MOSS Single Sign-On

I've started diving into the world of Sharepoint recently. One of our requirements of the project I am working on was for the user to be able to access content off existing external systems. MOSS provides SSO as an out of the box solution to enable this functionality.

What is SSO?

The default SSO service simply put, is a secure, pluggable storage mechanism for credential mapping between Sharepoint and other external systems.

Microsoft Office SharePoint Server 2007 provides a default single sign-on (SSO) service for the storage and mapping of credentials for use in connecting with third-party or back-end systems.

You can even plug-in an existing credential mapping system by implementing the ISSOProvider interface.

Setting up the SSO Service

using the service account to initially create the SSO database.

Using SSO

Now setup the application definitions and you're pretty much setting up the service. There are a few different ways we can use SSO:

Retrieving Credentials
http://mcse-blogs.com/certification/implementing-single-sign-on-sso-with-moss-2007.html

Logging into SQL Server as a data source for a DVWP http://blogs.msdn.com/sharepointdesigner/archive/2007/08/27/an-introduction-to-single-sign-on-sso-with-data-views.aspx

Logging into SQL Server using Windows Authentication
http://blogs.msdn.com/edhild/articles/377362.aspx

Forms Authentication and Screen scraping
http://odetocode.com/articles/162.aspx

To what extent is the out of the box functionality?

http://technet.microsoft.com/en-us/library/cc262932.aspx