mirror of
https://mau.dev/maunium/synapse.git
synced 2024-10-01 01:36:05 -04:00
7eb6e39a8f
This great big stack of commits is a a whole load of hoop-jumping to make it easier to store additional values in login tokens, and then to actually store the SSO Identity Provider in the login token. (Making use of that data will follow in a subsequent PR.)
647 lines
24 KiB
Python
647 lines
24 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014 - 2016 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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import logging
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from typing import List, Optional, Tuple
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import pymacaroons
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from netaddr import IPAddress
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from twisted.web.server import Request
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import synapse.types
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from synapse import event_auth
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from synapse.api.auth_blocking import AuthBlocking
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from synapse.api.constants import EventTypes, HistoryVisibility, Membership
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from synapse.api.errors import (
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AuthError,
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Codes,
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InvalidClientTokenError,
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MissingClientTokenError,
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)
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from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
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from synapse.appservice import ApplicationService
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from synapse.events import EventBase
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from synapse.http import get_request_user_agent
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from synapse.http.site import SynapseRequest
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from synapse.logging import opentracing as opentracing
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from synapse.storage.databases.main.registration import TokenLookupResult
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from synapse.types import StateMap, UserID
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from synapse.util.caches.lrucache import LruCache
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from synapse.util.macaroons import get_value_from_macaroon, satisfy_expiry
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from synapse.util.metrics import Measure
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logger = logging.getLogger(__name__)
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AuthEventTypes = (
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EventTypes.Create,
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EventTypes.Member,
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EventTypes.PowerLevels,
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EventTypes.JoinRules,
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EventTypes.RoomHistoryVisibility,
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EventTypes.ThirdPartyInvite,
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)
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# guests always get this device id.
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GUEST_DEVICE_ID = "guest_device"
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class _InvalidMacaroonException(Exception):
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pass
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class Auth:
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"""
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FIXME: This class contains a mix of functions for authenticating users
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of our client-server API and authenticating events added to room graphs.
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"""
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def __init__(self, hs):
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self.hs = hs
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self.clock = hs.get_clock()
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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_cache = LruCache(
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10000, "token_cache"
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) # type: LruCache[str, Tuple[str, bool]]
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self._auth_blocking = AuthBlocking(self.hs)
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self._account_validity = hs.config.account_validity
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self._track_appservice_user_ips = hs.config.track_appservice_user_ips
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self._macaroon_secret_key = hs.config.macaroon_secret_key
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async def check_from_context(
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self, room_version: str, event, context, do_sig_check=True
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):
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prev_state_ids = await context.get_prev_state_ids()
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auth_events_ids = self.compute_auth_events(
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event, prev_state_ids, for_verification=True
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)
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auth_events = await self.store.get_events(auth_events_ids)
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auth_events = {(e.type, e.state_key): e for e in auth_events.values()}
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room_version_obj = KNOWN_ROOM_VERSIONS[room_version]
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event_auth.check(
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room_version_obj, event, auth_events=auth_events, do_sig_check=do_sig_check
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)
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async def check_user_in_room(
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self,
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room_id: str,
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user_id: str,
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current_state: Optional[StateMap[EventBase]] = None,
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allow_departed_users: bool = False,
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) -> EventBase:
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"""Check if the user is in the room, or was at some point.
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Args:
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room_id: The room to check.
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user_id: The user to check.
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current_state: 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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allow_departed_users: if True, accept users that were previously
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members but have now departed.
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Raises:
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AuthError if the user is/was not in the room.
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Returns:
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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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if current_state:
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member = current_state.get((EventTypes.Member, user_id), None)
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else:
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member = await self.state.get_current_state(
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room_id=room_id, event_type=EventTypes.Member, state_key=user_id
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)
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if member:
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membership = member.membership
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if membership == Membership.JOIN:
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return member
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# XXX this looks totally bogus. Why do we not allow users who have been banned,
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# or those who were members previously and have been re-invited?
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if allow_departed_users and membership == Membership.LEAVE:
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forgot = await self.store.did_forget(user_id, room_id)
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if not forgot:
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return member
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raise AuthError(403, "User %s not in room %s" % (user_id, room_id))
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async def check_host_in_room(self, room_id, host):
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with Measure(self.clock, "check_host_in_room"):
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latest_event_ids = await self.store.is_host_joined(room_id, host)
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return latest_event_ids
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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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def get_public_keys(self, invite_event):
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return event_auth.get_public_keys(invite_event)
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async def get_user_by_req(
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self,
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request: Request,
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allow_guest: bool = False,
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rights: str = "access",
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allow_expired: bool = False,
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) -> synapse.types.Requester:
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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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allow_guest: If False, will raise an AuthError if the user making the
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request is a guest.
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rights: The operation being performed; the access token must allow this
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allow_expired: If True, allow the request through even if the account
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is expired, or session token lifetime has ended. Note that
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/login will deliver access tokens regardless of expiration.
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Returns:
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Resolves to the requester
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Raises:
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InvalidClientCredentialsError if no user by that token exists or the token
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is invalid.
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AuthError if access is denied for the user in the access token
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"""
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try:
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ip_addr = request.getClientIP()
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user_agent = get_request_user_agent(request)
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access_token = self.get_access_token_from_request(request)
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user_id, app_service = await self._get_appservice_user_id(request)
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if user_id:
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if ip_addr and self._track_appservice_user_ips:
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await self.store.insert_client_ip(
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user_id=user_id,
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access_token=access_token,
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ip=ip_addr,
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user_agent=user_agent,
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device_id="dummy-device", # stubbed
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)
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requester = synapse.types.create_requester(
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user_id, app_service=app_service
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)
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request.requester = user_id
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opentracing.set_tag("authenticated_entity", user_id)
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opentracing.set_tag("user_id", user_id)
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opentracing.set_tag("appservice_id", app_service.id)
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return requester
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user_info = await self.get_user_by_access_token(
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access_token, rights, allow_expired=allow_expired
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)
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token_id = user_info.token_id
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is_guest = user_info.is_guest
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shadow_banned = user_info.shadow_banned
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# Deny the request if the user account has expired.
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if self._account_validity.enabled and not allow_expired:
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if await self.store.is_account_expired(
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user_info.user_id, self.clock.time_msec()
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):
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raise AuthError(
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403, "User account has expired", errcode=Codes.EXPIRED_ACCOUNT
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)
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device_id = user_info.device_id
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if access_token and ip_addr:
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await self.store.insert_client_ip(
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user_id=user_info.token_owner,
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access_token=access_token,
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ip=ip_addr,
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user_agent=user_agent,
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device_id=device_id,
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)
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if is_guest and not allow_guest:
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raise AuthError(
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403,
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"Guest access not allowed",
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errcode=Codes.GUEST_ACCESS_FORBIDDEN,
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)
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requester = synapse.types.create_requester(
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user_info.user_id,
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token_id,
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is_guest,
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shadow_banned,
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device_id,
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app_service=app_service,
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authenticated_entity=user_info.token_owner,
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)
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request.requester = requester
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opentracing.set_tag("authenticated_entity", user_info.token_owner)
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opentracing.set_tag("user_id", user_info.user_id)
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if device_id:
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opentracing.set_tag("device_id", device_id)
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return requester
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except KeyError:
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raise MissingClientTokenError()
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async def _get_appservice_user_id(self, request):
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app_service = self.store.get_app_service_by_token(
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self.get_access_token_from_request(request)
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)
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if app_service is None:
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return None, None
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if app_service.ip_range_whitelist:
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ip_address = IPAddress(request.getClientIP())
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if ip_address not in app_service.ip_range_whitelist:
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return None, None
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if b"user_id" not in request.args:
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return app_service.sender, app_service
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user_id = request.args[b"user_id"][0].decode("utf8")
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if app_service.sender == user_id:
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return app_service.sender, app_service
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if not app_service.is_interested_in_user(user_id):
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raise AuthError(403, "Application service cannot masquerade as this user.")
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if not (await self.store.get_user_by_id(user_id)):
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raise AuthError(403, "Application service has not registered this user")
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return user_id, app_service
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async def get_user_by_access_token(
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self,
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token: str,
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rights: str = "access",
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allow_expired: bool = False,
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) -> TokenLookupResult:
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"""Validate access token and get user_id from it
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Args:
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token: The access token to get the user by
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rights: The operation being performed; the access token must
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allow this
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allow_expired: If False, raises an InvalidClientTokenError
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if the token is expired
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Raises:
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InvalidClientTokenError if a user by that token exists, but the token is
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expired
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InvalidClientCredentialsError if no user by that token exists or the token
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is invalid
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"""
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if rights == "access":
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# first look in the database
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r = await self.store.get_user_by_access_token(token)
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if r:
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valid_until_ms = r.valid_until_ms
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if (
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not allow_expired
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and valid_until_ms is not None
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and valid_until_ms < self.clock.time_msec()
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):
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# there was a valid access token, but it has expired.
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# soft-logout the user.
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raise InvalidClientTokenError(
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msg="Access token has expired", soft_logout=True
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)
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return r
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# otherwise it needs to be a valid macaroon
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try:
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user_id, guest = self._parse_and_validate_macaroon(token, rights)
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if rights == "access":
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if not guest:
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# non-guest access tokens must be in the database
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logger.warning("Unrecognised access token - not in store.")
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raise InvalidClientTokenError()
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# Guest access tokens are not stored in the database (there can
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# only be one access token per guest, anyway).
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#
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# In order to prevent guest access tokens being used as regular
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# user access tokens (and hence getting around the invalidation
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# process), we look up the user id and check that it is indeed
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# a guest user.
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#
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# It would of course be much easier to store guest access
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# tokens in the database as well, but that would break existing
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# guest tokens.
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stored_user = await self.store.get_user_by_id(user_id)
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if not stored_user:
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raise InvalidClientTokenError("Unknown user_id %s" % user_id)
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if not stored_user["is_guest"]:
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raise InvalidClientTokenError(
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"Guest access token used for regular user"
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)
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ret = TokenLookupResult(
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user_id=user_id,
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is_guest=True,
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# all guests get the same device id
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device_id=GUEST_DEVICE_ID,
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)
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elif rights == "delete_pusher":
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# We don't store these tokens in the database
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ret = TokenLookupResult(user_id=user_id, is_guest=False)
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else:
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raise RuntimeError("Unknown rights setting %s", rights)
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return ret
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except (
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_InvalidMacaroonException,
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pymacaroons.exceptions.MacaroonException,
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TypeError,
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ValueError,
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) as e:
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logger.warning("Invalid macaroon in auth: %s %s", type(e), e)
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raise InvalidClientTokenError("Invalid macaroon passed.")
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def _parse_and_validate_macaroon(self, token, rights="access"):
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"""Takes a macaroon and tries to parse and validate it. This is cached
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if and only if rights == access and there isn't an expiry.
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On invalid macaroon raises _InvalidMacaroonException
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Returns:
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(user_id, is_guest)
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"""
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if rights == "access":
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cached = self.token_cache.get(token, None)
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if cached:
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return cached
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try:
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macaroon = pymacaroons.Macaroon.deserialize(token)
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except Exception: # deserialize can throw more-or-less anything
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# doesn't look like a macaroon: treat it as an opaque token which
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# must be in the database.
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# TODO: it would be nice to get rid of this, but apparently some
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# people use access tokens which aren't macaroons
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raise _InvalidMacaroonException()
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try:
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user_id = get_value_from_macaroon(macaroon, "user_id")
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guest = False
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for caveat in macaroon.caveats:
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if caveat.caveat_id == "guest = true":
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guest = True
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self.validate_macaroon(macaroon, rights, user_id=user_id)
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except (
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pymacaroons.exceptions.MacaroonException,
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KeyError,
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TypeError,
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ValueError,
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):
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raise InvalidClientTokenError("Invalid macaroon passed.")
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if rights == "access":
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self.token_cache[token] = (user_id, guest)
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return user_id, guest
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def validate_macaroon(self, macaroon, type_string, user_id):
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"""
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validate that a Macaroon is understood by and was signed by this server.
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Args:
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macaroon(pymacaroons.Macaroon): The macaroon to validate
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type_string(str): The kind of token required (e.g. "access",
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"delete_pusher")
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user_id (str): The user_id required
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"""
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v = pymacaroons.Verifier()
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# the verifier runs a test for every caveat on the macaroon, to check
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# that it is met for the current request. Each caveat must match at
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# least one of the predicates specified by satisfy_exact or
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# specify_general.
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v.satisfy_exact("gen = 1")
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v.satisfy_exact("type = " + type_string)
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v.satisfy_exact("user_id = %s" % user_id)
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v.satisfy_exact("guest = true")
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satisfy_expiry(v, self.clock.time_msec)
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# access_tokens include a nonce for uniqueness: any value is acceptable
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v.satisfy_general(lambda c: c.startswith("nonce = "))
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v.verify(macaroon, self._macaroon_secret_key)
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def get_appservice_by_req(self, request: SynapseRequest) -> ApplicationService:
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token = self.get_access_token_from_request(request)
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service = self.store.get_app_service_by_token(token)
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if not service:
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logger.warning("Unrecognised appservice access token.")
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raise InvalidClientTokenError()
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request.requester = synapse.types.create_requester(
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service.sender, app_service=service
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)
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return service
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async def is_server_admin(self, user: UserID) -> bool:
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"""Check if the given user is a local server admin.
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Args:
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user: user to check
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Returns:
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True if the user is an admin
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"""
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return await self.store.is_server_admin(user)
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def compute_auth_events(
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self,
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event,
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current_state_ids: StateMap[str],
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for_verification: bool = False,
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) -> List[str]:
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"""Given an event and current state return the list of event IDs used
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to auth an event.
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If `for_verification` is False then only return auth events that
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should be added to the event's `auth_events`.
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Returns:
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List of event IDs.
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"""
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if event.type == EventTypes.Create:
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return []
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# Currently we ignore the `for_verification` flag even though there are
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# some situations where we can drop particular auth events when adding
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# to the event's `auth_events` (e.g. joins pointing to previous joins
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# when room is publicly joinable). Dropping event IDs has the
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# advantage that the auth chain for the room grows slower, but we use
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# the auth chain in state resolution v2 to order events, which means
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# care must be taken if dropping events to ensure that it doesn't
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# introduce undesirable "state reset" behaviour.
|
|
#
|
|
# All of which sounds a bit tricky so we don't bother for now.
|
|
|
|
auth_ids = []
|
|
for etype, state_key in event_auth.auth_types_for_event(event):
|
|
auth_ev_id = current_state_ids.get((etype, state_key))
|
|
if auth_ev_id:
|
|
auth_ids.append(auth_ev_id)
|
|
|
|
return auth_ids
|
|
|
|
async def check_can_change_room_list(self, room_id: str, user: UserID):
|
|
"""Determine whether the user is allowed to edit the room's entry in the
|
|
published room list.
|
|
|
|
Args:
|
|
room_id
|
|
user
|
|
"""
|
|
|
|
is_admin = await self.is_server_admin(user)
|
|
if is_admin:
|
|
return True
|
|
|
|
user_id = user.to_string()
|
|
await self.check_user_in_room(room_id, user_id)
|
|
|
|
# We currently require the user is a "moderator" in the room. We do this
|
|
# by checking if they would (theoretically) be able to change the
|
|
# m.room.canonical_alias events
|
|
power_level_event = await self.state.get_current_state(
|
|
room_id, EventTypes.PowerLevels, ""
|
|
)
|
|
|
|
auth_events = {}
|
|
if power_level_event:
|
|
auth_events[(EventTypes.PowerLevels, "")] = power_level_event
|
|
|
|
send_level = event_auth.get_send_level(
|
|
EventTypes.CanonicalAlias, "", power_level_event
|
|
)
|
|
user_level = event_auth.get_user_power_level(user_id, auth_events)
|
|
|
|
return user_level >= send_level
|
|
|
|
@staticmethod
|
|
def has_access_token(request: Request):
|
|
"""Checks if the request has an access_token.
|
|
|
|
Returns:
|
|
bool: False if no access_token was given, True otherwise.
|
|
"""
|
|
query_params = request.args.get(b"access_token")
|
|
auth_headers = request.requestHeaders.getRawHeaders(b"Authorization")
|
|
return bool(query_params) or bool(auth_headers)
|
|
|
|
@staticmethod
|
|
def get_access_token_from_request(request: Request):
|
|
"""Extracts the access_token from the request.
|
|
|
|
Args:
|
|
request: The http request.
|
|
Returns:
|
|
unicode: The access_token
|
|
Raises:
|
|
MissingClientTokenError: If there isn't a single access_token in the
|
|
request
|
|
"""
|
|
|
|
auth_headers = request.requestHeaders.getRawHeaders(b"Authorization")
|
|
query_params = request.args.get(b"access_token")
|
|
if auth_headers:
|
|
# Try the get the access_token from a "Authorization: Bearer"
|
|
# header
|
|
if query_params is not None:
|
|
raise MissingClientTokenError(
|
|
"Mixing Authorization headers and access_token query parameters."
|
|
)
|
|
if len(auth_headers) > 1:
|
|
raise MissingClientTokenError("Too many Authorization headers.")
|
|
parts = auth_headers[0].split(b" ")
|
|
if parts[0] == b"Bearer" and len(parts) == 2:
|
|
return parts[1].decode("ascii")
|
|
else:
|
|
raise MissingClientTokenError("Invalid Authorization header.")
|
|
else:
|
|
# Try to get the access_token from the query params.
|
|
if not query_params:
|
|
raise MissingClientTokenError()
|
|
|
|
return query_params[0].decode("ascii")
|
|
|
|
async def check_user_in_room_or_world_readable(
|
|
self, room_id: str, user_id: str, allow_departed_users: bool = False
|
|
) -> Tuple[str, Optional[str]]:
|
|
"""Checks that the user is or was in the room or the room is world
|
|
readable. If it isn't then an exception is raised.
|
|
|
|
Args:
|
|
room_id: room to check
|
|
user_id: user to check
|
|
allow_departed_users: if True, accept users that were previously
|
|
members but have now departed
|
|
|
|
Returns:
|
|
Resolves to the current membership of the user in the room and the
|
|
membership event ID of the user. If the user is not in the room and
|
|
never has been, then `(Membership.JOIN, None)` is returned.
|
|
"""
|
|
|
|
try:
|
|
# check_user_in_room will return the most recent membership
|
|
# event for the user if:
|
|
# * The user is a non-guest user, and was ever in the room
|
|
# * The user is a guest user, and has joined the room
|
|
# else it will throw.
|
|
member_event = await self.check_user_in_room(
|
|
room_id, user_id, allow_departed_users=allow_departed_users
|
|
)
|
|
return member_event.membership, member_event.event_id
|
|
except AuthError:
|
|
visibility = await self.state.get_current_state(
|
|
room_id, EventTypes.RoomHistoryVisibility, ""
|
|
)
|
|
if (
|
|
visibility
|
|
and visibility.content.get("history_visibility")
|
|
== HistoryVisibility.WORLD_READABLE
|
|
):
|
|
return Membership.JOIN, None
|
|
raise AuthError(
|
|
403,
|
|
"User %s not in room %s, and room previews are disabled"
|
|
% (user_id, room_id),
|
|
)
|
|
|
|
def check_auth_blocking(self, *args, **kwargs):
|
|
return self._auth_blocking.check_auth_blocking(*args, **kwargs)
|