How to implement SAML SSO

A_M picture A_M · Apr 30, 2009 · Viewed 48.3k times · Source

How is SAML SSO typically implemented?

I've read this (n.b. obsolete) about using SAML with Google Apps, and the wikipedia entry on SAML.

The wikipedia entry talks about responding with forms containing details of the SAMLRequest and SAMLResponse. Does this mean that the user has to physically submit the form in order to proceed with the single sign on?

The google entry talks about using redirects, which seems more seemless to me. However, it also talks about using a form for the response which the user must submit (although it does talk about using JavaScript to automatically submit the form).

Is this the standard way of doing this? Using redirects and JavaScript for form submission?

Does anyone know of any other good resources about how to go about implementing SSO between a Windows Domain and a J2EE web application. The web application is on a separate network/domain. My client wants to use CA Siteminder (with SAML).

Answer

metadaddy picture metadaddy · May 3, 2009

The way this works is that, after authenticating the user, the SAML identity provider (IdP) renders a form to the browser containing the SAML response - the form's 'action' (i.e. target) is the service provider (SP). In the HTML, there is a JavaScript onLoad event that submits the form, so the net effect is that the user is automatically taken from the IdP to the SP, SAML response in hand.

The only time a user would have to click anything to submit the form is if they have JavaScript disabled. In this case, SAML implementations typically provide a message with a button to press in the <noscript> tag.

For more detail see this article I wrote a few years ago - but note, 'Lightbulb' is long obsolete now - for PHP SAML see simpleSAMLphp.

It's a shame your client wants to use CA SiteMinder - the open source OpenAM (formerly known as OpenSSO) does this pretty easily.