Hi. The functions send HEAD and GET requests. You can see an example in
this thread.
Basically the HEAD requests check status and the GET requests grab content. There is nothing in these functions to be turned on so PhpDig can crawl authenticated pages.
One thing you might try in the authenticated pages is adding a check for PhpDig. If PhpDig, show content from pages normally needing authentication, if not PhpDig, require user to authenticate.
If the authenticated pages are using PHP, you may find the list of reserved variables
here useful.