Admin API for creating new users (#3415)

docs/admin_api/register_api.rst

@@ -0,0 +1,63 @@
+Shared-Secret Registration
+==========================
+
+This API allows for the creation of users in an administrative and
+non-interactive way. This is generally used for bootstrapping a Synapse
+instance with administrator accounts.
+
+To authenticate yourself to the server, you will need both the shared secret
+(``registration_shared_secret`` in the homeserver configuration), and a
+one-time nonce. If the registration shared secret is not configured, this API
+is not enabled.
+
+To fetch the nonce, you need to request one from the API::
+
+  > GET /_matrix/client/r0/admin/register
+
+  < {"nonce": "thisisanonce"}
+
+Once you have the nonce, you can make a ``POST`` to the same URL with a JSON
+body containing the nonce, username, password, whether they are an admin
+(optional, False by default), and a HMAC digest of the content.
+
+As an example::
+
+  > POST /_matrix/client/r0/admin/register
+  > {
+     "nonce": "thisisanonce",
+     "username": "pepper_roni",
+     "password": "pizza",
+     "admin": true,
+     "mac": "mac_digest_here"
+    }
+
+  < {
+     "access_token": "token_here",
+     "user_id": "@pepper_roni@test",
+     "home_server": "test",
+     "device_id": "device_id_here"
+    }
+
+The MAC is the hex digest output of the HMAC-SHA1 algorithm, with the key being
+the shared secret and the content being the nonce, user, password, and either
+the string "admin" or "notadmin", each separated by NULs. For an example of
+generation in Python::
+
+  import hmac, hashlib
+
+  def generate_mac(nonce, user, password, admin=False):
+
+      mac = hmac.new(
+        key=shared_secret,
+        digestmod=hashlib.sha1,
+      )
+
+      mac.update(nonce.encode('utf8'))
+      mac.update(b"\x00")
+      mac.update(user.encode('utf8'))
+      mac.update(b"\x00")
+      mac.update(password.encode('utf8'))
+      mac.update(b"\x00")
+      mac.update(b"admin" if admin else b"notadmin")
+
+      return mac.hexdigest()

scripts/register_new_matrix_user

@@ -26,11 +26,37 @@ import yaml
 
 
 def request_registration(user, password, server_location, shared_secret, admin=False):
+    req = urllib2.Request(
+        "%s/_matrix/client/r0/admin/register" % (server_location,),
+        headers={'Content-Type': 'application/json'}
+    )
+
+    try:
+        if sys.version_info[:3] >= (2, 7, 9):
+            # As of version 2.7.9, urllib2 now checks SSL certs
+            import ssl
+            f = urllib2.urlopen(req, context=ssl.SSLContext(ssl.PROTOCOL_SSLv23))
+        else:
+            f = urllib2.urlopen(req)
+        body = f.read()
+        f.close()
+        nonce = json.loads(body)["nonce"]
+    except urllib2.HTTPError as e:
+        print "ERROR! Received %d %s" % (e.code, e.reason,)
+        if 400 <= e.code < 500:
+            if e.info().type == "application/json":
+                resp = json.load(e)
+                if "error" in resp:
+                    print resp["error"]
+        sys.exit(1)
+
     mac = hmac.new(
         key=shared_secret,
         digestmod=hashlib.sha1,
     )
 
+    mac.update(nonce)
+    mac.update("\x00")
     mac.update(user)
     mac.update("\x00")
     mac.update(password)
@@ -40,10 +66,10 @@ def request_registration(user, password, server_location, shared_secret, admin=F
     mac = mac.hexdigest()
 
     data = {
-        "user": user,
+        "nonce": nonce,
+        "username": user,
         "password": password,
         "mac": mac,
-        "type": "org.matrix.login.shared_secret",
         "admin": admin,
     }
 
@@ -52,7 +78,7 @@ def request_registration(user, password, server_location, shared_secret, admin=F
     print "Sending registration request..."
 
     req = urllib2.Request(
-        "%s/_matrix/client/api/v1/register" % (server_location,),
+        "%s/_matrix/client/r0/admin/register" % (server_location,),
         data=json.dumps(data),
         headers={'Content-Type': 'application/json'}
     )

synapse/rest/client/v1/admin.py

@@ -14,6 +14,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import hashlib
+import hmac
 import logging
 
 from six.moves import http_client
@@ -63,6 +65,125 @@ def on_GET(self, request, user_id):
         defer.returnValue((200, ret))
 
 
+class UserRegisterServlet(ClientV1RestServlet):
+    """
+    Attributes:
+         NONCE_TIMEOUT (int): Seconds until a generated nonce won't be accepted
+         nonces (dict[str, int]): The nonces that we will accept. A dict of
+             nonce to the time it was generated, in int seconds.
+    """
+    PATTERNS = client_path_patterns("/admin/register")
+    NONCE_TIMEOUT = 60
+
+    def __init__(self, hs):
+        super(UserRegisterServlet, self).__init__(hs)
+        self.handlers = hs.get_handlers()
+        self.reactor = hs.get_reactor()
+        self.nonces = {}
+        self.hs = hs
+
+    def _clear_old_nonces(self):
+        """
+        Clear out old nonces that are older than NONCE_TIMEOUT.
+        """
+        now = int(self.reactor.seconds())
+
+        for k, v in list(self.nonces.items()):
+            if now - v > self.NONCE_TIMEOUT:
+                del self.nonces[k]
+
+    def on_GET(self, request):
+        """
+        Generate a new nonce.
+        """
+        self._clear_old_nonces()
+
+        nonce = self.hs.get_secrets().token_hex(64)
+        self.nonces[nonce] = int(self.reactor.seconds())
+        return (200, {"nonce": nonce.encode('ascii')})
+
+    @defer.inlineCallbacks
+    def on_POST(self, request):
+        self._clear_old_nonces()
+
+        if not self.hs.config.registration_shared_secret:
+            raise SynapseError(400, "Shared secret registration is not enabled")
+
+        body = parse_json_object_from_request(request)
+
+        if "nonce" not in body:
+            raise SynapseError(
+                400, "nonce must be specified", errcode=Codes.BAD_JSON,
+            )
+
+        nonce = body["nonce"]
+
+        if nonce not in self.nonces:
+            raise SynapseError(
+                400, "unrecognised nonce",
+            )
+
+        # Delete the nonce, so it can't be reused, even if it's invalid
+        del self.nonces[nonce]
+
+        if "username" not in body:
+            raise SynapseError(
+                400, "username must be specified", errcode=Codes.BAD_JSON,
+            )
+        else:
+            if (not isinstance(body['username'], str) or len(body['username']) > 512):
+                raise SynapseError(400, "Invalid username")
+
+            username = body["username"].encode("utf-8")
+            if b"\x00" in username:
+                raise SynapseError(400, "Invalid username")
+
+        if "password" not in body:
+            raise SynapseError(
+                400, "password must be specified", errcode=Codes.BAD_JSON,
+            )
+        else:
+            if (not isinstance(body['password'], str) or len(body['password']) > 512):
+                raise SynapseError(400, "Invalid password")
+
+            password = body["password"].encode("utf-8")
+            if b"\x00" in password:
+                raise SynapseError(400, "Invalid password")
+
+        admin = body.get("admin", None)
+        got_mac = body["mac"]
+
+        want_mac = hmac.new(
+            key=self.hs.config.registration_shared_secret.encode(),
+            digestmod=hashlib.sha1,
+        )
+        want_mac.update(nonce)
+        want_mac.update(b"\x00")
+        want_mac.update(username)
+        want_mac.update(b"\x00")
+        want_mac.update(password)
+        want_mac.update(b"\x00")
+        want_mac.update(b"admin" if admin else b"notadmin")
+        want_mac = want_mac.hexdigest()
+
+        if not hmac.compare_digest(want_mac, got_mac):
+            raise SynapseError(
+                403, "HMAC incorrect",
+            )
+
+        # Reuse the parts of RegisterRestServlet to reduce code duplication
+        from synapse.rest.client.v2_alpha.register import RegisterRestServlet
+        register = RegisterRestServlet(self.hs)
+
+        (user_id, _) = yield register.registration_handler.register(
+            localpart=username.lower(), password=password, admin=bool(admin),
+            generate_token=False,
+        )
+
+        result = yield register._create_registration_details(user_id, body)
+        defer.returnValue((200, result))
+
+
 class WhoisRestServlet(ClientV1RestServlet):
     PATTERNS = client_path_patterns("/admin/whois/(?P<user_id>[^/]*)")
 
@@ -614,3 +735,4 @@ def register_servlets(hs, http_server):
     ShutdownRoomRestServlet(hs).register(http_server)
     QuarantineMediaInRoom(hs).register(http_server)
     ListMediaInRoom(hs).register(http_server)
+    UserRegisterServlet(hs).register(http_server)

synapse/secrets.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector 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.
+
+"""
+Injectable secrets module for Synapse.
+
+See https://docs.python.org/3/library/secrets.html#module-secrets for the API
+used in Python 3.6, and the API emulated in Python 2.7.
+"""
+
+import six
+
+if six.PY3:
+    import secrets
+
+    def Secrets():
+        return secrets
+
+
+else:
+
+    import os
+    import binascii
+
+    class Secrets(object):
+        def token_bytes(self, nbytes=32):
+            return os.urandom(nbytes)
+
+        def token_hex(self, nbytes=32):
+            return binascii.hexlify(self.token_bytes(nbytes))

synapse/server.py

@@ -74,6 +74,7 @@
     MediaRepository,
     MediaRepositoryResource,
 )
+from synapse.secrets import Secrets
 from synapse.server_notices.server_notices_manager import ServerNoticesManager
 from synapse.server_notices.server_notices_sender import ServerNoticesSender
 from synapse.server_notices.worker_server_notices_sender import WorkerServerNoticesSender
@@ -158,6 +159,7 @@ def build_DEPENDENCY(self)
         'groups_server_handler',
         'groups_attestation_signing',
         'groups_attestation_renewer',
+        'secrets',
         'spam_checker',
         'room_member_handler',
         'federation_registry',
@@ -405,6 +407,9 @@ def build_groups_attestation_signing(self):
     def build_groups_attestation_renewer(self):
         return GroupAttestionRenewer(self)
 
+    def build_secrets(self):
+        return Secrets()
+
     def build_spam_checker(self):
         return SpamChecker(self)