<?php
function hex2bin($h)
{
return pack("H*" , $h);
}
function modhex2hex($m)
{
return strtr($m, "cbdefghijklnrtuv", "0123456789abcdef");
}
function aes128ecb_decrypt($key,$in)
{
return bin2hex(mcrypt_ecb(MCRYPT_RIJNDAEL_128,
hex2bin($key),
hex2bin($in),
MCRYPT_DECRYPT,
hex2bin('00000000000000000000000000000000')));
}
function calculate_crc($token)
{
$crc = 0xffff;
for ($i = 0; $i < 16; $i++ ) {
$b = hexdec($token[$i*2].$token[($i*2)+1]);
$crc = $crc ^ ($b & 0xff);
for ($j = 0; $j < 8; $j++) {
$n = $crc & 1;
$crc = $crc >> 1;
if ($n != 0) {
$crc = $crc ^ 0x8408;
}
}
}
return $crc;
}
function crc_is_good($token) {
$crc = calculate_crc($token);
return $crc == 0xf0b8;
}
?>