How to provide a Session/Host object for use in both a windows and web application?

((UserSession)HttpContext.Current.Session["UserSession"]).User.Info

IHost.User.Info

((UserSession) DualContext.Current["UserSession"]).User.Info

public class DualContext
{
   private Dictionary<string, object> winFormsSession = new Dictionary<string, object>();
   private static readonly DualContext instance = new DualContext();

   public static DualContext Current
   {
      get {  return instance; }
   }

   public object this[string key]
   {
      get
      {
         if (HttpContext.Current != null)
            return HttpContext.Current.Session[key];
         else
            return winFormsSession[key];
      }
      set
      {
         if (HttpContext.Current != null)
            HttpContext.Current.Session[key] = value;
         else
            winFormsSession[key] = value;
      }
   }
}