IF you write your own authentication module its fairly easy to retrieve it, basically you parse the tokens for the username and password and use it ..
If not you can use the profile api's to get the username but you have to prepopulate the password somewhere as a user attribute, if your using ldap server than that is fairly straight forward using external ldap server mapping ..
Hi,
The Singl Signon mechanism let users to access the applications freely after the initial session signon rather than prompting for authentication information to access each application during that session.
It requires developers to :
1. Use the Session API to validate an HTTP request from the user into an iPlanet Portal Server session.
2. Use the Profile and Policy API to access the application-specific authentication information that is stored in the iPlanet Portal Server profile.
3.Pass that information to application
For more details visit the following url:
http://docs.iplanet.com/docs/manuals/ portal/30/progref/signon.htm#11284"
Thanks,
Raj_indts
Developer Technical Support
Sun Microsystems
http://www.sun.com/developers/support"