895 lines
		
	
	
		
			32 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			895 lines
		
	
	
		
			32 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
 | |
| # Copyright 2014, 2015 OpenMarket Ltd
 | |
| #
 | |
| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # 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.
 | |
| 
 | |
| """This module contains classes for authenticating the user."""
 | |
| from nacl.exceptions import BadSignatureError
 | |
| 
 | |
| from twisted.internet import defer
 | |
| 
 | |
| from synapse.api.constants import EventTypes, Membership, JoinRules
 | |
| from synapse.api.errors import AuthError, Codes, SynapseError
 | |
| from synapse.types import RoomID, UserID, EventID
 | |
| from synapse.util.logutils import log_function
 | |
| from synapse.util import third_party_invites
 | |
| from unpaddedbase64 import decode_base64
 | |
| 
 | |
| import logging
 | |
| import nacl.signing
 | |
| import pymacaroons
 | |
| 
 | |
| logger = logging.getLogger(__name__)
 | |
| 
 | |
| 
 | |
| AuthEventTypes = (
 | |
|     EventTypes.Create, EventTypes.Member, EventTypes.PowerLevels,
 | |
|     EventTypes.JoinRules, EventTypes.RoomHistoryVisibility,
 | |
|     EventTypes.ThirdPartyInvite,
 | |
| )
 | |
| 
 | |
| 
 | |
| class Auth(object):
 | |
| 
 | |
|     def __init__(self, hs):
 | |
|         self.hs = hs
 | |
|         self.store = hs.get_datastore()
 | |
|         self.state = hs.get_state_handler()
 | |
|         self.TOKEN_NOT_FOUND_HTTP_STATUS = 401
 | |
|         self._KNOWN_CAVEAT_PREFIXES = set([
 | |
|             "gen = ",
 | |
|             "type = ",
 | |
|             "time < ",
 | |
|             "user_id = ",
 | |
|         ])
 | |
| 
 | |
|     def check(self, event, auth_events):
 | |
|         """ Checks if this event is correctly authed.
 | |
| 
 | |
|         Args:
 | |
|             event: the event being checked.
 | |
|             auth_events (dict: event-key -> event): the existing room state.
 | |
| 
 | |
| 
 | |
|         Returns:
 | |
|             True if the auth checks pass.
 | |
|         """
 | |
|         try:
 | |
|             if not hasattr(event, "room_id"):
 | |
|                 raise AuthError(500, "Event has no room_id: %s" % event)
 | |
|             if auth_events is None:
 | |
|                 # Oh, we don't know what the state of the room was, so we
 | |
|                 # are trusting that this is allowed (at least for now)
 | |
|                 logger.warn("Trusting event: %s", event.event_id)
 | |
|                 return True
 | |
| 
 | |
|             if event.type == EventTypes.Create:
 | |
|                 # FIXME
 | |
|                 return True
 | |
| 
 | |
|             creation_event = auth_events.get((EventTypes.Create, ""), None)
 | |
| 
 | |
|             if not creation_event:
 | |
|                 raise SynapseError(
 | |
|                     403,
 | |
|                     "Room %r does not exist" % (event.room_id,)
 | |
|                 )
 | |
| 
 | |
|             creating_domain = RoomID.from_string(event.room_id).domain
 | |
|             originating_domain = UserID.from_string(event.sender).domain
 | |
|             if creating_domain != originating_domain:
 | |
|                 if not self.can_federate(event, auth_events):
 | |
|                     raise AuthError(
 | |
|                         403,
 | |
|                         "This room has been marked as unfederatable."
 | |
|                     )
 | |
| 
 | |
|             # FIXME: Temp hack
 | |
|             if event.type == EventTypes.Aliases:
 | |
|                 return True
 | |
| 
 | |
|             logger.debug(
 | |
|                 "Auth events: %s",
 | |
|                 [a.event_id for a in auth_events.values()]
 | |
|             )
 | |
| 
 | |
|             if event.type == EventTypes.Member:
 | |
|                 allowed = self.is_membership_change_allowed(
 | |
|                     event, auth_events
 | |
|                 )
 | |
|                 if allowed:
 | |
|                     logger.debug("Allowing! %s", event)
 | |
|                 else:
 | |
|                     logger.debug("Denying! %s", event)
 | |
|                 return allowed
 | |
| 
 | |
|             self.check_event_sender_in_room(event, auth_events)
 | |
|             self._can_send_event(event, auth_events)
 | |
| 
 | |
|             if event.type == EventTypes.PowerLevels:
 | |
|                 self._check_power_levels(event, auth_events)
 | |
| 
 | |
|             if event.type == EventTypes.Redaction:
 | |
|                 self.check_redaction(event, auth_events)
 | |
| 
 | |
|             logger.debug("Allowing! %s", event)
 | |
|         except AuthError as e:
 | |
|             logger.info(
 | |
|                 "Event auth check failed on event %s with msg: %s",
 | |
|                 event, e.msg
 | |
|             )
 | |
|             logger.info("Denying! %s", event)
 | |
|             raise
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def check_joined_room(self, room_id, user_id, current_state=None):
 | |
|         """Check if the user is currently joined in the room
 | |
|         Args:
 | |
|             room_id(str): The room to check.
 | |
|             user_id(str): The user to check.
 | |
|             current_state(dict): Optional map of the current state of the room.
 | |
|                 If provided then that map is used to check whether they are a
 | |
|                 member of the room. Otherwise the current membership is
 | |
|                 loaded from the database.
 | |
|         Raises:
 | |
|             AuthError if the user is not in the room.
 | |
|         Returns:
 | |
|             A deferred membership event for the user if the user is in
 | |
|             the room.
 | |
|         """
 | |
|         if current_state:
 | |
|             member = current_state.get(
 | |
|                 (EventTypes.Member, user_id),
 | |
|                 None
 | |
|             )
 | |
|         else:
 | |
|             member = yield self.state.get_current_state(
 | |
|                 room_id=room_id,
 | |
|                 event_type=EventTypes.Member,
 | |
|                 state_key=user_id
 | |
|             )
 | |
| 
 | |
|         self._check_joined_room(member, user_id, room_id)
 | |
|         defer.returnValue(member)
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def check_user_was_in_room(self, room_id, user_id, current_state=None):
 | |
|         """Check if the user was in the room at some point.
 | |
|         Args:
 | |
|             room_id(str): The room to check.
 | |
|             user_id(str): The user to check.
 | |
|             current_state(dict): Optional map of the current state of the room.
 | |
|                 If provided then that map is used to check whether they are a
 | |
|                 member of the room. Otherwise the current membership is
 | |
|                 loaded from the database.
 | |
|         Raises:
 | |
|             AuthError if the user was never in the room.
 | |
|         Returns:
 | |
|             A deferred membership event for the user if the user was in the
 | |
|             room. This will be the join event if they are currently joined to
 | |
|             the room. This will be the leave event if they have left the room.
 | |
|         """
 | |
|         if current_state:
 | |
|             member = current_state.get(
 | |
|                 (EventTypes.Member, user_id),
 | |
|                 None
 | |
|             )
 | |
|         else:
 | |
|             member = yield self.state.get_current_state(
 | |
|                 room_id=room_id,
 | |
|                 event_type=EventTypes.Member,
 | |
|                 state_key=user_id
 | |
|             )
 | |
|         membership = member.membership if member else None
 | |
| 
 | |
|         if membership not in (Membership.JOIN, Membership.LEAVE):
 | |
|             raise AuthError(403, "User %s not in room %s" % (
 | |
|                 user_id, room_id
 | |
|             ))
 | |
| 
 | |
|         defer.returnValue(member)
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def check_host_in_room(self, room_id, host):
 | |
|         curr_state = yield self.state.get_current_state(room_id)
 | |
| 
 | |
|         for event in curr_state.values():
 | |
|             if event.type == EventTypes.Member:
 | |
|                 try:
 | |
|                     if UserID.from_string(event.state_key).domain != host:
 | |
|                         continue
 | |
|                 except:
 | |
|                     logger.warn("state_key not user_id: %s", event.state_key)
 | |
|                     continue
 | |
| 
 | |
|                 if event.content["membership"] == Membership.JOIN:
 | |
|                     defer.returnValue(True)
 | |
| 
 | |
|         defer.returnValue(False)
 | |
| 
 | |
|     def check_event_sender_in_room(self, event, auth_events):
 | |
|         key = (EventTypes.Member, event.user_id, )
 | |
|         member_event = auth_events.get(key)
 | |
| 
 | |
|         return self._check_joined_room(
 | |
|             member_event,
 | |
|             event.user_id,
 | |
|             event.room_id
 | |
|         )
 | |
| 
 | |
|     def _check_joined_room(self, member, user_id, room_id):
 | |
|         if not member or member.membership != Membership.JOIN:
 | |
|             raise AuthError(403, "User %s not in room %s (%s)" % (
 | |
|                 user_id, room_id, repr(member)
 | |
|             ))
 | |
| 
 | |
|     def can_federate(self, event, auth_events):
 | |
|         creation_event = auth_events.get((EventTypes.Create, ""))
 | |
| 
 | |
|         return creation_event.content.get("m.federate", True) is True
 | |
| 
 | |
|     @log_function
 | |
|     def is_membership_change_allowed(self, event, auth_events):
 | |
|         membership = event.content["membership"]
 | |
| 
 | |
|         # Check if this is the room creator joining:
 | |
|         if len(event.prev_events) == 1 and Membership.JOIN == membership:
 | |
|             # Get room creation event:
 | |
|             key = (EventTypes.Create, "", )
 | |
|             create = auth_events.get(key)
 | |
|             if create and event.prev_events[0][0] == create.event_id:
 | |
|                 if create.content["creator"] == event.state_key:
 | |
|                     return True
 | |
| 
 | |
|         target_user_id = event.state_key
 | |
| 
 | |
|         creating_domain = RoomID.from_string(event.room_id).domain
 | |
|         target_domain = UserID.from_string(target_user_id).domain
 | |
|         if creating_domain != target_domain:
 | |
|             if not self.can_federate(event, auth_events):
 | |
|                 raise AuthError(
 | |
|                     403,
 | |
|                     "This room has been marked as unfederatable."
 | |
|                 )
 | |
| 
 | |
|         # get info about the caller
 | |
|         key = (EventTypes.Member, event.user_id, )
 | |
|         caller = auth_events.get(key)
 | |
| 
 | |
|         caller_in_room = caller and caller.membership == Membership.JOIN
 | |
|         caller_invited = caller and caller.membership == Membership.INVITE
 | |
| 
 | |
|         # get info about the target
 | |
|         key = (EventTypes.Member, target_user_id, )
 | |
|         target = auth_events.get(key)
 | |
| 
 | |
|         target_in_room = target and target.membership == Membership.JOIN
 | |
|         target_banned = target and target.membership == Membership.BAN
 | |
| 
 | |
|         key = (EventTypes.JoinRules, "", )
 | |
|         join_rule_event = auth_events.get(key)
 | |
|         if join_rule_event:
 | |
|             join_rule = join_rule_event.content.get(
 | |
|                 "join_rule", JoinRules.INVITE
 | |
|             )
 | |
|         else:
 | |
|             join_rule = JoinRules.INVITE
 | |
| 
 | |
|         user_level = self._get_user_power_level(event.user_id, auth_events)
 | |
|         target_level = self._get_user_power_level(
 | |
|             target_user_id, auth_events
 | |
|         )
 | |
| 
 | |
|         # FIXME (erikj): What should we do here as the default?
 | |
|         ban_level = self._get_named_level(auth_events, "ban", 50)
 | |
| 
 | |
|         logger.debug(
 | |
|             "is_membership_change_allowed: %s",
 | |
|             {
 | |
|                 "caller_in_room": caller_in_room,
 | |
|                 "caller_invited": caller_invited,
 | |
|                 "target_banned": target_banned,
 | |
|                 "target_in_room": target_in_room,
 | |
|                 "membership": membership,
 | |
|                 "join_rule": join_rule,
 | |
|                 "target_user_id": target_user_id,
 | |
|                 "event.user_id": event.user_id,
 | |
|             }
 | |
|         )
 | |
| 
 | |
|         if Membership.JOIN != membership:
 | |
|             # JOIN is the only action you can perform if you're not in the room
 | |
|             if not caller_in_room:  # caller isn't joined
 | |
|                 raise AuthError(
 | |
|                     403,
 | |
|                     "%s not in room %s." % (event.user_id, event.room_id,)
 | |
|                 )
 | |
| 
 | |
|         if Membership.INVITE == membership:
 | |
|             # TODO (erikj): We should probably handle this more intelligently
 | |
|             # PRIVATE join rules.
 | |
| 
 | |
|             # Invites are valid iff caller is in the room and target isn't.
 | |
|             if target_banned:
 | |
|                 raise AuthError(
 | |
|                     403, "%s is banned from the room" % (target_user_id,)
 | |
|                 )
 | |
|             elif target_in_room:  # the target is already in the room.
 | |
|                 raise AuthError(403, "%s is already in the room." %
 | |
|                                      target_user_id)
 | |
|             else:
 | |
|                 invite_level = self._get_named_level(auth_events, "invite", 0)
 | |
| 
 | |
|                 if user_level < invite_level:
 | |
|                     raise AuthError(
 | |
|                         403, "You cannot invite user %s." % target_user_id
 | |
|                     )
 | |
|         elif Membership.JOIN == membership:
 | |
|             # Joins are valid iff caller == target and they were:
 | |
|             # invited: They are accepting the invitation
 | |
|             # joined: It's a NOOP
 | |
|             if event.user_id != target_user_id:
 | |
|                 raise AuthError(403, "Cannot force another user to join.")
 | |
|             elif target_banned:
 | |
|                 raise AuthError(403, "You are banned from this room")
 | |
|             elif join_rule == JoinRules.PUBLIC:
 | |
|                 pass
 | |
|             elif join_rule == JoinRules.INVITE:
 | |
|                 if not caller_in_room and not caller_invited:
 | |
|                     if not self._verify_third_party_invite(event, auth_events):
 | |
|                         raise AuthError(403, "You are not invited to this room.")
 | |
|             else:
 | |
|                 # TODO (erikj): may_join list
 | |
|                 # TODO (erikj): private rooms
 | |
|                 raise AuthError(403, "You are not allowed to join this room")
 | |
|         elif Membership.LEAVE == membership:
 | |
|             # TODO (erikj): Implement kicks.
 | |
|             if target_banned and user_level < ban_level:
 | |
|                 raise AuthError(
 | |
|                     403, "You cannot unban user &s." % (target_user_id,)
 | |
|                 )
 | |
|             elif target_user_id != event.user_id:
 | |
|                 kick_level = self._get_named_level(auth_events, "kick", 50)
 | |
| 
 | |
|                 if user_level < kick_level or user_level <= target_level:
 | |
|                     raise AuthError(
 | |
|                         403, "You cannot kick user %s." % target_user_id
 | |
|                     )
 | |
|         elif Membership.BAN == membership:
 | |
|             if user_level < ban_level or user_level <= target_level:
 | |
|                 raise AuthError(403, "You don't have permission to ban")
 | |
|         else:
 | |
|             raise AuthError(500, "Unknown membership %s" % membership)
 | |
| 
 | |
|         return True
 | |
| 
 | |
|     def _verify_third_party_invite(self, event, auth_events):
 | |
|         """
 | |
|         Validates that the join event is authorized by a previous third-party invite.
 | |
| 
 | |
|         Checks that the public key, and keyserver, match those in the invite,
 | |
|         and that the join event has a signature issued using that public key.
 | |
| 
 | |
|         Args:
 | |
|             event: The m.room.member join event being validated.
 | |
|             auth_events: All relevant previous context events which may be used
 | |
|                 for authorization decisions.
 | |
| 
 | |
|         Return:
 | |
|             True if the event fulfills the expectations of a previous third party
 | |
|             invite event.
 | |
|         """
 | |
|         if not third_party_invites.join_has_third_party_invite(event.content):
 | |
|             return False
 | |
|         join_third_party_invite = event.content["third_party_invite"]
 | |
|         token = join_third_party_invite["token"]
 | |
|         invite_event = auth_events.get(
 | |
|             (EventTypes.ThirdPartyInvite, token,)
 | |
|         )
 | |
|         if not invite_event:
 | |
|             logger.info("Failing 3pid invite because no invite found for token %s", token)
 | |
|             return False
 | |
|         try:
 | |
|             public_key = join_third_party_invite["public_key"]
 | |
|             key_validity_url = join_third_party_invite["key_validity_url"]
 | |
|             if invite_event.content["public_key"] != public_key:
 | |
|                 logger.info(
 | |
|                     "Failing 3pid invite because public key invite: %s != join: %s",
 | |
|                     invite_event.content["public_key"],
 | |
|                     public_key
 | |
|                 )
 | |
|                 return False
 | |
|             if invite_event.content["key_validity_url"] != key_validity_url:
 | |
|                 logger.info(
 | |
|                     "Failing 3pid invite because key_validity_url invite: %s != join: %s",
 | |
|                     invite_event.content["key_validity_url"],
 | |
|                     key_validity_url
 | |
|                 )
 | |
|                 return False
 | |
|             for _, signature_block in join_third_party_invite["signatures"].items():
 | |
|                 for key_name, encoded_signature in signature_block.items():
 | |
|                     if not key_name.startswith("ed25519:"):
 | |
|                         return False
 | |
|                     verify_key = nacl.signing.VerifyKey(decode_base64(public_key))
 | |
|                     signature = decode_base64(encoded_signature)
 | |
|                     verify_key.verify(token, signature)
 | |
|                     return True
 | |
|             return False
 | |
|         except (KeyError, BadSignatureError,):
 | |
|             return False
 | |
| 
 | |
|     def _get_power_level_event(self, auth_events):
 | |
|         key = (EventTypes.PowerLevels, "", )
 | |
|         return auth_events.get(key)
 | |
| 
 | |
|     def _get_user_power_level(self, user_id, auth_events):
 | |
|         power_level_event = self._get_power_level_event(auth_events)
 | |
| 
 | |
|         if power_level_event:
 | |
|             level = power_level_event.content.get("users", {}).get(user_id)
 | |
|             if not level:
 | |
|                 level = power_level_event.content.get("users_default", 0)
 | |
| 
 | |
|             if level is None:
 | |
|                 return 0
 | |
|             else:
 | |
|                 return int(level)
 | |
|         else:
 | |
|             key = (EventTypes.Create, "", )
 | |
|             create_event = auth_events.get(key)
 | |
|             if (create_event is not None and
 | |
|                     create_event.content["creator"] == user_id):
 | |
|                 return 100
 | |
|             else:
 | |
|                 return 0
 | |
| 
 | |
|     def _get_named_level(self, auth_events, name, default):
 | |
|         power_level_event = self._get_power_level_event(auth_events)
 | |
| 
 | |
|         if not power_level_event:
 | |
|             return default
 | |
| 
 | |
|         level = power_level_event.content.get(name, None)
 | |
|         if level is not None:
 | |
|             return int(level)
 | |
|         else:
 | |
|             return default
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def get_user_by_req(self, request):
 | |
|         """ Get a registered user's ID.
 | |
| 
 | |
|         Args:
 | |
|             request - An HTTP request with an access_token query parameter.
 | |
|         Returns:
 | |
|             tuple of:
 | |
|                 UserID (str)
 | |
|                 Access token ID (str)
 | |
|         Raises:
 | |
|             AuthError if no user by that token exists or the token is invalid.
 | |
|         """
 | |
|         # Can optionally look elsewhere in the request (e.g. headers)
 | |
|         try:
 | |
|             access_token = request.args["access_token"][0]
 | |
| 
 | |
|             # Check for application service tokens with a user_id override
 | |
|             try:
 | |
|                 app_service = yield self.store.get_app_service_by_token(
 | |
|                     access_token
 | |
|                 )
 | |
|                 if not app_service:
 | |
|                     raise KeyError
 | |
| 
 | |
|                 user_id = app_service.sender
 | |
|                 if "user_id" in request.args:
 | |
|                     user_id = request.args["user_id"][0]
 | |
|                     if not app_service.is_interested_in_user(user_id):
 | |
|                         raise AuthError(
 | |
|                             403,
 | |
|                             "Application service cannot masquerade as this user."
 | |
|                         )
 | |
| 
 | |
|                 if not user_id:
 | |
|                     raise KeyError
 | |
| 
 | |
|                 request.authenticated_entity = user_id
 | |
| 
 | |
|                 defer.returnValue((UserID.from_string(user_id), ""))
 | |
|                 return
 | |
|             except KeyError:
 | |
|                 pass  # normal users won't have the user_id query parameter set.
 | |
| 
 | |
|             user_info = yield self._get_user_by_access_token(access_token)
 | |
|             user = user_info["user"]
 | |
|             token_id = user_info["token_id"]
 | |
| 
 | |
|             ip_addr = self.hs.get_ip_from_request(request)
 | |
|             user_agent = request.requestHeaders.getRawHeaders(
 | |
|                 "User-Agent",
 | |
|                 default=[""]
 | |
|             )[0]
 | |
|             if user and access_token and ip_addr:
 | |
|                 self.store.insert_client_ip(
 | |
|                     user=user,
 | |
|                     access_token=access_token,
 | |
|                     ip=ip_addr,
 | |
|                     user_agent=user_agent
 | |
|                 )
 | |
| 
 | |
|             request.authenticated_entity = user.to_string()
 | |
| 
 | |
|             defer.returnValue((user, token_id,))
 | |
|         except KeyError:
 | |
|             raise AuthError(
 | |
|                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "Missing access token.",
 | |
|                 errcode=Codes.MISSING_TOKEN
 | |
|             )
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def _get_user_by_access_token(self, token):
 | |
|         """ Get a registered user's ID.
 | |
| 
 | |
|         Args:
 | |
|             token (str): The access token to get the user by.
 | |
|         Returns:
 | |
|             dict : dict that includes the user and the ID of their access token.
 | |
|         Raises:
 | |
|             AuthError if no user by that token exists or the token is invalid.
 | |
|         """
 | |
|         try:
 | |
|             ret = yield self._get_user_from_macaroon(token)
 | |
|         except AuthError:
 | |
|             # TODO(daniel): Remove this fallback when all existing access tokens
 | |
|             # have been re-issued as macaroons.
 | |
|             ret = yield self._look_up_user_by_access_token(token)
 | |
|         defer.returnValue(ret)
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def _get_user_from_macaroon(self, macaroon_str):
 | |
|         try:
 | |
|             macaroon = pymacaroons.Macaroon.deserialize(macaroon_str)
 | |
|             self._validate_macaroon(macaroon)
 | |
| 
 | |
|             user_prefix = "user_id = "
 | |
|             for caveat in macaroon.caveats:
 | |
|                 if caveat.caveat_id.startswith(user_prefix):
 | |
|                     user = UserID.from_string(caveat.caveat_id[len(user_prefix):])
 | |
|                     # This codepath exists so that we can actually return a
 | |
|                     # token ID, because we use token IDs in place of device
 | |
|                     # identifiers throughout the codebase.
 | |
|                     # TODO(daniel): Remove this fallback when device IDs are
 | |
|                     # properly implemented.
 | |
|                     ret = yield self._look_up_user_by_access_token(macaroon_str)
 | |
|                     if ret["user"] != user:
 | |
|                         logger.error(
 | |
|                             "Macaroon user (%s) != DB user (%s)",
 | |
|                             user,
 | |
|                             ret["user"]
 | |
|                         )
 | |
|                         raise AuthError(
 | |
|                             self.TOKEN_NOT_FOUND_HTTP_STATUS,
 | |
|                             "User mismatch in macaroon",
 | |
|                             errcode=Codes.UNKNOWN_TOKEN
 | |
|                         )
 | |
|                     defer.returnValue(ret)
 | |
|             raise AuthError(
 | |
|                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "No user caveat in macaroon",
 | |
|                 errcode=Codes.UNKNOWN_TOKEN
 | |
|             )
 | |
|         except (pymacaroons.exceptions.MacaroonException, TypeError, ValueError):
 | |
|             raise AuthError(
 | |
|                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "Invalid macaroon passed.",
 | |
|                 errcode=Codes.UNKNOWN_TOKEN
 | |
|             )
 | |
| 
 | |
|     def _validate_macaroon(self, macaroon):
 | |
|         v = pymacaroons.Verifier()
 | |
|         v.satisfy_exact("gen = 1")
 | |
|         v.satisfy_exact("type = access")
 | |
|         v.satisfy_general(lambda c: c.startswith("user_id = "))
 | |
|         v.satisfy_general(self._verify_expiry)
 | |
|         v.verify(macaroon, self.hs.config.macaroon_secret_key)
 | |
| 
 | |
|         v = pymacaroons.Verifier()
 | |
|         v.satisfy_general(self._verify_recognizes_caveats)
 | |
|         v.verify(macaroon, self.hs.config.macaroon_secret_key)
 | |
| 
 | |
|     def _verify_expiry(self, caveat):
 | |
|         prefix = "time < "
 | |
|         if not caveat.startswith(prefix):
 | |
|             return False
 | |
|         # TODO(daniel): Enable expiry check when clients actually know how to
 | |
|         # refresh tokens. (And remember to enable the tests)
 | |
|         return True
 | |
|         expiry = int(caveat[len(prefix):])
 | |
|         now = self.hs.get_clock().time_msec()
 | |
|         return now < expiry
 | |
| 
 | |
|     def _verify_recognizes_caveats(self, caveat):
 | |
|         first_space = caveat.find(" ")
 | |
|         if first_space < 0:
 | |
|             return False
 | |
|         second_space = caveat.find(" ", first_space + 1)
 | |
|         if second_space < 0:
 | |
|             return False
 | |
|         return caveat[:second_space + 1] in self._KNOWN_CAVEAT_PREFIXES
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def _look_up_user_by_access_token(self, token):
 | |
|         ret = yield self.store.get_user_by_access_token(token)
 | |
|         if not ret:
 | |
|             raise AuthError(
 | |
|                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "Unrecognised access token.",
 | |
|                 errcode=Codes.UNKNOWN_TOKEN
 | |
|             )
 | |
|         user_info = {
 | |
|             "user": UserID.from_string(ret.get("name")),
 | |
|             "token_id": ret.get("token_id", None),
 | |
|         }
 | |
|         defer.returnValue(user_info)
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def get_appservice_by_req(self, request):
 | |
|         try:
 | |
|             token = request.args["access_token"][0]
 | |
|             service = yield self.store.get_app_service_by_token(token)
 | |
|             if not service:
 | |
|                 raise AuthError(
 | |
|                     self.TOKEN_NOT_FOUND_HTTP_STATUS,
 | |
|                     "Unrecognised access token.",
 | |
|                     errcode=Codes.UNKNOWN_TOKEN
 | |
|                 )
 | |
|             request.authenticated_entity = service.sender
 | |
|             defer.returnValue(service)
 | |
|         except KeyError:
 | |
|             raise AuthError(
 | |
|                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "Missing access token."
 | |
|             )
 | |
| 
 | |
|     def is_server_admin(self, user):
 | |
|         return self.store.is_server_admin(user)
 | |
| 
 | |
|     @defer.inlineCallbacks
 | |
|     def add_auth_events(self, builder, context):
 | |
|         auth_ids = self.compute_auth_events(builder, context.current_state)
 | |
| 
 | |
|         auth_events_entries = yield self.store.add_event_hashes(
 | |
|             auth_ids
 | |
|         )
 | |
| 
 | |
|         builder.auth_events = auth_events_entries
 | |
| 
 | |
|     def compute_auth_events(self, event, current_state):
 | |
|         if event.type == EventTypes.Create:
 | |
|             return []
 | |
| 
 | |
|         auth_ids = []
 | |
| 
 | |
|         key = (EventTypes.PowerLevels, "", )
 | |
|         power_level_event = current_state.get(key)
 | |
| 
 | |
|         if power_level_event:
 | |
|             auth_ids.append(power_level_event.event_id)
 | |
| 
 | |
|         key = (EventTypes.JoinRules, "", )
 | |
|         join_rule_event = current_state.get(key)
 | |
| 
 | |
|         key = (EventTypes.Member, event.user_id, )
 | |
|         member_event = current_state.get(key)
 | |
| 
 | |
|         key = (EventTypes.Create, "", )
 | |
|         create_event = current_state.get(key)
 | |
|         if create_event:
 | |
|             auth_ids.append(create_event.event_id)
 | |
| 
 | |
|         if join_rule_event:
 | |
|             join_rule = join_rule_event.content.get("join_rule")
 | |
|             is_public = join_rule == JoinRules.PUBLIC if join_rule else False
 | |
|         else:
 | |
|             is_public = False
 | |
| 
 | |
|         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)
 | |
| 
 | |
|             if e_type == Membership.JOIN:
 | |
|                 if member_event and not is_public:
 | |
|                     auth_ids.append(member_event.event_id)
 | |
|                 if third_party_invites.join_has_third_party_invite(event.content):
 | |
|                     key = (
 | |
|                         EventTypes.ThirdPartyInvite,
 | |
|                         event.content["third_party_invite"]["token"]
 | |
|                     )
 | |
|                     invite = current_state.get(key)
 | |
|                     if invite:
 | |
|                         auth_ids.append(invite.event_id)
 | |
|             else:
 | |
|                 if member_event:
 | |
|                     auth_ids.append(member_event.event_id)
 | |
|         elif member_event:
 | |
|             if member_event.content["membership"] == Membership.JOIN:
 | |
|                 auth_ids.append(member_event.event_id)
 | |
| 
 | |
|         return auth_ids
 | |
| 
 | |
|     @log_function
 | |
|     def _can_send_event(self, event, auth_events):
 | |
|         key = (EventTypes.PowerLevels, "", )
 | |
|         send_level_event = auth_events.get(key)
 | |
|         send_level = None
 | |
|         if send_level_event:
 | |
|             send_level = send_level_event.content.get("events", {}).get(
 | |
|                 event.type
 | |
|             )
 | |
|             if send_level is None:
 | |
|                 if hasattr(event, "state_key"):
 | |
|                     send_level = send_level_event.content.get(
 | |
|                         "state_default", 50
 | |
|                     )
 | |
|                 else:
 | |
|                     send_level = send_level_event.content.get(
 | |
|                         "events_default", 0
 | |
|                     )
 | |
| 
 | |
|         if send_level:
 | |
|             send_level = int(send_level)
 | |
|         else:
 | |
|             send_level = 0
 | |
| 
 | |
|         user_level = self._get_user_power_level(event.user_id, auth_events)
 | |
| 
 | |
|         if user_level < send_level:
 | |
|             raise AuthError(
 | |
|                 403,
 | |
|                 "You don't have permission to post that to the room. " +
 | |
|                 "user_level (%d) < send_level (%d)" % (user_level, send_level)
 | |
|             )
 | |
| 
 | |
|         # Check state_key
 | |
|         if hasattr(event, "state_key"):
 | |
|             if event.state_key.startswith("@"):
 | |
|                 if event.state_key != event.user_id:
 | |
|                     raise AuthError(
 | |
|                         403,
 | |
|                         "You are not allowed to set others state"
 | |
|                     )
 | |
|                 else:
 | |
|                     sender_domain = UserID.from_string(
 | |
|                         event.user_id
 | |
|                     ).domain
 | |
| 
 | |
|                     if sender_domain != event.state_key:
 | |
|                         raise AuthError(
 | |
|                             403,
 | |
|                             "You are not allowed to set others state"
 | |
|                         )
 | |
| 
 | |
|         return True
 | |
| 
 | |
|     def check_redaction(self, event, auth_events):
 | |
|         """Check whether the event sender is allowed to redact the target event.
 | |
| 
 | |
|         Returns:
 | |
|             True if the the sender is allowed to redact the target event if the
 | |
|             target event was created by them.
 | |
|             False if the sender is allowed to redact the target event with no
 | |
|             further checks.
 | |
| 
 | |
|         Raises:
 | |
|             AuthError if the event sender is definitely not allowed to redact
 | |
|             the target event.
 | |
|         """
 | |
|         user_level = self._get_user_power_level(event.user_id, auth_events)
 | |
| 
 | |
|         redact_level = self._get_named_level(auth_events, "redact", 50)
 | |
| 
 | |
|         if user_level > redact_level:
 | |
|             return False
 | |
| 
 | |
|         redacter_domain = EventID.from_string(event.event_id).domain
 | |
|         redactee_domain = EventID.from_string(event.redacts).domain
 | |
|         if redacter_domain == redactee_domain:
 | |
|             return True
 | |
| 
 | |
|         raise AuthError(
 | |
|             403,
 | |
|             "You don't have permission to redact events"
 | |
|         )
 | |
| 
 | |
|     def _check_power_levels(self, event, auth_events):
 | |
|         user_list = event.content.get("users", {})
 | |
|         # Validate users
 | |
|         for k, v in user_list.items():
 | |
|             try:
 | |
|                 UserID.from_string(k)
 | |
|             except:
 | |
|                 raise SynapseError(400, "Not a valid user_id: %s" % (k,))
 | |
| 
 | |
|             try:
 | |
|                 int(v)
 | |
|             except:
 | |
|                 raise SynapseError(400, "Not a valid power level: %s" % (v,))
 | |
| 
 | |
|         key = (event.type, event.state_key, )
 | |
|         current_state = auth_events.get(key)
 | |
| 
 | |
|         if not current_state:
 | |
|             return
 | |
| 
 | |
|         user_level = self._get_user_power_level(event.user_id, auth_events)
 | |
| 
 | |
|         # Check other levels:
 | |
|         levels_to_check = [
 | |
|             ("users_default", None),
 | |
|             ("events_default", None),
 | |
|             ("state_default", None),
 | |
|             ("ban", None),
 | |
|             ("redact", None),
 | |
|             ("kick", None),
 | |
|             ("invite", None),
 | |
|         ]
 | |
| 
 | |
|         old_list = current_state.content.get("users")
 | |
|         for user in set(old_list.keys() + user_list.keys()):
 | |
|             levels_to_check.append(
 | |
|                 (user, "users")
 | |
|             )
 | |
| 
 | |
|         old_list = current_state.content.get("events")
 | |
|         new_list = event.content.get("events")
 | |
|         for ev_id in set(old_list.keys() + new_list.keys()):
 | |
|             levels_to_check.append(
 | |
|                 (ev_id, "events")
 | |
|             )
 | |
| 
 | |
|         old_state = current_state.content
 | |
|         new_state = event.content
 | |
| 
 | |
|         for level_to_check, dir in levels_to_check:
 | |
|             old_loc = old_state
 | |
|             new_loc = new_state
 | |
|             if dir:
 | |
|                 old_loc = old_loc.get(dir, {})
 | |
|                 new_loc = new_loc.get(dir, {})
 | |
| 
 | |
|             if level_to_check in old_loc:
 | |
|                 old_level = int(old_loc[level_to_check])
 | |
|             else:
 | |
|                 old_level = None
 | |
| 
 | |
|             if level_to_check in new_loc:
 | |
|                 new_level = int(new_loc[level_to_check])
 | |
|             else:
 | |
|                 new_level = None
 | |
| 
 | |
|             if new_level is not None and old_level is not None:
 | |
|                 if new_level == old_level:
 | |
|                     continue
 | |
| 
 | |
|             if dir == "users" and level_to_check != event.user_id:
 | |
|                 if old_level == user_level:
 | |
|                     raise AuthError(
 | |
|                         403,
 | |
|                         "You don't have permission to remove ops level equal "
 | |
|                         "to your own"
 | |
|                     )
 | |
| 
 | |
|             if old_level > user_level or new_level > user_level:
 | |
|                 raise AuthError(
 | |
|                     403,
 | |
|                     "You don't have permission to add ops level greater "
 | |
|                     "than your own"
 | |
|                 )
 |