百度mp3加密算法破解PHP版

<?php
/**
* @author qqzer.com
* @copyright 2010
*/
function baidu_decode($url,$sertim='',$k=array())
{
$E=strlen($url);
$C="";
$I=array();
$F=array();
$J=$sertim % 26;
$J=$J?$J:1;
foreach((array)$k as $str){
list($O,$L,$M) = explode(',',$str);
for($N=$O;$N<=$L;$N++){
$I[$N]=$N+$M;
$F[$N+$M]=$N;
}
}
for($D=0;$D<$E;$D++){
$A=$url{$D};
if(preg_match('/[A-Za-z0-9]/',$A)){
$H=$F[ord(substr($url,$D))]-$J;
if($H<0){
$H+=62;
}
$A = fromCharCode($I[$H]);
}
$C .=$A;
}
return $C;
}
function fromCharCode($codes) {
if (is_scalar($codes)) $codes= func_get_args();
$str= '';
foreach ($codes as $code) $str.= chr($code);
return $str;
}
echo baidu_decode('w884://2tB7.wp2vEw39.r31.r2/7x8tH/HFFOFNHN/FFGtrOJtKGKuFrFGLKNHFI.14I',1268169359,array('0,9,48','10,35,55','36,61,61'));
?>