JS逆向 js 混淆 - 源码乱码

练习

题目

图一

分析

右键检查，会debugger
点一下第二行，右键点击never pause here

点击下图按钮即可正常抓包
查看参数

发现m是加密的，
m: 1692f18c681cbae905aec5e3c7d47c05丨1616239690经常爬虫的人会比较熟悉1616239690是一个时间戳

在python环境下打印当前时间，发现前面几乎是一样的，所以就是时间戳了
那么丨前面的参数怎么找呢，

• 如果直接搜m，匹配的太多了，肯定不可行
• 会不会是时间戳md5加密呢，打开鬼鬼JS调试工具，将输入进去，点击MD5加密，发现，结果并不一样
• 那只能从丨下手了
  
  在调试里面搜索发现只有一个文件里有，点进去看看，在图一网页源代码里也可以看，把丨复制一下（注意不是英文的哦），搜索一下
  
  那我们把<script></script>中间包含m的代码抠出来，放入notepad++,并js格式化
  

然后把无用的代码删除，剩下以下几行代码

然后从代码中可看出我们还需要找oo0O0函数，和刚刚一样，在源代码里找oo0O0，抠出来，放入同一个文件中，代码变成如下图所示

在代码的64行会发现返回一个空字符串，跟这个同级返回的并没有，说明70行的oo0O0(timestamp.toString()) 是空的，那搜索一下window.f，发现没有什么卵用，那就有点陷入死局了，我们只能依旧通过oo0O0找答案
有没有可能在运行oo0O0时里面的参数发生某些变化赋值给window.f呢
那么继续看63行eval函数是及其常见的，我们详细的看看里面都是什么，

• 在chrome控制台输入atob(window[‘b’])，
  得到一些js代码，我们复制一下，打开notepad++,复制到一个新文件中，并格式化，如下图
  
  中有window.f，说明我们思路是正确的，将最后一行的window. 去掉（图中已去除），最后一行中又有一个参数mwqqppz，在源码中并未搜索到，先不管这个，继续看
• J(‘0x0’, ‘]dQW’)在控制台输入提示没有J这个函数，可以先把文件中的J函数复制下来输入到控制台里，再输入J(‘0x0’, ‘]dQW’)
  发现是replace,将J(‘0x0’, ‘]dQW’)替换成replace
• J(‘0x1’, ‘GTu!’)
• 把J(‘0x1’, ‘GTu!’)，换成mwqqppz,
  我们再来看看这一个文件,mwqqppz不正是刚刚新建的文件里要找的吗
• mw正好为oo0O0函数的参数，var m = oo0O0(timestamp.toString()) + window.f;说明mw就是timestamp，将其替换掉，
• ‘\x27’ + timestamp + ‘\x27’ 将timestamp 随便换成一个数字123，在控制台输入，发现只是将123加一个单引号而已

那么我们就知道了mwqqppz就是mw,mw就是timestamp

那我们就分析完了，测试一下是正确的的

timestamp 后面加3个0是默认的，后面又除于1000，也可以在控制台测试，发现默认是加3个0的

代码

JS代码（命名1.js）：

var hexcase = 0;
var b64pad = "";
var chrsz = 16;
function hex_md5(a) {
    
    
return binl2hex(core_md5(str2binl(a), a.length * chrsz))
}
function b64_md5(a) {
    
    
return binl2b64(core_md5(str2binl(a), a.length * chrsz))
}
function str_md5(a) {
    
    
return binl2str(core_md5(str2binl(a), a.length * chrsz))
}
function hex_hmac_md5(a, b) {
    
    
return binl2hex(core_hmac_md5(a, b))
}
function b64_hmac_md5(a, b) {
    
    
return binl2b64(core_hmac_md5(a, b))
}
function str_hmac_md5(a, b) {
    
    
return binl2str(core_hmac_md5(a, b))
}
function md5_vm_test() {
    
    
return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72"
}
function core_md5(p, k) {
    
    
p[k >> 5] |= 128 << ((k) % 32);
p[(((k + 64) >>> 9) << 4) + 14] = k;
var o = 1732584193;
var n = -271733879;
var m = -1732584194;
var l = 271733878;
for (var g = 0; g < p.length; g += 16) {
    
    
    var j = o;
    var h = n;
    var f = m;
    var e = l;
    o = md5_ff(o, n, m, l, p[g + 0], 7, -680976936);
    l = md5_ff(l, o, n, m, p[g + 1], 12, -389564586);
    m = md5_ff(m, l, o, n, p[g + 2], 17, 606105819);
    n = md5_ff(n, m, l, o, p[g + 3], 22, -1044525330);
    o = md5_ff(o, n, m, l, p[g + 4], 7, -176418897);
    l = md5_ff(l, o, n, m, p[g + 5], 12, 1200080426);
    m = md5_ff(m, l, o, n, p[g + 6], 17, -1473231341);
    n = md5_ff(n, m, l, o, p[g + 7], 22, -45705983);
    o = md5_ff(o, n, m, l, p[g + 8], 7, 1770035416);
    l = md5_ff(l, o, n, m, p[g + 9], 12, -1958414417);
    m = md5_ff(m, l, o, n, p[g + 10], 17, -42063);
    n = md5_ff(n, m, l, o, p[g + 11], 22, -1990404162);
    o = md5_ff(o, n, m, l, p[g + 12], 7, 1804660682);
    l = md5_ff(l, o, n, m, p[g + 13], 12, -40341101);
    m = md5_ff(m, l, o, n, p[g + 14], 17, -1502002290);
    n = md5_ff(n, m, l, o, p[g + 15], 22, 1236535329);
    o = md5_gg(o, n, m, l, p[g + 1], 5, -165796510);
    l = md5_gg(l, o, n, m, p[g + 6], 9, -1069501632);
    m = md5_gg(m, l, o, n, p[g + 11], 14, 643717713);
    n = md5_gg(n, m, l, o, p[g + 0], 20, -373897302);
    o = md5_gg(o, n, m, l, p[g + 5], 5, -701558691);
    l = md5_gg(l, o, n, m, p[g + 10], 9, 38016083);
    m = md5_gg(m, l, o, n, p[g + 15], 14, -660478335);
    n = md5_gg(n, m, l, o, p[g + 4], 20, -405537848);
    o = md5_gg(o, n, m, l, p[g + 9], 5, 568446438);
    l = md5_gg(l, o, n, m, p[g + 14], 9, -1019803690);
    m = md5_gg(m, l, o, n, p[g + 3], 14, -187363961);
    n = md5_gg(n, m, l, o, p[g + 8], 20, 1163531501);
    o = md5_gg(o, n, m, l, p[g + 13], 5, -1444681467);
    l = md5_gg(l, o, n, m, p[g + 2], 9, -51403784);
    m = md5_gg(m, l, o, n, p[g + 7], 14, 1735328473);
    n = md5_gg(n, m, l, o, p[g + 12], 20, -1921207734);
    o = md5_hh(o, n, m, l, p[g + 5], 4, -378558);
    l = md5_hh(l, o, n, m, p[g + 8], 11, -2022574463);
    m = md5_hh(m, l, o, n, p[g + 11], 16, 1839030562);
    n = md5_hh(n, m, l, o, p[g + 14], 23, -35309556);
    o = md5_hh(o, n, m, l, p[g + 1], 4, -1530992060);
    l = md5_hh(l, o, n, m, p[g + 4], 11, 1272893353);
    m = md5_hh(m, l, o, n, p[g + 7], 16, -155497632);
    n = md5_hh(n, m, l, o, p[g + 10], 23, -1094730640);
    o = md5_hh(o, n, m, l, p[g + 13], 4, 681279174);
    l = md5_hh(l, o, n, m, p[g + 0], 11, -358537222);
    m = md5_hh(m, l, o, n, p[g + 3], 16, -722881979);
    n = md5_hh(n, m, l, o, p[g + 6], 23, 76029189);
    o = md5_hh(o, n, m, l, p[g + 9], 4, -640364487);
    l = md5_hh(l, o, n, m, p[g + 12], 11, -421815835);
    m = md5_hh(m, l, o, n, p[g + 15], 16, 530742520);
    n = md5_hh(n, m, l, o, p[g + 2], 23, -995338651);
    o = md5_ii(o, n, m, l, p[g + 0], 6, -198630844);
    l = md5_ii(l, o, n, m, p[g + 7], 10, 11261161415);
    m = md5_ii(m, l, o, n, p[g + 14], 15, -1416354905);
    n = md5_ii(n, m, l, o, p[g + 5], 21, -57434055);
    o = md5_ii(o, n, m, l, p[g + 12], 6, 1700485571);
    l = md5_ii(l, o, n, m, p[g + 3], 10, -1894446606);
    m = md5_ii(m, l, o, n, p[g + 10], 15, -1051523);
    n = md5_ii(n, m, l, o, p[g + 1], 21, -2054922799);
    o = md5_ii(o, n, m, l, p[g + 8], 6, 1873313359);
    l = md5_ii(l, o, n, m, p[g + 15], 10, -30611744);
    m = md5_ii(m, l, o, n, p[g + 6], 15, -1560198380);
    n = md5_ii(n, m, l, o, p[g + 13], 21, 1309151649);
    o = md5_ii(o, n, m, l, p[g + 4], 6, -145523070);
    l = md5_ii(l, o, n, m, p[g + 11], 10, -1120210379);
    m = md5_ii(m, l, o, n, p[g + 2], 15, 718787259);
    n = md5_ii(n, m, l, o, p[g + 9], 21, -343485551);
    o = safe_add(o, j);
    n = safe_add(n, h);
    m = safe_add(m, f);
    l = safe_add(l, e)
}
return Array(o, n, m, l)
}
function md5_cmn(h, e, d, c, g, f) {
    
    
return safe_add(bit_rol(safe_add(safe_add(e, h), safe_add(c, f)), g), d)
}
function md5_ff(g, f, k, j, e, i, h) {
    
    
return md5_cmn((f & k) | ((~f) & j), g, f, e, i, h)
}
function md5_gg(g, f, k, j, e, i, h) {
    
    
return md5_cmn((f & j) | (k & (~j)), g, f, e, i, h)
}
function md5_hh(g, f, k, j, e, i, h) {
    
    
return md5_cmn(f ^ k ^ j, g, f, e, i, h)
}
function md5_ii(g, f, k, j, e, i, h) {
    
    
return md5_cmn(k ^ (f | (~j)), g, f, e, i, h)
}
function core_hmac_md5(c, f) {
    
    
var e = str2binl(c);
if (e.length > 16) {
    
    
    e = core_md5(e, c.length * chrsz)
}
var a = Array(16),
d = Array(16);
for (var b = 0; b < 16; b++) {
    
    
    a[b] = e[b] ^ 909522486;
    d[b] = e[b] ^ 1549556828
}
var g = core_md5(a.concat(str2binl(f)), 512 + f.length * chrsz);
return core_md5(d.concat(g), 512 + 128)
}
function safe_add(a, d) {
    
    
var c = (a & 65535) + (d & 65535);
var b = (a >> 16) + (d >> 16) + (c >> 16);
return (b << 16) | (c & 65535)
}
function bit_rol(a, b) {
    
    
return (a << b) | (a >>> (32 - b))
}
function str2binl(d) {
    
    
var c = Array();
var a = (1 << chrsz) - 1;
for (var b = 0; b < d.length * chrsz; b += chrsz) {
    
    
    c[b >> 5] |= (d.charCodeAt(b / chrsz) & a) << (b % 32)
}
return c
}
function binl2str(c) {
    
    
var d = "";
var a = (1 << chrsz) - 1;
for (var b = 0; b < c.length * 32; b += chrsz) {
    
    
    d += String.fromCharCode((c[b >> 5] >>> (b % 32)) & a)
}
return d
}
function binl2hex(c) {
    
    
var b = hexcase ? "0123456789ABCDEF": "0123456789abcdef";
var d = "";
for (var a = 0; a < c.length * 4; a++) {
    
    
    d += b.charAt((c[a >> 2] >> ((a % 4) * 8 + 4)) & 15) + b.charAt((c[a >> 2] >> ((a % 4) * 8)) & 15)
}
return d
}
function binl2b64(d) {
    
    
var c = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var f = "";
for (var b = 0; b < d.length * 4; b += 3) {
    
    
    var e = (((d[b >> 2] >> 8 * (b % 4)) & 255) << 16) | (((d[b + 1 >> 2] >> 8 * ((b + 1) % 4)) & 255) << 8) | ((d[b + 2 >> 2] >> 8 * ((b + 2) % 4)) & 255);
    for (var a = 0; a < 4; a++) {
    
    
        if (b * 8 + a * 6 > d.length * 32) {
    
    
            f += b64pad
        } else {
    
    
            f += c.charAt((e >> 6 * (3 - a)) & 63)
        }
    }
}
return f
};
function get_val() {
    
    
var timestamp = Date.parse(new Date()) + 100000000;
timestamp += '';
f = hex_md5(timestamp);
return f+"丨"+timestamp/1000;
}

python代码：

import requests,execjs,time,json
sum0 = 0
leng = 0
def calculate_m_value():
    with open('1.js','r',encoding='utf-8')as f:
        Jsdata = f.read()
        
    data = execjs.compile(Jsdata).call('get_val')
    return data
    
def parse_page(url):
    global leng,sum0
    headers = {
    
    
        'Host':'match.yuanrenxue.com',
        'Pragma':'no-cache',
        'Referer':'http://match.yuanrenxue.com/match/1',
        'User-Agent':'yuanrenxue.project',
        'X-Requested-With':'XMLHttpRequest'
    }
    r = requests.get(url,headers=headers)
    js = json.loads(r.text)
    leg = len(js['data'])
    leng=leng+leg
    x = [int(one['value']) for one in js['data']]
    sum0 += sum(x)
    print(x)
def main():
    for i in range(1,6):
        data = calculate_m_value()
        url = f'http://match.yuanrenxue.com/api/match/1?page={i}&m={data}'
        print(data)
        parse_page(url)

        
if __name__ == '__main__':
    main()
    print(sum0/leng)

结果