Invalidate an old session in Flask

Question

How do I create a new clean session and invalidate the current one in Flask?

Do I use make_null_session() or open_session()?

Answer 1

If you use default flask sessions and set the app.permanent_session_lifetime, then the session will not work if a user tries to replay the same session as long as the session has expired.If you look at the source code for open_session, there is line:

max_age = total_seconds(app.permanent_session_lifetime)
try:            
    data = s.loads(val, max_age=max_age)
    return self.session_class(data)
    except BadSignature:
        return self.session_class()