Username: example
Password: password

<?php
  $source = 'very long text';
  $iv = "1234567812345678";
  $pass = 'difficultpassphrase';
  $method = 'aes-256-ofb';

  $encrypted = openssl_encrypt ($source, $method, $pass, true, $iv);
  echo $encrypted;

  $decrypted = openssl_decrypt ($encrypted, $method, $pass, true, $iv);
  echo $decrypted;
?>