448 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			448 lines
		
	
	
		
			16 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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| 
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| from twisted.internet import defer
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| 
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| from ._base import BaseHandler
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| from synapse.api.constants import LoginType
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| from synapse.types import UserID
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| from synapse.api.errors import LoginError, Codes
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| from synapse.util.async import run_on_reactor
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| 
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| from twisted.web.client import PartialDownloadError
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| 
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| import logging
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| import bcrypt
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| import pymacaroons
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| import simplejson
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| 
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| import synapse.util.stringutils as stringutils
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| 
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| 
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| logger = logging.getLogger(__name__)
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| 
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| 
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| class AuthHandler(BaseHandler):
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| 
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|     def __init__(self, hs):
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|         super(AuthHandler, self).__init__(hs)
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|         self.checkers = {
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|             LoginType.PASSWORD: self._check_password_auth,
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|             LoginType.RECAPTCHA: self._check_recaptcha,
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|             LoginType.EMAIL_IDENTITY: self._check_email_identity,
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|             LoginType.DUMMY: self._check_dummy_auth,
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|         }
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|         self.sessions = {}
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| 
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|     @defer.inlineCallbacks
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|     def check_auth(self, flows, clientdict, clientip):
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|         """
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|         Takes a dictionary sent by the client in the login / registration
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|         protocol and handles the login flow.
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| 
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|         As a side effect, this function fills in the 'creds' key on the user's
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|         session with a map, which maps each auth-type (str) to the relevant
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|         identity authenticated by that auth-type (mostly str, but for captcha, bool).
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| 
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|         Args:
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|             flows (list): A list of login flows. Each flow is an ordered list of
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|                           strings representing auth-types. At least one full
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|                           flow must be completed in order for auth to be successful.
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|             clientdict: The dictionary from the client root level, not the
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|                         'auth' key: this method prompts for auth if none is sent.
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|             clientip (str): The IP address of the client.
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|         Returns:
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|             A tuple of (authed, dict, dict) where authed is true if the client
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|             has successfully completed an auth flow. If it is true, the first
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|             dict contains the authenticated credentials of each stage.
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| 
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|             If authed is false, the first dictionary is the server response to
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|             the login request and should be passed back to the client.
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| 
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|             In either case, the second dict contains the parameters for this
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|             request (which may have been given only in a previous call).
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|         """
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| 
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|         authdict = None
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|         sid = None
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|         if clientdict and 'auth' in clientdict:
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|             authdict = clientdict['auth']
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|             del clientdict['auth']
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|             if 'session' in authdict:
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|                 sid = authdict['session']
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|         session = self._get_session_info(sid)
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| 
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|         if len(clientdict) > 0:
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|             # This was designed to allow the client to omit the parameters
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|             # and just supply the session in subsequent calls so it split
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|             # auth between devices by just sharing the session, (eg. so you
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|             # could continue registration from your phone having clicked the
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|             # email auth link on there). It's probably too open to abuse
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|             # because it lets unauthenticated clients store arbitrary objects
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|             # on a home server.
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|             # Revisit: Assumimg the REST APIs do sensible validation, the data
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|             # isn't arbintrary.
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|             session['clientdict'] = clientdict
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|             self._save_session(session)
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|         elif 'clientdict' in session:
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|             clientdict = session['clientdict']
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| 
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|         if not authdict:
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|             defer.returnValue(
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|                 (False, self._auth_dict_for_flows(flows, session), clientdict)
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|             )
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| 
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|         if 'creds' not in session:
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|             session['creds'] = {}
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|         creds = session['creds']
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| 
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|         # check auth type currently being presented
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|         if 'type' in authdict:
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|             if authdict['type'] not in self.checkers:
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|                 raise LoginError(400, "", Codes.UNRECOGNIZED)
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|             result = yield self.checkers[authdict['type']](authdict, clientip)
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|             if result:
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|                 creds[authdict['type']] = result
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|                 self._save_session(session)
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| 
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|         for f in flows:
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|             if len(set(f) - set(creds.keys())) == 0:
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|                 logger.info("Auth completed with creds: %r", creds)
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|                 self._remove_session(session)
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|                 defer.returnValue((True, creds, clientdict))
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| 
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|         ret = self._auth_dict_for_flows(flows, session)
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|         ret['completed'] = creds.keys()
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|         defer.returnValue((False, ret, clientdict))
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| 
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|     @defer.inlineCallbacks
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|     def add_oob_auth(self, stagetype, authdict, clientip):
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|         """
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|         Adds the result of out-of-band authentication into an existing auth
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|         session. Currently used for adding the result of fallback auth.
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|         """
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|         if stagetype not in self.checkers:
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|             raise LoginError(400, "", Codes.MISSING_PARAM)
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|         if 'session' not in authdict:
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|             raise LoginError(400, "", Codes.MISSING_PARAM)
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| 
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|         sess = self._get_session_info(
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|             authdict['session']
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|         )
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|         if 'creds' not in sess:
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|             sess['creds'] = {}
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|         creds = sess['creds']
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| 
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|         result = yield self.checkers[stagetype](authdict, clientip)
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|         if result:
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|             creds[stagetype] = result
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|             self._save_session(sess)
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|             defer.returnValue(True)
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|         defer.returnValue(False)
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| 
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|     @defer.inlineCallbacks
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|     def _check_password_auth(self, authdict, _):
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|         if "user" not in authdict or "password" not in authdict:
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|             raise LoginError(400, "", Codes.MISSING_PARAM)
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| 
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|         user_id = authdict["user"]
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|         password = authdict["password"]
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|         if not user_id.startswith('@'):
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|             user_id = UserID.create(user_id, self.hs.hostname).to_string()
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| 
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|         user_id, password_hash = yield self._find_user_id_and_pwd_hash(user_id)
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|         self._check_password(user_id, password, password_hash)
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|         defer.returnValue(user_id)
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| 
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|     @defer.inlineCallbacks
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|     def _check_recaptcha(self, authdict, clientip):
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|         try:
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|             user_response = authdict["response"]
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|         except KeyError:
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|             # Client tried to provide captcha but didn't give the parameter:
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|             # bad request.
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|             raise LoginError(
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|                 400, "Captcha response is required",
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|                 errcode=Codes.CAPTCHA_NEEDED
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|             )
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| 
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|         logger.info(
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|             "Submitting recaptcha response %s with remoteip %s",
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|             user_response, clientip
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|         )
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| 
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|         # TODO: get this from the homeserver rather than creating a new one for
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|         # each request
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|         try:
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|             client = self.hs.get_simple_http_client()
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|             resp_body = yield client.post_urlencoded_get_json(
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|                 self.hs.config.recaptcha_siteverify_api,
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|                 args={
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|                     'secret': self.hs.config.recaptcha_private_key,
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|                     'response': user_response,
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|                     'remoteip': clientip,
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|                 }
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|             )
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|         except PartialDownloadError as pde:
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|             # Twisted is silly
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|             data = pde.response
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|             resp_body = simplejson.loads(data)
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| 
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|         if 'success' in resp_body and resp_body['success']:
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|             defer.returnValue(True)
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|         raise LoginError(401, "", errcode=Codes.UNAUTHORIZED)
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| 
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|     @defer.inlineCallbacks
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|     def _check_email_identity(self, authdict, _):
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|         yield run_on_reactor()
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| 
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|         if 'threepid_creds' not in authdict:
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|             raise LoginError(400, "Missing threepid_creds", Codes.MISSING_PARAM)
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| 
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|         threepid_creds = authdict['threepid_creds']
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|         identity_handler = self.hs.get_handlers().identity_handler
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| 
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|         logger.info("Getting validated threepid. threepidcreds: %r" % (threepid_creds,))
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|         threepid = yield identity_handler.threepid_from_creds(threepid_creds)
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| 
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|         if not threepid:
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|             raise LoginError(401, "", errcode=Codes.UNAUTHORIZED)
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| 
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|         threepid['threepid_creds'] = authdict['threepid_creds']
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| 
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|         defer.returnValue(threepid)
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| 
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|     @defer.inlineCallbacks
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|     def _check_dummy_auth(self, authdict, _):
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|         yield run_on_reactor()
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|         defer.returnValue(True)
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| 
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|     def _get_params_recaptcha(self):
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|         return {"public_key": self.hs.config.recaptcha_public_key}
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| 
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|     def _auth_dict_for_flows(self, flows, session):
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|         public_flows = []
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|         for f in flows:
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|             public_flows.append(f)
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| 
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|         get_params = {
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|             LoginType.RECAPTCHA: self._get_params_recaptcha,
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|         }
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| 
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|         params = {}
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| 
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|         for f in public_flows:
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|             for stage in f:
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|                 if stage in get_params and stage not in params:
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|                     params[stage] = get_params[stage]()
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| 
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|         return {
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|             "session": session['id'],
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|             "flows": [{"stages": f} for f in public_flows],
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|             "params": params
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|         }
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| 
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|     def _get_session_info(self, session_id):
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|         if session_id not in self.sessions:
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|             session_id = None
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| 
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|         if not session_id:
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|             # create a new session
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|             while session_id is None or session_id in self.sessions:
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|                 session_id = stringutils.random_string(24)
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|             self.sessions[session_id] = {
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|                 "id": session_id,
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|             }
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| 
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|         return self.sessions[session_id]
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| 
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|     @defer.inlineCallbacks
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|     def login_with_password(self, user_id, password):
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|         """
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|         Authenticates the user with their username and password.
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| 
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|         Used only by the v1 login API.
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| 
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|         Args:
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|             user_id (str): User ID
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|             password (str): Password
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|         Returns:
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|             A tuple of:
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|               The user's ID.
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|               The access token for the user's session.
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|               The refresh token for the user's session.
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|         Raises:
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|             StoreError if there was a problem storing the token.
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|             LoginError if there was an authentication problem.
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|         """
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|         user_id, password_hash = yield self._find_user_id_and_pwd_hash(user_id)
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|         self._check_password(user_id, password, password_hash)
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| 
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|         logger.info("Logging in user %s", user_id)
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|         access_token = yield self.issue_access_token(user_id)
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|         refresh_token = yield self.issue_refresh_token(user_id)
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|         defer.returnValue((user_id, access_token, refresh_token))
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| 
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|     @defer.inlineCallbacks
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|     def login_with_cas_user_id(self, user_id):
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|         """
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|         Authenticates the user with the given user ID,
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|         intended to have been captured from a CAS response
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| 
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|         Args:
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|             user_id (str): User ID
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|         Returns:
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|             A tuple of:
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|               The user's ID.
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|               The access token for the user's session.
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|               The refresh token for the user's session.
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|         Raises:
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|             StoreError if there was a problem storing the token.
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|             LoginError if there was an authentication problem.
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|         """
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|         user_id, ignored = yield self._find_user_id_and_pwd_hash(user_id)
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| 
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|         logger.info("Logging in user %s", user_id)
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|         access_token = yield self.issue_access_token(user_id)
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|         refresh_token = yield self.issue_refresh_token(user_id)
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|         defer.returnValue((user_id, access_token, refresh_token))
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| 
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|     @defer.inlineCallbacks
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|     def does_user_exist(self, user_id):
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|         try:
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|             yield self._find_user_id_and_pwd_hash(user_id)
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|             defer.returnValue(True)
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|         except LoginError:
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|             defer.returnValue(False)
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| 
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|     @defer.inlineCallbacks
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|     def _find_user_id_and_pwd_hash(self, user_id):
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|         """Checks to see if a user with the given id exists. Will check case
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|         insensitively, but will throw if there are multiple inexact matches.
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| 
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|         Returns:
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|             tuple: A 2-tuple of `(canonical_user_id, password_hash)`
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|         """
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|         user_infos = yield self.store.get_users_by_id_case_insensitive(user_id)
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|         if not user_infos:
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|             logger.warn("Attempted to login as %s but they do not exist", user_id)
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|             raise LoginError(403, "", errcode=Codes.FORBIDDEN)
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| 
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|         if len(user_infos) > 1:
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|             if user_id not in user_infos:
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|                 logger.warn(
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|                     "Attempted to login as %s but it matches more than one user "
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|                     "inexactly: %r",
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|                     user_id, user_infos.keys()
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|                 )
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|                 raise LoginError(403, "", errcode=Codes.FORBIDDEN)
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| 
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|             defer.returnValue((user_id, user_infos[user_id]))
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|         else:
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|             defer.returnValue(user_infos.popitem())
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| 
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|     def _check_password(self, user_id, password, stored_hash):
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|         """Checks that user_id has passed password, raises LoginError if not."""
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|         if not self.validate_hash(password, stored_hash):
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|             logger.warn("Failed password login for user %s", user_id)
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|             raise LoginError(403, "", errcode=Codes.FORBIDDEN)
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| 
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|     @defer.inlineCallbacks
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|     def issue_access_token(self, user_id):
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|         access_token = self.generate_access_token(user_id)
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|         yield self.store.add_access_token_to_user(user_id, access_token)
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|         defer.returnValue(access_token)
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| 
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|     @defer.inlineCallbacks
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|     def issue_refresh_token(self, user_id):
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|         refresh_token = self.generate_refresh_token(user_id)
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|         yield self.store.add_refresh_token_to_user(user_id, refresh_token)
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|         defer.returnValue(refresh_token)
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| 
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|     def generate_access_token(self, user_id):
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|         macaroon = self._generate_base_macaroon(user_id)
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|         macaroon.add_first_party_caveat("type = access")
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|         now = self.hs.get_clock().time_msec()
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|         expiry = now + (60 * 60 * 1000)
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|         macaroon.add_first_party_caveat("time < %d" % (expiry,))
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|         return macaroon.serialize()
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| 
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|     def generate_refresh_token(self, user_id):
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|         m = self._generate_base_macaroon(user_id)
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|         m.add_first_party_caveat("type = refresh")
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|         # Important to add a nonce, because otherwise every refresh token for a
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|         # user will be the same.
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|         m.add_first_party_caveat("nonce = %s" % (
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|             stringutils.random_string_with_symbols(16),
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|         ))
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|         return m.serialize()
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| 
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|     def _generate_base_macaroon(self, user_id):
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|         macaroon = pymacaroons.Macaroon(
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|             location=self.hs.config.server_name,
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|             identifier="key",
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|             key=self.hs.config.macaroon_secret_key)
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|         macaroon.add_first_party_caveat("gen = 1")
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|         macaroon.add_first_party_caveat("user_id = %s" % (user_id,))
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|         return macaroon
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| 
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|     @defer.inlineCallbacks
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|     def set_password(self, user_id, newpassword):
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|         password_hash = self.hash(newpassword)
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| 
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|         yield self.store.user_set_password_hash(user_id, password_hash)
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|         yield self.store.user_delete_access_tokens(user_id)
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|         yield self.hs.get_pusherpool().remove_pushers_by_user(user_id)
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|         yield self.store.flush_user(user_id)
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| 
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|     @defer.inlineCallbacks
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|     def add_threepid(self, user_id, medium, address, validated_at):
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|         yield self.store.user_add_threepid(
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|             user_id, medium, address, validated_at,
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|             self.hs.get_clock().time_msec()
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|         )
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| 
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|     def _save_session(self, session):
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|         # TODO: Persistent storage
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|         logger.debug("Saving session %s", session)
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|         self.sessions[session["id"]] = session
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| 
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|     def _remove_session(self, session):
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|         logger.debug("Removing session %s", session)
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|         del self.sessions[session["id"]]
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| 
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|     def hash(self, password):
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|         """Computes a secure hash of password.
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| 
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|         Args:
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|             password (str): Password to hash.
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| 
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|         Returns:
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|             Hashed password (str).
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|         """
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|         return bcrypt.hashpw(password, bcrypt.gensalt())
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| 
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|     def validate_hash(self, password, stored_hash):
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|         """Validates that self.hash(password) == stored_hash.
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| 
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|         Args:
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|             password (str): Password to hash.
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|             stored_hash (str): Expected hash value.
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| 
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|         Returns:
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|             Whether self.hash(password) == stored_hash (bool).
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|         """
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|         return bcrypt.checkpw(password, stored_hash)
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