SSO with Header Variable Authentication

Hi All,

I am trying to implement SSO from Non-SAP system (CAS - Central authentication server) to SAP Portal.

I modified the login stack to use Header authentication module as per the below link and changed the ticket template to use Header Auth Login Module.

http://help.sap.com/saphelp_nw73/helpdata/en/4a/47abb3e1f41cd4e10000000a421937/frameset.htm

To test - a JSP have been developed which set's the Header variable IV_HTTP_USER and redirects to SAP Portal. when we test this JSP the Header login module doesn't succeed and Login page come's up.

When i do trace using the Security Troubleshooting wizard for Authentication type - I see that IV_HTTP_USER is null.

Few Questions that i have:

1. Do we have to change the authschemes file to include the header authscheme ? I ask this because of the discussion from the below thread.

http://scn.sap.com/thread/2127692

2. In case we have - i made the changes to authscheme file as mentioned in the above discussion. But when i navigate to NWA->Configuration->Auth and Single Signon - the information says Invalid file.

Please help.

Thanks

Hussain