js逆向，今晚找了一个小说网站，分析一下登录密码的解密逆向过程，过程不是很难，分享下
学习网站'aHR0cHM6Ly91LmZhbG9vLmNvbS9yZWdpc3QvbG9naW4uYXNweA=='

这个就是加密后的密码，今晚就逆向它，其他参数暂时不研究，留做以后分析
1.先找登录的调用方法，这里明显看到login

 

2.搜索login，发现可疑js，名为md5.js，跟进去

3.下断以后，发现是这里进行的加密，通过明文和时间戳进行的加密

 

4.login_md5里调用了hex_md5方法

 

5.hex_md5又调用了一堆方法，一个方法套一个方法，大概套了6、7层，这里不一一赘述了，把所有用到的代码都扣下来就好了
6.需要注意有2个常量，一个是chrsz = 8;一个是 hexcase = 0;
7.扣完所有代码以后我们校验一下结果，可以看到结果是一样的

 

总结：整体过程不是特别复杂，就是扣代码跟栈一个一个找有点费时间，但是非常适合新手练手，大佬直接跳过就好。
最后附上扣的代码，方便和新手对照着调试

var chrsz = 8;
var hexcase = 0;
var datetime_num = Math.round(new Date() / 1000);
function login_md5(pwd, datetime_num) {
    return hex_md5("@345Kie(873_dfbKe>d3<.d23432=" + hex_md5("EW234@![#$&]*{,OP}Kd^w349Op+-32_" + pwd + datetime_num));
}
function hex_md5(s) {
    return binl2hex(core_md5(str2binl(s), s.length * chrsz));
}
function core_md5(x, len) {
 
    x[len >> 5] |= 0x80 << ((len) % 32);
    x[(((len + 64) >>> 9) << 4) + 14] = len;
    var a = 1732584193;
    var b = -271733879;
    var c = -1732584194;
    var d = 271733878;
    for (var i = 0; i < x.length; i += 16) {
        var olda = a;
        var oldb = b;
        var oldc = c;
        var oldd = d;
 
        a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936);
        d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
        c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
        b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
        a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
        d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
        c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
        b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
        a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
        d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
        c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
        b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
        a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
        d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
        c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
        b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);
        a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
        d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
        c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
        b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302);
        a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
        d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
        c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
        b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
        a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
        d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
        c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
        b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
        a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
        d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
        c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
        b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);
        a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
        d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
        c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
        b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
        a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
        d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
        c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
        b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
        a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
        d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222);
        c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
        b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
        a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
        d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
        c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
        b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);
        a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844);
        d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
        c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
        b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
        a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
        d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
        c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
        b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
        a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
        d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
        c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
        b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
        a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
        d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
        c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
        b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);
 
        a = safe_add(a, olda);
        b = safe_add(b, oldb);
        c = safe_add(c, oldc);
        d = safe_add(d, oldd);
    }
    return Array(a, b, c, d);
 
}
function str2binl(str) {
    var bin = Array();
    var mask = (1 << chrsz) - 1;
    for (var i = 0; i < str.length * chrsz; i += chrsz)
        bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << (i % 32);
    return bin;
}
function binl2hex(binarray) {
    var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
    var str = "";
    for (var i = 0; i < binarray.length * 4; i++) {
        str += hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) + hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8)) & 0xF);
    }
    return str;
}
function md5_ff(a, b, c, d, x, s, t) {
    return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t) {
    return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_cmn(q, a, b, x, s, t) {
    return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}
function safe_add(x, y) {
    var lsw = (x & 0xFFFF) + (y & 0xFFFF);
    var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
    return (msw << 16) | (lsw & 0xFFFF);
}
function bit_rol(num, cnt) {
    return (num << cnt) | (num >>> (32 - cnt));
}
function md5_hh(a, b, c, d, x, s, t) {
    return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t) {
    return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}
console.log(login_md5("123456",'1690810935'))

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