Merge pull request from GHSA-gprj-3p75-f996

globus: apply identity_provider restriction in `check_blocked_users`

Author: yuvipanda

oauthenticator/globus.py

@@ -297,30 +297,39 @@ async def check_allowed(self, username, auth_model):
         if auth_model is None:
             return True
 
+        if await super().check_allowed(username, auth_model):
+            return True
+
+        if self.allowed_globus_groups:
+            user_groups = set(auth_model["auth_state"]["globus_groups"])
+            if user_groups & self.allowed_globus_groups:
+                return True
+            self.log.warning(f"{username} not in an allowed Globus Group")
+
+        # users should be explicitly allowed via config, otherwise they aren't
+        return False
+
+    async def check_blocked_users(self, username, authentication):
+        """Check if the user should be blocked
+
+        Called _before_ checking if the user should be allowed
+        """
+        # any restrictions on access go here - allow config only _grants_ access,
+        # restrictions belong in the `block` stage
         # before considering allowing a username by being recognized in a list
         # of usernames or similar, we must ensure that the authenticated user is
         # from an allowed identity provider domain.
         if self.identity_provider:
             # It's possible for identity provider domains to be namespaced
             # https://docs.globus.org/api/auth/specification/#identity_provider_namespaces
-            user_info = auth_model["auth_state"][self.user_auth_state_key]
+            user_info = authentication["auth_state"][self.user_auth_state_key]
             user_domain = user_info.get(self.username_claim).split('@', 1)[-1]
             if user_domain != self.identity_provider:
                 message = f"This site is restricted to {self.identity_provider} accounts. Link your account at app.globus.org/account."
                 self.log.warning(message)
                 raise web.HTTPError(403, message)
 
-        if await super().check_allowed(username, auth_model):
-            return True
-
-        if self.allowed_globus_groups:
-            user_groups = set(auth_model["auth_state"]["globus_groups"])
-            if user_groups & self.allowed_globus_groups:
-                return True
-            self.log.warning(f"{username} not in an allowed Globus Group")
-
-        # users should be explicitly allowed via config, otherwise they aren't
-        return False
+        return super().check_blocked_users(username, authentication)
 
     async def update_auth_model(self, auth_model):
         """