Merge pull request #3456 from matrix-org/hawkowl/federation-prevevent-checking

Check the state of prev_events a bit more thoroughly when coming over federation

1 files changed, 243 insertions, 0 deletions

diff --git a/tests/test_federation.py b/tests/test_federation.py
new file mode 100644
index 0000000000..fc80a69369
--- /dev/null
+++ b/tests/test_federation.py
@@ -0,0 +1,243 @@
+
+from twisted.internet.defer import succeed, maybeDeferred
+
+from synapse.util import Clock
+from synapse.events import FrozenEvent
+from synapse.types import Requester, UserID
+
+from tests import unittest
+from tests.server import setup_test_homeserver, ThreadedMemoryReactorClock
+
+from mock import Mock
+
+
+class MessageAcceptTests(unittest.TestCase):
+    def setUp(self):
+
+        self.http_client = Mock()
+        self.reactor = ThreadedMemoryReactorClock()
+        self.hs_clock = Clock(self.reactor)
+        self.homeserver = setup_test_homeserver(
+            http_client=self.http_client, clock=self.hs_clock, reactor=self.reactor
+        )
+
+        user_id = UserID("us", "test")
+        our_user = Requester(user_id, None, False, None, None)
+        room_creator = self.homeserver.get_room_creation_handler()
+        room = room_creator.create_room(
+            our_user, room_creator.PRESETS_DICT["public_chat"], ratelimit=False
+        )
+        self.reactor.advance(0.1)
+        self.room_id = self.successResultOf(room)["room_id"]
+
+        # Figure out what the most recent event is
+        most_recent = self.successResultOf(
+            maybeDeferred(
+                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+            )
+        )[0]
+
+        join_event = FrozenEvent(
+            {
+                "room_id": self.room_id,
+                "sender": "@baduser:test.serv",
+                "state_key": "@baduser:test.serv",
+                "event_id": "$join:test.serv",
+                "depth": 1000,
+                "origin_server_ts": 1,
+                "type": "m.room.member",
+                "origin": "test.servx",
+                "content": {"membership": "join"},
+                "auth_events": [],
+                "prev_state": [(most_recent, {})],
+                "prev_events": [(most_recent, {})],
+            }
+        )
+
+        self.handler = self.homeserver.get_handlers().federation_handler
+        self.handler.do_auth = lambda *a, **b: succeed(True)
+        self.client = self.homeserver.get_federation_client()
+        self.client._check_sigs_and_hash_and_fetch = lambda dest, pdus, **k: succeed(
+            pdus
+        )
+
+        # Send the join, it should return None (which is not an error)
+        d = self.handler.on_receive_pdu(
+            "test.serv", join_event, sent_to_us_directly=True
+        )
+        self.reactor.advance(1)
+        self.assertEqual(self.successResultOf(d), None)
+
+        # Make sure we actually joined the room
+        self.assertEqual(
+            self.successResultOf(
+                maybeDeferred(
+                    self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                )
+            )[0],
+            "$join:test.serv",
+        )
+
+    def test_cant_hide_direct_ancestors(self):
+        """
+        If you send a message, you must be able to provide the direct
+        prev_events that said event references.
+        """
+
+        def post_json(destination, path, data, headers=None, timeout=0):
+            # If it asks us for new missing events, give them NOTHING
+            if path.startswith("/_matrix/federation/v1/get_missing_events/"):
+                return {"events": []}
+
+        self.http_client.post_json = post_json
+
+        # Figure out what the most recent event is
+        most_recent = self.successResultOf(
+            maybeDeferred(
+                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+            )
+        )[0]
+
+        # Now lie about an event
+        lying_event = FrozenEvent(
+            {
+                "room_id": self.room_id,
+                "sender": "@baduser:test.serv",
+                "event_id": "one:test.serv",
+                "depth": 1000,
+                "origin_server_ts": 1,
+                "type": "m.room.message",
+                "origin": "test.serv",
+                "content": "hewwo?",
+                "auth_events": [],
+                "prev_events": [("two:test.serv", {}), (most_recent, {})],
+            }
+        )
+
+        d = self.handler.on_receive_pdu(
+            "test.serv", lying_event, sent_to_us_directly=True
+        )
+
+        # Step the reactor, so the database fetches come back
+        self.reactor.advance(1)
+
+        # on_receive_pdu should throw an error
+        failure = self.failureResultOf(d)
+        self.assertEqual(
+            failure.value.args[0],
+            (
+                "ERROR 403: Your server isn't divulging details about prev_events "
+                "referenced in this event."
+            ),
+        )
+
+        # Make sure the invalid event isn't there
+        extrem = maybeDeferred(
+            self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+        )
+        self.assertEqual(self.successResultOf(extrem)[0], "$join:test.serv")
+
+    @unittest.DEBUG
+    def test_cant_hide_past_history(self):
+        """
+        If you send a message, you must be able to provide the direct
+        prev_events that said event references.
+        """
+
+        def post_json(destination, path, data, headers=None, timeout=0):
+            if path.startswith("/_matrix/federation/v1/get_missing_events/"):
+                return {
+                    "events": [
+                        {
+                            "room_id": self.room_id,
+                            "sender": "@baduser:test.serv",
+                            "event_id": "three:test.serv",
+                            "depth": 1000,
+                            "origin_server_ts": 1,
+                            "type": "m.room.message",
+                            "origin": "test.serv",
+                            "content": "hewwo?",
+                            "auth_events": [],
+                            "prev_events": [("four:test.serv", {})],
+                        }
+                    ]
+                }
+
+        self.http_client.post_json = post_json
+
+        def get_json(destination, path, args, headers=None):
+            if path.startswith("/_matrix/federation/v1/state_ids/"):
+                d = self.successResultOf(
+                    self.homeserver.datastore.get_state_ids_for_event("one:test.serv")
+                )
+
+                return succeed(
+                    {
+                        "pdu_ids": [
+                            y
+                            for x, y in d.items()
+                            if x == ("m.room.member", "@us:test")
+                        ],
+                        "auth_chain_ids": d.values(),
+                    }
+                )
+
+        self.http_client.get_json = get_json
+
+        # Figure out what the most recent event is
+        most_recent = self.successResultOf(
+            maybeDeferred(
+                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+            )
+        )[0]
+
+        # Make a good event
+        good_event = FrozenEvent(
+            {
+                "room_id": self.room_id,
+                "sender": "@baduser:test.serv",
+                "event_id": "one:test.serv",
+                "depth": 1000,
+                "origin_server_ts": 1,
+                "type": "m.room.message",
+                "origin": "test.serv",
+                "content": "hewwo?",
+                "auth_events": [],
+                "prev_events": [(most_recent, {})],
+            }
+        )
+
+        d = self.handler.on_receive_pdu(
+            "test.serv", good_event, sent_to_us_directly=True
+        )
+        self.reactor.advance(1)
+        self.assertEqual(self.successResultOf(d), None)
+
+        bad_event = FrozenEvent(
+            {
+                "room_id": self.room_id,
+                "sender": "@baduser:test.serv",
+                "event_id": "two:test.serv",
+                "depth": 1000,
+                "origin_server_ts": 1,
+                "type": "m.room.message",
+                "origin": "test.serv",
+                "content": "hewwo?",
+                "auth_events": [],
+                "prev_events": [("one:test.serv", {}), ("three:test.serv", {})],
+            }
+        )
+
+        d = self.handler.on_receive_pdu(
+            "test.serv", bad_event, sent_to_us_directly=True
+        )
+        self.reactor.advance(1)
+
+        extrem = maybeDeferred(
+            self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+        )
+        self.assertEqual(self.successResultOf(extrem)[0], "two:test.serv")
+
+        state = self.homeserver.get_state_handler().get_current_state_ids(self.room_id)
+        self.reactor.advance(1)
+        self.assertIn(("m.room.member", "@us:test"), self.successResultOf(state).keys())