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Diffstat (limited to 'synapse/handlers/auth.py')
| -rw-r--r-- | synapse/handlers/auth.py | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py new file mode 100644 index 00000000..be157e2b --- /dev/null +++ b/synapse/handlers/auth.py @@ -0,0 +1,480 @@ +# -*- coding: utf-8 -*- +# Copyright 2014, 2015 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from twisted.internet import defer + +from ._base import BaseHandler +from synapse.api.constants import LoginType +from synapse.types import UserID +from synapse.api.errors import AuthError, LoginError, Codes +from synapse.util.async import run_on_reactor + +from twisted.web.client import PartialDownloadError + +import logging +import bcrypt +import pymacaroons +import simplejson + +import synapse.util.stringutils as stringutils + + +logger = logging.getLogger(__name__) + + +class AuthHandler(BaseHandler): + + def __init__(self, hs): + super(AuthHandler, self).__init__(hs) + self.checkers = { + LoginType.PASSWORD: self._check_password_auth, + LoginType.RECAPTCHA: self._check_recaptcha, + LoginType.EMAIL_IDENTITY: self._check_email_identity, + LoginType.DUMMY: self._check_dummy_auth, + } + self.bcrypt_rounds = hs.config.bcrypt_rounds + self.sessions = {} + self.INVALID_TOKEN_HTTP_STATUS = 401 + + @defer.inlineCallbacks + def check_auth(self, flows, clientdict, clientip): + """ + Takes a dictionary sent by the client in the login / registration + protocol and handles the login flow. + + As a side effect, this function fills in the 'creds' key on the user's + session with a map, which maps each auth-type (str) to the relevant + identity authenticated by that auth-type (mostly str, but for captcha, bool). + + Args: + flows (list): A list of login flows. Each flow is an ordered list of + strings representing auth-types. At least one full + flow must be completed in order for auth to be successful. + clientdict: The dictionary from the client root level, not the + 'auth' key: this method prompts for auth if none is sent. + clientip (str): The IP address of the client. + Returns: + A tuple of (authed, dict, dict) where authed is true if the client + has successfully completed an auth flow. If it is true, the first + dict contains the authenticated credentials of each stage. + + If authed is false, the first dictionary is the server response to + the login request and should be passed back to the client. + + In either case, the second dict contains the parameters for this + request (which may have been given only in a previous call). + """ + + authdict = None + sid = None + if clientdict and 'auth' in clientdict: + authdict = clientdict['auth'] + del clientdict['auth'] + if 'session' in authdict: + sid = authdict['session'] + session = self._get_session_info(sid) + + if len(clientdict) > 0: + # This was designed to allow the client to omit the parameters + # and just supply the session in subsequent calls so it split + # auth between devices by just sharing the session, (eg. so you + # could continue registration from your phone having clicked the + # email auth link on there). It's probably too open to abuse + # because it lets unauthenticated clients store arbitrary objects + # on a home server. + # Revisit: Assumimg the REST APIs do sensible validation, the data + # isn't arbintrary. + session['clientdict'] = clientdict + self._save_session(session) + elif 'clientdict' in session: + clientdict = session['clientdict'] + + if not authdict: + defer.returnValue( + (False, self._auth_dict_for_flows(flows, session), clientdict) + ) + + if 'creds' not in session: + session['creds'] = {} + creds = session['creds'] + + # check auth type currently being presented + if 'type' in authdict: + if authdict['type'] not in self.checkers: + raise LoginError(400, "", Codes.UNRECOGNIZED) + result = yield self.checkers[authdict['type']](authdict, clientip) + if result: + creds[authdict['type']] = result + self._save_session(session) + + for f in flows: + if len(set(f) - set(creds.keys())) == 0: + logger.info("Auth completed with creds: %r", creds) + self._remove_session(session) + defer.returnValue((True, creds, clientdict)) + + ret = self._auth_dict_for_flows(flows, session) + ret['completed'] = creds.keys() + defer.returnValue((False, ret, clientdict)) + + @defer.inlineCallbacks + def add_oob_auth(self, stagetype, authdict, clientip): + """ + Adds the result of out-of-band authentication into an existing auth + session. Currently used for adding the result of fallback auth. + """ + if stagetype not in self.checkers: + raise LoginError(400, "", Codes.MISSING_PARAM) + if 'session' not in authdict: + raise LoginError(400, "", Codes.MISSING_PARAM) + + sess = self._get_session_info( + authdict['session'] + ) + if 'creds' not in sess: + sess['creds'] = {} + creds = sess['creds'] + + result = yield self.checkers[stagetype](authdict, clientip) + if result: + creds[stagetype] = result + self._save_session(sess) + defer.returnValue(True) + defer.returnValue(False) + + @defer.inlineCallbacks + def _check_password_auth(self, authdict, _): + if "user" not in authdict or "password" not in authdict: + raise LoginError(400, "", Codes.MISSING_PARAM) + + user_id = authdict["user"] + password = authdict["password"] + if not user_id.startswith('@'): + user_id = UserID.create(user_id, self.hs.hostname).to_string() + + user_id, password_hash = yield self._find_user_id_and_pwd_hash(user_id) + self._check_password(user_id, password, password_hash) + defer.returnValue(user_id) + + @defer.inlineCallbacks + def _check_recaptcha(self, authdict, clientip): + try: + user_response = authdict["response"] + except KeyError: + # Client tried to provide captcha but didn't give the parameter: + # bad request. + raise LoginError( + 400, "Captcha response is required", + errcode=Codes.CAPTCHA_NEEDED + ) + + logger.info( + "Submitting recaptcha response %s with remoteip %s", + user_response, clientip + ) + + # TODO: get this from the homeserver rather than creating a new one for + # each request + try: + client = self.hs.get_simple_http_client() + resp_body = yield client.post_urlencoded_get_json( + self.hs.config.recaptcha_siteverify_api, + args={ + 'secret': self.hs.config.recaptcha_private_key, + 'response': user_response, + 'remoteip': clientip, + } + ) + except PartialDownloadError as pde: + # Twisted is silly + data = pde.response + resp_body = simplejson.loads(data) + + if 'success' in resp_body and resp_body['success']: + defer.returnValue(True) + raise LoginError(401, "", errcode=Codes.UNAUTHORIZED) + + @defer.inlineCallbacks + def _check_email_identity(self, authdict, _): + yield run_on_reactor() + + if 'threepid_creds' not in authdict: + raise LoginError(400, "Missing threepid_creds", Codes.MISSING_PARAM) + + threepid_creds = authdict['threepid_creds'] + identity_handler = self.hs.get_handlers().identity_handler + + logger.info("Getting validated threepid. threepidcreds: %r" % (threepid_creds,)) + threepid = yield identity_handler.threepid_from_creds(threepid_creds) + + if not threepid: + raise LoginError(401, "", errcode=Codes.UNAUTHORIZED) + + threepid['threepid_creds'] = authdict['threepid_creds'] + + defer.returnValue(threepid) + + @defer.inlineCallbacks + def _check_dummy_auth(self, authdict, _): + yield run_on_reactor() + defer.returnValue(True) + + def _get_params_recaptcha(self): + return {"public_key": self.hs.config.recaptcha_public_key} + + def _auth_dict_for_flows(self, flows, session): + public_flows = [] + for f in flows: + public_flows.append(f) + + get_params = { + LoginType.RECAPTCHA: self._get_params_recaptcha, + } + + params = {} + + for f in public_flows: + for stage in f: + if stage in get_params and stage not in params: + params[stage] = get_params[stage]() + + return { + "session": session['id'], + "flows": [{"stages": f} for f in public_flows], + "params": params + } + + def _get_session_info(self, session_id): + if session_id not in self.sessions: + session_id = None + + if not session_id: + # create a new session + while session_id is None or session_id in self.sessions: + session_id = stringutils.random_string(24) + self.sessions[session_id] = { + "id": session_id, + } + + return self.sessions[session_id] + + @defer.inlineCallbacks + def login_with_password(self, user_id, password): + """ + Authenticates the user with their username and password. + + Used only by the v1 login API. + + Args: + user_id (str): User ID + password (str): Password + Returns: + A tuple of: + The user's ID. + The access token for the user's session. + The refresh token for the user's session. + Raises: + StoreError if there was a problem storing the token. + LoginError if there was an authentication problem. + """ + user_id, password_hash = yield self._find_user_id_and_pwd_hash(user_id) + self._check_password(user_id, password, password_hash) + + logger.info("Logging in user %s", user_id) + access_token = yield self.issue_access_token(user_id) + refresh_token = yield self.issue_refresh_token(user_id) + defer.returnValue((user_id, access_token, refresh_token)) + + @defer.inlineCallbacks + def get_login_tuple_for_user_id(self, user_id): + """ + Gets login tuple for the user with the given user ID. + The user is assumed to have been authenticated by some other + machanism (e.g. CAS) + + Args: + user_id (str): User ID + Returns: + A tuple of: + The user's ID. + The access token for the user's session. + The refresh token for the user's session. + Raises: + StoreError if there was a problem storing the token. + LoginError if there was an authentication problem. + """ + user_id, ignored = yield self._find_user_id_and_pwd_hash(user_id) + + logger.info("Logging in user %s", user_id) + access_token = yield self.issue_access_token(user_id) + refresh_token = yield self.issue_refresh_token(user_id) + defer.returnValue((user_id, access_token, refresh_token)) + + @defer.inlineCallbacks + def does_user_exist(self, user_id): + try: + yield self._find_user_id_and_pwd_hash(user_id) + defer.returnValue(True) + except LoginError: + defer.returnValue(False) + + @defer.inlineCallbacks + def _find_user_id_and_pwd_hash(self, user_id): + """Checks to see if a user with the given id exists. Will check case + insensitively, but will throw if there are multiple inexact matches. + + Returns: + tuple: A 2-tuple of `(canonical_user_id, password_hash)` + """ + user_infos = yield self.store.get_users_by_id_case_insensitive(user_id) + if not user_infos: + logger.warn("Attempted to login as %s but they do not exist", user_id) + raise LoginError(403, "", errcode=Codes.FORBIDDEN) + + if len(user_infos) > 1: + if user_id not in user_infos: + logger.warn( + "Attempted to login as %s but it matches more than one user " + "inexactly: %r", + user_id, user_infos.keys() + ) + raise LoginError(403, "", errcode=Codes.FORBIDDEN) + + defer.returnValue((user_id, user_infos[user_id])) + else: + defer.returnValue(user_infos.popitem()) + + def _check_password(self, user_id, password, stored_hash): + """Checks that user_id has passed password, raises LoginError if not.""" + if not self.validate_hash(password, stored_hash): + logger.warn("Failed password login for user %s", user_id) + raise LoginError(403, "", errcode=Codes.FORBIDDEN) + + @defer.inlineCallbacks + def issue_access_token(self, user_id): + access_token = self.generate_access_token(user_id) + yield self.store.add_access_token_to_user(user_id, access_token) + defer.returnValue(access_token) + + @defer.inlineCallbacks + def issue_refresh_token(self, user_id): + refresh_token = self.generate_refresh_token(user_id) + yield self.store.add_refresh_token_to_user(user_id, refresh_token) + defer.returnValue(refresh_token) + + def generate_access_token(self, user_id, extra_caveats=None): + extra_caveats = extra_caveats or [] + macaroon = self._generate_base_macaroon(user_id) + macaroon.add_first_party_caveat("type = access") + now = self.hs.get_clock().time_msec() + expiry = now + (60 * 60 * 1000) + macaroon.add_first_party_caveat("time < %d" % (expiry,)) + for caveat in extra_caveats: + macaroon.add_first_party_caveat(caveat) + return macaroon.serialize() + + def generate_refresh_token(self, user_id): + m = self._generate_base_macaroon(user_id) + m.add_first_party_caveat("type = refresh") + # Important to add a nonce, because otherwise every refresh token for a + # user will be the same. + m.add_first_party_caveat("nonce = %s" % ( + stringutils.random_string_with_symbols(16), + )) + return m.serialize() + + def generate_short_term_login_token(self, user_id): + macaroon = self._generate_base_macaroon(user_id) + macaroon.add_first_party_caveat("type = login") + now = self.hs.get_clock().time_msec() + expiry = now + (2 * 60 * 1000) + macaroon.add_first_party_caveat("time < %d" % (expiry,)) + return macaroon.serialize() + + def validate_short_term_login_token_and_get_user_id(self, login_token): + try: + macaroon = pymacaroons.Macaroon.deserialize(login_token) + auth_api = self.hs.get_auth() + auth_api.validate_macaroon(macaroon, "login", [auth_api.verify_expiry]) + return self._get_user_from_macaroon(macaroon) + except (pymacaroons.exceptions.MacaroonException, TypeError, ValueError): + raise AuthError(401, "Invalid token", errcode=Codes.UNKNOWN_TOKEN) + + def _generate_base_macaroon(self, user_id): + macaroon = pymacaroons.Macaroon( + location=self.hs.config.server_name, + identifier="key", + key=self.hs.config.macaroon_secret_key) + macaroon.add_first_party_caveat("gen = 1") + macaroon.add_first_party_caveat("user_id = %s" % (user_id,)) + return macaroon + + def _get_user_from_macaroon(self, macaroon): + user_prefix = "user_id = " + for caveat in macaroon.caveats: + if caveat.caveat_id.startswith(user_prefix): + return caveat.caveat_id[len(user_prefix):] + raise AuthError( + self.INVALID_TOKEN_HTTP_STATUS, "No user_id found in token", + errcode=Codes.UNKNOWN_TOKEN + ) + + @defer.inlineCallbacks + def set_password(self, user_id, newpassword): + password_hash = self.hash(newpassword) + + yield self.store.user_set_password_hash(user_id, password_hash) + yield self.store.user_delete_access_tokens(user_id) + yield self.hs.get_pusherpool().remove_pushers_by_user(user_id) + yield self.store.flush_user(user_id) + + @defer.inlineCallbacks + def add_threepid(self, user_id, medium, address, validated_at): + yield self.store.user_add_threepid( + user_id, medium, address, validated_at, + self.hs.get_clock().time_msec() + ) + + def _save_session(self, session): + # TODO: Persistent storage + logger.debug("Saving session %s", session) + self.sessions[session["id"]] = session + + def _remove_session(self, session): + logger.debug("Removing session %s", session) + del self.sessions[session["id"]] + + def hash(self, password): + """Computes a secure hash of password. + + Args: + password (str): Password to hash. + + Returns: + Hashed password (str). + """ + return bcrypt.hashpw(password, bcrypt.gensalt(self.bcrypt_rounds)) + + def validate_hash(self, password, stored_hash): + """Validates that self.hash(password) == stored_hash. + + Args: + password (str): Password to hash. + stored_hash (str): Expected hash value. + + Returns: + Whether self.hash(password) == stored_hash (bool). + """ + return bcrypt.checkpw(password, stored_hash) |