Footer on all EXCEPT "unknown or private" pages

I have a footer successfully deployed on all pages except the login page (ultimately, I’d like to know how to put a footer there as well). I would like to not show the footer on the “unknown or private” page that is visible to people who hit the site who are not logged in. Is there a way to either a) prevent non-logged in users from seeing that footer and/or b) remove the footer entirely from those pages? Thanks!