Vaadin and j_security_check

Hi all,
I trying to create application using Vaadin where user login to the app using standard
form. Problem is that I need to keep user ID, password and one additional information and use it in vaadin part of the application. How can I do that?
I do something like that in JSF project using ManagedBean and SessionScoped but how can I do that in Vaadin?

User is not a problem:
String u = request.getUserPrincipal().getName();
String user = request.getRemoteUser();

but what with password? I try to use:
String pasw = request.getParameter(“j_password”);
String kk = (String) request.getWrappedSession().getAttribute(“j_password”);
String o = (String)request.getAttribute(“j_password”);
String pp = (String) VaadinService.getCurrentRequest().getWrappedSession().getAttribute(“j_password”);

And nothing still null:-(

Maybe is other way to authenticate user?