I'm trying to authenticate a username and password with a CAS server using phpCAS but didn't find anything relevant on the internet. Once the user inputs their username and password how do I authenticate it with a CAS server using phpCAS? Also, how do I redirect user to a different .php page? I saw that we can use phpCAS:foreAuthentication() to authenticate users, but I'm trying to understand how a user is authenticated using this. Thanks!