Leveraging Agile user authentication for external report

 Is there any way to leverage the Agile user authentication process or session info in custom apps or external reports using php?  For example, i want to create a php web-based report that pulls data from the Agile database.  However, when loading the page or at least before the results become available i'd like to require the user to provide login credentials to verify they are a registered Agile user.  If i used the same encryption method Agile does for it's passwords i could easily validate a user entered password against what is stored in the Agile database.  Is this possible?  Or maybe there's another way?  I'd really like