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![Erik Johnston](/assets/img/avatar_default.png)
Users only need their power level to be equal to the redact level for them to be allowed to redact events.
960 lines
34 KiB
Python
960 lines
34 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014, 2015 OpenMarket Ltd
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#
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# 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
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""This module contains classes for authenticating the user."""
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from canonicaljson import encode_canonical_json
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from signedjson.key import decode_verify_key_bytes
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from signedjson.sign import verify_signed_json, SignatureVerifyException
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from twisted.internet import defer
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from synapse.api.constants import EventTypes, Membership, JoinRules
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from synapse.api.errors import AuthError, Codes, SynapseError, EventSizeError
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from synapse.types import RoomID, UserID, EventID
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from synapse.util.logutils import log_function
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from unpaddedbase64 import decode_base64
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import logging
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import pymacaroons
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logger = logging.getLogger(__name__)
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AuthEventTypes = (
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EventTypes.Create, EventTypes.Member, EventTypes.PowerLevels,
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EventTypes.JoinRules, EventTypes.RoomHistoryVisibility,
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EventTypes.ThirdPartyInvite,
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)
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class Auth(object):
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def __init__(self, hs):
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self.hs = hs
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self.store = hs.get_datastore()
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self.state = hs.get_state_handler()
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self.TOKEN_NOT_FOUND_HTTP_STATUS = 401
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self._KNOWN_CAVEAT_PREFIXES = set([
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"gen = ",
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"guest = ",
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"type = ",
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"time < ",
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"user_id = ",
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])
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def check(self, event, auth_events):
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""" Checks if this event is correctly authed.
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Args:
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event: the event being checked.
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auth_events (dict: event-key -> event): the existing room state.
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Returns:
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True if the auth checks pass.
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"""
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self.check_size_limits(event)
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try:
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if not hasattr(event, "room_id"):
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raise AuthError(500, "Event has no room_id: %s" % event)
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if auth_events is None:
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# Oh, we don't know what the state of the room was, so we
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# are trusting that this is allowed (at least for now)
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logger.warn("Trusting event: %s", event.event_id)
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return True
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if event.type == EventTypes.Create:
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# FIXME
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return True
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creation_event = auth_events.get((EventTypes.Create, ""), None)
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if not creation_event:
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raise SynapseError(
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403,
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"Room %r does not exist" % (event.room_id,)
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)
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creating_domain = RoomID.from_string(event.room_id).domain
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originating_domain = UserID.from_string(event.sender).domain
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if creating_domain != originating_domain:
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if not self.can_federate(event, auth_events):
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raise AuthError(
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403,
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"This room has been marked as unfederatable."
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)
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# FIXME: Temp hack
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if event.type == EventTypes.Aliases:
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return True
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logger.debug(
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"Auth events: %s",
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[a.event_id for a in auth_events.values()]
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)
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if event.type == EventTypes.Member:
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allowed = self.is_membership_change_allowed(
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event, auth_events
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)
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if allowed:
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logger.debug("Allowing! %s", event)
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else:
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logger.debug("Denying! %s", event)
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return allowed
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self.check_event_sender_in_room(event, auth_events)
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self._can_send_event(event, auth_events)
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if event.type == EventTypes.PowerLevels:
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self._check_power_levels(event, auth_events)
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if event.type == EventTypes.Redaction:
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self.check_redaction(event, auth_events)
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logger.debug("Allowing! %s", event)
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except AuthError as e:
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logger.info(
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"Event auth check failed on event %s with msg: %s",
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event, e.msg
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)
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logger.info("Denying! %s", event)
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raise
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def check_size_limits(self, event):
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def too_big(field):
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raise EventSizeError("%s too large" % (field,))
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if len(event.user_id) > 255:
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too_big("user_id")
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if len(event.room_id) > 255:
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too_big("room_id")
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if event.is_state() and len(event.state_key) > 255:
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too_big("state_key")
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if len(event.type) > 255:
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too_big("type")
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if len(event.event_id) > 255:
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too_big("event_id")
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if len(encode_canonical_json(event.get_pdu_json())) > 65536:
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too_big("event")
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@defer.inlineCallbacks
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def check_joined_room(self, room_id, user_id, current_state=None):
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"""Check if the user is currently joined in the room
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Args:
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room_id(str): The room to check.
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user_id(str): The user to check.
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current_state(dict): Optional map of the current state of the room.
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If provided then that map is used to check whether they are a
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member of the room. Otherwise the current membership is
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loaded from the database.
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Raises:
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AuthError if the user is not in the room.
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Returns:
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A deferred membership event for the user if the user is in
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the room.
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"""
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if current_state:
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member = current_state.get(
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(EventTypes.Member, user_id),
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None
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)
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else:
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member = yield self.state.get_current_state(
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room_id=room_id,
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event_type=EventTypes.Member,
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state_key=user_id
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)
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self._check_joined_room(member, user_id, room_id)
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defer.returnValue(member)
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@defer.inlineCallbacks
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def check_user_was_in_room(self, room_id, user_id):
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"""Check if the user was in the room at some point.
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Args:
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room_id(str): The room to check.
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user_id(str): The user to check.
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Raises:
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AuthError if the user was never in the room.
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Returns:
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A deferred membership event for the user if the user was in the
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room. This will be the join event if they are currently joined to
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the room. This will be the leave event if they have left the room.
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"""
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member = yield self.state.get_current_state(
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room_id=room_id,
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event_type=EventTypes.Member,
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state_key=user_id
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)
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membership = member.membership if member else None
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if membership not in (Membership.JOIN, Membership.LEAVE):
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raise AuthError(403, "User %s not in room %s" % (
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user_id, room_id
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))
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if membership == Membership.LEAVE:
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forgot = yield self.store.did_forget(user_id, room_id)
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if forgot:
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raise AuthError(403, "User %s not in room %s" % (
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user_id, room_id
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))
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defer.returnValue(member)
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@defer.inlineCallbacks
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def check_host_in_room(self, room_id, host):
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curr_state = yield self.state.get_current_state(room_id)
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for event in curr_state.values():
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if event.type == EventTypes.Member:
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try:
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if UserID.from_string(event.state_key).domain != host:
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continue
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except:
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logger.warn("state_key not user_id: %s", event.state_key)
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continue
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if event.content["membership"] == Membership.JOIN:
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defer.returnValue(True)
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defer.returnValue(False)
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def check_event_sender_in_room(self, event, auth_events):
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key = (EventTypes.Member, event.user_id, )
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member_event = auth_events.get(key)
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return self._check_joined_room(
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member_event,
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event.user_id,
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event.room_id
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)
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def _check_joined_room(self, member, user_id, room_id):
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if not member or member.membership != Membership.JOIN:
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raise AuthError(403, "User %s not in room %s (%s)" % (
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user_id, room_id, repr(member)
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))
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def can_federate(self, event, auth_events):
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creation_event = auth_events.get((EventTypes.Create, ""))
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return creation_event.content.get("m.federate", True) is True
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@log_function
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def is_membership_change_allowed(self, event, auth_events):
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membership = event.content["membership"]
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# Check if this is the room creator joining:
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if len(event.prev_events) == 1 and Membership.JOIN == membership:
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# Get room creation event:
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key = (EventTypes.Create, "", )
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create = auth_events.get(key)
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if create and event.prev_events[0][0] == create.event_id:
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if create.content["creator"] == event.state_key:
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return True
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target_user_id = event.state_key
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creating_domain = RoomID.from_string(event.room_id).domain
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target_domain = UserID.from_string(target_user_id).domain
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if creating_domain != target_domain:
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if not self.can_federate(event, auth_events):
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raise AuthError(
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403,
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"This room has been marked as unfederatable."
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)
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# get info about the caller
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key = (EventTypes.Member, event.user_id, )
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caller = auth_events.get(key)
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caller_in_room = caller and caller.membership == Membership.JOIN
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caller_invited = caller and caller.membership == Membership.INVITE
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# get info about the target
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key = (EventTypes.Member, target_user_id, )
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target = auth_events.get(key)
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target_in_room = target and target.membership == Membership.JOIN
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target_banned = target and target.membership == Membership.BAN
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key = (EventTypes.JoinRules, "", )
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join_rule_event = auth_events.get(key)
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if join_rule_event:
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join_rule = join_rule_event.content.get(
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"join_rule", JoinRules.INVITE
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)
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else:
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join_rule = JoinRules.INVITE
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user_level = self._get_user_power_level(event.user_id, auth_events)
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target_level = self._get_user_power_level(
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target_user_id, auth_events
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)
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# FIXME (erikj): What should we do here as the default?
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ban_level = self._get_named_level(auth_events, "ban", 50)
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logger.debug(
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"is_membership_change_allowed: %s",
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{
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"caller_in_room": caller_in_room,
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"caller_invited": caller_invited,
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"target_banned": target_banned,
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"target_in_room": target_in_room,
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"membership": membership,
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"join_rule": join_rule,
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"target_user_id": target_user_id,
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"event.user_id": event.user_id,
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}
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)
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if Membership.INVITE == membership and "third_party_invite" in event.content:
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if not self._verify_third_party_invite(event, auth_events):
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raise AuthError(403, "You are not invited to this room.")
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return True
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if Membership.JOIN != membership:
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if (caller_invited
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and Membership.LEAVE == membership
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and target_user_id == event.user_id):
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return True
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if not caller_in_room: # caller isn't joined
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raise AuthError(
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403,
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"%s not in room %s." % (event.user_id, event.room_id,)
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)
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if Membership.INVITE == membership:
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# TODO (erikj): We should probably handle this more intelligently
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# PRIVATE join rules.
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# Invites are valid iff caller is in the room and target isn't.
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if target_banned:
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raise AuthError(
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403, "%s is banned from the room" % (target_user_id,)
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)
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elif target_in_room: # the target is already in the room.
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raise AuthError(403, "%s is already in the room." %
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target_user_id)
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else:
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invite_level = self._get_named_level(auth_events, "invite", 0)
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if user_level < invite_level:
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raise AuthError(
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403, "You cannot invite user %s." % target_user_id
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)
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elif Membership.JOIN == membership:
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# Joins are valid iff caller == target and they were:
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# invited: They are accepting the invitation
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# joined: It's a NOOP
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if event.user_id != target_user_id:
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raise AuthError(403, "Cannot force another user to join.")
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elif target_banned:
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raise AuthError(403, "You are banned from this room")
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elif join_rule == JoinRules.PUBLIC:
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pass
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elif join_rule == JoinRules.INVITE:
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if not caller_in_room and not caller_invited:
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raise AuthError(403, "You are not invited to this room.")
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else:
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# TODO (erikj): may_join list
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# TODO (erikj): private rooms
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raise AuthError(403, "You are not allowed to join this room")
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elif Membership.LEAVE == membership:
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# TODO (erikj): Implement kicks.
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if target_banned and user_level < ban_level:
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raise AuthError(
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403, "You cannot unban user &s." % (target_user_id,)
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)
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elif target_user_id != event.user_id:
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kick_level = self._get_named_level(auth_events, "kick", 50)
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if user_level < kick_level or user_level <= target_level:
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raise AuthError(
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403, "You cannot kick user %s." % target_user_id
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)
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elif Membership.BAN == membership:
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if user_level < ban_level or user_level <= target_level:
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raise AuthError(403, "You don't have permission to ban")
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else:
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raise AuthError(500, "Unknown membership %s" % membership)
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return True
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def _verify_third_party_invite(self, event, auth_events):
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"""
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Validates that the invite event is authorized by a previous third-party invite.
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Checks that the public key, and keyserver, match those in the third party invite,
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and that the invite event has a signature issued using that public key.
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Args:
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event: The m.room.member join event being validated.
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auth_events: All relevant previous context events which may be used
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for authorization decisions.
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Return:
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True if the event fulfills the expectations of a previous third party
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invite event.
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"""
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if "third_party_invite" not in event.content:
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return False
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if "signed" not in event.content["third_party_invite"]:
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return False
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signed = event.content["third_party_invite"]["signed"]
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for key in {"mxid", "token"}:
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if key not in signed:
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return False
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token = signed["token"]
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invite_event = auth_events.get(
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(EventTypes.ThirdPartyInvite, token,)
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)
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if not invite_event:
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return False
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if event.user_id != invite_event.user_id:
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return False
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try:
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public_key = invite_event.content["public_key"]
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if signed["mxid"] != event.state_key:
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return False
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if signed["token"] != token:
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return False
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for server, signature_block in signed["signatures"].items():
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for key_name, encoded_signature in signature_block.items():
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if not key_name.startswith("ed25519:"):
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return False
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verify_key = decode_verify_key_bytes(
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key_name,
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decode_base64(public_key)
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)
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verify_signed_json(signed, server, verify_key)
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# We got the public key from the invite, so we know that the
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# correct server signed the signed bundle.
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# The caller is responsible for checking that the signing
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# server has not revoked that public key.
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return True
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return False
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except (KeyError, SignatureVerifyException,):
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return False
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def _get_power_level_event(self, auth_events):
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key = (EventTypes.PowerLevels, "", )
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return auth_events.get(key)
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def _get_user_power_level(self, user_id, auth_events):
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power_level_event = self._get_power_level_event(auth_events)
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if power_level_event:
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level = power_level_event.content.get("users", {}).get(user_id)
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if not level:
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level = power_level_event.content.get("users_default", 0)
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if level is None:
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return 0
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else:
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return int(level)
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else:
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key = (EventTypes.Create, "", )
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create_event = auth_events.get(key)
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if (create_event is not None and
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create_event.content["creator"] == user_id):
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return 100
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else:
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return 0
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def _get_named_level(self, auth_events, name, default):
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power_level_event = self._get_power_level_event(auth_events)
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if not power_level_event:
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return default
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level = power_level_event.content.get(name, None)
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if level is not None:
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return int(level)
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else:
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return default
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@defer.inlineCallbacks
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def get_user_by_req(self, request, allow_guest=False):
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""" Get a registered user's ID.
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Args:
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request - An HTTP request with an access_token query parameter.
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Returns:
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tuple of:
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UserID (str)
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Access token ID (str)
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Raises:
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AuthError if no user by that token exists or the token is invalid.
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"""
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# Can optionally look elsewhere in the request (e.g. headers)
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try:
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access_token = request.args["access_token"][0]
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# Check for application service tokens with a user_id override
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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), "", False))
|
|
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"]
|
|
is_guest = user_info["is_guest"]
|
|
|
|
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
|
|
)
|
|
|
|
if is_guest and not allow_guest:
|
|
raise AuthError(
|
|
403, "Guest access not allowed", errcode=Codes.GUEST_ACCESS_FORBIDDEN
|
|
)
|
|
|
|
request.authenticated_entity = user.to_string()
|
|
|
|
defer.returnValue((user, token_id, is_guest,))
|
|
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, "access", False)
|
|
|
|
user_prefix = "user_id = "
|
|
user = None
|
|
guest = False
|
|
for caveat in macaroon.caveats:
|
|
if caveat.caveat_id.startswith(user_prefix):
|
|
user = UserID.from_string(caveat.caveat_id[len(user_prefix):])
|
|
elif caveat.caveat_id == "guest = true":
|
|
guest = True
|
|
|
|
if user is None:
|
|
raise AuthError(
|
|
self.TOKEN_NOT_FOUND_HTTP_STATUS, "No user caveat in macaroon",
|
|
errcode=Codes.UNKNOWN_TOKEN
|
|
)
|
|
|
|
if guest:
|
|
ret = {
|
|
"user": user,
|
|
"is_guest": True,
|
|
"token_id": None,
|
|
}
|
|
else:
|
|
# 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)
|
|
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, type_string, verify_expiry):
|
|
"""
|
|
validate that a Macaroon is understood by and was signed by this server.
|
|
|
|
Args:
|
|
macaroon(pymacaroons.Macaroon): The macaroon to validate
|
|
type_string(str): The kind of token this is (e.g. "access", "refresh")
|
|
verify_expiry(bool): Whether to verify whether the macaroon has expired.
|
|
This should really always be True, but no clients currently implement
|
|
token refresh, so we can't enforce expiry yet.
|
|
"""
|
|
v = pymacaroons.Verifier()
|
|
v.satisfy_exact("gen = 1")
|
|
v.satisfy_exact("type = " + type_string)
|
|
v.satisfy_general(lambda c: c.startswith("user_id = "))
|
|
v.satisfy_exact("guest = true")
|
|
if verify_expiry:
|
|
v.satisfy_general(self._verify_expiry)
|
|
else:
|
|
v.satisfy_general(lambda c: c.startswith("time < "))
|
|
|
|
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
|
|
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),
|
|
"is_guest": False,
|
|
}
|
|
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)
|
|
else:
|
|
if member_event:
|
|
auth_ids.append(member_event.event_id)
|
|
|
|
if e_type == Membership.INVITE:
|
|
if "third_party_invite" in event.content:
|
|
key = (
|
|
EventTypes.ThirdPartyInvite,
|
|
event.content["third_party_invite"]["token"]
|
|
)
|
|
third_party_invite = current_state.get(key)
|
|
if third_party_invite:
|
|
auth_ids.append(third_party_invite.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"
|
|
)
|