RIJNDAEL 128 CBC encryption PHP snippet

rijndael_128_cbc_encrypt.php

<?php
function addpadding($string, $blocksize = 32) {
  $len = strlen($string);
  $pad = $blocksize - ($len % $blocksize);
  $string .= str_repeat(chr($pad), $pad);
  return $string;
}

$key = '12345678901234567890123456789012';
$post_data_str = 'abcdefghijklmnop';
$iv = '1234567890123456';

$encrypted = bin2hex(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, addpadding($post_data_str), MCRYPT_MODE_CBC, $iv));
echo $encrypted; // b91d3ece42c203729b38ae004e96efb9b64c41eeb074cad7ebafa3973181d233