mcrypt 如何加/解密 ?

mcrypt 如何加/解密 ?

$td = mcrypt_module_open('twofish', '', 'ecb', '');

$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
$ks = mcrypt_enc_get_key_size($td);

$key = substr(md5('very secret key'), 0, $ks);

mcrypt_generic_init($td, $key, $iv);

print $encrypted = mcrypt_generic($td, 'This is very important data');

mcrypt_generic_deinit($td);

mcrypt_generic_init($td, $key, $iv);$decrypted = mdecrypt_generic($td, $encrypted);

mcrypt_generic_deinit($td);
mcrypt_module_close($td);

期待看到有用的回答！