Fix callback handling

UniAuth/auth.py

@@ -5,6 +5,7 @@ import typing
 from datetime import datetime, timedelta
 
 import flask
+import itsdangerous
 import werkzeug
 from itsdangerous.url_safe import URLSafeTimedSerializer
 
@@ -29,7 +30,7 @@ def verify_secure_token(token: str, salt: str, max_age: int) -> str | None:
     serializer = URLSafeTimedSerializer(flask.current_app.config["SECRET_KEY"])
     try:
         data = serializer.loads(token, salt=salt, max_age=max_age)
-    except Exception:
+    except itsdangerous.exc.BadTimeSignature:
         return None
 
     assert isinstance(data, str)
@@ -53,6 +54,9 @@ def require_authentication() -> werkzeug.Response | None:
     if not flask.current_app.config.get("REQUIRE_AUTH"):
         return None
 
+    if flask.request.endpoint == "auth_callback":
+        return None
+
     token = flask.request.cookies.get("auth_token")
     if token and verify_auth_token(token):
         return None
@@ -77,9 +81,11 @@ def auth_callback() -> tuple[str, int] | werkzeug.Response:
     ]  # The original token passed to UniAuth
     expire_date = datetime.now() + timedelta(days=180)
 
-    original_url = verify_secure_token(token, salt="secure-redirect", max_age=600)
+    token_payload = verify_secure_token(token, salt="secure-redirect", max_age=600)
-    if not original_url:
+    if not token_payload:
         return "Invalid or expired token", 400
+    original_url = json.loads(token_payload)["original_url"]
+
     # Proceed with setting the auth_token cookie and redirecting to the original_url
     # This is where you set the auth_token received from UniAuth in the client's cookies
     response = flask.make_response(flask.redirect(original_url))