php phar 解包 以及 O0O0000O0解密 方法函数

遇到一个引入phar包的代码, 总体两大步 解包 和 O0O0000O0解密

<?php
// require 'phar://' . __DIR__ . '/phar/collector.phar/index.php';
// 第一步
function unphar($pharpath = 'collector.phar'){
    try {
        $phar = new Phar($pharpath);
        $phar->convertToData(Phar::ZIP); //提取到zip 直接用extractTo解包实际测试是乱码
        //$phar->extractTo('extract');
        foreach ($phar as $file) {
          file_get_contents($file);
        }
        $phar->extractTo('extract', null, true); //提取一份原项目文件目录
    } catch (Exception $e) {}
}

//第二步
//explorerdir("./collector");    //目录解密
//decode("./collector/class.php"); //单个解密
function explorerdir($dir)
{
    $dp=opendir($dir); //打开目录句柄
    //echo " ".$dir."\r\n"; //输出目录
    while ($file = readdir($dp)) //遍历目录
    {
        if ($file !='.'&&$file !='..') //如果文件不是当前目录及父目录
        {
            $path=$dir.DIRECTORY_SEPARATOR.$file; //获取路径
            if(is_dir($path)) //如果当前文件为目录
            {
                explorerdir($path);   //递归调用
            }
            else   //如果不是目录
            {

                //echo "-".$path."\n"; //输出文件名

                echo decode($path);

            }
        }
    }
    closedir($dp);    //关闭文件名柄

}

function decode($filename="")
{
    if(pathinfo($filename, PATHINFO_EXTENSION)!="php" || strpos($filename,".bak.php") || realpath($filename) == __FILE__ ){return;}
    //$filename="intro.class.php";//要解密的文件
    if(!file_exists($filename)){exit("file is not exist;");}
    $lines = file($filename);//0,1,2行
    //第一次base64解密
    $content="";
    if(preg_match("/O0O0000O0\('.*'\)/",$lines[1],$y)){
        $content=str_replace("O0O0000O0('","",$y[0]);
        $content=str_replace("')","",$content);
        $content=base64_decode($content);
    }
    else{
        weidun_log(false,realpath($filename)." is not Encrypted!");
        return false;
    }
    //第一次base64解密后的内容中查找密钥
    $decode_key="";
    if(preg_match("/\),'.*',/",$content,$k))
    {
        $decode_key=str_replace("),'","",$k[0]);
        $decode_key=str_replace("',","",$decode_key);
    }
    //查找要截取字符串长度
    $str_length="";
    if(preg_match("/,\d*\),/",$content,$k))
    {
        $str_length=str_replace("),","",$k[0]);
        $str_length=str_replace(",","",$str_length);
    }
    //截取文件加密后的密文
    $Secret=substr($lines[2],$str_length);
    //echo $Secret;

    //直接还原密文输出
    echo "<!-- <?php\n".base64_decode(strtr($Secret,$decode_key,'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'))."?> -->"; //很奇怪，去掉这行，下面的代码就出现问题，可能跟编码有关，在这里我就暂时不做进一步分析了，注视掉避免界面缭乱。
    //echo "解密中....\<br>";
    $filecontent = "<?php\n".base64_decode(strtr($Secret,$decode_key,'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'))."?>";
    //echo $filecontent;
    $filenamebak = str_replace(".php",".bak.php",$filename);
    if(!file_exists($filenamebak)){
        if(rename($filename,$filenamebak))
        {
            if(!file_exists($filename) && file_exists($filenamebak))//文件被更改成功
            {
                $fp = fopen($filename,"w");
                fwrite($fp,$filecontent);
                fclose($fp);
                @unlink($filenamebak);
            }

        }

    }else{
        //return("备份文件".$filenamebak."已存在，停止解密。");
        weidun_log(false,realpath($filenamebak)." is exist!");
        return false;
    }
    weidun_log(true,realpath($filename)." - successful!");
    return $filename." - successful! \n";
}
function weidun_log($s = true,$c ="")
{
    if($s)
    {
        $fp = fopen("./log.txt","a+");
        fwrite($fp,$c."\n");
        fclose($fp);
    }
    else
    {
        $fp = fopen("./log_error.txt","a+");
        fwrite($fp,$c."\n");
        fclose($fp);
    }

}

?>

参考
https://github.com/hyperzlib/phar-online-pack-unpack
https://stackoverflow.com/questions/12997385/extracting-files-from-phar-archive