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要挖掘登陆模块，首先查看其登陆POST请求，其中password字段需要逆向，这里是随机输入的密码【321654】：
要找到password字段的生成方式，可以从接口入手，全局搜“/user/login”：
找到对应的js文件后，由于代码被压缩成一行了，点进去是无法直接达到目标位置，但可以格式化后搜索“/user/login”找到目标位置：
此处下断点调试，发现在发出请求时已经生成了加密后的password：
从调用栈往上跟，最终找到此处是明文->密文的地方：
跟进去发现最终是调用了 /chunks/cacd27eb40cd7e51ddd90f7c7da2b1f265682e63.f9f37c164718db9c218f.js 中的函数。这里我加的是【e == ‘321654’】的条件断点，防止其他地方调用此函数干扰判断：
该函数源码：
aCH8: function(e, t, n) {
!function() {
var t = n("ANhw")
, r = n("mmNF").utf8
, o = n("BEtg")
, i = n("mmNF").bin
, s = function(e, n) {
e.constructor == String ? e = n && "binary" === n.encoding ? i.stringToBytes(e) : r.stringToBytes(e) : o(e) ? e = Array.prototype.slice.call(e, 0) : Array.isArray(e) || (e = e.toString());
for (var a = t.bytesToWords(e), u = 8 * e.length, c = 1732584193, f = -271733879, p = -1732584194, h = 271733878, l = 0; l < a.length; l++)
a[l] = 16711935 & (a[l] << 8 | a[l] >>> 24) | 4278255360 & (a[l] << 24 | a[l] >>> 8);
a[u >>> 5] |= 128 << u % 32,
a[14 + (u + 64 >>> 9 << 4)] = u;
var d = s._ff
, y = s._gg
, m = s._hh
, g = s._ii;
for (l = 0; l < a.length; l += 16) {
var v = c
, w = f
, x = p
, b = h;
c = d(c, f, p, h, a[l + 0], 7, -680876936),
h = d(h, c, f, p, a[l + 1], 12, -389564586),
p = d(p, h, c, f, a[l + 2], 17, 606105819),
f = d(f, p, h, c, a[l + 3], 22, -1044525330),
c = d(c, f, p, h, a[l + 4], 7, -176418897),
h = d(h, c, f, p, a[l + 5], 12, 1200080426),
p = d(p, h, c, f, a[l + 6], 17, -1473231341),
f = d(f, p, h, c, a[l + 7], 22, -45705983),
c = d(c, f, p, h, a[l + 8], 7, 1770035416),
h = d(h, c, f, p, a[l + 9], 12, -1958414417),
p = d(p, h, c, f, a[l + 10], 17, -42063),
f = d(f, p, h, c, a[l + 11], 22, -1990404162),
c = d(c, f, p, h, a[l + 12], 7, 1804603682),
h = d(h, c, f, p, a[l + 13], 12, -40341101),
p = d(p, h, c, f, a[l + 14], 17, -1502002290),
c = y(c, f = d(f, p, h, c, a[l + 15], 22, 1236535329), p, h, a[l + 1], 5, -165796510),
h = y(h, c, f, p, a[l + 6], 9, -1069501632),
p = y(p, h, c, f, a[l + 11], 14, 643717713),
f = y(f, p, h, c, a[l + 0], 20, -373897302),
c = y(c, f, p, h, a[l + 5], 5, -701558691),
h = y(h, c, f, p, a[l + 10], 9, 38016083),
p = y(p, h, c, f, a[l + 15], 14, -660478335),
f = y(f, p, h, c, a[l + 4], 20, -405537848),
c = y(c, f, p, h, a[l + 9], 5, 568446438),
h = y(h, c, f, p, a[l + 14], 9, -1019803690),
p = y(p, h, c, f, a[l + 3], 14, -187363961),
f = y(f, p, h, c, a[l + 8], 20, 1163531501),
c = y(c, f, p, h, a[l + 13], 5, -1444681467),
h = y(h, c, f, p, a[l + 2], 9, -51403784),
p = y(p, h, c, f, a[l + 7], 14, 1735328473),
c = m(c, f = y(f, p, h, c, a[l + 12], 20, -1926607734), p, h, a[l + 5], 4, -378558),
h = m(h, c, f, p, a[l + 8], 11, -2022574463),
p = m(p, h, c, f, a[l + 11], 16, 1839030562),
f = m(f, p, h, c, a[l + 14], 23, -35309556),
c = m(c, f, p, h, a[l + 1], 4, -1530992060),
h = m(h, c, f, p, a[l + 4], 11, 1272893353),
p = m(p, h, c, f, a[l + 7], 16, -155497632),
f = m(f, p, h, c, a[l + 10], 23, -1094730640),
c = m(c, f, p, h, a[l + 13], 4, 681279174),
h = m(h, c, f, p, a[l + 0], 11, -358537222),
p = m(p, h, c, f, a[l + 3], 16, -722521979),
f = m(f, p, h, c, a[l + 6], 23, 76029189),
c = m(c, f, p, h, a[l + 9], 4, -640364487),
h = m(h, c, f, p, a[l + 12], 11, -421815835),
p = m(p, h, c, f, a[l + 15], 16, 530742520),
c = g(c, f = m(f, p, h, c, a[l + 2], 23, -995338651), p, h, a[l + 0], 6, -198630844),
h = g(h, c, f, p, a[l + 7], 10, 1126891415),
p = g(p, h, c, f, a[l + 14], 15, -1416354905),
f = g(f, p, h, c, a[l + 5], 21, -57434055),
c = g(c, f, p, h, a[l + 12], 6, 1700485571),
h = g(h, c, f, p, a[l + 3], 10, -1894986606),
p = g(p, h, c, f, a[l + 10], 15, -1051523),
f = g(f, p, h, c, a[l + 1], 21, -2054922799),
c = g(c, f, p, h, a[l + 8], 6, 1873313359),
h = g(h, c, f, p, a[l + 15], 10, -30611744),
p = g(p, h, c, f, a[l + 6], 15, -1560198380),
f = g(f, p, h, c, a[l + 13], 21, 1309151649),
c = g(c, f, p, h, a[l + 4], 6, -145523070),
h = g(h, c, f, p, a[l + 11], 10, -1120210379),
p = g(p, h, c, f, a[l + 2], 15, 718787259),
f = g(f, p, h, c, a[l + 9], 21, -343485551),
c = c + v >>> 0,
f = f + w >>> 0,
p = p + x >>> 0,
h = h + b >>> 0
}
return t.endian([c, f, p, h])
};
s._ff = function(e, t, n, r, o, i, s) {
var a = e + (t & n | ~t & r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
}
,
s._gg = function(e, t, n, r, o, i, s) {
var a = e + (t & r | n & ~r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
}
,
s._hh = function(e, t, n, r, o, i, s) {
var a = e + (t ^ n ^ r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
}
,
s._ii = function(e, t, n, r, o, i, s) {
var a = e + (n ^ (t | ~r)) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
}
,
s._blocksize = 16,
s._digestsize = 16,
e.exports = function(e, n) {
if (void 0 === e || null === e)
throw new Error("Illegal argument " + e);
var r = t.wordsToBytes(s(e, n));
return n && n.asBytes ? r : n && n.asString ? i.bytesToString(r) : t.bytesToHex(r)
}
}()
},
如果我们要直接调用这个函数模块，首先就要把代码开始的 n(“XXXX”) 代表的模块都“拿过来”。这里给出三种方案：
- 搜索“XXXX”模块名找到对应函数，缺点：模块名混淆后搜索结果过多时不好排查。
- 在 n(“XXXX”) 下断点，执行时定位到函数，缺点：webpack把所有代码打包进一个js，内容过多导致调试卡死。
- 在 n(“XXXX”) 使用 console.log() 插桩打印出函数，缺点：需要替换对应js文件响应，如果是动态地址响应，需要正则表达式，较为繁琐。
这里我们使用方案3，在开头 n(“XXXX”) 处插桩：
console.log("插桩开始------------------");
var t = n("ANhw");
console.log(n("ANhw"));
var r = n("mmNF").utf8;
console.log(n("mmNF"));
var o = n("BEtg");
console.log(n("BEtg"));
var i = n("mmNF").bin
console.log(n("mmNF"));
console.log("插桩结束------------------");
使用Fiddler的自动响应替换js文件请求返回我们插桩后的，该网站是静态地址，直接偷梁换柱：
清除缓存后刷新网页，成功请求到了我们替换的js：
控制台打印了各模块：
分别定位过去就能找到源码（这里以BEtg为例）：
BEtg: function(e, t) {
function n(e) {
return !!e.constructor && "function" === typeof e.constructor.isBuffer && e.constructor.isBuffer(e)
}
e.exports = function(e) {
return null != e && (n(e) || function(e) {
return "function" === typeof e.readFloatLE && "function" === typeof e.slice && n(e.slice(0, 0))
}(e) || !!e._isBuffer)
}
},
要放进我们的代码里需要稍微改动一下，为了防止混淆的变量名冲突，这里用了闭包：
var BEtg = (function(e, t) {
function n(e) {
return !!e.constructor && "function" === typeof e.constructor.isBuffer && e.constructor.isBuffer(e)
}
return function(e) {
return null != e && (n(e) || function(e) {
return "function" === typeof e.readFloatLE && "function" === typeof e.slice && n(e.slice(0, 0))
}(e) || !!e._isBuffer)
}
})();
其他模块使用做类似修改，最终我们的js文件：
//ANhw
var ANhw = (function (e, t) {
var t = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
, n = {
rotl: function (e, t) {
return e << t | e >>> 32 - t
},
rotr: function (e, t) {
return e << 32 - t | e >>> t
},
endian: function (e) {
if (e.constructor == Number)
return 16711935 & n.rotl(e, 8) | 4278255360 & n.rotl(e, 24);
for (var t = 0; t < e.length; t++)
e[t] = n.endian(e[t]);
return e
},
randomBytes: function (e) {
for (var t = []; e > 0; e--)
t.push(Math.floor(256 * Math.random()));
return t
},
bytesToWords: function (e) {
for (var t = [], n = 0, r = 0; n < e.length; n++,
r += 8)
t[r >>> 5] |= e[n] << 24 - r % 32;
return t
},
wordsToBytes: function (e) {
for (var t = [], n = 0; n < 32 * e.length; n += 8)
t.push(e[n >>> 5] >>> 24 - n % 32 & 255);
return t
},
bytesToHex: function (e) {
for (var t = [], n = 0; n < e.length; n++)
t.push((e[n] >>> 4).toString(16)),
t.push((15 & e[n]).toString(16));
return t.join("")
},
hexToBytes: function (e) {
for (var t = [], n = 0; n < e.length; n += 2)
t.push(parseInt(e.substr(n, 2), 16));
return t
},
bytesToBase64: function (e) {
for (var n = [], r = 0; r < e.length; r += 3)
for (var o = e[r] << 16 | e[r + 1] << 8 | e[r + 2], i = 0; i < 4; i++)
8 * r + 6 * i <= 8 * e.length ? n.push(t.charAt(o >>> 6 * (3 - i) & 63)) : n.push("=");
return n.join("")
},
base64ToBytes: function (e) {
e = e.replace(/[^A-Z0-9+\/]/gi, "");
for (var n = [], r = 0, o = 0; r < e.length; o = ++r % 4)
0 != o && n.push((t.indexOf(e.charAt(r - 1)) & Math.pow(2, -2 * o + 8) - 1) << 2 * o | t.indexOf(e.charAt(r)) >>> 6 - 2 * o);
return n
}
};
return n;
})();
//mmNF
var mmNF = (function (e, t) {
var n = {
utf8: {
stringToBytes: function (e) {
return n.bin.stringToBytes(unescape(encodeURIComponent(e)))
},
bytesToString: function (e) {
return decodeURIComponent(escape(n.bin.bytesToString(e)))
}
},
bin: {
stringToBytes: function (e) {
for (var t = [], n = 0; n < e.length; n++)
t.push(255 & e.charCodeAt(n));
return t
},
bytesToString: function (e) {
for (var t = [], n = 0; n < e.length; n++)
t.push(String.fromCharCode(e[n]));
return t.join("")
}
}
};
return n;
})();
//BEtg
var BEtg = (function (e, t) {
function n(e) {
return !!e.constructor && "function" === typeof e.constructor.isBuffer && e.constructor.isBuffer(e)
}
return function (e) {
return null != e && (n(e) || function (e) {
return "function" === typeof e.readFloatLE && "function" === typeof e.slice && n(e.slice(0, 0))
}(e) || !!e._isBuffer)
}
})();
//aCH8
var t = ANhw,
r = mmNF.utf8,
o = BEtg,
i = mmNF.bin,
s = function (e, n) {
e.constructor == String ? e = n && "binary" === n.encoding ? i.stringToBytes(e) : r.stringToBytes(e) : o(e) ? e = Array.prototype.slice.call(e, 0) : Array.isArray(e) || (e = e.toString());
for (var a = t.bytesToWords(e), u = 8 * e.length, c = 1732584193, f = -271733879, p = -1732584194, h = 271733878, l = 0; l < a.length; l++)
a[l] = 16711935 & (a[l] << 8 | a[l] >>> 24) | 4278255360 & (a[l] << 24 | a[l] >>> 8);
a[u >>> 5] |= 128 << u % 32,
a[14 + (u + 64 >>> 9 << 4)] = u;
var d = s._ff,
y = s._gg,
m = s._hh,
g = s._ii;
for (l = 0; l < a.length; l += 16) {
var v = c
, w = f
, x = p
, b = h;
c = d(c, f, p, h, a[l + 0], 7, -680876936),
h = d(h, c, f, p, a[l + 1], 12, -389564586),
p = d(p, h, c, f, a[l + 2], 17, 606105819),
f = d(f, p, h, c, a[l + 3], 22, -1044525330),
c = d(c, f, p, h, a[l + 4], 7, -176418897),
h = d(h, c, f, p, a[l + 5], 12, 1200080426),
p = d(p, h, c, f, a[l + 6], 17, -1473231341),
f = d(f, p, h, c, a[l + 7], 22, -45705983),
c = d(c, f, p, h, a[l + 8], 7, 1770035416),
h = d(h, c, f, p, a[l + 9], 12, -1958414417),
p = d(p, h, c, f, a[l + 10], 17, -42063),
f = d(f, p, h, c, a[l + 11], 22, -1990404162),
c = d(c, f, p, h, a[l + 12], 7, 1804603682),
h = d(h, c, f, p, a[l + 13], 12, -40341101),
p = d(p, h, c, f, a[l + 14], 17, -1502002290),
c = y(c, f = d(f, p, h, c, a[l + 15], 22, 1236535329), p, h, a[l + 1], 5, -165796510),
h = y(h, c, f, p, a[l + 6], 9, -1069501632),
p = y(p, h, c, f, a[l + 11], 14, 643717713),
f = y(f, p, h, c, a[l + 0], 20, -373897302),
c = y(c, f, p, h, a[l + 5], 5, -701558691),
h = y(h, c, f, p, a[l + 10], 9, 38016083),
p = y(p, h, c, f, a[l + 15], 14, -660478335),
f = y(f, p, h, c, a[l + 4], 20, -405537848),
c = y(c, f, p, h, a[l + 9], 5, 568446438),
h = y(h, c, f, p, a[l + 14], 9, -1019803690),
p = y(p, h, c, f, a[l + 3], 14, -187363961),
f = y(f, p, h, c, a[l + 8], 20, 1163531501),
c = y(c, f, p, h, a[l + 13], 5, -1444681467),
h = y(h, c, f, p, a[l + 2], 9, -51403784),
p = y(p, h, c, f, a[l + 7], 14, 1735328473),
c = m(c, f = y(f, p, h, c, a[l + 12], 20, -1926607734), p, h, a[l + 5], 4, -378558),
h = m(h, c, f, p, a[l + 8], 11, -2022574463),
p = m(p, h, c, f, a[l + 11], 16, 1839030562),
f = m(f, p, h, c, a[l + 14], 23, -35309556),
c = m(c, f, p, h, a[l + 1], 4, -1530992060),
h = m(h, c, f, p, a[l + 4], 11, 1272893353),
p = m(p, h, c, f, a[l + 7], 16, -155497632),
f = m(f, p, h, c, a[l + 10], 23, -1094730640),
c = m(c, f, p, h, a[l + 13], 4, 681279174),
h = m(h, c, f, p, a[l + 0], 11, -358537222),
p = m(p, h, c, f, a[l + 3], 16, -722521979),
f = m(f, p, h, c, a[l + 6], 23, 76029189),
c = m(c, f, p, h, a[l + 9], 4, -640364487),
h = m(h, c, f, p, a[l + 12], 11, -421815835),
p = m(p, h, c, f, a[l + 15], 16, 530742520),
c = g(c, f = m(f, p, h, c, a[l + 2], 23, -995338651), p, h, a[l + 0], 6, -198630844),
h = g(h, c, f, p, a[l + 7], 10, 1126891415),
p = g(p, h, c, f, a[l + 14], 15, -1416354905),
f = g(f, p, h, c, a[l + 5], 21, -57434055),
c = g(c, f, p, h, a[l + 12], 6, 1700485571),
h = g(h, c, f, p, a[l + 3], 10, -1894986606),
p = g(p, h, c, f, a[l + 10], 15, -1051523),
f = g(f, p, h, c, a[l + 1], 21, -2054922799),
c = g(c, f, p, h, a[l + 8], 6, 1873313359),
h = g(h, c, f, p, a[l + 15], 10, -30611744),
p = g(p, h, c, f, a[l + 6], 15, -1560198380),
f = g(f, p, h, c, a[l + 13], 21, 1309151649),
c = g(c, f, p, h, a[l + 4], 6, -145523070),
h = g(h, c, f, p, a[l + 11], 10, -1120210379),
p = g(p, h, c, f, a[l + 2], 15, 718787259),
f = g(f, p, h, c, a[l + 9], 21, -343485551),
c = c + v >>> 0,
f = f + w >>> 0,
p = p + x >>> 0,
h = h + b >>> 0
}
return t.endian([c, f, p, h])
};
s._ff = function (e, t, n, r, o, i, s) {
var a = e + (t & n | ~t & r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
},
s._gg = function (e, t, n, r, o, i, s) {
var a = e + (t & r | n & ~r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
},
s._hh = function (e, t, n, r, o, i, s) {
var a = e + (t ^ n ^ r) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
},
s._ii = function (e, t, n, r, o, i, s) {
var a = e + (n ^ (t | ~r)) + (o >>> 0) + s;
return (a << i | a >>> 32 - i) + t
},
s._blocksize = 16,
s._digestsize = 16,
MD5 = function (e, n) { //e.exports改为函数名方便调用
if (void 0 === e || null === e)
throw new Error("Illegal argument " + e);
var r = t.wordsToBytes(s(e, n));
return n && n.asBytes ? r : n && n.asString ? i.bytesToString(r) : t.bytesToHex(r)
}
//测试调用
let res = MD5("321654");
console.log(res);
运行，正确打印了加密后的password。其实这套算法只是对password做了MD5而已：
