currently, there are 3 classes that are added by Kerberos:
javax.security.auth.kerberos.KerberosPrincipal
javax.security.auth.kerberos.DelegationPermission
javax.security.auth.kerberos.ServicePermission

These classes need to be included into PolicyTool so user can simply pick them instead of typing them into the text box. Also, the correspondingf action set should be enforced.