JS逆向爬虫----响应结果加密③【某名科技爬虫响应解密】

接口分析

1. 打开链接 ： 爬虫链接
2. f12抓包,搜索关键词
   
   3. 查找特殊数据：
   打开xhr抓包，下拉加载数据。
   
   打开数据包查看：
   数据疑似被加密，最后通过前端js解密生成想要数据。
   在尝试了很多次搜索都搜不到页面内的可用关键词，我们需要根据响应包的关键词搜索，了解前端是如何使用响应并渲染出想要的数据。

解密代码定位

重新抓包，搜索关键词：encrypt_data

定位到包含关键词的js，在来源面板打开。

在如图所示位置打断点，刷新页面。
zai
页面在加载到如上位置时，会在断点停顿几次，直接点击继续执行脚本，知道右侧n值为：/DataList/productListVip&post，t下encrypt_data加载出来。

在控制台输入**(t.data = Object(d.a)(t.encrypt_data))**
获取到如下数据，其中的list就是我们需要的数据。

到此，我们只需要逆向(t.data = Object(d.a)(t.encrypt_data))这个代码就可以了
t.encrypt_data值就是xhr的接口响应的encryt_data字段。

进入d.a函数，到达如下位置

在如下位置打断点，并继续执行脚本到return位置
在控制台输入 JSON.parse(o(“5e5062e82f15fe4ca9d24bc5”, a.a.decode(e), 0, 0, “012345677890123”, 1))
查看函数运行结果，如下：

依然有我们需要的结果，我们只需要逆向o(“5e5062e82f15fe4ca9d24bc5”, a.a.decode(e), 0, 0, “012345677890123”, 1)函数即可。
函数内其他参数都固定，只有a.a.decode(e)未知，我们下面来解析这个参数。

逆向【手撕js源码+补充依赖】

参数a.a.decode(e)解密

观察下图，在函数停顿到return位置时，e的值即为原来需要解密的数据。

进入a.a.decode函数，解密函数实现流程。

我们将此函数直接复制到js文件内，并传递参数，查看是否缺乏依赖，并补充。

缺乏f,l变量，查看页面函数前面，有变量定义。

还原整个依赖与函数如下：

函数运行成功。
为函数传真实参数，并调用结果，结果如下。

到这里我们a.a.decode函数还原完毕，下面开始还原外层o函数

o函数还原

我们点击进入o函数位置，发现o函数如下

直接复制整个o函数到js文件内，并传参测试：

解析成功，说明o函数依赖不缺失。

完整逆向代码

l = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
f = /[\t\n\f\r ]/g;

function jesse(t) {
    var e = (t = String(t).replace(f, "")).length;
    e % 4 == 0 && (e = (t = t.replace(/==?$/, "")).length),
        (e % 4 == 1 || /[^+a-zA-Z0-9/]/.test(t));
    for (var n, r, i = 0, o = "", a = -1; ++a < e;)
        r = l.indexOf(t.charAt(a)),
            n = i % 4 ? 64 * n + r : r,
        i++ % 4 && (o += String.fromCharCode(255 & n >> (-2 * i & 6)));
    return o
};

const e = "由于数据太长，就不贴图了，你们自己复制数据吧";
function o(e, t, i, n, a, o) {
            var s, c, r, l, d, u, h, p, f, m, v, g, y, b, C = new Array(16843776,0,65536,16843780,16842756,66564,4,65536,1024,16843776,16843780,1024,16778244,16842756,16777216,4,1028,16778240,16778240,66560,66560,16842752,16842752,16778244,65540,16777220,16777220,65540,0,1028,66564,16777216,65536,16843780,4,16842752,16843776,16777216,16777216,1024,16842756,65536,66560,16777220,1024,4,16778244,66564,16843780,65540,16842752,16778244,16777220,1028,66564,16843776,1028,16778240,16778240,0,65540,66560,0,16842756), _ = new Array(-2146402272,-2147450880,32768,1081376,1048576,32,-2146435040,-2147450848,-2147483616,-2146402272,-2146402304,-2147483648,-2147450880,1048576,32,-2146435040,1081344,1048608,-2147450848,0,-2147483648,32768,1081376,-2146435072,1048608,-2147483616,0,1081344,32800,-2146402304,-2146435072,32800,0,1081376,-2146435040,1048576,-2147450848,-2146435072,-2146402304,32768,-2146435072,-2147450880,32,-2146402272,1081376,32,32768,-2147483648,32800,-2146402304,1048576,-2147483616,1048608,-2147450848,-2147483616,1048608,1081344,0,-2147450880,32800,-2147483648,-2146435040,-2146402272,1081344), w = new Array(520,134349312,0,134348808,134218240,0,131592,134218240,131080,134217736,134217736,131072,134349320,131080,134348800,520,134217728,8,134349312,512,131584,134348800,134348808,131592,134218248,131584,131072,134218248,8,134349320,512,134217728,134349312,134217728,131080,520,131072,134349312,134218240,0,512,131080,134349320,134218240,134217736,512,0,134348808,134218248,131072,134217728,134349320,8,131592,131584,134217736,134348800,134218248,520,134348800,131592,8,134348808,131584), k = new Array(8396801,8321,8321,128,8396928,8388737,8388609,8193,0,8396800,8396800,8396929,129,0,8388736,8388609,1,8192,8388608,8396801,128,8388608,8193,8320,8388737,1,8320,8388736,8192,8396928,8396929,129,8388736,8388609,8396800,8396929,129,0,0,8396800,8320,8388736,8388737,1,8396801,8321,8321,128,8396929,129,1,8192,8388609,8193,8396928,8388737,8193,8320,8388608,8396801,128,8388608,8192,8396928), x = new Array(256,34078976,34078720,1107296512,524288,256,1073741824,34078720,1074266368,524288,33554688,1074266368,1107296512,1107820544,524544,1073741824,33554432,1074266112,1074266112,0,1073742080,1107820800,1107820800,33554688,1107820544,1073742080,0,1107296256,34078976,33554432,1107296256,524544,524288,1107296512,256,33554432,1073741824,34078720,1107296512,1074266368,33554688,1073741824,1107820544,34078976,1074266368,256,33554432,1107820544,1107820800,524544,1107296256,1107820800,34078720,0,1074266112,1107296256,524544,33554688,1073742080,524288,0,1074266112,34078976,1073742080), T = new Array(536870928,541065216,16384,541081616,541065216,16,541081616,4194304,536887296,4210704,4194304,536870928,4194320,536887296,536870912,16400,0,4194320,536887312,16384,4210688,536887312,16,541065232,541065232,0,4210704,541081600,16400,4210688,541081600,536870912,536887296,16,541065232,4210688,541081616,4194304,16400,536870928,4194304,536887296,536870912,16400,536870928,541081616,4210688,541065216,4210704,541081600,0,541065232,16,16384,541065216,4210704,16384,4194320,536887312,0,541081600,536870912,4194320,536887312), A = new Array(2097152,69206018,67110914,0,2048,67110914,2099202,69208064,69208066,2097152,0,67108866,2,67108864,69206018,2050,67110912,2099202,2097154,67110912,67108866,69206016,69208064,2097154,69206016,2048,2050,69208066,2099200,2,67108864,2099200,67108864,2099200,2097152,67110914,67110914,69206018,69206018,2,2097154,67108864,67110912,2097152,69208064,2050,2099202,69208064,2050,67108866,69208066,69206016,2099200,0,2,69208066,0,2099202,69206016,2048,67108866,67110912,2048,2097154), N = new Array(268439616,4096,262144,268701760,268435456,268439616,64,268435456,262208,268697600,268701760,266240,268701696,266304,4096,64,268697600,268435520,268439552,4160,266240,262208,268697664,268701696,4160,0,0,268697664,268435520,268439552,266304,262144,266304,262144,268701696,4096,64,268697664,4096,266304,268439552,64,268435520,268697600,268697664,268435456,262144,268439616,0,268701760,262208,268435520,268697600,268439552,268439616,0,268701760,266240,266240,4160,4160,262208,268435456,268701696), $ = function(e) {
                for (var t, i, n, a = new Array(0,4,536870912,536870916,65536,65540,536936448,536936452,512,516,536871424,536871428,66048,66052,536936960,536936964), o = new Array(0,1,1048576,1048577,67108864,67108865,68157440,68157441,256,257,1048832,1048833,67109120,67109121,68157696,68157697), s = new Array(0,8,2048,2056,16777216,16777224,16779264,16779272,0,8,2048,2056,16777216,16777224,16779264,16779272), c = new Array(0,2097152,134217728,136314880,8192,2105344,134225920,136323072,131072,2228224,134348800,136445952,139264,2236416,134356992,136454144), r = new Array(0,262144,16,262160,0,262144,16,262160,4096,266240,4112,266256,4096,266240,4112,266256), l = new Array(0,1024,32,1056,0,1024,32,1056,33554432,33555456,33554464,33555488,33554432,33555456,33554464,33555488), d = new Array(0,268435456,524288,268959744,2,268435458,524290,268959746,0,268435456,524288,268959744,2,268435458,524290,268959746), u = new Array(0,65536,2048,67584,536870912,536936448,536872960,536938496,131072,196608,133120,198656,537001984,537067520,537004032,537069568), h = new Array(0,262144,0,262144,2,262146,2,262146,33554432,33816576,33554432,33816576,33554434,33816578,33554434,33816578), p = new Array(0,268435456,8,268435464,0,268435456,8,268435464,1024,268436480,1032,268436488,1024,268436480,1032,268436488), f = new Array(0,32,0,32,1048576,1048608,1048576,1048608,8192,8224,8192,8224,1056768,1056800,1056768,1056800), m = new Array(0,16777216,512,16777728,2097152,18874368,2097664,18874880,67108864,83886080,67109376,83886592,69206016,85983232,69206528,85983744), v = new Array(0,4096,134217728,134221824,524288,528384,134742016,134746112,16,4112,134217744,134221840,524304,528400,134742032,134746128), g = new Array(0,4,256,260,0,4,256,260,1,5,257,261,1,5,257,261), y = e.length > 8 ? 3 : 1, b = new Array(32 * y), C = new Array(0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0), _ = 0, w = 0, k = 0; k < y; k++) {
                    var x = e.charCodeAt(_++) << 24 | e.charCodeAt(_++) << 16 | e.charCodeAt(_++) << 8 | e.charCodeAt(_++)
                      , T = e.charCodeAt(_++) << 24 | e.charCodeAt(_++) << 16 | e.charCodeAt(_++) << 8 | e.charCodeAt(_++);
                    x ^= (n = 252645135 & (x >>> 4 ^ T)) << 4,
                    x ^= n = 65535 & ((T ^= n) >>> -16 ^ x),
                    x ^= (n = 858993459 & (x >>> 2 ^ (T ^= n << -16))) << 2,
                    x ^= n = 65535 & ((T ^= n) >>> -16 ^ x),
                    x ^= (n = 1431655765 & (x >>> 1 ^ (T ^= n << -16))) << 1,
                    x ^= n = 16711935 & ((T ^= n) >>> 8 ^ x),
                    n = (x ^= (n = 1431655765 & (x >>> 1 ^ (T ^= n << 8))) << 1) << 8 | (T ^= n) >>> 20 & 240,
                    x = T << 24 | T << 8 & 16711680 | T >>> 8 & 65280 | T >>> 24 & 240,
                    T = n;
                    for (var A = 0; A < C.length; A++)
                        C[A] ? (x = x << 2 | x >>> 26,
                        T = T << 2 | T >>> 26) : (x = x << 1 | x >>> 27,
                        T = T << 1 | T >>> 27),
                        T &= -15,
                        t = a[(x &= -15) >>> 28] | o[x >>> 24 & 15] | s[x >>> 20 & 15] | c[x >>> 16 & 15] | r[x >>> 12 & 15] | l[x >>> 8 & 15] | d[x >>> 4 & 15],
                        i = u[T >>> 28] | h[T >>> 24 & 15] | p[T >>> 20 & 15] | f[T >>> 16 & 15] | m[T >>> 12 & 15] | v[T >>> 8 & 15] | g[T >>> 4 & 15],
                        n = 65535 & (i >>> 16 ^ t),
                        b[w++] = t ^ n,
                        b[w++] = i ^ n << 16
                }
                return b
            }(e), L = 0, S = t.length, z = 0, I = 32 == $.length ? 3 : 9;
            p = 3 == I ? i ? new Array(0,32,2) : new Array(30,-2,-2) : i ? new Array(0,32,2,62,30,-2,64,96,2) : new Array(94,62,-2,32,64,2,30,-2,-2),
            2 == o ? t += "        " : 1 == o ? i && (r = 8 - S % 8,
            t += String.fromCharCode(r, r, r, r, r, r, r, r),
            8 === r && (S += 8)) : o || (t += "\0\0\0\0\0\0\0\0");
            var B = ""
              , F = "";
            for (1 == n && (f = a.charCodeAt(L++) << 24 | a.charCodeAt(L++) << 16 | a.charCodeAt(L++) << 8 | a.charCodeAt(L++),
            v = a.charCodeAt(L++) << 24 | a.charCodeAt(L++) << 16 | a.charCodeAt(L++) << 8 | a.charCodeAt(L++),
            L = 0); L < S; ) {
                for (u = t.charCodeAt(L++) << 24 | t.charCodeAt(L++) << 16 | t.charCodeAt(L++) << 8 | t.charCodeAt(L++),
                h = t.charCodeAt(L++) << 24 | t.charCodeAt(L++) << 16 | t.charCodeAt(L++) << 8 | t.charCodeAt(L++),
                1 == n && (i ? (u ^= f,
                h ^= v) : (m = f,
                g = v,
                f = u,
                v = h)),
                u ^= (r = 252645135 & (u >>> 4 ^ h)) << 4,
                u ^= (r = 65535 & (u >>> 16 ^ (h ^= r))) << 16,
                u ^= r = 858993459 & ((h ^= r) >>> 2 ^ u),
                u ^= r = 16711935 & ((h ^= r << 2) >>> 8 ^ u),
                u = (u ^= (r = 1431655765 & (u >>> 1 ^ (h ^= r << 8))) << 1) << 1 | u >>> 31,
                h = (h ^= r) << 1 | h >>> 31,
                c = 0; c < I; c += 3) {
                    for (y = p[c + 1],
                    b = p[c + 2],
                    s = p[c]; s != y; s += b)
                        l = h ^ $[s],
                        d = (h >>> 4 | h << 28) ^ $[s + 1],
                        r = u,
                        u = h,
                        h = r ^ (_[l >>> 24 & 63] | k[l >>> 16 & 63] | T[l >>> 8 & 63] | N[63 & l] | C[d >>> 24 & 63] | w[d >>> 16 & 63] | x[d >>> 8 & 63] | A[63 & d]);
                    r = u,
                    u = h,
                    h = r
                }
                h = h >>> 1 | h << 31,
                h ^= r = 1431655765 & ((u = u >>> 1 | u << 31) >>> 1 ^ h),
                h ^= (r = 16711935 & (h >>> 8 ^ (u ^= r << 1))) << 8,
                h ^= (r = 858993459 & (h >>> 2 ^ (u ^= r))) << 2,
                h ^= r = 65535 & ((u ^= r) >>> 16 ^ h),
                h ^= r = 252645135 & ((u ^= r << 16) >>> 4 ^ h),
                u ^= r << 4,
                1 == n && (i ? (f = u,
                v = h) : (u ^= m,
                h ^= g)),
                F += String.fromCharCode(u >>> 24, u >>> 16 & 255, u >>> 8 & 255, 255 & u, h >>> 24, h >>> 16 & 255, h >>> 8 & 255, 255 & h),
                512 == (z += 8) && (B += F,
                F = "",
                z = 0)
            }
            if (B = (B += F).replace(/\0*$/g, ""),
            !i) {
                if (1 === o) {
                    var j = 0;
                    (S = B.length) && (j = B.charCodeAt(S - 1)),
                    j <= 8 && (B = B.substring(0, S - j))
                }
                B = decodeURIComponent(escape(B))
            }
            return B
        };
result = JSON.parse(o("5e5062e82f15fe4ca9d24bc5", jesse(e), 0, 0, "012345677890123", 1));

console.log(result);