adfs windows authentication - adfs2.0

Question

I have tried searching for this and can't find anything.
I want users to have a true SSO experience. Meaning they login to their computer and when they hit a web app that we have set up trust with in ADFS they are taken straight to that website. Right now no matter what they are taken to the ADFS forms login page. We only want the forms login page to appear if the user is not already connected to the network. Otherwise, ADFS should recoginize that the user is on the network and use the windows authentication.
What do I have to change in ADFS to make this happen?

Answer 1

In ADFS web.config, what order do you have for:
<localAuthenticationTypes>
<add name="Integrated" page="auth/integrated/" />
<add name="Forms" page="FormsSignIn.aspx" />
<add name="TlsClient" page="auth/sslclient/" />
<add name="Basic" page="auth/basic/" />
</localAuthenticationTypes>
Is Forms on top?
Are these users on the internet or intranet?
Do you use an ADFS proxy?

Answer 2

One option is to add a handler for the RedirectingToIdentityProvider event by placing the code just below this paragraph in your global.asax. This gives you a chance to jump in before the browser is redirected to ADFS and modify what the request (query string) looks like. You can do this to specify authentication types, or home realms (if you have multiple federations and want to skip HRD), and probably a lot of other stuff I don't know about.
void Application_Init()
{
FederatedAuthentication.WSFederationAuthenticationModule.RedirectingToIdentityProvider += new EventHandler<RedirectingToIdentityProviderEventArgs>(WSFederationAuthentication_RedirectingToIdentityProvider);
}
Then you would add code to your handler that might look something like this:
void WSFederationAuthentication_RedirectingToIdentityProvider(object sender, RedirectingToIdentityProviderEventArgs e)
{
WSFederationAuthenticationModule instance = FederatedAuthentication.WSFederationAuthenticationModule;
SignInRequestMessage request = instance.CreateSignInRequest(Guid.NewGuid().ToString(), instance.Realm, true);
request.AuthenticationType = "urn:federation:authentication:windows";
Response.Redirect(request.WriteQueryString());
}
When you set the request.AuthenticationType to that value, you're telling ADFS that you want to do windows (integrated) authentication. This was all that was required for me to get it to work. I didn't have to bother with switching the order of the authentication types in the web.config as nzpcmad suggested.
Also, for this to work, IIS and your web browser are working some magic outside of AD FS and your relying party, so in IE your users have to go to tools > Internet Options > Security and add the site to your Local Intranet sites. There's probably a way to push this out with group policies or something, but that's another question. Anyway, now that I think of it, this may be the only step you're missing.