forked-synapse/synapse/rest/register.py
2014-09-23 19:07:16 +01:00

279 lines
9.8 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014 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.
"""This module contains REST servlets to do with registration: /register"""
from twisted.internet import defer
from synapse.api.errors import SynapseError, Codes
from synapse.api.constants import LoginType
from base import RestServlet, client_path_pattern
import synapse.util.stringutils as stringutils
from hashlib import sha1
import hmac
import json
import logging
import urllib
logger = logging.getLogger(__name__)
# We ought to be using hmac.compare_digest() but on older pythons it doesn't
# exist. It's a _really minor_ security flaw to use plain string comparison
# because the timing attack is so obscured by all the other code here it's
# unlikely to make much difference
if hasattr(hmac, "compare_digest"):
compare_digest = hmac.compare_digest
else:
compare_digest = lambda a, b: a == b
class RegisterRestServlet(RestServlet):
"""Handles registration with the home server.
This servlet is in control of the registration flow; the registration
handler doesn't have a concept of multi-stages or sessions.
"""
PATTERN = client_path_pattern("/register$")
def __init__(self, hs):
super(RegisterRestServlet, self).__init__(hs)
# sessions are stored as:
# self.sessions = {
# "session_id" : { __session_dict__ }
# }
# TODO: persistent storage
self.sessions = {}
def on_GET(self, request):
if self.hs.config.enable_registration_captcha:
return (200, {
"flows": [
{
"type": LoginType.RECAPTCHA,
"stages": ([LoginType.RECAPTCHA,
LoginType.EMAIL_IDENTITY,
LoginType.PASSWORD])
},
{
"type": LoginType.RECAPTCHA,
"stages": [LoginType.RECAPTCHA, LoginType.PASSWORD]
}
]
})
else:
return (200, {
"flows": [
{
"type": LoginType.EMAIL_IDENTITY,
"stages": ([LoginType.EMAIL_IDENTITY,
LoginType.PASSWORD])
},
{
"type": LoginType.PASSWORD
}
]
})
@defer.inlineCallbacks
def on_POST(self, request):
register_json = _parse_json(request)
session = (register_json["session"] if "session" in register_json
else None)
login_type = None
if "type" not in register_json:
raise SynapseError(400, "Missing 'type' key.")
try:
login_type = register_json["type"]
stages = {
LoginType.RECAPTCHA: self._do_recaptcha,
LoginType.PASSWORD: self._do_password,
LoginType.EMAIL_IDENTITY: self._do_email_identity
}
session_info = self._get_session_info(request, session)
logger.debug("%s : session info %s request info %s",
login_type, session_info, register_json)
response = yield stages[login_type](
request,
register_json,
session_info
)
if "access_token" not in response:
# isn't a final response
response["session"] = session_info["id"]
defer.returnValue((200, response))
except KeyError as e:
logger.exception(e)
raise SynapseError(400, "Missing JSON keys for login type %s." % login_type)
def on_OPTIONS(self, request):
return (200, {})
def _get_session_info(self, request, session_id):
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,
LoginType.EMAIL_IDENTITY: False,
LoginType.RECAPTCHA: False
}
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)
self.sessions.pop(session["id"])
@defer.inlineCallbacks
def _do_recaptcha(self, request, register_json, session):
if not self.hs.config.enable_registration_captcha:
raise SynapseError(400, "Captcha not required.")
yield self._check_recaptcha(request, register_json, session)
session[LoginType.RECAPTCHA] = True # mark captcha as done
self._save_session(session)
defer.returnValue({
"next": [LoginType.PASSWORD, LoginType.EMAIL_IDENTITY]
})
@defer.inlineCallbacks
def _check_recaptcha(self, request, register_json, session):
if ("captcha_bypass_hmac" in register_json and
self.hs.config.captcha_bypass_secret):
if "user" not in register_json:
raise SynapseError(400, "Captcha bypass needs 'user'")
want = hmac.new(
key=self.hs.config.captcha_bypass_secret,
msg=register_json["user"],
digestmod=sha1,
).hexdigest()
# str() because otherwise hmac complains that 'unicode' does not
# have the buffer interface
got = str(register_json["captcha_bypass_hmac"])
if compare_digest(want, got):
session["user"] = register_json["user"]
defer.returnValue(None)
else:
raise SynapseError(400, "Captcha bypass HMAC incorrect",
errcode=Codes.CAPTCHA_NEEDED)
challenge = None
user_response = None
try:
challenge = register_json["challenge"]
user_response = register_json["response"]
except KeyError:
raise SynapseError(400, "Captcha response is required",
errcode=Codes.CAPTCHA_NEEDED)
# May be an X-Forwarding-For header depending on config
ip_addr = request.getClientIP()
if self.hs.config.captcha_ip_origin_is_x_forwarded:
# use the header
if request.requestHeaders.hasHeader("X-Forwarded-For"):
ip_addr = request.requestHeaders.getRawHeaders(
"X-Forwarded-For")[0]
handler = self.handlers.registration_handler
yield handler.check_recaptcha(
ip_addr,
self.hs.config.recaptcha_private_key,
challenge,
user_response
)
@defer.inlineCallbacks
def _do_email_identity(self, request, register_json, session):
if (self.hs.config.enable_registration_captcha and
not session[LoginType.RECAPTCHA]):
raise SynapseError(400, "Captcha is required.")
threepidCreds = register_json['threepidCreds']
handler = self.handlers.registration_handler
yield handler.register_email(threepidCreds)
session["threepidCreds"] = threepidCreds # store creds for next stage
session[LoginType.EMAIL_IDENTITY] = True # mark email as done
self._save_session(session)
defer.returnValue({
"next": LoginType.PASSWORD
})
@defer.inlineCallbacks
def _do_password(self, request, register_json, session):
if (self.hs.config.enable_registration_captcha and
not session[LoginType.RECAPTCHA]):
# captcha should've been done by this stage!
raise SynapseError(400, "Captcha is required.")
if ("user" in session and "user" in register_json and
session["user"] != register_json["user"]):
raise SynapseError(400, "Cannot change user ID during registration")
password = register_json["password"].encode("utf-8")
desired_user_id = (register_json["user"].encode("utf-8") if "user"
in register_json else None)
if desired_user_id and urllib.quote(desired_user_id) != desired_user_id:
raise SynapseError(
400,
"User ID must only contain characters which do not " +
"require URL encoding.")
handler = self.handlers.registration_handler
(user_id, token) = yield handler.register(
localpart=desired_user_id,
password=password
)
if session[LoginType.EMAIL_IDENTITY]:
yield handler.bind_emails(user_id, session["threepidCreds"])
result = {
"user_id": user_id,
"access_token": token,
"home_server": self.hs.hostname,
}
self._remove_session(session)
defer.returnValue(result)
def _parse_json(request):
try:
content = json.loads(request.content.read())
if type(content) != dict:
raise SynapseError(400, "Content must be a JSON object.")
return content
except ValueError:
raise SynapseError(400, "Content not JSON.")
def register_servlets(hs, http_server):
RegisterRestServlet(hs).register(http_server)