Inbound SSO Map PHP Help!!!!

We are using phptoolkit 2013. This code always throws exception "An unexpected error occurred."


global $nsendpoint, $nshost, $nsemail, $nspassword, $nsrole, $nsaccount, $partnerId;
  $service = new NetSuiteService();
  $role = new RecordRef();
  $role->internalId = 3;
 

  $priv_key_der = file_get_contents(APP_PATH . 'rsa-Private.der');
  $priv_key_pem = chunk_split(base64_encode($priv_key_der), 64, "\n");
  $priv_key_pem = "-----BEGIN RSA PRIVATE KEY-----\n" . $priv_key_pem . "-----END RSA PRIVATE KEY-----\n";
  $priv_res = openssl_pkey_get_private($priv_key_pem);
  $timestamp = round(vsprintf("%d%d", gettimeofday()), -3) / 1000;
  $userId = $nsemail;

  $ssotoken = $role->externalId . " " . $nsemail . " " . $timestamp;
  openssl_private_encrypt($ssotoken, $ssotokenEnc, $priv_res);
  $authToken = strtoupper(bin2hex($ssotokenEnc));