猿人学— 第一届第1题（解题思路附源码）

猿人学 --- 第一届第1题（解题思路附源码）

F12进入开发者工具---> 发现停止在debugger 处 ---> 右键点击Never pause here 后下一步
翻页，抓包后发现请求携带page 和m 两个参数，page 应该就是页数，m 则需要逆向
依次查找文件，寻找m 在哪里被赋值，随后在VM14235：6中发现混淆代码比较可疑
- 进入文件，给request函数中的赋值语句给上断点，重新请求
- 发现'\x6d'='m'，而_0x5d83a3['\x6d']的值则与Payload中m的值神似
- 继续调试，让请求过去，验证，发现Payload中m确实与此处的值对应

手动翻译一下代码

javascript 复制代码

var _0x2268f9 = Date['parse'](new Date()) + 100000000
var _0x57feae = ooΘ0Θ(_0x2268f9['toString'()])+window['f'];
const _0x5d83a3 = {};
_0x5d83a3['page'] = window['page']
_0x5d83a3['m'] = _0x57feaa + '丨'+ _0x2268f9 / 1000;

逆向m ，则必须知道_0x57feaa和_0x2268f9，而_0x2268f9很明显是一个时间戳，因此主要解决_0x57feaa
- 多次请求后发现ooΘ0Θ(_0x2268f9['toString'()])返回一个空字符串，因此主要关注window['f']
- 通过Console面板 定义Hook，定位window['f']在哪里被赋值
  javascript 复制代码
```
Object.defineProperty(window, 'f', {
   set: function(val) {
            console.log('f的值:', val);
           	debugger
            return val;
        }
    }
)
```
- 再次请求，停止后，向上寻找调用栈，发现是一个hex_md5函数的返回值 ，而这个函数的形参则是之前的_0x2268f9，即时间戳，不过注意类型是字符串（我开始没有注意，导致得到的m一直是一个错误的固定值）

最后就是去扣hex_md5函数及其运行依赖放到node中执行（当然也可以将整个js文件copy下来），源码如下

javascript 复制代码

window = global
var hexcase = 0;
var chrsz = 16;
function hex_md5(a) {
    return binl2hex(core_md5(str2binl(a), a.length * chrsz))
}
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 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 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 playload_m(){
    var _0x2268f9 = Date['parse'](new Date()) + (100000000)
    return hex_md5(_0x2268f9.toString()) + '丨' + _0x2268f9 / (1000);
}

python 复制代码

import requests
import execjs


# 请求获取页面数据
def get_data(page, m):
    res = requests.get(
        url='https://match.yuanrenxue.cn/api/match/1',
        params={
            'page': page,
            'm': m
        }
    )
    return res


# 执行js代码获得参数m
def get_m():
    with open('v1.js', 'rt', encoding='utf-8') as f:
        js_string = f.read()
    js_code = execjs.compile(js_string)
    param_m = js_code.call('playload_m')
    return param_m


# 处理请求返回的数据，计算机票平均价格
def get_average(page):
    count = 0
    value = 0
    param_m = get_m()
    for pid in range(1, page + 1):

        url_res = get_data(pid,param_m)
        if url_res.status_code == 200:
            page_data = get_data(pid,param_m).json()['data']
            for item in page_data:
                value += int(item['value'])
            count += len(page_data)
        else:
            print(f"{pid}页数据请求失败:{url_res.json()}")
    print(f"前{page}页机票平均价格:{value / count}")


if __name__ == '__main__':
    get_average(5)

运行结果
笔者为刚接触逆向的小白，若上面有错误、不合理和值得优化的地方，欢迎各位大佬批评指正！