[JS逆向] JS逆向之MD5加密

这两天碰到了两个MD5加密的js逆向，一个是猿人学第一题，还有一个就是在工作中。
然后发现了些规律，一般MD5加密之后的字符串是32位,也有16位，这基本都知道

但是在MD5加密的js代码中也有一些规律。
这是我昨天在猿人学里面获取到的MD5加密代码

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
};
window.f = hex_md5(mwqqppz)

然后这是今天我发现的一个MD5加密代码

define("sc-list/m/compare-full-layout/src/js/md5.js", [], function(require, e, t) {
    t.exports = function() {
        var e = 0;
        var t = "";
        var i = 8;
        function a(e) {
            return w(u(y(e), e.length * i))
        }
        function s(e) {
            return x(u(y(e), e.length * i))
        }
        function n(e) {
            return _(u(y(e), e.length * i))
        }
        function r(e, t) {
            return w(g(e, t))
        }
        function o(e, t) {
            return x(g(e, t))
        }
        function l(e, t) {
            return _(g(e, t))
        }
        function c() {
            return a("abc") == "900150983cd24fb0d6963f7d28e17f72"
        }
        function u(e, t) {
            e[t >> 5] |= 128 << t % 32;
            e[(t + 64 >>> 9 << 4) + 14] = t;
            var i = 1732584193;
            var a = -271733879;
            var s = -1732584194;
            var n = 271733878;
            for (var r = 0; r < e.length; r += 16) {
                var o = i;
                var l = a;
                var c = s;
                var u = n;
                i = h(i, a, s, n, e[r + 0], 7, -680876936);
                n = h(n, i, a, s, e[r + 1], 12, -389564586);
                s = h(s, n, i, a, e[r + 2], 17, 606105819);
                a = h(a, s, n, i, e[r + 3], 22, -1044525330);
                i = h(i, a, s, n, e[r + 4], 7, -176418897);
                n = h(n, i, a, s, e[r + 5], 12, 1200080426);
                s = h(s, n, i, a, e[r + 6], 17, -1473231341);
                a = h(a, s, n, i, e[r + 7], 22, -45705983);
                i = h(i, a, s, n, e[r + 8], 7, 1770035416);
                n = h(n, i, a, s, e[r + 9], 12, -1958414417);
                s = h(s, n, i, a, e[r + 10], 17, -42063);
                a = h(a, s, n, i, e[r + 11], 22, -1990404162);
                i = h(i, a, s, n, e[r + 12], 7, 1804603682);
                n = h(n, i, a, s, e[r + 13], 12, -40341101);
                s = h(s, n, i, a, e[r + 14], 17, -1502002290);
                a = h(a, s, n, i, e[r + 15], 22, 1236535329);
                i = p(i, a, s, n, e[r + 1], 5, -165796510);
                n = p(n, i, a, s, e[r + 6], 9, -1069501632);
                s = p(s, n, i, a, e[r + 11], 14, 643717713);
                a = p(a, s, n, i, e[r + 0], 20, -373897302);
                i = p(i, a, s, n, e[r + 5], 5, -701558691);
                n = p(n, i, a, s, e[r + 10], 9, 38016083);
                s = p(s, n, i, a, e[r + 15], 14, -660478335);
                a = p(a, s, n, i, e[r + 4], 20, -405537848);
                i = p(i, a, s, n, e[r + 9], 5, 568446438);
                n = p(n, i, a, s, e[r + 14], 9, -1019803690);
                s = p(s, n, i, a, e[r + 3], 14, -187363961);
                a = p(a, s, n, i, e[r + 8], 20, 1163531501);
                i = p(i, a, s, n, e[r + 13], 5, -1444681467);
                n = p(n, i, a, s, e[r + 2], 9, -51403784);
                s = p(s, n, i, a, e[r + 7], 14, 1735328473);
                a = p(a, s, n, i, e[r + 12], 20, -1926607734);
                i = f(i, a, s, n, e[r + 5], 4, -378558);
                n = f(n, i, a, s, e[r + 8], 11, -2022574463);
                s = f(s, n, i, a, e[r + 11], 16, 1839030562);
                a = f(a, s, n, i, e[r + 14], 23, -35309556);
                i = f(i, a, s, n, e[r + 1], 4, -1530992060);
                n = f(n, i, a, s, e[r + 4], 11, 1272893353);
                s = f(s, n, i, a, e[r + 7], 16, -155497632);
                a = f(a, s, n, i, e[r + 10], 23, -1094730640);
                i = f(i, a, s, n, e[r + 13], 4, 681279174);
                n = f(n, i, a, s, e[r + 0], 11, -358537222);
                s = f(s, n, i, a, e[r + 3], 16, -722521979);
                a = f(a, s, n, i, e[r + 6], 23, 76029189);
                i = f(i, a, s, n, e[r + 9], 4, -640364487);
                n = f(n, i, a, s, e[r + 12], 11, -421815835);
                s = f(s, n, i, a, e[r + 15], 16, 530742520);
                a = f(a, s, n, i, e[r + 2], 23, -995338651);
                i = m(i, a, s, n, e[r + 0], 6, -198630844);
                n = m(n, i, a, s, e[r + 7], 10, 1126891415);
                s = m(s, n, i, a, e[r + 14], 15, -1416354905);
                a = m(a, s, n, i, e[r + 5], 21, -57434055);
                i = m(i, a, s, n, e[r + 12], 6, 1700485571);
                n = m(n, i, a, s, e[r + 3], 10, -1894986606);
                s = m(s, n, i, a, e[r + 10], 15, -1051523);
                a = m(a, s, n, i, e[r + 1], 21, -2054922799);
                i = m(i, a, s, n, e[r + 8], 6, 1873313359);
                n = m(n, i, a, s, e[r + 15], 10, -30611744);
                s = m(s, n, i, a, e[r + 6], 15, -1560198380);
                a = m(a, s, n, i, e[r + 13], 21, 1309151649);
                i = m(i, a, s, n, e[r + 4], 6, -145523070);
                n = m(n, i, a, s, e[r + 11], 10, -1120210379);
                s = m(s, n, i, a, e[r + 2], 15, 718787259);
                a = m(a, s, n, i, e[r + 9], 21, -343485551);
                i = v(i, o);
                a = v(a, l);
                s = v(s, c);
                n = v(n, u)
            }
            return Array(i, a, s, n)
        }
        function d(e, t, i, a, s, n) {
            return v(b(v(v(t, e), v(a, n)), s), i)
        }
        function h(e, t, i, a, s, n, r) {
            return d(t & i | ~t & a, e, t, s, n, r)
        }
        function p(e, t, i, a, s, n, r) {
            return d(t & a | i & ~a, e, t, s, n, r)
        }
        function f(e, t, i, a, s, n, r) {
            return d(t ^ i ^ a, e, t, s, n, r)
        }
        function m(e, t, i, a, s, n, r) {
            return d(i ^ (t | ~a), e, t, s, n, r)
        }
        function g(e, t) {
            var a = y(e);
            if (a.length > 16)
                a = u(a, e.length * i);
            var s = Array(16)
              , n = Array(16);
            for (var r = 0; r < 16; r++) {
                s[r] = a[r] ^ 909522486;
                n[r] = a[r] ^ 1549556828
            }
            var o = u(s.concat(y(t)), 512 + t.length * i);
            return u(n.concat(o), 512 + 128)
        }
        function v(e, t) {
            var i = (e & 65535) + (t & 65535);
            var a = (e >> 16) + (t >> 16) + (i >> 16);
            return a << 16 | i & 65535
        }
        function b(e, t) {
            return e << t | e >>> 32 - t
        }
        function y(e) {
            var t = Array();
            var a = (1 << i) - 1;
            for (var s = 0; s < e.length * i; s += i)
                t[s >> 5] |= (e.charCodeAt(s / i) & a) << s % 32;
            return t
        }
        function _(e) {
            var t = "";
            var a = (1 << i) - 1;
            for (var s = 0; s < e.length * 32; s += i)
                t += String.fromCharCode(e[s >> 5] >>> s % 32 & a);
            return t
        }
        function w(t) {
            var i = e ? "0123456789ABCDEF" : "0123456789abcdef";
            var a = "";
            for (var s = 0; s < t.length * 4; s++) {
                a += i.charAt(t[s >> 2] >> s % 4 * 8 + 4 & 15) + i.charAt(t[s >> 2] >> s % 4 * 8 & 15)
            }
            return a
        }
        function x(e) {
            var i = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
            var a = "";
            for (var s = 0; s < e.length * 4; s += 3) {
                var n = (e[s >> 2] >> 8 * (s % 4) & 255) << 16 | (e[s + 1 >> 2] >> 8 * ((s + 1) % 4) & 255) << 8 | e[s + 2 >> 2] >> 8 * ((s + 2) % 4) & 255;
                for (var r = 0; r < 4; r++) {
                    if (s * 8 + r * 6 > e.length * 32)
                        a += t;
                    else
                        a += i.charAt(n >> 6 * (3 - r) & 63)
                }
            }
            return a
        }
        return a
    }()
});

且不看第一行，毕竟第一行直接表示他引用了MD5加密了。。。
一对比发现，里面除了变量名改了一下，不能说很像，只能说一模一样。
比如都有一个验证md5的

function md5_vm_test() {
    return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72"
}

abc都一样。。。
感觉大概看一下，基本上以后看到MD5都能发现了