How to identify whether the SSO session already exists or not using Pre-Authentication rule in OAM A

Folks,

Use case is to detect whether the SSO session exists (on the browser) or not..

If SSO session does not exist, user will be blocked access to the requested resource. (User is only supposed to access the entry point URL first rather than accessing the high secure URL)

If SSO session exists then keep the same authentication scheme.

E.g.

If we need to carry out OAAM Risk Evaluation for one resource whenever user requests it. But at the same time, if user requests that resource without first logging in with a custom scheme other than TAP scheme (through the entry point), he should be denied the access.