Question

以下是完整的脚本来源：https://gist.github.com/x10hassan/454347585de3c2312f1c#file-cipher

关于脚本和小背景：

这个脚本用于获取和解码Youtube下载链接，它只是结构代码，目前工作良好，服务器的目的，我正在尝试将其转换为功能。

我的问题：

查看完整的源代码，第94行

上有Foreach声明

foreach ($links as $link) {
                    parse_str($link,$linkarr);

                    // parse link array one by one and decrypt the signature
                    $dlinks[$linkarr['itag']] = $linkarr['url'] . "&signature=" . decrypt($linkarr['s'],$algo);
                    echo $linkarr['itag'].'<br />';
                    echo $dlinks[$linkarr['itag']].'<br /><br />';
                }

有一个$ linkarr变量，它来自何处以及它的用途，编译结果可以在这里找到：http://yt.hassannaseer.com/sb/cipher.php

我正在尝试创建一个接受视频ID的函数，并返回一个关联数组，其中包含“itag”的键，值为“decode youtube download link”？有人可以帮助我吗？

Answer 1

请在此处找到完整代码：Github/bitnol

供参考检查：

<?php

/**
 * Author: Akhilesh Chandra Gupta
 * Author URI: http://www.bitnol.com
 * API URI: http://api.gitnol.com
 * Description: Modular demo of the application of Cipher API
 * License: MIT License
 */

// Video with cipher signature 
$video_id = "zDrNLZ1uJ2w";
$results = getYTLink($video_id);
var_dump($results);

function getYTLink($video_id){

    // get_video_info url formation
    // although for cipher signature we have to get the details from the video's webapge not from get_video_info object
    $info_url = "http://www.youtube.com/get_video_info?el=detailpage&asv=3&video_id=".$video_id;

    // youtube webpage url formation
    $yt_url = 'http://www.youtube.com/watch?v='.$video_id.'&gl=US&persist_gl=1&hl=en&persist_hl=1';;

    // get the contents from the url
    $raw_data = file_get_contents($info_url);

    // parse the data received and save it as an array
    $output = array();
    parse_str($raw_data,$output);

    // check the status of the get_video_info object
    if($output['status']=='ok'){

        // check for the cipher signature
        $cipher = (isset($output['use_cipher_signature']) &&  $output['use_cipher_signature']=='True') ? true : false;

        // If cipher is true then we have to decode it
        if($cipher == true){

            // if cipher is true then we have to change the plan and get the details from the video's youtube wbe page
            $yt_html = file_get_contents($yt_url);

            // parse for the script containing the configuration
            preg_match('/ytplayer.config = {(.*?)};/',$yt_html,$match);
            $yt_object = @json_decode('{'.$match[1].'}') ;

            /// check if we are able to parse data
            if(!is_object($yt_object)){
                //'Sorry! Unable to parse Data';
                return 'Error Code 1';
            }else{

                // parse available formats
                $formats = $yt_object->args->url_encoded_fmt_stream_map;
                // get the player id from assets section
                $player_id = strbtwn($yt_object->assets->js,'html5player-','.js');
                $player_id = explode("/", $player_id);
                $player_id = $player_id[0];

                // get the algo dictionary
                // first check if the file exists
                if(file_exists('./algo.json'))
                    $algos = json_decode(file_get_contents('algo.json'),true);
                else{
                    // API call to fetch the algo dictionary
                    $algos_dict = file_get_contents("http://api.gitnol.com/getAlgo.php?playerID=".$player_id);

                    // saving the algo dictonary in local env for easy access
                    // Note: Developers should save the dictionary in their local env. 
                    // Only make the API call for the new player ids which is not present in the algo dictionary.
                    // Repeated violation will results in IP ban.
                    file_put_contents('algo.json', $algos_dict);

                    $algos = json_decode($algos_dict,true);
                }

                /// check if the algo exist for the given player id
                if(!array_key_exists($player_id, $algos)){

                    // if the algo dictionary is old then fetch a new one
                    $algos_dict = file_get_contents("http://api.gitnol.com/getAlgo.php?playerID=".$player_id);
                    file_put_contents('algo.json', $algos_dict);

                    $algos = json_decode($algos_dict,true);
                    $algo = $algos[$player_id][1];

                }else{
                    $algo = $algos[$player_id][1];
                }

                // download links formation
                $dlinks = array();
                $links  = explode(',',$formats);


                foreach ($links as $link) {
                    parse_str($link,$linkarr);

                    // parse link array one by one and decrypt the signature
                    $dlinks[$linkarr['itag']] = $linkarr['url'] . "&signature=" . decrypt($linkarr['s'],$algo);
                }
                return $dlinks;
            }

        }else{
            //'Video Is not cipher not needed to decode';
            return 'Error Code 2'; 
        }
    }else{
        //'Unable to get Video Info';
        return 'Error Code 3'; 
    }
}
// string helper function
function strbtwn($content,$start,$end){
    $r = explode($start, $content);
    if (isset($r[1])){
        $r = explode($end, $r[1]);
        return $r[0];
    }
    return '';
}

// signature decoding 
// parse the python string operation into php string operation
function decrypt($sig,$algo){
    $funcarr = explode(' + ', $algo);
    $decrypt = '';
    foreach($funcarr as $singfunc){
        $singfunc = substr($singfunc,2,-1);
        $operators = explode(':', $singfunc);
        if (sizeof($operators) == 1) {
            $decrypt .= $sig[$operators[0]];
        }
        if (sizeof($operators) == 2) {
            if($operators[0] == ''){
                $decrypt .= substr($sig, 0 ,$operators[1]);
            }
            if($operators[1] == ''){
                $decrypt .= substr($sig, $operators[0]);
            }
            if($operators[0] >= 0 && $operators[1] >= 0){
                $decrypt .= substr($sig, $operators[0], $operators[1] - $operators[0]);
            }
        }
        if (sizeof($operators) == 3) {
            if($operators[0] == '' && $operators[1] == ''){
                $decrypt .= strrev($sig);
            }
            if($operators[0] >=0 && $operators[1] == ''){
                $decrypt .= strrev(substr($sig, 0, $operators[0] + 1));
            }
            if($operators[0] >=0 && $operators[1] >= 0){
                $decrypt .= strrev(substr($sig, $operators[1] + 1, $operators[0] - $operators[1]));
            }
        }
    }
    return $decrypt;
}
?>

我认为这将解决您的问题。

我怎么知道arr变量的来源？

1 个答案: