[keycloak-dev] Social saving state

The social providers needs to save some state between a request and a callback (client_id, state, etc.). I've come up with 3 alternatives of how to save this state: * In http session * In a session cookie (encoded json) * In-memory - this would require a flushing mechanism (if callback never happens, for example user just closes browser) I'm not able to convince myself which is the better (or least bad), so do you have any thoughts?