What is PHP Mcrypt Extension

Blowfish Cipher Tutorials - Herong's Tutorial Examples

∟What is PHP Mcrypt Extension

This section describes the PHP Mcrypt Extension - a built-in PHP extension that allows to access the mcrypt library, which supports Blowfish and a number of other cipher encryption algorithms.

What is PHP Mcrypt Extension? PHP Mcrypt Extension is a built-in PHP extension that allows to access the mcrypt library, which supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes.

PHP Mcrypt Extension is marked as "DEPRECATED in PHP 7.1.0, and REMOVED in PHP 7.2.0". You may consider to Sodium or OpenSSL extensions.

There are a number of ways to use PHP Mcrypt Extension for Blowfish cipher encryption:

1. Calling mcrypt_ecb(), mcrypt_cbc(), mcrypt_cfb(), or mcrypt_ofb() functions. But they are DEPRECATED and REMOVED in PHP 7.0.0.

$cipher = mcrypt_ecb(MCRYPT_BLOWFISH, $key, $data, MCRYPT_ENCRYPT); 
$cipher = mcrypt_cbc(MCRYPT_BLOWFISH, $key, $data, MCRYPT_ENCRYPT, $iv); 
$cipher = mcrypt_cfb(MCRYPT_BLOWFISH, $key, $data, MCRYPT_ENCRYPT, $iv); 
$cipher = mcrypt_ofb(MCRYPT_BLOWFISH, $key, $data, MCRYPT_ENCRYPT, $iv);

2. Calling the mcrypt_decrypt() function:

$cipher = mcrypt_decrypt(MCRYPT_BLOWFISH, $key, $data, MCRYPT_MODE_ECB);
$cipher = mcrypt_decrypt(MCRYPT_BLOWFISH, $key, $data, MCRYPT_MODE_CBC, $iv);
$cipher = mcrypt_decrypt(MCRYPT_BLOWFISH, $key, $data, MCRYPT_MODE_CFB, $iv);
$cipher = mcrypt_decrypt(MCRYPT_BLOWFISH, $key, $data, MCRYPT_MODE_OFB, $iv);

3. Calling mcrypt_module_open(), mcrypt_generic_init(), mcrypt_generic(), mcrypt_generic_deinit(), and mcrypt_module_close() functions:

$obj = mcrypt_module_open(MCRYPT_BLOWFISH, '', MCRYPT_MODE_CBC, '');
mcrypt_generic_init($obj, $key, $iv);
$cipher = mcrypt_generic($obj, $data);
mcrypt_generic_deinit($obj);
mcrypt_module_close($obj);