverTestCase + + +class RedactionsTestCase(HomeserverTestCase): + """Tests that various redaction events are handled correctly""" + + servlets = [ + admin.register_servlets, + room.register_servlets, + login.register_servlets, + sync.register_servlets, + ] + + def prepare(self, reactor, clock, hs): + # register a couple of users + self.mod_user_id = self.register_user("user1", "pass") + self.mod_access_token = self.login("user1", "pass") + self.other_user_id = self.register_user("otheruser", "pass") + self.other_access_token = self.login("otheruser", "pass") + + # Create a room + self.room_id = self.helper.create_room_as( + self.mod_user_id, tok=self.mod_access_token + ) + + # Invite the other user + self.helper.invite( + room=self.room_id, + src=self.mod_user_id, + tok=self.mod_access_token, + targ=self.other_user_id, + ) + # The other user joins + self.helper.join( + room=self.room_id, user=self.other_user_id, tok=self.other_access_token + ) + + def _redact_event(self, access_token, room_id, event_id, expect_code=200): + """Helper function to send a redaction event. + + Returns the json body. + """ + path = "/_matrix/client/r0/rooms/%s/redact/%s" % (room_id, event_id) + + request, channel = self.make_request( + "POST", path, content={}, access_token=access_token + ) + self.render(request) + self.assertEqual(int(channel.result["code"]), expect_code) + return channel.json_body + + def _sync_room_timeline(self, access_token, room_id): + request, channel = self.make_request( + "GET", "sync", access_token=self.mod_access_token + ) + self.render(request) + self.assertEqual(channel.result["code"], b"200") + room_sync = channel.json_body["rooms"]["join"][room_id] + return room_sync["timeline"]["events"] + + def test_redact_event_as_moderator(self): + # as a regular user, send a message to redact + b = self.helper.send(room_id=self.room_id, tok=self.other_access_token) + msg_id = b["event_id"] + + # as the moderator, send a redaction + b = self._redact_event(self.mod_access_token, self.room_id, msg_id) + redaction_id = b["event_id"] + + # now sync + timeline = self._sync_room_timeline(self.mod_access_token, self.room_id) + + # the last event should be the redaction + self.assertEqual(timeline[-1]["event_id"], redaction_id) + self.assertEqual(timeline[-1]["redacts"], msg_id) + + # and the penultimate should be the redacted original + self.assertEqual(timeline[-2]["event_id"], msg_id) + self.assertEqual(timeline[-2]["unsigned"]["redacted_by"], redaction_id) + self.assertEqual(timeline[-2]["content"], {}) + + def test_redact_event_as_normal(self): + # as a regular user, send a message to redact + b = self.helper.send(room_id=self.room_id, tok=self.other_access_token) + normal_msg_id = b["event_id"] + + # also send one as the admin + b = self.helper.send(room_id=self.room_id, tok=self.mod_access_token) + admin_msg_id = b["event_id"] + + # as a normal, try to redact the admin's event + self._redact_event( + self.other_access_token, self.room_id, admin_msg_id, expect_code=403 + ) + + # now try to redact our own event + b = self._redact_event(self.other_access_token, self.room_id, normal_msg_id) + redaction_id = b["event_id"] + + # now sync + timeline = self._sync_room_timeline(self.other_access_token, self.room_id) + + # the last event should be the redaction of the normal event + self.assertEqual(timeline[-1]["event_id"], redaction_id) + self.assertEqual(timeline[-1]["redacts"], normal_msg_id) + + # the penultimate should be the unredacted one from the admin + self.assertEqual(timeline[-2]["event_id"], admin_msg_id) + self.assertNotIn("redacted_by", timeline[-2]["unsigned"]) + self.assertTrue(timeline[-2]["content"]["body"], {}) + + # and the antepenultimate should be the redacted normal + self.assertEqual(timeline[-3]["event_id"], normal_msg_id) + self.assertEqual(timeline[-3]["unsigned"]["redacted_by"], redaction_id) + self.assertEqual(timeline[-3]["content"], {}) + + def test_redact_nonexistent_event(self): + # control case: an existing event + b = self.helper.send(room_id=self.room_id, tok=self.other_access_token) + msg_id = b["event_id"] + b = self._redact_event(self.other_access_token, self.room_id, msg_id) + redaction_id = b["event_id"] + + # room moderators can send redactions for non-existent events + self._redact_event(self.mod_access_token, self.room_id, "$zzz") + + # ... but normals cannot + self._redact_event( + self.other_access_token, self.room_id, "$zzz", expect_code=404 + ) + + # when we sync, we should see only the valid redaction + timeline = self._sync_room_timeline(self.other_access_token, self.room_id) + self.assertEqual(timeline[-1]["event_id"], redaction_id) + self.assertEqual(timeline[-1]["redacts"], msg_id) + + # and the penultimate should be the redacted original + self.assertEqual(timeline[-2]["event_id"], msg_id) + self.assertEqual(timeline[-2]["unsigned"]["redacted_by"], redaction_id) + self.assertEqual(timeline[-2]["content"], {}) diff --git a/tests/unittest.py b/tests/unittest.py index cabe787cb4..f5fae21317 100644 --- a/tests/unittest.py +++ b/tests/unittest.py @@ -447,6 +447,7 @@ class HomeserverTestCase(TestCase): # Create the user request, channel = self.make_request("GET", "/_matrix/client/r0/admin/register") self.render(request) + self.assertEqual(channel.code, 200) nonce = channel.json_body["nonce"] want_mac = hmac.new(key=b"shared", digestmod=hashlib.sha1) |