Editplus registration code generator written in Javascript

Today, my colleague was surprised to tell me that I had found an online editplus registration code generator and I had to check it out.

There are too many viruses on the EXE registration machine, so the pure JS online registration machine can be assured.

I found out the algorithm from the disassembly of another Registrar. what's even more surprising is that demon, the author, had just obtained a legal professional qualification certificate and admired it.

Demo

The main JS function is as follows:

function generate_editplus_regcode(username){    var list = [0,49345,49537,320,49921,960,640,49729,50689,1728,1920,51009,1280,50625,50305,1088,52225,3264,3456,52545,3840,53185,52865,3648,2560,51905,52097,2880,51457,2496,2176,51265,55297,6336,6528,55617,6912,56257,55937,6720,7680,57025,57217,8000,56577,7616,7296,56385,5120,54465,54657,5440,55041,6080,5760,54849,53761,4800,4992,54081,4352,53697,53377,4160,61441,12480,12672,61761,13056,62401,62081,12864,13824,63169,63361,14144,62721,13760,13440,62529,15360,64705,64897,15680,65281,16320,16000,65089,64001,15040,15232,64321,14592,63937,63617,14400,10240,59585,59777,10560,60161,11200,10880,59969,60929,11968,12160,61249,11520,60865,60545,11328,58369,9408,9600,58689,9984,59329,59009,9792,8704,58049,58241,9024,57601,8640,8320,57409,40961,24768,24960,41281,25344,41921,41601,25152,26112,42689,42881,26432,42241,26048,25728,42049,27648,44225,44417,27968,44801,28608,28288,44609,43521,27328,27520,43841,26880,43457,43137,26688,30720,47297,47489,31040,47873,31680,31360,47681,48641,32448,32640,48961,32000,48577,48257,31808,46081,29888,30080,46401,30464,47041,46721,30272,29184,45761,45953,29504,45313,29120,28800,45121,20480,37057,37249,20800,37633,21440,21120,37441,38401,22208,22400,38721,21760,38337,38017,21568,39937,23744,23936,40257,24320,40897,40577,24128,23040,39617,39809,23360,39169,22976,22656,38977,34817,18624,18816,35137,19200,35777,35457,19008,19968,36545,36737,20288,36097,19904,19584,35905,17408,33985,34177,17728,34561,18368,18048,34369,33281,17088,17280,33601,16640,33217,32897,16448];    var hexchars = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'];    var regcode = new Array(29);    var i = 0, j = 0, k = 0;    var len, temp, sum, result;    username = username.replace(/^\s+|\s+$/g, "");    for(i = 0;i < 5;i++,k++)    {        for(j = 0;j < 5;j++,k++)        {            regcode[k] = hexchars[parseInt(Math.random() * 16)];        }        if(k == 29) break;        regcode[k] = '-';    }        len = username.length;    sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp = (parseInt( (sum + 23) / 6 ) + 3) * 7 % 16;    regcode[6] = hexchars[temp & 0xF];        sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp = parseInt( (3 * sum + 39) / 8 ) % 16;    regcode[9] = hexchars[temp & 0xF];        sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp = parseInt( (3 * sum + 19) / 9 ) % 16;    regcode[7] = hexchars[temp & 0xF];        sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp = parseInt( (sum + 10) / 3 ) * 8 % 16;    regcode[10] = hexchars[temp & 0xF];        sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp = (parseInt( (9 * sum + 10) / 3 ) + 36) % 16;    regcode[4] = hexchars[temp & 0xF];        sum = 1;    for(i = 0;i < len;i++){        sum += username.charCodeAt(i);    }    temp =  parseInt( (5 * sum + 11) / 5 ) % 16;    regcode[8] = hexchars[temp & 0xF];    result = 0;    for(i = 0;i < len;i++){        result = ((result >> 8) & 0xFF) ^ list[username.charCodeAt(i) ^ (result & 0xFF)];    }    result = result.toString(16).toUpperCase();    regcode[2] = result.charAt(0);    regcode[3] = result.charAt(1);        len = regcode.length;    result = 0;    for(i = 2;i < len;i++){        result = ((result >> 8) & 0xFF) ^ list[regcode[i].toString().charCodeAt(0) ^ (result & 0xFF)];    }    result = result.toString(16).toUpperCase();    regcode[0] = result.charAt(0);    regcode[1] = result.charAt(1);    return regcode.join("");}