SSO with HTTP Header Authentication

Hi All,

I
am trying to implement SSO from Non SAP system (CAS - Central authentication system) to SAP Portal. I have configured the HTTP Header Login module in the Login Module stack as per the below link.

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

I have developed a Test JSP which set's the Header Variable IV_HTTP_USER with Portal login ID and re-directs to SAP Portal. When we test now, the HTTP Header Login module doesnt succeed and Login page comes up.

I have generated trace from NWA-Troubleshooting->Security troubleshooting wizard for authentication type and below the error i see. IV_HTTP_USER variable always show's as null.

Few Questions I have:

1. Do we have to change Authschemes file inculde authschem "Header" as mentioned in the below thread.

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

2. In case yes - I did change the authscheme's file as per above discussion and checked. But when i navigate to NWA->Configuration Management Security Authentication and Single Sign-On, I get and information saying Authscheme file is invalid.

Please help.

Portal Version: NW7.3 SP08

Thanks

Hussain