Rejections

synapse/api/auth.py

@@ -102,6 +102,8 @@ def check_joined_room(self, room_id, user_id):
     def check_host_in_room(self, room_id, host):
         curr_state = yield self.state.get_current_state(room_id)
 
+        logger.debug("Got curr_state %s", curr_state)
+
         for event in curr_state:
             if event.type == EventTypes.Member:
                 try:
@@ -358,9 +360,23 @@ def is_server_admin(self, user):
     def add_auth_events(self, builder, context):
         yield run_on_reactor()
 
-        if builder.type == EventTypes.Create:
-            builder.auth_events = []
-            return
+        auth_ids = self.compute_auth_events(builder, context)
+
+        auth_events_entries = yield self.store.add_event_hashes(
+            auth_ids
+        )
+
+        builder.auth_events = auth_events_entries
+
+        context.auth_events = {
+            k: v
+            for k, v in context.current_state.items()
+            if v.event_id in auth_ids
+        }
+
+    def compute_auth_events(self, event, context):
+        if event.type == EventTypes.Create:
+            return []
 
         auth_ids = []
 
@@ -373,7 +389,7 @@ def add_auth_events(self, builder, context):
         key = (EventTypes.JoinRules, "", )
         join_rule_event = context.current_state.get(key)
 
-        key = (EventTypes.Member, builder.user_id, )
+        key = (EventTypes.Member, event.user_id, )
         member_event = context.current_state.get(key)
 
         key = (EventTypes.Create, "", )
@@ -387,8 +403,8 @@ def add_auth_events(self, builder, context):
         else:
             is_public = False
 
-        if builder.type == EventTypes.Member:
-            e_type = builder.content["membership"]
+        if event.type == EventTypes.Member:
+            e_type = event.content["membership"]
             if e_type in [Membership.JOIN, Membership.INVITE]:
                 if join_rule_event:
                     auth_ids.append(join_rule_event.event_id)
@@ -403,17 +419,7 @@ def add_auth_events(self, builder, context):
             if member_event.content["membership"] == Membership.JOIN:
                 auth_ids.append(member_event.event_id)
 
-        auth_events_entries = yield self.store.add_event_hashes(
-            auth_ids
-        )
-
-        builder.auth_events = auth_events_entries
-
-        context.auth_events = {
-            k: v
-            for k, v in context.current_state.items()
-            if v.event_id in auth_ids
-        }
+        return auth_ids
 
     @log_function
     def _can_send_event(self, event, auth_events):

synapse/api/constants.py

@@ -74,3 +74,9 @@ class EventTypes(object):
     Message = "m.room.message"
     Topic = "m.room.topic"
     Name = "m.room.name"
+
+
+class RejectedReason(object):
+    AUTH_ERROR = "auth_error"
+    REPLACED = "replaced"
+    NOT_ANCESTOR = "not_ancestor"

synapse/crypto/keyclient.py

@@ -61,9 +61,11 @@ class SynapseKeyClientProtocol(HTTPClient):
 
     def __init__(self):
         self.remote_key = defer.Deferred()
+        self.host = None
 
     def connectionMade(self):
-        logger.debug("Connected to %s", self.transport.getHost())
+        self.host = self.transport.getHost()
+        logger.debug("Connected to %s", self.host)
         self.sendCommand(b"GET", b"/_matrix/key/v1/")
         self.endHeaders()
         self.timer = reactor.callLater(
@@ -92,8 +94,7 @@ def handleResponse(self, response_body_bytes):
         self.timer.cancel()
 
     def on_timeout(self):
-        logger.debug("Timeout waiting for response from %s",
-                     self.transport.getHost())
+        logger.debug("Timeout waiting for response from %s", self.host)
         self.remote_key.errback(IOError("Timeout waiting for response"))
         self.transport.abortConnection()
 

synapse/events/__init__.py

@@ -18,7 +18,7 @@
 
 class _EventInternalMetadata(object):
     def __init__(self, internal_metadata_dict):
-        self.__dict__ = internal_metadata_dict
+        self.__dict__ = dict(internal_metadata_dict)
 
     def get_dict(self):
         return dict(self.__dict__)

synapse/events/builder.py

@@ -23,14 +23,15 @@
 
 
 class EventBuilder(EventBase):
-    def __init__(self, key_values={}):
+    def __init__(self, key_values={}, internal_metadata_dict={}):
         signatures = copy.deepcopy(key_values.pop("signatures", {}))
         unsigned = copy.deepcopy(key_values.pop("unsigned", {}))
 
         super(EventBuilder, self).__init__(
             key_values,
             signatures=signatures,
-            unsigned=unsigned
+            unsigned=unsigned,
+            internal_metadata_dict=internal_metadata_dict,
         )
 
     def build(self):

synapse/events/utils.py

@@ -45,12 +45,14 @@ def prune_event(event):
         "membership",
     ]
 
+    event_dict = event.get_dict()
+
     new_content = {}
 
     def add_fields(*fields):
         for field in fields:
             if field in event.content:
-                new_content[field] = event.content[field]
+                new_content[field] = event_dict["content"][field]
 
     if event_type == EventTypes.Member:
         add_fields("membership")
@@ -75,7 +77,7 @@ def add_fields(*fields):
 
     allowed_fields = {
         k: v
-        for k, v in event.get_dict().items()
+        for k, v in event_dict.items()
         if k in allowed_keys
     }
 
@@ -86,7 +88,10 @@ def add_fields(*fields):
     if "age_ts" in event.unsigned:
         allowed_fields["unsigned"]["age_ts"] = event.unsigned["age_ts"]
 
-    return type(event)(allowed_fields)
+    return type(event)(
+        allowed_fields,
+        internal_metadata_dict=event.internal_metadata.get_dict()
+    )
 
 
 def serialize_event(e, time_now_ms, client_event=True):

synapse/federation/federation_client.py

@@ -20,6 +20,13 @@
 
 from synapse.util.logutils import log_function
 from synapse.events import FrozenEvent
+from synapse.events.utils import prune_event
+
+from syutil.jsonutil import encode_canonical_json
+
+from synapse.crypto.event_signing import check_event_content_hash
+
+from synapse.api.errors import SynapseError
 
 import logging
 
@@ -126,6 +133,11 @@ def backfill(self, dest, context, limit, extremities):
             for p in transaction_data["pdus"]
         ]
 
+        for i, pdu in enumerate(pdus):
+            pdus[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
         defer.returnValue(pdus)
 
     @defer.inlineCallbacks
@@ -159,25 +171,29 @@ def get_pdu(self, destinations, event_id, outlier=False):
                 transaction_data = yield self.transport_layer.get_event(
                     destination, event_id
                 )
+
+                logger.debug("transaction_data %r", transaction_data)
+
+                pdu_list = [
+                    self.event_from_pdu_json(p, outlier=outlier)
+                    for p in transaction_data["pdus"]
+                ]
+
+                if pdu_list:
+                    pdu = pdu_list[0]
+
+                    # Check signatures are correct.
+                    pdu = yield self._check_sigs_and_hash(pdu)
+
+                    break
+
             except Exception as e:
                 logger.info(
                     "Failed to get PDU %s from %s because %s",
                     event_id, destination, e,
                 )
                 continue
 
-            logger.debug("transaction_data %r", transaction_data)
-
-            pdu_list = [
-                self.event_from_pdu_json(p, outlier=outlier)
-                for p in transaction_data["pdus"]
-            ]
-
-            if pdu_list:
-                pdu = pdu_list[0]
-                # TODO: We need to check signatures here
-                break
-
         defer.returnValue(pdu)
 
     @defer.inlineCallbacks
@@ -208,6 +224,16 @@ def get_state_for_room(self, destination, room_id, event_id):
             for p in result.get("auth_chain", [])
         ]
 
+        for i, pdu in enumerate(pdus):
+            pdus[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
+        for i, pdu in enumerate(auth_chain):
+            auth_chain[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
         defer.returnValue((pdus, auth_chain))
 
     @defer.inlineCallbacks
@@ -222,6 +248,11 @@ def get_event_auth(self, destination, room_id, event_id):
             for p in res["auth_chain"]
         ]
 
+        for i, pdu in enumerate(auth_chain):
+            auth_chain[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
         auth_chain.sort(key=lambda e: e.depth)
 
         defer.returnValue(auth_chain)
@@ -260,6 +291,16 @@ def send_join(self, destination, pdu):
             for p in content.get("auth_chain", [])
         ]
 
+        for i, pdu in enumerate(state):
+            state[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
+        for i, pdu in enumerate(auth_chain):
+            auth_chain[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
         auth_chain.sort(key=lambda e: e.depth)
 
         defer.returnValue({
@@ -281,7 +322,48 @@ def send_invite(self, destination, room_id, event_id, pdu):
 
         logger.debug("Got response to send_invite: %s", pdu_dict)
 
-        defer.returnValue(self.event_from_pdu_json(pdu_dict))
+        pdu = self.event_from_pdu_json(pdu_dict)
+
+        # Check signatures are correct.
+        pdu = yield self._check_sigs_and_hash(pdu)
+
+        # FIXME: We should handle signature failures more gracefully.
+
+        defer.returnValue(pdu)
+
+    @defer.inlineCallbacks
+    def query_auth(self, destination, room_id, event_id, local_auth):
+        """
+        Params:
+            destination (str)
+            event_it (str)
+            local_auth (list)
+        """
+        time_now = self._clock.time_msec()
+
+        send_content = {
+            "auth_chain": [e.get_pdu_json(time_now) for e in local_auth],
+        }
+
+        code, content = yield self.transport_layer.send_query_auth(
+            destination=destination,
+            room_id=room_id,
+            event_id=event_id,
+            content=send_content,
+        )
+
+        auth_chain = [
+            (yield self._check_sigs_and_hash(self.event_from_pdu_json(e)))
+            for e in content["auth_chain"]
+        ]
+
+        ret = {
+            "auth_chain": auth_chain,
+            "rejects": content.get("rejects", []),
+            "missing": content.get("missing", []),
+        }
+
+        defer.returnValue(ret)
 
     def event_from_pdu_json(self, pdu_json, outlier=False):
         event = FrozenEvent(
@@ -291,3 +373,37 @@ def event_from_pdu_json(self, pdu_json, outlier=False):
         event.internal_metadata.outlier = outlier
 
         return event
+
+    @defer.inlineCallbacks
+    def _check_sigs_and_hash(self, pdu):
+        """Throws a SynapseError if the PDU does not have the correct
+        signatures.
+
+        Returns:
+            FrozenEvent: Either the given event or it redacted if it failed the
+            content hash check.
+        """
+        # Check signatures are correct.
+        redacted_event = prune_event(pdu)
+        redacted_pdu_json = redacted_event.get_pdu_json()
+
+        try:
+            yield self.keyring.verify_json_for_server(
+                pdu.origin, redacted_pdu_json
+            )
+        except SynapseError:
+            logger.warn(
+                "Signature check failed for %s redacted to %s",
+                encode_canonical_json(pdu.get_pdu_json()),
+                encode_canonical_json(redacted_pdu_json),
+            )
+            raise
+
+        if not check_event_content_hash(pdu):
+            logger.warn(
+                "Event content has been tampered, redacting %s, %s",
+                pdu.event_id, encode_canonical_json(pdu.get_dict())
+            )
+            defer.returnValue(redacted_event)
+
+        defer.returnValue(pdu)