爬虫逆向实战（四）--猿人学第一题

一、数据接口分析

主页地址：猿人学第一题

1、抓包

当我们打开F12时会发现直接debugger了，是一个无限debugger，我们直接右键debugger那一行，然后选择“一律不再此处暂停”就可以了

通过抓包可以发现登录接口是api/match/1

2、判断是否有加密参数

1. 请求参数是否加密？
   查看“载荷”模块可以发现有一个m加密参数
   
2. 请求头是否加密？
   无
3. 响应是否加密？
   无
4. cookie是否加密？
   无

二、加密位置定位

1、看启动器

查看启动器发现有一个调用堆栈中request，点进去查看

点进去之后，发现代码是混淆的，虽然是混淆的，但是格式有点类似jQuery发ajax请求，所以打断点尝试一下

点击翻页，发现可以断住，此处就是ajax请求，并且m参数的生成就在此行上方

查看m的加密时，发现m的生成是将window中的f与时间戳进行拼接，所以我们还需要找到f是如何生成的

2、hook

因为代码是混淆的，并且f无法作为关键字进行搜索，所以我们可以对window.f进行hook
hook代码：

(function () {
    var window_f = '';
    Object.defineProperty(window, 'f', {
        set: function (val) {
            debugger;
            window_f = val;
            return val;
        },
        get: function () {
            return window_f;
        },
    });
})();

执行hook代码之后，我们再次点击翻页，此时hook代码断住了，接着往下方跟，可以找到window.f的赋值位置

三、扣js代码

上方找到的f的加密方法是hex_md5，此时我们可以推测此处可能是标准md5加密，在控制台中使用此方法加密字符串’1’进行尝试，结果发现并不是标准的md5加密
所以我们只能扣网站的加密方法了，可以看到加密所在的这个js文件中代码并不是很多，所以我们可以直接全扣。
源代码：

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 hex_md5(a) {
    return binl2hex(core_md5(str2binl(a), a.length * 16))
}


function get_m() {
    var time_str = Date.parse(new Date()) + 100000000

    var str_a = hex_md5(time_str.toString())

    return str_a + '丨' + time_str / 1000
}