sitemap.xml for auth sites

I have created a sitemap.xml for a project with an auth system. So far I have just added the pages outside that wall. Is there a way to let crawlers login and crawl on the pages that requires authentication? If so, I like to add that pages in my sitemap. 
I am trying to get an app SEO friendly. 

Eh, not much Codeigniter in there, but what could possibly go wrong by posting to this friendly community?