Merge branch 'develop' into key_distribution

Conflicts:
	synapse/config/homeserver.py

1 files changed, 277 insertions, 0 deletions

diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
new file mode 100644
index 0000000000..2e8009d3c3
--- /dev/null
+++ b/synapse/handlers/auth.py
@@ -0,0 +1,277 @@
+# -*- 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 LoginError, Codes
+from synapse.http.client import SimpleHttpClient
+from synapse.util.async import run_on_reactor
+
+from twisted.web.client import PartialDownloadError
+
+import logging
+import bcrypt
+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.sessions = {}
+
+    @defer.inlineCallbacks
+    def check_auth(self, flows, clientdict, clientip=None):
+        """
+        Takes a dictionary sent by the client in the login / registration
+        protocol and handles the login flow.
+
+        Args:
+            flows: list of list of stages
+            authdict: The dictionary from the client root level, not the
+                      'auth' key: this method prompts for auth if none is sent.
+        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']
+        sess = 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.
+            # sess['clientdict'] = clientdict
+            # self._save_session(sess)
+            pass
+        elif 'clientdict' in sess:
+            clientdict = sess['clientdict']
+
+        if not authdict:
+            defer.returnValue(
+                (False, self._auth_dict_for_flows(flows, sess), clientdict)
+            )
+
+        if 'creds' not in sess:
+            sess['creds'] = {}
+        creds = sess['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(sess)
+
+        for f in flows:
+            if len(set(f) - set(creds.keys())) == 0:
+                logger.info("Auth completed with creds: %r", creds)
+                self._remove_session(sess)
+                defer.returnValue((True, creds, clientdict))
+
+        ret = self._auth_dict_for_flows(flows, sess)
+        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 = authdict["user"]
+        password = authdict["password"]
+        if not user.startswith('@'):
+            user = UserID.create(user, self.hs.hostname).to_string()
+
+        user_info = yield self.store.get_user_by_id(user_id=user)
+        if not user_info:
+            logger.warn("Attempted to login as %s but they do not exist", user)
+            raise LoginError(401, "", errcode=Codes.UNAUTHORIZED)
+
+        stored_hash = user_info[0]["password_hash"]
+        if bcrypt.checkpw(password, stored_hash):
+            defer.returnValue(user)
+        else:
+            logger.warn("Failed password login for user %s", user)
+            raise LoginError(401, "", errcode=Codes.UNAUTHORIZED)
+
+    @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 = SimpleHttpClient(self.hs)
+            data = yield client.post_urlencoded_get_json(
+                "https://www.google.com/recaptcha/api/siteverify",
+                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]
+
+    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"]]