How to get the active Subject?

[Oleg Nitz]

Hello all,

Now I am migrating our system from JBoss to Geronimo, and I met the
following problem. During login we attach some tecnical info about
the current user to the Subject as a public credintial. Then at any
point inside EJB we need to be able to find the active Subject in order
to get the tech info. In JBoss the following code does the trick:
ic = new InitialContext();
jsm = (JaasSecurityManager) ic.lookup("java:/jaas/our-security-domain");
subject = jsm.getActiveSubject();

Is such thing possible in Geronimo? What the correspondent code for 
Geronimo would look like?

Thanks in advance,
Oleg