Implement access token expiry (#5660)

Record how long an access token is valid for, and raise a soft-logout once it
expires.

2 files changed, 38 insertions, 14 deletions

diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index da312b188e..b74a6e9c62 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -15,6 +15,7 @@
 # limitations under the License.
 
 import logging
+import time
 import unicodedata
 
 import attr
@@ -558,7 +559,7 @@ class AuthHandler(BaseHandler):
         return self.sessions[session_id]
 
     @defer.inlineCallbacks
-    def get_access_token_for_user_id(self, user_id, device_id=None):
+    def get_access_token_for_user_id(self, user_id, device_id, valid_until_ms):
         """
         Creates a new access token for the user with the given user ID.
 
@@ -572,16 +573,26 @@ class AuthHandler(BaseHandler):
             device_id (str|None): the device ID to associate with the tokens.
                None to leave the tokens unassociated with a device (deprecated:
                we should always have a device ID)
+            valid_until_ms (int|None): when the token is valid until. None for
+                no expiry.
         Returns:
               The access token for the user's session.
         Raises:
             StoreError if there was a problem storing the token.
         """
-        logger.info("Logging in user %s on device %s", user_id, device_id)
+        fmt_expiry = ""
+        if valid_until_ms is not None:
+            fmt_expiry = time.strftime(
+                " until %Y-%m-%d %H:%M:%S", time.localtime(valid_until_ms / 1000.0)
+            )
+        logger.info("Logging in user %s on device %s%s", user_id, device_id, fmt_expiry)
+
         yield self.auth.check_auth_blocking(user_id)
 
         access_token = self.macaroon_gen.generate_access_token(user_id)
-        yield self.store.add_access_token_to_user(user_id, access_token, device_id)
+        yield self.store.add_access_token_to_user(
+            user_id, access_token, device_id, valid_until_ms
+        )
 
         # the device *should* have been registered before we got here; however,
         # it's possible we raced against a DELETE operation. The thing we
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 420c5cb5bc..bb7cfd71b9 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -84,6 +84,8 @@ class RegistrationHandler(BaseHandler):
             self.device_handler = hs.get_device_handler()
             self.pusher_pool = hs.get_pusherpool()
 
+        self.session_lifetime = hs.config.session_lifetime
+
     @defer.inlineCallbacks
     def check_username(self, localpart, guest_access_token=None, assigned_user_id=None):
         if types.contains_invalid_mxid_characters(localpart):
@@ -599,6 +601,8 @@ class RegistrationHandler(BaseHandler):
     def register_device(self, user_id, device_id, initial_display_name, is_guest=False):
         """Register a device for a user and generate an access token.
 
+        The access token will be limited by the homeserver's session_lifetime config.
+
         Args:
             user_id (str): full canonical @user:id
             device_id (str|None): The device ID to check, or None to generate
@@ -619,20 +623,29 @@ class RegistrationHandler(BaseHandler):
                 is_guest=is_guest,
             )
             defer.returnValue((r["device_id"], r["access_token"]))
-        else:
-            device_id = yield self.device_handler.check_device_registered(
-                user_id, device_id, initial_display_name
-            )
+
+        valid_until_ms = None
+        if self.session_lifetime is not None:
             if is_guest:
-                access_token = self.macaroon_gen.generate_access_token(
-                    user_id, ["guest = true"]
-                )
-            else:
-                access_token = yield self._auth_handler.get_access_token_for_user_id(
-                    user_id, device_id=device_id
+                raise Exception(
+                    "session_lifetime is not currently implemented for guest access"
                 )
+            valid_until_ms = self.clock.time_msec() + self.session_lifetime
+
+        device_id = yield self.device_handler.check_device_registered(
+            user_id, device_id, initial_display_name
+        )
+        if is_guest:
+            assert valid_until_ms is None
+            access_token = self.macaroon_gen.generate_access_token(
+                user_id, ["guest = true"]
+            )
+        else:
+            access_token = yield self._auth_handler.get_access_token_for_user_id(
+                user_id, device_id=device_id, valid_until_ms=valid_until_ms
+            )
 
-            defer.returnValue((device_id, access_token))
+        defer.returnValue((device_id, access_token))
 
     @defer.inlineCallbacks
     def post_registration_actions(