I've given a try to posh and it seems to be a good application for what I need to do.
I have a problem still with CAS authentication.
Interaction with the CAS server is working great, auto-creation of the user on first connection is OK.
But when a user authenticate throuh CAS, instead of being redirected directly into it's posh home page, it's the posh login page that appears and it seems that for posh, the authentication is not OK.
This is how the return page is configured for CAS :
Thank you for your help.