We have the following structure:

Windows (probably vista)
WPF
Service Layer
WCF in IIS
Service Layer
Business Objects
Domain Model
Database

We need to use the WindowsIdentity from the user logged on to the windows
machine all the way through to the database. We'd like to make sure that
they have single sign-on (i.e. they log onto windows and that's it). With
Windows Authentication, I think that's going to be pretty easy to do, since
WCF and IIS support it natively.

However, we have to also support Novell NDS (EDirectory).

1. Can we use WindowsIdentity for this?
2. Does anything in IIS and WCF help us here.
3. Are we going to have to do an LDAP query and is the user going to have
to supply username and password credentials when the app opens for non-AD
security providers?

Any help here would be greatly appreciated.

Robert