使用JS计算Google Authenticator Code

sjcl.js

斯坦福大学JS加密库

"use strict";var sjcl={cipher:{},hash:{},keyexchange:{},mode:{},misc:{},codec:{},exception:{corrupt:function(a){this.toString=function(){return"CORRUPT: "+this.message};this.message=a},invalid:function(a){this.toString=function(){return"INVALID: "+this.message};this.message=a},bug:function(a){this.toString=function(){return"BUG: "+this.message};this.message=a},notReady:function(a){this.toString=function(){return"NOT READY: "+this.message};this.message=a}}};
"undefined"!=typeof module&&module.exports&&(module.exports=sjcl);
sjcl.bitArray={bitSlice:function(a,b,c){a=sjcl.bitArray.g(a.slice(b/32),32-(b&31)).slice(1);return void 0===c?a:sjcl.bitArray.clamp(a,c-b)},extract:function(a,b,c){var d=Math.floor(-b-c&31);return((b+c-1^b)&-32?a[b/32|0]<<32-d^a[b/32+1|0]>>>d:a[b/32|0]>>>d)&(1<<c)-1},concat:function(a,b){if(0===a.length||0===b.length)return a.concat(b);var c=a[a.length-1],d=sjcl.bitArray.getPartial(c);return 32===d?a.concat(b):sjcl.bitArray.g(b,d,c|0,a.slice(0,a.length-1))},bitLength:function(a){var b=a.length;return 0===
b?0:32*(b-1)+sjcl.bitArray.getPartial(a[b-1])},clamp:function(a,b){if(32*a.length<b)return a;a=a.slice(0,Math.ceil(b/32));var c=a.length;b&=31;0<c&&b&&(a[c-1]=sjcl.bitArray.partial(b,a[c-1]&2147483648>>b-1,1));return a},partial:function(a,b,c){return 32===a?b:(c?b|0:b<<32-a)+0x10000000000*a},getPartial:function(a){return Math.round(a/0x10000000000)||32},equal:function(a,b){if(sjcl.bitArray.bitLength(a)!==sjcl.bitArray.bitLength(b))return!1;var c=0,d;for(d=0;d<a.length;d++)c|=a[d]^b[d];return 0===
c},g:function(a,b,c,d){var e;e=0;for(void 0===d&&(d=[]);32<=b;b-=32)d.push(c),c=0;if(0===b)return d.concat(a);for(e=0;e<a.length;e++)d.push(c|a[e]>>>b),c=a[e]<<32-b;e=a.length?a[a.length-1]:0;a=sjcl.bitArray.getPartial(e);d.push(sjcl.bitArray.partial(b+a&31,32<b+a?c:d.pop(),1));return d},j:function(a,b){return[a[0]^b[0],a[1]^b[1],a[2]^b[2],a[3]^b[3]]}};
sjcl.codec.base32={e:"ABCDEFGHIJKLMNOPQRSTUVWXYZ234567",fromBits:function(a,b){var c="",d,e=0,g=sjcl.codec.base32.e,f=0,k=sjcl.bitArray.bitLength(a);for(d=0;5*c.length<k;)c+=g.charAt((f^a[d]>>>e)>>>27),5>e?(f=a[d]<<5-e,e+=27,d++):(f<<=5,e-=5);for(;c.length&5&&!b;)c+="=";return c},toBits:function(a){a=a.replace(/s|=/g,"").toUpperCase();var b=[],c,d=0,e=sjcl.codec.base32.e,g=0,f;for(c=0;c<a.length;c++){f=e.indexOf(a.charAt(c));if(0>f)throw new sjcl.exception.invalid("this isn't base32!");27<d?(d-=
27,b.push(g^f>>>d),g=f<<32-d):(d+=5,g^=f<<32-d)}d&56&&b.push(sjcl.bitArray.partial(d&56,g,1));return b}};sjcl.hash.sha1=function(a){a?(this.d=a.d.slice(0),this.b=a.b.slice(0),this.a=a.a):this.reset()};sjcl.hash.sha1.hash=function(a){return(new sjcl.hash.sha1).update(a).finalize()};
sjcl.hash.sha1.prototype={blockSize:512,reset:function(){this.d=this.h.slice(0);this.b=[];this.a=0;return this},update:function(a){"string"===typeof a&&(a=sjcl.codec.utf8String.toBits(a));var b,c=this.b=sjcl.bitArray.concat(this.b,a);b=this.a;a=this.a=b+sjcl.bitArray.bitLength(a);for(b=this.blockSize+b&-this.blockSize;b<=a;b+=this.blockSize)n(this,c.splice(0,16));return this},finalize:function(){var a,b=this.b,c=this.d,b=sjcl.bitArray.concat(b,[sjcl.bitArray.partial(1,1)]);for(a=b.length+2;a&15;a++)b.push(0);
b.push(Math.floor(this.a/0x100000000));for(b.push(this.a|0);b.length;)n(this,b.splice(0,16));this.reset();return c},h:[1732584193,4023233417,2562383102,271733878,3285377520],i:[1518500249,1859775393,2400959708,3395469782]};
function n(a,b){var c,d,e,g,f,k,m,l=b.slice(0),h=a.d;e=h[0];g=h[1];f=h[2];k=h[3];m=h[4];for(c=0;79>=c;c++)16<=c&&(l[c]=(l[c-3]^l[c-8]^l[c-14]^l[c-16])<<1|(l[c-3]^l[c-8]^l[c-14]^l[c-16])>>>31),d=19>=c?g&f|~g&k:39>=c?g^f^k:59>=c?g&f|g&k|f&k:79>=c?g^f^k:void 0,d=(e<<5|e>>>27)+d+m+l[c]+a.i[Math.floor(c/20)]|0,m=k,k=f,f=g<<30|g>>>2,g=e,e=d;h[0]=h[0]+e|0;h[1]=h[1]+g|0;h[2]=h[2]+f|0;h[3]=h[3]+k|0;h[4]=h[4]+m|0}
sjcl.misc.hmac=function(a,b){this.f=b=b||sjcl.hash.sha256;var c=[[],[]],d,e=b.prototype.blockSize/32;this.c=[new b,new b];a.length>e&&(a=b.hash(a));for(d=0;d<e;d++)c[0][d]=a[d]^909522486,c[1][d]=a[d]^1549556828;this.c[0].update(c[0]);this.c[1].update(c[1])};sjcl.misc.hmac.prototype.encrypt=sjcl.misc.hmac.prototype.mac=function(a){a=(new this.f(this.c[0])).update(a).finalize();return(new this.f(this.c[1])).update(a).finalize()};

计算Gcode JS

(function () {

    function HOTP(K, C)
    {
        var key = sjcl.codec.base32.toBits(K);

        // Count is 64 bits long.  Note that JavaScript bitwise operations make
        // the MSB effectively 0 in this case.
        var count = [((C & 0xffffffff00000000) >> 32), C & 0xffffffff];
        var otplength = 6;

        var hmacsha1 = new sjcl.misc.hmac(key, sjcl.hash.sha1);
        var code = hmacsha1.encrypt(count);

        var offset = sjcl.bitArray.extract(code, 152, 8) & 0x0f;
        var startBits = offset * 8;
        var endBits = startBits + 4 * 8;
        var slice = sjcl.bitArray.bitSlice(code, startBits, endBits);
        var dbc1 = slice[0];
        var dbc2 = dbc1 & 0x7fffffff;
        var otp = dbc2 % Math.pow(10, otplength);
        var result = otp.toString();
        while (result.length < otplength)
        {
            result = '0' + result;
        }
        return result
    }


    function GenerateTOTP() {
        var Gkeys = document.getElementsByClassName('Gkey')[0].value;
        var Gcodes = document.getElementsByClassName('Gcode')[0];
        var ctime = Math.floor((new Date() - 0) / 30000);
        var code = HOTP(Gkeys, ctime);
        Gcodes.innerText = code
    }

    function ConfigureHandlers()
    {
        setInterval(GenerateTOTP, 1500);
    }
    GenerateTOTP();
    ConfigureHandlers();


})();

HTML页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Google Authenticator</title>
    <style>
        .Gcode{
            color: red
        }    
    </style>
</head>
<body>

    <p>
        <h3>计算Google Code</h3>
		<input type="text" class="Gkey" value='XXXXXXXXXXXXXX'>
        <P>
            <span class='Gcode' id="GCSCODE"></span>
        </P>
    </p>

    <script src="sjcl.js"></script>
    <script src="code_totp.js"></script>

</body>
</html>

网页效果