If you want to get access of the portlet request with in a primefaces bridged portlet you can use a method likethis:

private static PortletRequest getPortletRequest()	{
	FacesContext facesContext = FacesContext.getCurrentInstance();
	ExternalContext externalContext = facesContext.getExternalContext();
	PortletRequest portletRequest =  (PortletRequest) externalContext.getRequest();
	return portletRequest;
	}

Then you can get user information from liferay by using

user = PortalUtil.getUser(portletRequest);

and generally have access to liferay api