KeyStoreException, CertificateException, IOException, NoSuchAlgorithmException,
UnrecoverableKeyException {
final String an = getAlias(at);
final PasswordAdapter pa = masterPasswordHelper.getMasterPasswordAdapter(); // use default password store
final boolean exists = pa.aliasExists(an);
if (!exists) {
final String msg = String.format("Alias %s does not exist",an);
throw new IllegalArgumentException(msg);
}