js逆向

微信公众号加密算法分析

打开谷歌开发者工具,登录账户密码抓包。

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username: 1234
pwd: 81dc9bdb52d04dc20036dbd8313ed055

查看调用栈,发现几个和loginpage相关,打上断点。

重新登录,开始调试

在第一个断点处并未加密,跳到下一个断点

这里pwd也还未加密,继续调试

仍未加密,跳到p函数处下断点,继续调试

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k.exports = function(n, u, i) {
if (!u) {
if (!i) {
return x(n)
} else {
return B(n)
}
}
if (!i) {
return R(u, n)
} else {
return M(u, n)
}
}
// x(n)
// '81dc9bdb52d04dc20036dbd8313ed055'

那么这里就找到了加密函数位置,将代码复制到本地,改为自执行函数,并将上述函数结果用getStr变量接收。同时不能忘记加上substr()

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pwd: p(r.pwd.substr(0, 16))

那么最终代码如下

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var getStr
!function(I, T, h) {
"use strict";
var v;
;!(v = function(m, D, k) {
function _(n, u) {
var i = (n & 65535) + (u & 65535)
, b = (n >> 16) + (u >> 16) + (i >> 16);
return b << 16 | i & 65535
}
function E(n, u) {
return n << u | n >>> 32 - u
}
function w(n, u, i, b, S, j) {
return _(E(_(_(u, n), _(b, j)), S), i)
}
function C(n, u, i, b, S, j, F) {
return w(u & i | ~u & b, n, u, S, j, F)
}
function d(n, u, i, b, S, j, F) {
return w(u & b | i & ~b, n, u, S, j, F)
}
function l(n, u, i, b, S, j, F) {
return w(u ^ i ^ b, n, u, S, j, F)
}
function p(n, u, i, b, S, j, F) {
return w(i ^ (u | ~b), n, u, S, j, F)
}
function f(n, u) {
n[u >> 5] |= 128 << u % 32;
n[(u + 64 >>> 9 << 4) + 14] = u;
var i, b, S, j, F, s = 1732584193, o = -271733879, a = -1732584194, t = 271733878;
for (i = 0; i < n.length; i += 16) {
b = s;
S = o;
j = a;
F = t;
s = C(s, o, a, t, n[i], 7, -680876936);
t = C(t, s, o, a, n[i + 1], 12, -389564586);
a = C(a, t, s, o, n[i + 2], 17, 606105819);
o = C(o, a, t, s, n[i + 3], 22, -1044525330);
s = C(s, o, a, t, n[i + 4], 7, -176418897);
t = C(t, s, o, a, n[i + 5], 12, 1200080426);
a = C(a, t, s, o, n[i + 6], 17, -1473231341);
o = C(o, a, t, s, n[i + 7], 22, -45705983);
s = C(s, o, a, t, n[i + 8], 7, 1770035416);
t = C(t, s, o, a, n[i + 9], 12, -1958414417);
a = C(a, t, s, o, n[i + 10], 17, -42063);
o = C(o, a, t, s, n[i + 11], 22, -1990404162);
s = C(s, o, a, t, n[i + 12], 7, 1804603682);
t = C(t, s, o, a, n[i + 13], 12, -40341101);
a = C(a, t, s, o, n[i + 14], 17, -1502002290);
o = C(o, a, t, s, n[i + 15], 22, 1236535329);
s = d(s, o, a, t, n[i + 1], 5, -165796510);
t = d(t, s, o, a, n[i + 6], 9, -1069501632);
a = d(a, t, s, o, n[i + 11], 14, 643717713);
o = d(o, a, t, s, n[i], 20, -373897302);
s = d(s, o, a, t, n[i + 5], 5, -701558691);
t = d(t, s, o, a, n[i + 10], 9, 38016083);
a = d(a, t, s, o, n[i + 15], 14, -660478335);
o = d(o, a, t, s, n[i + 4], 20, -405537848);
s = d(s, o, a, t, n[i + 9], 5, 568446438);
t = d(t, s, o, a, n[i + 14], 9, -1019803690);
a = d(a, t, s, o, n[i + 3], 14, -187363961);
o = d(o, a, t, s, n[i + 8], 20, 1163531501);
s = d(s, o, a, t, n[i + 13], 5, -1444681467);
t = d(t, s, o, a, n[i + 2], 9, -51403784);
a = d(a, t, s, o, n[i + 7], 14, 1735328473);
o = d(o, a, t, s, n[i + 12], 20, -1926607734);
s = l(s, o, a, t, n[i + 5], 4, -378558);
t = l(t, s, o, a, n[i + 8], 11, -2022574463);
a = l(a, t, s, o, n[i + 11], 16, 1839030562);
o = l(o, a, t, s, n[i + 14], 23, -35309556);
s = l(s, o, a, t, n[i + 1], 4, -1530992060);
t = l(t, s, o, a, n[i + 4], 11, 1272893353);
a = l(a, t, s, o, n[i + 7], 16, -155497632);
o = l(o, a, t, s, n[i + 10], 23, -1094730640);
s = l(s, o, a, t, n[i + 13], 4, 681279174);
t = l(t, s, o, a, n[i], 11, -358537222);
a = l(a, t, s, o, n[i + 3], 16, -722521979);
o = l(o, a, t, s, n[i + 6], 23, 76029189);
s = l(s, o, a, t, n[i + 9], 4, -640364487);
t = l(t, s, o, a, n[i + 12], 11, -421815835);
a = l(a, t, s, o, n[i + 15], 16, 530742520);
o = l(o, a, t, s, n[i + 2], 23, -995338651);
s = p(s, o, a, t, n[i], 6, -198630844);
t = p(t, s, o, a, n[i + 7], 10, 1126891415);
a = p(a, t, s, o, n[i + 14], 15, -1416354905);
o = p(o, a, t, s, n[i + 5], 21, -57434055);
s = p(s, o, a, t, n[i + 12], 6, 1700485571);
t = p(t, s, o, a, n[i + 3], 10, -1894986606);
a = p(a, t, s, o, n[i + 10], 15, -1051523);
o = p(o, a, t, s, n[i + 1], 21, -2054922799);
s = p(s, o, a, t, n[i + 8], 6, 1873313359);
t = p(t, s, o, a, n[i + 15], 10, -30611744);
a = p(a, t, s, o, n[i + 6], 15, -1560198380);
o = p(o, a, t, s, n[i + 13], 21, 1309151649);
s = p(s, o, a, t, n[i + 4], 6, -145523070);
t = p(t, s, o, a, n[i + 11], 10, -1120210379);
a = p(a, t, s, o, n[i + 2], 15, 718787259);
o = p(o, a, t, s, n[i + 9], 21, -343485551);
s = _(s, b);
o = _(o, S);
a = _(a, j);
t = _(t, F)
}
return [s, o, a, t]
}
function L(n) {
var u, i = "";
for (u = 0; u < n.length * 32; u += 8) {
i += String.fromCharCode(n[u >> 5] >>> u % 32 & 255)
}
return i
}
function y(n) {
var u, i = [];
i[(n.length >> 2) - 1] = void 0;
for (u = 0; u < i.length; u += 1) {
i[u] = 0
}
for (u = 0; u < n.length * 8; u += 8) {
i[u >> 5] |= (n.charCodeAt(u / 8) & 255) << u % 32
}
return i
}
function $(n) {
return L(f(y(n), n.length * 8))
}
function q(n, u) {
var i, b = y(n), S = [], j = [], F;
S[15] = j[15] = void 0;
if (b.length > 16) {
b = f(b, n.length * 8)
}
for (i = 0; i < 16; i += 1) {
S[i] = b[i] ^ 909522486;
j[i] = b[i] ^ 1549556828
}
F = f(S.concat(y(u)), 512 + u.length * 8);
return L(f(j.concat(F), 512 + 128))
}
function z(n) {
var u = "0123456789abcdef", i = "", b, S;
for (S = 0; S < n.length; S += 1) {
b = n.charCodeAt(S);
i += u.charAt(b >>> 4 & 15) + u.charAt(b & 15)
}
return i
}
function Q(n) {
return unescape(encodeURIComponent(n))
}
function B(n) {
return $(Q(n))
}
function x(n) {
return z(B(n))
}
function M(n, u) {
return q(Q(n), Q(u))
}
function R(n, u) {
return z(M(n, u))
}
getStr = function(n, u, i) {
if (!u) {
if (!i) {
return x(n)
} else {
return B(n)
}
}
if (!i) {
return R(u, n)
} else {
return M(u, n)
}
}
}
.call(T, h, T, I),
v !== void 0 && (I.exports = v))
}()

var password = "1234"
console.log(getStr(password.substr(0, 16)))
// 81dc9bdb52d04dc20036dbd8313ed055