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# -*- coding: utf-8 -*-
# Copyright 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 synapse.api.constants import LoginType
from synapse.api.errors import SynapseError, Codes
from synapse.http.servlet import RestServlet
from ._base import client_v2_pattern, parse_request_allow_empty
import logging
import hmac
from hashlib import sha1
from synapse.util.async import run_on_reactor
# 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
logger = logging.getLogger(__name__)
class RegisterRestServlet(RestServlet):
PATTERN = client_v2_pattern("/register")
def __init__(self, hs):
super(RegisterRestServlet, self).__init__()
self.hs = hs
self.auth = hs.get_auth()
self.auth_handler = hs.get_handlers().auth_handler
self.registration_handler = hs.get_handlers().registration_handler
@defer.inlineCallbacks
def on_POST(self, request):
yield run_on_reactor()
body = parse_request_allow_empty(request)
is_using_shared_secret = False
is_application_server = False
service = None
if 'access_token' in request.args:
service = yield self.auth.get_appservice_by_req(request)
if service:
is_application_server = True
elif 'mac' in body:
# Check registration-specific shared secret auth
if 'username' not in body:
raise SynapseError(400, "", Codes.MISSING_PARAM)
self._check_shared_secret_auth(
body['username'], body['mac']
)
is_using_shared_secret = True
else:
authed, result, params = yield self.auth_handler.check_auth([
[LoginType.RECAPTCHA],
[LoginType.EMAIL_IDENTITY, LoginType.RECAPTCHA],
], body, self.hs.get_ip_from_request(request))
if not authed:
defer.returnValue((401, result))
can_register = (
not self.hs.config.disable_registration
or is_application_server
or is_using_shared_secret
)
if not can_register:
raise SynapseError(403, "Registration has been disabled")
if 'username' not in params or 'password' not in params:
raise SynapseError(400, "", Codes.MISSING_PARAM)
desired_username = params['username']
new_password = params['password']
(user_id, token) = yield self.registration_handler.register(
localpart=desired_username,
password=new_password
)
result = {
"user_id": user_id,
"access_token": token,
"home_server": self.hs.hostname,
}
defer.returnValue((200, result))
def on_OPTIONS(self, _):
return 200, {}
def _check_shared_secret_auth(self, username, mac):
if not self.hs.config.registration_shared_secret:
raise SynapseError(400, "Shared secret registration is not enabled")
user = username.encode("utf-8")
# str() because otherwise hmac complains that 'unicode' does not
# have the buffer interface
got_mac = str(mac)
want_mac = hmac.new(
key=self.hs.config.registration_shared_secret,
msg=user,
digestmod=sha1,
).hexdigest()
if compare_digest(want_mac, got_mac):
return True
else:
raise SynapseError(
403, "HMAC incorrect",
)
def register_servlets(hs, http_server):
RegisterRestServlet(hs).register(http_server)
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