PHP AES CBC encryption then MAX example

encryption.php

<?php

$method = MCRYPT_RIJNDAEL_128;
$block_cypher_mode = MCRYPT_MODE_CBC;

$clean = "Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Sed molestie augue sit amet leo consequat posuere. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Proin vel ante a orci tempus eleifend ut et magna. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus luctus urna sed urna ultricies ac tempor dui sagittis. In condimentum facilisis porta. Sed nec diam eu diam mattis viverra. Nulla fringilla, orci ac euismod semper, magna diam porttitor mauris, quis sollicitudin sapien justo in libero. Vestibulum mollis mauris enim. Morbi euismod magna ac lorem rutrum elementum. Donec viverra auctor lobortis. Pellentesque eu est a nulla placerat dignissim. Morbi a enim in magna semper bibendum. Etiam scelerisque, nunc ac egestas consequat, odio nibh euismod nulla.";
$keyOriginal = "abcdefghijklmop";

$encrypted = encrypt($clean, $keyOriginal, 16, $method, $block_cypher_mode);
$decrypted = decrypt($encrypted, $keyOriginal, 16, $method, $block_cypher_mode);

function encrypt($clean, $key, $key_size, $method, $block_cypher_mode) {
  // Hashing key.
  $key = hash('sha256', $key, TRUE);
  $key = substr($key, 0, $key_size);

  // Creating IV.
  $iv_size = mcrypt_get_iv_size($method, $block_cypher_mode);
  $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);

  // Padding clean text.
  $block = mcrypt_get_block_size($method, $block_cypher_mode);
  $pad = $block - (strlen($clean) % $block);
  $clean .= str_repeat(chr($pad), $pad);

  // Encrypt.
  $cipherText = mcrypt_encrypt($method, $key, $clean, $block_cypher_mode, $iv);

  // MAC.
  $mac = hash_hmac('sha256', $cipherText, $key);

  return $mac . $iv . $cipherText;
}

function decrypt($cipher, $key, $key_size, $method, $block_cypher_mode) {
  // Extract MAC.
  $mac = substr($cipher, 0, 64);

  // Extracting IV.
  $ivSize = mcrypt_get_iv_size($method, $block_cypher_mode);
  $iv = substr($cipher, 64, $ivSize);

  // Extracting text.
  $cipherText = substr($cipher, 64 + $ivSize);

  // Hashing key.
  $key = hash('sha256', $key, TRUE);
  $key = substr($key, 0, $key_size);

  // Check MAC.
  $macControl = hash_hmac('sha256', $cipherText, $key);
  if ($macControl !== $mac) {
    return FALSE;
  }

  // Decrypt.
  return mcrypt_decrypt($method, $key, $cipherText, $block_cypher_mode, $iv);
}