title: do I use Krb5LoginModule or LdapLoginModule
body: <p>Sorry if this is a silly question.
  Do I use LdapLoginModule when I want to check if user exist or authorized?
  Do I use Krb5LoginMoudle when I want to check if user has a ticket to do work?</p>
  <p>Regards,
  JemRug</p>