/tokenrefresh POST endpoint

This allows refresh tokens to be exchanged for (access_token,
refresh_token).

It also starts issuing them on login, though no clients currently
interpret them.

8 files changed, 177 insertions, 8 deletions

diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 0bf917efdd..65bd8189dc 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -279,15 +279,18 @@ class AuthHandler(BaseHandler):
             user_id (str): User ID
             password (str): Password
         Returns:
-            The access token for the user's session.
+            A tuple of:
+              The access token for the user's session.
+              The refresh token for the user's session.
         Raises:
             StoreError if there was a problem storing the token.
             LoginError if there was an authentication problem.
         """
         yield self._check_password(user_id, password)
         logger.info("Logging in user %s", user_id)
-        token = yield self.issue_access_token(user_id)
-        defer.returnValue(token)
+        access_token = yield self.issue_access_token(user_id)
+        refresh_token = yield self.issue_refresh_token(user_id)
+        defer.returnValue((access_token, refresh_token))
 
     @defer.inlineCallbacks
     def _check_password(self, user_id, password):
@@ -304,11 +307,16 @@ class AuthHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def issue_access_token(self, user_id):
-        reg_handler = self.hs.get_handlers().registration_handler
-        access_token = reg_handler.generate_access_token(user_id)
+        access_token = self.generate_access_token(user_id)
         yield self.store.add_access_token_to_user(user_id, access_token)
         defer.returnValue(access_token)
 
+    @defer.inlineCallbacks
+    def issue_refresh_token(self, user_id):
+        refresh_token = self.generate_refresh_token(user_id)
+        yield self.store.add_refresh_token_to_user(user_id, refresh_token)
+        defer.returnValue(refresh_token)
+
     def generate_access_token(self, user_id):
         macaroon = pymacaroons.Macaroon(
             location = self.hs.config.server_name,
@@ -323,6 +331,23 @@ class AuthHandler(BaseHandler):
 
         return macaroon.serialize()
 
+    def generate_refresh_token(self, user_id):
+        m = self._generate_base_macaroon(user_id)
+        m.add_first_party_caveat("type = refresh")
+        # Important to add a nonce, because otherwise every refresh token for a
+        # user will be the same.
+        m.add_first_party_caveat("nonce = %s" % stringutils.random_string_with_symbols(16))
+        return m.serialize()
+
+    def _generate_base_macaroon(self, user_id):
+        macaroon = pymacaroons.Macaroon(
+            location = self.hs.config.server_name,
+            identifier = "key",
+            key = self.hs.config.macaroon_secret_key)
+        macaroon.add_first_party_caveat("gen = 1")
+        macaroon.add_first_party_caveat("user_id = %s" % (user_id,))
+        return macaroon
+
     @defer.inlineCallbacks
     def set_password(self, user_id, newpassword):
         password_hash = bcrypt.hashpw(newpassword, bcrypt.gensalt())
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 694072693d..b963a38618 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -78,13 +78,15 @@ class LoginRestServlet(ClientV1RestServlet):
             login_submission["user"] = UserID.create(
                 login_submission["user"], self.hs.hostname).to_string()
 
-        token = yield self.handlers.auth_handler.login_with_password(
+        auth_handler = self.handlers.auth_handler
+        access_token, refresh_token = yield auth_handler.login_with_password(
             user_id=login_submission["user"],
             password=login_submission["password"])
 
         result = {
             "user_id": login_submission["user"],  # may have changed
-            "access_token": token,
+            "access_token": access_token,
+            "refresh_token": refresh_token,
             "home_server": self.hs.hostname,
         }
 
diff --git a/synapse/rest/client/v2_alpha/__init__.py b/synapse/rest/client/v2_alpha/__init__.py
index 33f961e898..5831ff0e62 100644
--- a/synapse/rest/client/v2_alpha/__init__.py
+++ b/synapse/rest/client/v2_alpha/__init__.py
@@ -21,6 +21,7 @@ from . import (
     auth,
     receipts,
     keys,
+    tokenrefresh,
 )
 
 from synapse.http.server import JsonResource
@@ -42,3 +43,4 @@ class ClientV2AlphaRestResource(JsonResource):
         auth.register_servlets(hs, client_resource)
         receipts.register_servlets(hs, client_resource)
         keys.register_servlets(hs, client_resource)
+        tokenrefresh.register_servlets(hs, client_resource)
diff --git a/synapse/rest/client/v2_alpha/tokenrefresh.py b/synapse/rest/client/v2_alpha/tokenrefresh.py
new file mode 100644
index 0000000000..901e777983
--- /dev/null
+++ b/synapse/rest/client/v2_alpha/tokenrefresh.py
@@ -0,0 +1,56 @@
+# -*- 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.errors import AuthError, StoreError, SynapseError
+from synapse.http.servlet import RestServlet
+
+from ._base import client_v2_pattern, parse_json_dict_from_request
+
+
+class TokenRefreshRestServlet(RestServlet):
+    """
+    Exchanges refresh tokens for a pair of an access token and a new refresh
+    token.
+    """
+    PATTERN = client_v2_pattern("/tokenrefresh")
+
+    def __init__(self, hs):
+        super(TokenRefreshRestServlet, self).__init__()
+        self.hs = hs
+        self.store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request):
+        body = parse_json_dict_from_request(request)
+        try:
+            old_refresh_token = body["refresh_token"]
+            auth_handler = self.hs.get_handlers().auth_handler
+            (user_id, new_refresh_token) = yield self.store.exchange_refresh_token(
+                old_refresh_token, auth_handler.generate_refresh_token)
+            new_access_token = yield auth_handler.issue_access_token(user_id)
+            defer.returnValue((200, {
+                "access_token": new_access_token,
+                "refresh_token": new_refresh_token,
+            }))
+        except KeyError:
+            raise SynapseError(400, "Missing required key 'refresh_token'.")
+        except StoreError:
+            raise AuthError(403, "Did not recognize refresh token")
+
+
+def register_servlets(hs, http_server):
+    TokenRefreshRestServlet(hs).register(http_server)
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index f154b1c8ae..53673b3bf5 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -54,7 +54,7 @@ logger = logging.getLogger(__name__)
 
 # Remember to update this number every time a change is made to database
 # schema files, so the users will be informed on server restarts.
-SCHEMA_VERSION = 22
+SCHEMA_VERSION = 23
 
 dir_path = os.path.abspath(os.path.dirname(__file__))
 
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 1444767a52..ce71389f02 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -181,6 +181,7 @@ class SQLBaseStore(object):
         self._transaction_id_gen = IdGenerator("sent_transactions", "id", self)
         self._state_groups_id_gen = IdGenerator("state_groups", "id", self)
         self._access_tokens_id_gen = IdGenerator("access_tokens", "id", self)
+        self._refresh_tokens_id_gen = IdGenerator("refresh_tokens", "id", self)
         self._pushers_id_gen = IdGenerator("pushers", "id", self)
         self._push_rule_id_gen = IdGenerator("push_rules", "id", self)
         self._push_rules_enable_id_gen = IdGenerator("push_rules_enable", "id", self)
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 0e404afb7c..f632306688 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -51,6 +51,28 @@ class RegistrationStore(SQLBaseStore):
         )
 
     @defer.inlineCallbacks
+    def add_refresh_token_to_user(self, user_id, token):
+        """Adds a refresh token for the given user.
+
+        Args:
+            user_id (str): The user ID.
+            token (str): The new refresh token to add.
+        Raises:
+            StoreError if there was a problem adding this.
+        """
+        next_id = yield self._refresh_tokens_id_gen.get_next()
+
+        yield self._simple_insert(
+            "refresh_tokens",
+            {
+                "id": next_id,
+                "user_id": user_id,
+                "token": token
+            },
+            desc="add_refresh_token_to_user",
+        )
+
+    @defer.inlineCallbacks
     def register(self, user_id, token, password_hash):
         """Attempts to register an account.
 
@@ -152,6 +174,46 @@ class RegistrationStore(SQLBaseStore):
             token
         )
 
+    def exchange_refresh_token(self, refresh_token, token_generator):
+        """Exchange a refresh token for a new access token and refresh token.
+
+        Doing so invalidates the old refresh token - refresh tokens are single
+        use.
+
+        Args:
+            token (str): The refresh token of a user.
+            token_generator (fn: str -> str): Function which, when given a
+                user ID, returns a unique refresh token for that user. This
+                function must never return the same value twice.
+        Returns:
+            tuple of (user_id, refresh_token)
+        Raises:
+            StoreError if no user was found with that refresh token.
+        """
+        return self.runInteraction(
+            "exchange_refresh_token",
+            self._exchange_refresh_token,
+            refresh_token,
+            token_generator
+        )
+
+    def _exchange_refresh_token(self, txn, old_token, token_generator):
+        sql = "SELECT user_id FROM refresh_tokens WHERE token = ?"
+        txn.execute(sql, (old_token,))
+        rows = self.cursor_to_dict(txn)
+        if not rows:
+            raise StoreError(403, "Did not recognize refresh token")
+        user_id = rows[0]["user_id"]
+
+        # TODO(danielwh): Maybe perform a validation on the macaroon that
+        # macaroon.user_id == user_id.
+
+        new_token = token_generator(user_id)
+        sql = "UPDATE refresh_tokens SET token = ? WHERE token = ?"
+        txn.execute(sql, (new_token, old_token,))
+
+        return user_id, new_token
+
     @defer.inlineCallbacks
     def is_server_admin(self, user):
         res = yield self._simple_select_one_onecol(
diff --git a/synapse/storage/schema/delta/23/refresh_tokens.sql b/synapse/storage/schema/delta/23/refresh_tokens.sql
new file mode 100644
index 0000000000..46839e016c
--- /dev/null
+++ b/synapse/storage/schema/delta/23/refresh_tokens.sql
@@ -0,0 +1,21 @@
+/* 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.
+ */
+
+CREATE TABLE IF NOT EXISTS refresh_tokens(
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    token TEXT NOT NULL,
+    user_id TEXT NOT NULL,
+    UNIQUE (token)
+);