SSO: Active login to Office 365 Sharepoint using CSOM and the credentials of the curent user's passive login

Hi,

I find plenty of examples performing an active login by passing username/password.

I would like to use CSOM from my MVC application and authenticate using the current user's credentials.

I found one example using InternetGetCookieEx(), but this only seems to work in a console application.

This requirement must be common, I would think, calling into Office 365 from an MVC application, using the current user's security context. This user authenticated against Office 365's WAAD.

Any help would greatly appreciated.

Michel.