Google Authenticator compatible fob on Espruino Pico

totp_google_authenticator_espruino_pico.js

// This particular assembly of code from three sources by Conor O'Neill. None of it copyright me.
// This code copyright Brian Turek https://github.com/Caligatio/jsSHA https://github.com/Caligatio/jsSHA/blob/master/LICENSE
'use strict';(function(E){function t(c,a,e){var g=0,b=[],d=0,f,k,l,h,m,w,n,q=!1,r=!1,p=[],t=[],v,u=!1;e=e||{};f=e.encoding||"UTF8";v=e.numRounds||1;l=y(a,f);if(v!==parseInt(v,10)||1>v)throw Error("numRounds must a integer >= 1");if("SHA-1"===c)m=512,w=z,n=F,h=160;else throw Error("Chosen SHA variant is not supported");k=x(c);this.setHMACKey=function(a,b,d){var e;if(!0===r)throw Error("HMAC key already set");if(!0===q)throw Error("Cannot set HMAC key after finalizing hash");if(!0===u)throw Error("Cannot set HMAC key after calling update");
f=(d||{}).encoding||"UTF8";b=y(b,f)(a);a=b.binLen;b=b.value;e=m>>>3;d=e/4-1;if(e<a/8){for(b=n(b,a,0,x(c));b.length<=d;)b.push(0);b[d]&=4294967040}else if(e>a/8){for(;b.length<=d;)b.push(0);b[d]&=4294967040}for(a=0;a<=d;a+=1)p[a]=b[a]^909522486,t[a]=b[a]^1549556828;k=w(p,k);g=m;r=!0};this.update=function(a){var c,e,f,h=0,n=m>>>5;c=l(a,b,d);a=c.binLen;e=c.value;c=a>>>5;for(f=0;f<c;f+=n)h+m<=a&&(k=w(e.slice(f,f+n),k),h+=m);g+=h;b=e.slice(h>>>5);d=a%m;u=!0};this.getHash=function(a,e){var f,l,m;if(!0===
r)throw Error("Cannot call getHash after setting HMAC key");m=A(e);switch(a){case "HEX":f=function(a){return B(a,m)};break;case "B64":f=function(a){return C(a,m)};break;case "BYTES":f=D;break;default:throw Error("format must be HEX, B64, or BYTES");}if(!1===q)for(k=n(b,d,g,k),l=1;l<v;l+=1)k=n(k,h,0,x(c));q=!0;return f(k)};this.getHMAC=function(a,e){var f,l,p;if(!1===r)throw Error("Cannot call getHMAC without first setting HMAC key");p=A(e);switch(a){case "HEX":f=function(a){return B(a,p)};break;case "B64":f=
function(a){return C(a,p)};break;case "BYTES":f=D;break;default:throw Error("outputFormat must be HEX, B64, or BYTES");}!1===q&&(l=n(b,d,g,k),k=w(t,x(c)),k=n(l,h,m,k));q=!0;return f(k)}}function G(c,a,e){var g=c.length,b,d,f,k,l;a=a||[0];e=e||0;l=e>>>3;if(0!==g%2)throw Error("String of HEX type must be in byte increments");for(b=0;b<g;b+=2){d=parseInt(c.substr(b,2),16);if(isNaN(d))throw Error("String of HEX type contains invalid characters");k=(b>>>1)+l;for(f=k>>>2;a.length<=f;)a.push(0);a[f]|=d<<
8*(3-k%4)}return{value:a,binLen:4*g+e}}function H(c,a,e){var g=[],b,d,f,k,g=a||[0];e=e||0;d=e>>>3;for(b=0;b<c.length;b+=1)a=c.charCodeAt(b),k=b+d,f=k>>>2,g.length<=f&&g.push(0),g[f]|=a<<8*(3-k%4);return{value:g,binLen:8*c.length+e}}function I(c,a,e){var g=[],b=0,d,f,k,l,h,m,g=a||[0];e=e||0;a=e>>>3;if(-1===c.search(/^[a-zA-Z0-9=+\/]+$/))throw Error("Invalid character in base-64 string");f=c.indexOf("=");c=c.replace(/\=/g,"");if(-1!==f&&f<c.length)throw Error("Invalid '=' found in base-64 string");
for(f=0;f<c.length;f+=4){h=c.substr(f,4);for(k=l=0;k<h.length;k+=1)d="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".indexOf(h[k]),l|=d<<18-6*k;for(k=0;k<h.length-1;k+=1){m=b+a;for(d=m>>>2;g.length<=d;)g.push(0);g[d]|=(l>>>16-8*k&255)<<8*(3-m%4);b+=1}}return{value:g,binLen:8*b+e}}function B(c,a){var e="",g=4*c.length,b,d;for(b=0;b<g;b+=1)d=c[b>>>2]>>>8*(3-b%4),e+="0123456789abcdef".charAt(d>>>4&15)+"0123456789abcdef".charAt(d&15);return a.outputUpper?e.toUpperCase():e}function C(c,
a){var e="",g=4*c.length,b,d,f;for(b=0;b<g;b+=3)for(f=b+1>>>2,d=c.length<=f?0:c[f],f=b+2>>>2,f=c.length<=f?0:c[f],f=(c[b>>>2]>>>8*(3-b%4)&255)<<16|(d>>>8*(3-(b+1)%4)&255)<<8|f>>>8*(3-(b+2)%4)&255,d=0;4>d;d+=1)8*b+6*d<=32*c.length?e+="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".charAt(f>>>6*(3-d)&63):e+=a.b64Pad;return e}function D(c){var a="",e=4*c.length,g,b;for(g=0;g<e;g+=1)b=c[g>>>2]>>>8*(3-g%4)&255,a+=String.fromCharCode(b);return a}function A(c){var a={outputUpper:!1,b64Pad:"="};
c=c||{};a.outputUpper=c.outputUpper||!1;a.b64Pad=c.b64Pad||"=";if("boolean"!==typeof a.outputUpper)throw Error("Invalid outputUpper formatting option");if("string"!==typeof a.b64Pad)throw Error("Invalid b64Pad formatting option");return a}function y(c,a){var e;switch(a){case "UTF8":case "UTF16BE":case "UTF16LE":break;default:throw Error("encoding must be UTF8, UTF16BE, or UTF16LE");}switch(c){case "HEX":e=G;break;case "TEXT":e=function(e,b,d){var f=[],c=[],l=0,h,m,p,n,q,f=b||[0];b=d||0;p=b>>>3;if("UTF8"===
a)for(h=0;h<e.length;h+=1)for(d=e.charCodeAt(h),c=[],128>d?c.push(d):2048>d?(c.push(192|d>>>6),c.push(128|d&63)):55296>d||57344<=d?c.push(224|d>>>12,128|d>>>6&63,128|d&63):(h+=1,d=65536+((d&1023)<<10|e.charCodeAt(h)&1023),c.push(240|d>>>18,128|d>>>12&63,128|d>>>6&63,128|d&63)),m=0;m<c.length;m+=1){q=l+p;for(n=q>>>2;f.length<=n;)f.push(0);f[n]|=c[m]<<8*(3-q%4);l+=1}else if("UTF16BE"===a||"UTF16LE"===a)for(h=0;h<e.length;h+=1){d=e.charCodeAt(h);"UTF16LE"===a&&(m=d&255,d=m<<8|d>>>8);q=l+p;for(n=q>>>
2;f.length<=n;)f.push(0);f[n]|=d<<8*(2-q%4);l+=2}return{value:f,binLen:8*l+b}};break;case "B64":e=I;break;case "BYTES":e=H;break;default:throw Error("format must be HEX, TEXT, B64, or BYTES");}return e}function r(c,a){return c<<a|c>>>32-a}function p(c,a){var e=(c&65535)+(a&65535);return((c>>>16)+(a>>>16)+(e>>>16)&65535)<<16|e&65535}function u(c,a,e,g,b){var d=(c&65535)+(a&65535)+(e&65535)+(g&65535)+(b&65535);return((c>>>16)+(a>>>16)+(e>>>16)+(g>>>16)+(b>>>16)+(d>>>16)&65535)<<16|d&65535}function x(c){if("SHA-1"===
c)c=[1732584193,4023233417,2562383102,271733878,3285377520];else throw Error("No SHA variants supported");return c}function z(c,a){var e=[],g,b,d,f,k,l,h;g=a[0];b=a[1];d=a[2];f=a[3];k=a[4];for(h=0;80>h;h+=1)e[h]=16>h?c[h]:r(e[h-3]^e[h-8]^e[h-14]^e[h-16],1),l=20>h?u(r(g,5),b&d^~b&f,k,1518500249,e[h]):40>h?u(r(g,5),b^d^f,k,1859775393,e[h]):60>h?u(r(g,5),b&d^b&f^d&f,k,2400959708,e[h]):u(r(g,5),b^d^f,k,3395469782,e[h]),k=f,f=d,d=r(b,30),b=g,g=l;a[0]=p(g,a[0]);a[1]=p(b,a[1]);a[2]=p(d,a[2]);a[3]=p(f,a[3]);
a[4]=p(k,a[4]);return a}function F(c,a,e,g){var b;for(b=(a+65>>>9<<4)+15;c.length<=b;)c.push(0);c[a>>>5]|=128<<24-a%32;c[b]=a+e;e=c.length;for(a=0;a<e;a+=16)g=z(c.slice(a,a+16),g);return g}"function"===typeof define&&define.amd?define(function(){return t}):"undefined"!==typeof exports?"undefined"!==typeof module&&module.exports?module.exports=exports=t:exports=t:E.jsSHA=t})(this);

// This code copyright Nic Raboy https://blog.nraboy.com/2014/10/generate-time-based-one-time-passwords-javascript/
TOTP = function() {
 
    var dec2hex = function(s) {
        return (s < 15.5 ? "0" : "") + Math.round(s).toString(16);
    };
 
    var hex2dec = function(s) {
        return parseInt(s, 16);
    };
 
    var leftpad = function(s, l, p) {
        if(l + 1 >= s.length) {
            s = Array(l + 1 - s.length).join(p) + s;
        }
        return s;
    };
 
    var base32tohex = function(base32) {
        var base32chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
        var bits = "";
        var hex = "";
        for(var i = 0; i < base32.length; i++) {
            var val = base32chars.indexOf(base32.charAt(i).toUpperCase());
            bits += leftpad(val.toString(2), 5, '0');
        }
        for(var i = 0; i + 4 <= bits.length; i+=4) {
            var chunk = bits.substr(i, 4);
            hex = hex + parseInt(chunk, 2).toString(16) ;
        }
        return hex;
    };
 
    this.getOTP = function(secret) {
        try {
            var epoch = Math.round(new Date().getTime() / 1000.0);
            var time = leftpad(dec2hex(Math.floor(epoch / 30)), 16, "0");
            var hmacObj = new jsSHA("SHA-1", "HEX");
			hmacObj.setHMACKey(base32tohex(secret), "HEX")
			hmacObj.update(time);
            var hmac = hmacObj.getHMAC("HEX");
            var offset = hex2dec(hmac.substring(hmac.length - 1));
            var otp = (hex2dec(hmac.substr(offset * 2, 8)) & hex2dec("7fffffff")) + "";
            otp = (otp).substr(otp.length - 6, 6);
        } catch (error) {
            throw error;
        }
        return otp;
    };
 
}

var totpObj = new TOTP();

// This code copyright Gordon Williams, Pur3 Ltd.,  https://github.com/espruino/Espruino/blob/master/LICENSE
var kb = require("USBKeyboard");

setWatch(function() {
  // These two lines by Conor O'Neill :-)
	var pin = "put_your_PIN_Prefix_here";
  kb.type(pin + totpObj.getOTP("put_your_google_authenticator_secret_here").toString(), function() {
        kb.tap(kb.KEY.ENTER); 
    });
}, BTN, {debounce:100,repeat:true, edge:"rising"});