Hi,
I just wanted to bring to your attention our approach to handing a CAS-based single-sign-on solution with drupal.
In a nutshell, we wrote an apache auth module (using mod_python's auth support, not c, though a mod_perl port would probably be a snap) that does the CAS dance, and then adapts CAS to Basic Auth (namely, it populates the REMOTE_USER variable), allowing for the ordinary drupal remote user auth product to work for auth.
I wrote this up in more detail here: http://www.ja-sig.org/wiki/display/CASC/mod_python+auth+module
We had to tweak remoteuser a bit to make it work w/ drupal 5, though the main remote user might be up to snuff
http://svn.cc.columbia.edu/viewvc/auth/drupal/trunk/?root=ccnmtl
Hope this helps, /Jonah
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Jonah Bossewitch Senior Technical Architect ccnmtl.columbia.edu jonah at ccnmtl dot columbia dot edu 212.854.1815 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~