Salesforce : Extranet site with SalesForce.com users authentication

I would like to create an extranet with Force.com Sites pages with an authentication that allow access to my SalesForce.com users.

The FAQ indicates that it is possible : http://wiki.developerforce.com/index.php/Sites_FAQ

I tried with http://wiki.developerforce.com/index.php/Authenticating_Users_on_Force.com_Sites, but that only allow customers to login and 开发者_运维知识库it redirects to the customer portal.

But, what I need is to authenticate SalesForce.com users on Force.com Sites. Any Idea ? Is there a way to do this ?

The wiki page you referenced (http://wiki.developerforce.com/index.php/Authenticating_Users_on_Force.com_Sites) is the way to go here, just change the following code snippet:

public class SiteLoginController {
    public String username {get; set;}
    public String password {get; set;}

    public PageReference login() {
        String startUrl = '/my_site_homepage';  // change the startUrl
        return Site.login(username, password, startUrl);
    }

       public SiteLoginController () {}

    public static testMethod void testSiteLoginController () {
        // Instantiate a new controller with all parameters in the page
        SiteLoginController controller = new SiteLoginController ();
        controller.username = 'test@salesforce.com';
        controller.password = '123456';

        System.assertEquals(controller.login(),null);                           
    }    
}

As you can see in the PageReference login you have a startUrl just change that to the page you want to load after the login.