Remove non-functional 'expire_access_token' setting (#5782)

changelog.d/5782.removal

@@ -0,0 +1 @@
+Remove non-functional 'expire_access_token' setting.

docs/sample_config.yaml

@@ -1109,10 +1109,6 @@ uploads_path: "DATADIR/uploads"
 #
 # macaroon_secret_key: <PRIVATE STRING>
 
-# Used to enable access token expiration.
-#
-#expire_access_token: False
-
 # a secret which is used to calculate HMACs for form values, to stop
 # falsification of values. Must be specified for the User Consent
 # forms to work.

synapse/api/auth.py

@@ -415,21 +415,16 @@ def _parse_and_validate_macaroon(self, token, rights="access"):
         try:
             user_id = self.get_user_id_from_macaroon(macaroon)
 
-            has_expiry = False
             guest = False
             for caveat in macaroon.caveats:
-                if caveat.caveat_id.startswith("time "):
-                    has_expiry = True
-                elif caveat.caveat_id == "guest = true":
+                if caveat.caveat_id == "guest = true":
                     guest = True
 
-            self.validate_macaroon(
-                macaroon, rights, self.hs.config.expire_access_token, user_id=user_id
-            )
+            self.validate_macaroon(macaroon, rights, user_id=user_id)
         except (pymacaroons.exceptions.MacaroonException, TypeError, ValueError):
             raise InvalidClientTokenError("Invalid macaroon passed.")
 
-        if not has_expiry and rights == "access":
+        if rights == "access":
             self.token_cache[token] = (user_id, guest)
 
         return user_id, guest
@@ -455,15 +450,14 @@ def get_user_id_from_macaroon(self, macaroon):
                 return caveat.caveat_id[len(user_prefix) :]
         raise InvalidClientTokenError("No user caveat in macaroon")
 
-    def validate_macaroon(self, macaroon, type_string, verify_expiry, user_id):
+    def validate_macaroon(self, macaroon, type_string, user_id):
         """
         validate that a Macaroon is understood by and was signed by this server.
 
         Args:
             macaroon(pymacaroons.Macaroon): The macaroon to validate
             type_string(str): The kind of token required (e.g. "access",
                               "delete_pusher")
-            verify_expiry(bool): Whether to verify whether the macaroon has expired.
             user_id (str): The user_id required
         """
         v = pymacaroons.Verifier()
@@ -476,19 +470,7 @@ def validate_macaroon(self, macaroon, type_string, verify_expiry, user_id):
         v.satisfy_exact("type = " + type_string)
         v.satisfy_exact("user_id = %s" % user_id)
         v.satisfy_exact("guest = true")
-
-        # verify_expiry should really always be True, but there exist access
-        # tokens in the wild which expire when they should not, so we can't
-        # enforce expiry yet (so we have to allow any caveat starting with
-        # 'time < ' in access tokens).
-        #
-        # On the other hand, short-term login tokens (as used by CAS login, for
-        # example) have an expiry time which we do want to enforce.
-
-        if verify_expiry:
-            v.satisfy_general(self._verify_expiry)
-        else:
-            v.satisfy_general(lambda c: c.startswith("time < "))
+        v.satisfy_general(self._verify_expiry)
 
         # access_tokens include a nonce for uniqueness: any value is acceptable
         v.satisfy_general(lambda c: c.startswith("nonce = "))

synapse/config/key.py

@@ -116,8 +116,6 @@ def read_config(self, config, config_dir_path, **kwargs):
             seed = bytes(self.signing_key[0])
             self.macaroon_secret_key = hashlib.sha256(seed).digest()
 
-        self.expire_access_token = config.get("expire_access_token", False)
-
         # a secret which is used to calculate HMACs for form values, to stop
         # falsification of values
         self.form_secret = config.get("form_secret", None)
@@ -144,10 +142,6 @@ def generate_config_section(
         #
         %(macaroon_secret_key)s
 
-        # Used to enable access token expiration.
-        #
-        #expire_access_token: False
-
         # a secret which is used to calculate HMACs for form values, to stop
         # falsification of values. Must be specified for the User Consent
         # forms to work.

synapse/handlers/auth.py

@@ -860,7 +860,7 @@ def validate_short_term_login_token_and_get_user_id(self, login_token):
         try:
             macaroon = pymacaroons.Macaroon.deserialize(login_token)
             user_id = auth_api.get_user_id_from_macaroon(macaroon)
-            auth_api.validate_macaroon(macaroon, "login", True, user_id)
+            auth_api.validate_macaroon(macaroon, "login", user_id)
         except Exception:
             raise AuthError(403, "Invalid token", errcode=Codes.FORBIDDEN)
         self.ratelimit_login_per_account(user_id)

tests/handlers/test_register.py

@@ -45,7 +45,7 @@ def make_homeserver(self, reactor, clock):
         hs_config["max_mau_value"] = 50
         hs_config["limit_usage_by_mau"] = True
 
-        hs = self.setup_test_homeserver(config=hs_config, expire_access_token=True)
+        hs = self.setup_test_homeserver(config=hs_config)
         return hs
 
     def prepare(self, reactor, clock, hs):

tests/server_notices/test_resource_limits_server_notices.py

@@ -36,7 +36,7 @@ def make_homeserver(self, reactor, clock):
             "room_name": "Server Notices",
         }
 
-        hs = self.setup_test_homeserver(config=hs_config, expire_access_token=True)
+        hs = self.setup_test_homeserver(config=hs_config)
         return hs
 
     def prepare(self, reactor, clock, hs):

tests/utils.py

@@ -126,7 +126,6 @@ def default_config(name, parse=False):
         "enable_registration": True,
         "enable_registration_captcha": False,
         "macaroon_secret_key": "not even a little secret",
-        "expire_access_token": False,
         "trusted_third_party_id_servers": [],
         "room_invite_state_types": [],
         "password_providers": [],