1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
|
# -*- 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.
"""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 ClientV1RestServlet, client_path_pattern
import synapse.util.stringutils as stringutils
from synapse.util.async import run_on_reactor
from hashlib import sha1
import hmac
import simplejson as 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(ClientV1RestServlet):
"""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 = {}
self.disable_registration = hs.config.disable_registration
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"]
is_application_server = login_type == LoginType.APPLICATION_SERVICE
if self.disable_registration and not is_application_server:
raise SynapseError(403, "Registration has been disabled")
stages = {
LoginType.RECAPTCHA: self._do_recaptcha,
LoginType.PASSWORD: self._do_password,
LoginType.EMAIL_IDENTITY: self._do_email_identity,
LoginType.APPLICATION_SERVICE: self._do_app_service
}
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)
ip_addr = self.hs.get_ip_from_request(request)
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
logger.debug("Registering email. threepidcreds: %s" % (threepidCreds))
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):
yield run_on_reactor()
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]:
logger.debug("Binding emails %s to %s" % (
session["threepidCreds"], user_id)
)
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)
@defer.inlineCallbacks
def _do_app_service(self, request, register_json, session):
if "access_token" not in request.args:
raise SynapseError(400, "Expected application service token.")
if "user" not in register_json:
raise SynapseError(400, "Expected 'user' key.")
as_token = request.args["access_token"][0]
user_localpart = register_json["user"].encode("utf-8")
handler = self.handlers.registration_handler
(user_id, token) = yield handler.appservice_register(
user_localpart, as_token
)
self._remove_session(session)
defer.returnValue({
"user_id": user_id,
"access_token": token,
"home_server": self.hs.hostname,
})
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)
|