private static string GetFormattedPrincipal(string principalName, string hostName, string realm) { if (!String.IsNullOrEmpty(hostName)) { return String.Format(CultureInfo.InvariantCulture, "{0}/{1}@{2}", principalName, hostName, realm); } return String.Format(CultureInfo.InvariantCulture, "{0}@{1}", principalName, realm); }