<?php 
defined('IN_TS') or die('Access Denied.');

switch($ts){

    /**
     * 阿里云oss直传回调
     */
    case "callback":

        // 1.获取OSS的签名header和公钥url header
        $authorizationBase64 = "";
        $pubKeyUrlBase64 = "";
        /*
        * 注意：如果要使用HTTP_AUTHORIZATION头，你需要先在apache或者nginx中设置rewrite，以apache为例，修改
        * 配置文件/etc/httpd/conf/httpd.conf(以你的apache安装路径为准)，在DirectoryIndex index.php这行下面增加以下两行
            RewriteEngine On
            RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization},last]
        * */
        if (isset($_SERVER['HTTP_AUTHORIZATION']))
        {
            $authorizationBase64 = $_SERVER['HTTP_AUTHORIZATION'];
        }
        if (isset($_SERVER['HTTP_X_OSS_PUB_KEY_URL']))
        {
            $pubKeyUrlBase64 = $_SERVER['HTTP_X_OSS_PUB_KEY_URL'];
        }

        if ($authorizationBase64 == '' || $pubKeyUrlBase64 == '')
        {
            header("http/1.1 403 Forbidden");
            exit();
        }

        // 2.获取OSS的签名
        $authorization = base64_decode($authorizationBase64);

        // 3.获取公钥
        $pubKeyUrl = base64_decode($pubKeyUrlBase64);
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $pubKeyUrl);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
        $pubKey = curl_exec($ch);
        if ($pubKey == "")
        {
            //header("http/1.1 403 Forbidden");
            exit();
        }

        // 4.获取回调body
        $body = file_get_contents('php://input');

        // 5.拼接待签名字符串
        $authStr = '';
        $path = $_SERVER['REQUEST_URI'];
        $pos = strpos($path, '?');
        if ($pos === false)
        {
            $authStr = urldecode($path)."\n".$body;
        }
        else
        {
            $authStr = urldecode(substr($path, 0, $pos)).substr($path, $pos, strlen($path) - $pos)."\n".$body;
        }

        // 6.验证签名
        $ok = openssl_verify($authStr, $authorization, $pubKey, OPENSSL_ALGO_MD5);
        if ($ok == 1)
        {
            header("Content-Type: application/json");
            $data = array("Status"=>"Ok");
            echo json_encode($data);
        }
        else
        {
            //header("http/1.1 403 Forbidden");
            exit();
        }

        break;

}