diff options
Diffstat (limited to 'synapse/handlers')
| -rw-r--r-- | synapse/handlers/federation.py | 93 | ||||
| -rw-r--r-- | synapse/handlers/room.py | 67 |
2 files changed, 131 insertions, 29 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index ac15f9e5dd..3655b9e5e2 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -14,6 +14,9 @@ # limitations under the License. """Contains handlers for federation events.""" +from signedjson.key import decode_verify_key_bytes +from signedjson.sign import verify_signed_json +from unpaddedbase64 import decode_base64 from ._base import BaseHandler @@ -1620,19 +1623,15 @@ class FederationHandler(BaseHandler): @defer.inlineCallbacks @log_function - def exchange_third_party_invite(self, invite): - sender = invite["sender"] - room_id = invite["room_id"] - - if "signed" not in invite or "token" not in invite["signed"]: - logger.info( - "Discarding received notification of third party invite " - "without signed: %s" % (invite,) - ) - return - + def exchange_third_party_invite( + self, + sender_user_id, + target_user_id, + room_id, + signed, + ): third_party_invite = { - "signed": invite["signed"], + "signed": signed, } event_dict = { @@ -1642,8 +1641,8 @@ class FederationHandler(BaseHandler): "third_party_invite": third_party_invite, }, "room_id": room_id, - "sender": sender, - "state_key": invite["mxid"], + "sender": sender_user_id, + "state_key": target_user_id, } if (yield self.auth.check_host_in_room(room_id, self.hs.hostname)): @@ -1656,11 +1655,11 @@ class FederationHandler(BaseHandler): ) self.auth.check(event, context.current_state) - yield self._validate_keyserver(event, auth_events=context.current_state) + yield self._check_signature(event, auth_events=context.current_state) member_handler = self.hs.get_handlers().room_member_handler yield member_handler.send_membership_event(event, context, from_client=False) else: - destinations = set([x.split(":", 1)[-1] for x in (sender, room_id)]) + destinations = set(x.split(":", 1)[-1] for x in (sender_user_id, room_id)) yield self.replication_layer.forward_third_party_invite( destinations, room_id, @@ -1681,7 +1680,7 @@ class FederationHandler(BaseHandler): ) self.auth.check(event, auth_events=context.current_state) - yield self._validate_keyserver(event, auth_events=context.current_state) + yield self._check_signature(event, auth_events=context.current_state) returned_invite = yield self.send_invite(origin, event) # TODO: Make sure the signatures actually are correct. @@ -1711,17 +1710,69 @@ class FederationHandler(BaseHandler): defer.returnValue((event, context)) @defer.inlineCallbacks - def _validate_keyserver(self, event, auth_events): - token = event.content["third_party_invite"]["signed"]["token"] + def _check_signature(self, event, auth_events): + """ + Checks that the signature in the event is consistent with its invite. + :param event (Event): The m.room.member event to check + :param auth_events (dict<(event type, state_key), event>) + + :raises + AuthError if signature didn't match any keys, or key has been + revoked, + SynapseError if a transient error meant a key couldn't be checked + for revocation. + """ + signed = event.content["third_party_invite"]["signed"] + token = signed["token"] invite_event = auth_events.get( (EventTypes.ThirdPartyInvite, token,) ) + if not invite_event: + raise AuthError(403, "Could not find invite") + + last_exception = None + for public_key_object in self.hs.get_auth().get_public_keys(invite_event): + try: + for server, signature_block in signed["signatures"].items(): + for key_name, encoded_signature in signature_block.items(): + if not key_name.startswith("ed25519:"): + continue + + public_key = public_key_object["public_key"] + verify_key = decode_verify_key_bytes( + key_name, + decode_base64(public_key) + ) + verify_signed_json(signed, server, verify_key) + if "key_validity_url" in public_key_object: + yield self._check_key_revocation( + public_key, + public_key_object["key_validity_url"] + ) + return + except Exception as e: + last_exception = e + raise last_exception + + @defer.inlineCallbacks + def _check_key_revocation(self, public_key, url): + """ + Checks whether public_key has been revoked. + + :param public_key (str): base-64 encoded public key. + :param url (str): Key revocation URL. + + :raises + AuthError if they key has been revoked. + SynapseError if a transient error meant a key couldn't be checked + for revocation. + """ try: response = yield self.hs.get_simple_http_client().get_json( - invite_event.content["key_validity_url"], - {"public_key": invite_event.content["public_key"]} + url, + {"public_key": public_key} ) except Exception: raise SynapseError( diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py index b00cac4bd4..eb9700a35b 100644 --- a/synapse/handlers/room.py +++ b/synapse/handlers/room.py @@ -398,6 +398,7 @@ class RoomMemberHandler(BaseHandler): action, txn_id=None, remote_room_hosts=None, + third_party_signed=None, ratelimit=True, ): effective_membership_state = action @@ -406,6 +407,15 @@ class RoomMemberHandler(BaseHandler): elif action == "forget": effective_membership_state = "leave" + if third_party_signed is not None: + replication = self.hs.get_replication_layer() + yield replication.exchange_third_party_invite( + third_party_signed["sender"], + target.to_string(), + room_id, + third_party_signed, + ) + msg_handler = self.hs.get_handlers().message_handler content = {"membership": effective_membership_state} @@ -759,7 +769,7 @@ class RoomMemberHandler(BaseHandler): if room_avatar_event: room_avatar_url = room_avatar_event.content.get("url", "") - token, public_key, key_validity_url, display_name = ( + token, public_keys, fallback_public_key, display_name = ( yield self._ask_id_server_for_third_party_invite( id_server=id_server, medium=medium, @@ -774,14 +784,18 @@ class RoomMemberHandler(BaseHandler): inviter_avatar_url=inviter_avatar_url ) ) + msg_handler = self.hs.get_handlers().message_handler yield msg_handler.create_and_send_nonmember_event( { "type": EventTypes.ThirdPartyInvite, "content": { "display_name": display_name, - "key_validity_url": key_validity_url, - "public_key": public_key, + "public_keys": public_keys, + + # For backwards compatibility: + "key_validity_url": fallback_public_key["key_validity_url"], + "public_key": fallback_public_key["public_key"], }, "room_id": room_id, "sender": user.to_string(), @@ -806,6 +820,34 @@ class RoomMemberHandler(BaseHandler): inviter_display_name, inviter_avatar_url ): + """ + Asks an identity server for a third party invite. + + :param id_server (str): hostname + optional port for the identity server. + :param medium (str): The literal string "email". + :param address (str): The third party address being invited. + :param room_id (str): The ID of the room to which the user is invited. + :param inviter_user_id (str): The user ID of the inviter. + :param room_alias (str): An alias for the room, for cosmetic + notifications. + :param room_avatar_url (str): The URL of the room's avatar, for cosmetic + notifications. + :param room_join_rules (str): The join rules of the email + (e.g. "public"). + :param room_name (str): The m.room.name of the room. + :param inviter_display_name (str): The current display name of the + inviter. + :param inviter_avatar_url (str): The URL of the inviter's avatar. + + :return: A deferred tuple containing: + token (str): The token which must be signed to prove authenticity. + public_keys ([{"public_key": str, "key_validity_url": str}]): + public_key is a base64-encoded ed25519 public key. + fallback_public_key: One element from public_keys. + display_name (str): A user-friendly name to represent the invited + user. + """ + is_url = "%s%s/_matrix/identity/api/v1/store-invite" % ( id_server_scheme, id_server, ) @@ -826,12 +868,21 @@ class RoomMemberHandler(BaseHandler): ) # TODO: Check for success token = data["token"] - public_key = data["public_key"] + public_keys = data.get("public_keys", []) + if "public_key" in data: + fallback_public_key = { + "public_key": data["public_key"], + "key_validity_url": "%s%s/_matrix/identity/api/v1/pubkey/isvalid" % ( + id_server_scheme, id_server, + ), + } + else: + fallback_public_key = public_keys[0] + + if not public_keys: + public_keys.append(fallback_public_key) display_name = data["display_name"] - key_validity_url = "%s%s/_matrix/identity/api/v1/pubkey/isvalid" % ( - id_server_scheme, id_server, - ) - defer.returnValue((token, public_key, key_validity_url, display_name)) + defer.returnValue((token, public_keys, fallback_public_key, display_name)) def forget(self, user, room_id): return self.store.forget(user.to_string(), room_id) |