- substr: documentation ( source)
- bin2hex: documentation ( source)
<?php
$key = "8d30f9d3-083b-4ce0-b196-7364b2c3e2ef";
$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND);
$data = substr("4afc3e3d-bed1-42fd-85eb-06b8fbbc4925", 0, mcrypt_get_key_size(MCRYPT_RIJNDAEL_256));
$enc = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_ECB, $iv);
echo bin2hex($iv)."\n";
echo bin2hex($enc)."\n";