我应该如何处理@jwt_required装饰器中引发的异常？ （在flask-jwt-extended中）

Question

I have a function with @jwt_required decorator.

class Test(Resource):
    @jwt_required
    def get(self):
        return {"test": "ok" }

Which works fine when the correct HTTP header is set, ie

Authentication: Bearer [TOKEN]

but when the token is invalid/wrong or messed with, a jwt.exceptions.DecodeError is raised:

File "env/lib/python3.6/site-packages/flask_restplus/resource.py", line 44, in dispatch_request
    resp = meth(*args, **kwargs)
  File "env/lib/python3.6/site-packages/flask_jwt_extended/view_decorators.py", line 103, in wrapper
    verify_jwt_in_request()
  File "env/lib/python3.6/site-packages/flask_jwt_extended/view_decorators.py", line 32, in verify_jwt_in_request
    jwt_data = _decode_jwt_from_request(request_type='access')
  File "env/lib/python3.6/site-packages/flask_jwt_extended/view_decorators.py", line 267, in _decode_jwt_from_request
    decoded_token = decode_token(encoded_token, csrf_token)
  File "env/lib/python3.6/site-packages/flask_jwt_extended/utils.py", line 80, in decode_token
    encoded_token, verify=False, algorithms=config.algorithm
  File "env/lib/python3.6/site-packages/jwt/api_jwt.py", line 84, in decode
    payload, _, _, _ = self._load(jwt)
  File "env/lib/python3.6/site-packages/jwt/api_jws.py", line 183, in _load
    raise DecodeError('Not enough segments')
jwt.exceptions.DecodeError: Not enough segments

I cannot rely on clients always using correct tokens all the time. And I cannot catch the exception because it is raised in the decorator rather than my own function. So the result is a http 500 error. How should I handle the exception more gracefully?

Answer 1

Flask-jwt-extended should be handling those for you gracefully. If not, you are probably using another extension (like flask-restful for example) that is breaking native flask functionality. You can try setting this option to fix it app.config['PROPAGATE_EXCEPTIONS'] = True , or take a look at this thread for some advice if you are using a different flask extension that is causing problems https://github.com/vimalloc/flask-jwt-extended/issues/86