How to encrypt data with padding usign AES cipher, complatible with CryptoSwift defaults.

EncryptAESWithPHP

// Marcin Krzyżanwski
// Code for https://github.com/krzyzanowskim/CryptoSwift/issues/20
// PHP

function encrypt($plaintext, $key, $iv) {
  $ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $plaintext, MCRYPT_MODE_CBC, $iv);
  return base64_encode($ciphertext);
}

function decrypt($ciphertext_base64, $key, $iv) {
  $ciphertext = base64_decode($ciphertext_base64);
  $plaintext = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $ciphertext, MCRYPT_MODE_CBC, $iv);
  return $plaintext;
}

function addPadding($value)
{
    $pad = 16 - (strlen($value) % 16);
    return $value.str_repeat(chr($pad), $pad);
}

function stripPadding($value)
{
  $pad = ord($value[($len = strlen($value)) - 1]);
  return paddingIsValid($pad, $value) ? substr($value, 0, $len - $pad) : $value;
}

function paddingIsValid($pad, $value)
{
    $beforePad = strlen($value) - $pad;
    return substr($value, $beforePad) == str_repeat(substr($value, -1), $pad);
}


// Generate IV
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);


// Encrypt
$ciphertext_base64 = encrypt(addPadding("data"), "abcdefghijklmnop", $iv);
print $ciphertext_base64."\n";
// Decrypt
$plaintext = stripPadding(decrypt($ciphertext_base64, "abcdefghijklmnop", $iv));
print $plaintext."\n";