Merge e555680e1c into 7622972ab3

README

@@ -49,6 +49,7 @@ window.EllipticCurve		BSD License
 window.BigInteger		BSD License
 window.QRCode			MIT License
 window.Bitcoin			MIT License
+window.secrets                  MIT Licenses
 
 The bitaddress.org software is available under The MIT License (MIT)
 Copyright (c) 2011-2012 bitaddress.org

bitaddress.org.html

@@ -49,6 +49,535 @@
 	<title>bitaddress.org</title>
 	<meta charset="iso-8859-1">
 
+        <script type="text/javascript">
+        // secrets.js - by Alexander Stetsyuk - released under MIT License
+        (function(exports, global){
+        var defaults = {
+                bits: 8, // default number of bits
+                radix: 16, // work with HEX by default
+                minBits: 3,
+                maxBits: 20, // this permits 1,048,575 shares, though going this high is NOT recommended in JS!
+
+                bytesPerChar: 2,
+                maxBytesPerChar: 6, // Math.pow(256,7) > Math.pow(2,53)
+
+                // Primitive polynomials (in decimal form) for Galois Fields GF(2^n), for 2 <= n <= 30
+                // The index of each term in the array corresponds to the n for that polynomial
+                // i.e. to get the polynomial for n=16, use primitivePolynomials[16]
+                primitivePolynomials: [null,null,1,3,3,5,3,3,29,17,9,5,83,27,43,3,45,9,39,39,9,5,3,33,27,9,71,39,9,5,83],
+
+                // warning for insecure PRNG
+                warning: 'WARNING:\nA secure random number generator was not found.\nUsing Math.random(), which is NOT cryptographically strong!'
+        };
+
+        // Protected settings object
+        var config = {};
+
+        /** @expose **/
+        exports.getConfig = function(){
+                return {
+                        'bits': config.bits,
+                        'unsafePRNG': config.unsafePRNG
+                };
+        };
+
+        function init(bits){
+                if(bits && (typeof bits !== 'number' || bits%1 !== 0 || bits<defaults.minBits || bits>defaults.maxBits)){
+                        throw new Error('Number of bits must be an integer between ' + defaults.minBits + ' and ' + defaults.maxBits + ', inclusive.')
+                }
+
+                config.radix = defaults.radix;
+                config.bits = bits || defaults.bits;
+                config.size = Math.pow(2, config.bits);
+                config.max = config.size - 1;
+
+                // Construct the exp and log tables for multiplication.	
+                var logs = [], exps = [], x = 1, primitive = defaults.primitivePolynomials[config.bits];
+                for(var i=0; i<config.size; i++){
+                        exps[i] = x;
+                        logs[x] = i;
+                        x <<= 1;
+                        if(x >= config.size){
+                                x ^= primitive;
+                                x &= config.max;
+                        }
+                }
+
+                config.logs = logs;
+                config.exps = exps;
+        };
+
+        /** @expose **/
+        exports.init = init;
+
+        function isInited(){
+                if(!config.bits || !config.size || !config.max  || !config.logs || !config.exps || config.logs.length !== config.size || config.exps.length !== config.size){
+                        return false;
+                }
+                return true;
+        };
+
+        // Returns a pseudo-random number generator of the form function(bits){}
+        // which should output a random string of 1's and 0's of length `bits`
+        function getRNG(){
+                var randomBits, crypto;
+
+                function construct(bits, arr, radix, size){
+                        var str = '',
+                                i = 0,
+                                len = arr.length-1;
+                        while( i<len || (str.length < bits) ){
+                                str += padLeft(parseInt(arr[i], radix).toString(2), size);
+                                i++;
+                        }
+                        str = str.substr(-bits);
+                        if( (str.match(/0/g)||[]).length === str.length){ // all zeros?
+                                return null;
+                        }else{
+                                return str;
+                        }
+                }
+
+                // node.js crypto.randomBytes()
+                if(typeof require === 'function' && (crypto=require('crypto')) && (randomBits=crypto['randomBytes'])){
+                        return function(bits){
+                                var bytes = Math.ceil(bits/8),
+                                        str = null;
+
+                                while( str === null ){
+                                        str = construct(bits, randomBits(bytes).toString('hex'), 16, 4);
+                                }
+                                return str;
+                        }
+                }
+
+                // browsers with window.crypto.getRandomValues()
+                if(global['crypto'] && typeof global['crypto']['getRandomValues'] === 'function' && typeof global['Uint32Array'] === 'function'){
+                        crypto = global['crypto'];
+                        return function(bits){
+                                var elems = Math.ceil(bits/32),
+                                        str = null,
+                                        arr = new global['Uint32Array'](elems);
+
+                                while( str === null ){
+                                        crypto['getRandomValues'](arr);
+                                        str = construct(bits, arr, 10, 32);
+                                }
+
+                                return str;	
+                        }
+                }
+
+                // A totally insecure RNG!!! (except in Safari)
+                // Will produce a warning every time it is called.
+                config.unsafePRNG = true;
+                warn();
+
+                var bitsPerNum = 32;
+                var max = Math.pow(2,bitsPerNum)-1;
+                return function(bits){
+                        var elems = Math.ceil(bits/bitsPerNum);
+                        var arr = [], str=null;
+                        while(str===null){
+                                for(var i=0; i<elems; i++){
+                                        arr[i] = Math.floor(Math.random() * max + 1); 
+                                }
+                                str = construct(bits, arr, 10, bitsPerNum);
+                        }
+                        return str;
+                };
+        };
+
+        // Warn about using insecure rng.
+        // Called when Math.random() is being used.
+        function warn(){
+                global['console']['warn'](defaults.warning);
+                if(typeof global['alert'] === 'function' && config.alert){
+                        global['alert'](defaults.warning);
+                }
+        }
+
+        // Set the PRNG to use. If no RNG function is supplied, pick a default using getRNG()
+        /** @expose **/
+        exports.setRNG = function(rng, alert){
+                if(!isInited()){
+                        this.init();
+                }
+                config.unsafePRNG=false;
+                rng = rng || getRNG();
+
+                // test the RNG (5 times)
+                if(typeof rng !== 'function' || typeof rng(config.bits) !== 'string' || !parseInt(rng(config.bits),2) || rng(config.bits).length > config.bits || rng(config.bits).length < config.bits){
+                        throw new Error("Random number generator is invalid. Supply an RNG of the form function(bits){} that returns a string containing 'bits' number of random 1's and 0's.")
+                }else{
+                        config.rng = rng;
+                }
+                config.alert = !!alert;
+
+                return !!config.unsafePRNG;
+        };
+
+        function isSetRNG(){
+                return typeof config.rng === 'function'; 
+        };
+
+        // Generates a random bits-length number string using the PRNG
+        /** @expose **/
+        exports.random = function(bits){
+                if(!isSetRNG()){
+                        this.setRNG();
+                }
+
+                if(typeof bits !== 'number' || bits%1 !== 0 || bits < 2){
+                        throw new Error('Number of bits must be an integer greater than 1.')
+                }
+
+                if(config.unsafePRNG){
+                        warn();
+                }
+                return bin2hex(config.rng(bits));
+        }
+
+        // Divides a `secret` number String str expressed in radix `inputRadix` (optional, default 16) 
+        // into `numShares` shares, each expressed in radix `outputRadix` (optional, default to `inputRadix`), 
+        // requiring `threshold` number of shares to reconstruct the secret. 
+        // Optionally, zero-pads the secret to a length that is a multiple of padLength before sharing.
+        /** @expose **/
+        exports.share = function(secret, numShares, threshold, padLength){
+                if(!isInited()){
+                        this.init();
+                }
+                if(!isSetRNG()){
+                        this.setRNG();
+                }
+
+                padLength =  padLength || 0;
+
+                if(typeof secret !== 'string'){
+                        throw new Error('Secret must be a string.');
+                }
+                if(typeof numShares !== 'number' || numShares%1 !== 0 || numShares < 2){
+                        throw new Error('Number of shares must be an integer between 2 and 2^bits-1 (' + config.max + '), inclusive.')
+                }
+                if(numShares > config.max){
+                        var neededBits = Math.ceil(Math.log(numShares +1)/Math.LN2);
+                        throw new Error('Number of shares must be an integer between 2 and 2^bits-1 (' + config.max + '), inclusive. To create ' + numShares + ' shares, use at least ' + neededBits + ' bits.')	
+                }
+                if(typeof threshold !== 'number' || threshold%1 !== 0 || threshold < 2){
+                        throw new Error('Threshold number of shares must be an integer between 2 and 2^bits-1 (' + config.max + '), inclusive.');
+                }
+                if(threshold > config.max){
+                        var neededBits = Math.ceil(Math.log(threshold +1)/Math.LN2);
+                        throw new Error('Threshold number of shares must be an integer between 2 and 2^bits-1 (' + config.max + '), inclusive.  To use a threshold of ' + threshold + ', use at least ' + neededBits + ' bits.');
+                }
+                if(typeof padLength !== 'number' || padLength%1 !== 0 ){
+                        throw new Error('Zero-pad length must be an integer greater than 1.');
+                }
+
+                if(config.unsafePRNG){
+                        warn();
+                }
+
+                secret = '1' + hex2bin(secret); // append a 1 so that we can preserve the correct number of leading zeros in our secret
+                secret = split(secret, padLength);	
+                var x = new Array(numShares), y = new Array(numShares);
+                for(var i=0, len = secret.length; i<len; i++){
+                        var subShares = this._getShares(secret[i], numShares, threshold);
+                        for(var j=0; j<numShares; j++){
+                                x[j] = x[j] || subShares[j].x.toString(config.radix);
+                                y[j] = padLeft(subShares[j].y.toString(2)) + (y[j] ? y[j] : '');
+                        }
+                }
+                var padding = config.max.toString(config.radix).length;
+                for(var i=0; i<numShares; i++){
+                        x[i] = config.bits.toString(36) + padLeft(x[i],padding) + bin2hex(y[i]);
+                }
+
+                return x;
+        };
+
+        // This is the basic polynomial generation and evaluation function 
+        // for a `config.bits`-length secret (NOT an arbitrary length)
+        // Note: no error-checking at this stage! If `secrets` is NOT 
+        // a NUMBER less than 2^bits-1, the output will be incorrect!
+        /** @expose **/
+        exports._getShares = function(secret, numShares, threshold){	
+                var shares = [];
+                var coeffs = [secret]; 
+
+                for(var i=1; i<threshold; i++){
+                        coeffs[i] = parseInt(config.rng(config.bits),2);
+                }
+                for(var i=1, len = numShares+1; i<len; i++){
+                        shares[i-1] = {
+                                x: i,
+                                y: horner(i, coeffs)
+                        }
+                }
+                return shares;
+        };
+
+        // Polynomial evaluation at `x` using Horner's Method
+        // TODO: this can possibly be sped up using other methods
+        // NOTE: fx=fx * x + coeff[i] ->  exp(log(fx) + log(x)) + coeff[i], 
+        //       so if fx===0, just set fx to coeff[i] because
+        //       using the exp/log form will result in incorrect value
+        function horner(x, coeffs){
+                var logx = config.logs[x];
+                var fx = 0;
+                for(var i=coeffs.length-1; i>=0; i--){	
+                        if(fx === 0){
+                                fx = coeffs[i];
+                                continue;
+                        }
+                        fx = config.exps[ (logx + config.logs[fx]) % config.max ] ^ coeffs[i];
+                }
+                return fx;
+        };
+
+        function inArray(arr,val){
+                for(var i = 0,len=arr.length; i < len; i++) {
+                        if(arr[i] === val){
+                         return true;
+                        }
+                }
+                return false;
+        };
+
+        function processShare(share){
+
+                var bits = parseInt(share[0], 36);
+                if(bits && (typeof bits !== 'number' || bits%1 !== 0 || bits<defaults.minBits || bits>defaults.maxBits)){
+                        throw new Error('Number of bits must be an integer between ' + defaults.minBits + ' and ' + defaults.maxBits + ', inclusive.')
+                }
+
+                var max = Math.pow(2, bits) - 1;
+                var idLength = max.toString(config.radix).length;
+
+                var id = parseInt(share.substr(1, idLength), config.radix);
+                if(typeof id !== 'number' || id%1 !== 0 || id<1 || id>max){
+                        throw new Error('Share id must be an integer between 1 and ' + config.max + ', inclusive.');
+                }
+                share = share.substr(idLength + 1);
+                if(!share.length){
+                        throw new Error('Invalid share: zero-length share.')
+                }
+                return {
+                        'bits': bits,
+                        'id': id,
+                        'value': share
+                };
+        };
+
+        /** @expose **/
+        secrets._processShare = processShare;
+
+        // Protected method that evaluates the Lagrange interpolation
+        // polynomial at x=`at` for individual config.bits-length
+        // segments of each share in the `shares` Array.
+        // Each share is expressed in base `inputRadix`. The output 
+        // is expressed in base `outputRadix'
+        function combine(at, shares){
+                var setBits, share, x = [], y = [], result = '', idx;	
+
+                for(var i=0, len = shares.length; i<len; i++){
+                        share = processShare(shares[i]);
+                        if(typeof setBits === 'undefined'){
+                                setBits = share['bits'];
+                        }else if(share['bits'] !== setBits){
+                                throw new Error('Mismatched shares: Different bit settings.')
+                        }
+
+                        if(config.bits !== setBits){
+                                init(setBits);
+                        }
+
+                        if(inArray(x, share['id'])){ // repeated x value?
+                                continue;
+                        }
+
+                        idx = x.push(share['id']) - 1;
+                        share = split(hex2bin(share['value']));
+                        for(var j=0, len2 = share.length; j<len2; j++){
+                                y[j] = y[j] || [];
+                                y[j][idx] = share[j];
+                        }
+                }
+
+                for(var i=0, len=y.length; i<len; i++){
+                        result = padLeft(lagrange(at, x, y[i]).toString(2)) + result;
+                }
+
+                if(at===0){// reconstructing the secret
+                        var idx = result.indexOf('1'); //find the first 1
+                        return bin2hex(result.slice(idx+1));
+                }else{// generating a new share
+                        return bin2hex(result);
+                }
+        };
+
+        // Combine `shares` Array into the original secret
+        /** @expose **/
+        exports.combine = function(shares){
+                return combine(0, shares);
+        };
+
+        // Generate a new share with id `id` (a number between 1 and 2^bits-1)
+        // `id` can be a Number or a String in the default radix (16)
+        /** @expose **/
+        exports.newShare = function(id, shares){
+                if(typeof id === 'string'){
+                        id = parseInt(id, config.radix);	
+                }
+
+                var share = processShare(shares[0]);
+                var max = Math.pow(2, share['bits']) - 1;
+
+                if(typeof id !== 'number' || id%1 !== 0 || id<1 || id>max){
+                        throw new Error('Share id must be an integer between 1 and ' + config.max + ', inclusive.');
+                }
+
+                var padding = max.toString(config.radix).length;
+                return config.bits.toString(36) + padLeft(id.toString(config.radix), padding) + combine(id, shares);
+        };
+
+        // Evaluate the Lagrange interpolation polynomial at x = `at`
+        // using x and y Arrays that are of the same length, with
+        // corresponding elements constituting points on the polynomial.
+        function lagrange(at, x, y){
+                var sum = 0,
+                        product, 
+                        i, j;
+
+                for(var i=0, len = x.length; i<len; i++){
+                        if(!y[i]){
+                                continue; 
+                        }
+
+                        product = config.logs[y[i]];
+                        for(var j=0; j<len; j++){
+                                if(i === j){ continue; }
+                                if(at === x[j]){ // happens when computing a share that is in the list of shares used to compute it
+                                        product = -1; // fix for a zero product term, after which the sum should be sum^0 = sum, not sum^1
+                                        break; 
+                                }
+                                product = ( product + config.logs[at ^ x[j]] - config.logs[x[i] ^ x[j]] + config.max/* to make sure it's not negative */ ) % config.max;
+                        }
+
+                        sum = product === -1 ? sum : sum ^ config.exps[product]; // though exps[-1]= undefined and undefined ^ anything = anything in chrome, this behavior may not hold everywhere, so do the check
+                }
+                return sum;
+        };
+
+        /** @expose **/
+        exports._lagrange = lagrange;
+
+        // Splits a number string `bits`-length segments, after first 
+        // optionally zero-padding it to a length that is a multiple of `padLength.
+        // Returns array of integers (each less than 2^bits-1), with each element
+        // representing a `bits`-length segment of the input string from right to left, 
+        // i.e. parts[0] represents the right-most `bits`-length segment of the input string.
+        function split(str, padLength){
+                if(padLength){
+                        str = padLeft(str, padLength)
+                }
+                var parts = [];
+                for(var i=str.length; i>config.bits; i-=config.bits){
+                        parts.push(parseInt(str.slice(i-config.bits, i), 2));
+                }	
+                parts.push(parseInt(str.slice(0, i), 2));	
+                return parts;
+        };
+
+        // Pads a string `str` with zeros on the left so that its length is a multiple of `bits`
+        function padLeft(str, bits){
+                bits = bits || config.bits
+                var missing = str.length % bits;
+                return (missing ? new Array(bits - missing + 1).join('0') : '') + str;
+        };
+
+        function hex2bin(str){
+                var bin = '', num;
+                for(var i=str.length - 1; i>=0; i--){
+                        num = parseInt(str[i], 16)
+                        if(isNaN(num)){
+                                throw new Error('Invalid hex character.')
+                        }
+                        bin = padLeft(num.toString(2), 4) + bin;
+                }
+                return bin;
+        }
+
+        function bin2hex(str){
+                var hex = '', num;
+                str = padLeft(str, 4);
+                for(var i=str.length; i>=4; i-=4){
+                        num = parseInt(str.slice(i-4, i), 2);
+                        if(isNaN(num)){
+                                throw new Error('Invalid binary character.')
+                        }
+                        hex = num.toString(16) + hex;
+                }
+                return hex;
+        }
+
+        // Converts a given UTF16 character string to the HEX representation. 
+        // Each character of the input string is represented by 
+        // `bytesPerChar` bytes in the output string.
+        /** @expose **/
+        exports.str2hex = function(str, bytesPerChar){
+                if(typeof str !== 'string'){
+                        throw new Error('Input must be a character string.');
+                }
+                bytesPerChar = bytesPerChar || defaults.bytesPerChar;
+
+                if(typeof bytesPerChar !== 'number' || bytesPerChar%1 !== 0 || bytesPerChar<1 || bytesPerChar > defaults.maxBytesPerChar){
+                        throw new Error('Bytes per character must be an integer between 1 and ' + defaults.maxBytesPerChar + ', inclusive.')
+                }
+
+                var hexChars = 2*bytesPerChar;
+                var max = Math.pow(16, hexChars) - 1;
+                var out = '', num;
+                for(var i=0, len=str.length; i<len; i++){
+                        num = str[i].charCodeAt();
+                        if(isNaN(num)){
+                                throw new Error('Invalid character: ' + str[i]);
+                        }else if(num > max){
+                                var neededBytes = Math.ceil(Math.log(num+1)/Math.log(256));
+                                throw new Error('Invalid character code (' + num +'). Maximum allowable is 256^bytes-1 (' + max + '). To convert this character, use at least ' + neededBytes + ' bytes.')
+                        }else{
+                                out = padLeft(num.toString(16), hexChars) + out;
+                        }
+                }
+                return out;
+        };
+
+        // Converts a given HEX number string to a UTF16 character string. 
+        /** @expose **/
+        exports.hex2str = function(str, bytesPerChar){
+                if(typeof str !== 'string'){
+                        throw new Error('Input must be a hexadecimal string.');
+                }
+                bytesPerChar = bytesPerChar || defaults.bytesPerChar;
+
+                if(typeof bytesPerChar !== 'number' || bytesPerChar%1 !== 0 || bytesPerChar<1 || bytesPerChar > defaults.maxBytesPerChar){
+                        throw new Error('Bytes per character must be an integer between 1 and ' + defaults.maxBytesPerChar + ', inclusive.')
+                }
+
+                var hexChars = 2*bytesPerChar;
+                var out = '';
+                str = padLeft(str, hexChars);
+                for(var i=0, len = str.length; i<len; i+=hexChars){
+                        out = String.fromCharCode(parseInt(str.slice(i, i+hexChars),16)) + out;
+                }
+                return out;
+        };
+
+        // by default, initialize without an RNG
+        exports.init();
+        })(typeof module !== 'undefined' && module['exports'] ? module['exports'] : (window['secrets'] = {}), typeof GLOBAL !== 'undefined' ? GLOBAL : window );
+        </script>
+
 	<script type="text/javascript">
 	// Array.prototype.map function is in the public domain.
 	// Production steps of ECMA-262, Edition 5, 15.4.4.19  
@@ -185,7 +714,10 @@
 
 				// Convert a hex string to a byte array
 				hexToBytes: function (hex) {
-					for (var bytes = [], c = 0; c < hex.length; c += 2)
+                                        //if input has odd number of digits, pad it
+                                        if (hex.length % 2 == 1)
+                                                hex = "0" + hex;
+  					for (var bytes = [], c = 0; c < hex.length; c += 2)
 						bytes.push(parseInt(hex.substr(c, 2), 16));
 					return bytes;
 				},
@@ -5874,6 +6406,7 @@
 			<div class="tab" id="brainwallet" onclick="ninja.tabSwitch(this);">Brain Wallet</div>
 			<div class="tab" id="vanitywallet" onclick="ninja.tabSwitch(this);">Vanity Wallet</div>
 			<div class="tab" id="detailwallet" onclick="ninja.tabSwitch(this);">Wallet Details</div>
+	                <div class="tab" id="splitwallet" onclick="ninja.tabSwitch(this);">Split Wallet</div>
 		</div>
 		
 		<div id="generate">
@@ -6115,6 +6648,30 @@
 			</div>
 		</div>
 
+                <div id="splitarea" class="walletarea">
+                  <div id="splitcommands" class="left">
+		    <span>
+                      <label id="splitlabelshares">Number of shares</label> 
+                      <input type="text" id="splitshares" value="4" size="4"/><br/>
+                      <label id="splitlabelthreshhold">Minimum share threshhold needed to combine</label>
+                      <input type="text" id="splitthreshhold" value="2" size="4"/>
+                    </span>
+                    
+		    <span><input type="button" id="splitview" value="Generate" onclick="ninja.wallets.splitwallet.splitKey();"></span>
+		  </div>
+                  <div id="combinecommands" class="left commands">
+		    <span>
+                      <label id="combinelabelentershares">Enter Available Shares (whitespace separated)</label> 
+                      <textarea id="combineinput" cols="60" rows="10"/></textarea><br/>
+                    </span>
+                    
+		    <span>
+                      <input type="button" id="combineview" value="Combine Shares" onclick="ninja.wallets.splitwallet.combineShares();">
+                    </span>
+		  </div> 
+                </div>
+
+
 		<div id="footer" class="footer">
 			<div class="authorbtc">
 				<div>
@@ -7458,6 +8015,106 @@
 		};
 	</script>
 
+	<script type="text/javascript">
+		ninja.wallets.splitwallet = {
+			open: function () {
+				document.getElementById("splitarea").style.display = "block";
+				secrets.setRNG();
+				secrets.init(3);
+			},
+		
+			close: function () {
+				document.getElementById("splitarea").style.display = "none";
+			},
+		
+			mkOutputRow: function(s,id,lbltxt) {
+				var row = document.createElement("span");
+				var label = document.createElement("label");
+				label.innerHTML= lbltxt + s;
+				var qr = document.createElement("div");
+		
+				qr.setAttribute("id", id);
+				row.appendChild(label);
+				row.appendChild(qr);
+				row.appendChild(document.createElement("br"));
+		
+				return row;
+		
+			},
+		
+			stripLeadZeros: function(hex) { return hex.split(/^0+/).slice(-1)[0]; },
+		
+			// Split a private key and update information in the HTML
+			splitKey: function () {
+				try {
+					var key = new Bitcoin.ECKey(false);
+					var bitcoinAddress = key.getBitcoinAddress();
+					var element = document.getElementById("splitoutput");
+					if (element != null) element.parentNode.removeChild(element);
+					
+					var numshares = parseInt(document.getElementById('splitshares').value);
+					var threshhold =  parseInt(document.getElementById('splitthreshhold').value);
+					var shares = secrets.share(Crypto.util.bytesToHex(key.getBitcoinPrivateKeyByteArray()),
+											   numshares, threshhold).map(Crypto.util.hexToBytes).map(Bitcoin.Base58.encode);
+					var output = document.createElement("div");
+					output.setAttribute("id", "splitoutput");
+					var m = {};
+					output.appendChild(this.mkOutputRow(bitcoinAddress, "split_addr", "Bitcoin Address:	   "));
+					m["split_addr"] = bitcoinAddress;
+					
+					for (var i=0; i < shares.length; i++) {
+						var id = "split_qr_"+ i;
+						output.appendChild(this.mkOutputRow(shares[i], id, "Share " + (i+1) + ":	  "));
+						m[id]=shares[i];
+					}
+		
+					document.getElementById("splitcommands").appendChild(output);
+					ninja.qrCode.showQrCode(m);
+		
+				}
+				catch (e) {
+					// browser does not have sufficient JavaScript support to generate a bitcoin address
+					alert(e);
+					document.getElementById("btcaddress").innerHTML = "error";
+					document.getElementById("btcprivwif").innerHTML = "error";
+					document.getElementById("qrcode_public").innerHTML = "";
+					document.getElementById("qrcode_private").innerHTML = "";
+				}
+			},
+		
+			// Combine shares of a private key to retrieve the key
+			combineShares: function () {
+				try {
+					var element = document.getElementById("combineoutput");
+					if (element != null) element.parentNode.removeChild(element);
+		
+					var shares = document.getElementById("combineinput").value.trim().split(/\W+/);
+		
+					var combined = secrets.combine(shares.map(Bitcoin.Base58.decode).
+												   map(Crypto.util.bytesToHex).
+												   map(this.stripLeadZeros));
+		
+					var privkeyBase58 = new Bitcoin.ECKey(Crypto.util.hexToBytes(combined)).getBitcoinWalletImportFormat();
+					var output = document.createElement("div");
+					output.setAttribute("id", "combineoutput");
+					var txt = document.createElement("input");
+					txt.setAttribute("id","combineoutputtext");
+					txt.setAttribute("value",privkeyBase58);
+					txt.setAttribute("size",55);
+					var lbl = document.createElement("label");
+					lbl.innerHTML="Private key";
+					output.appendChild(lbl);
+					output.appendChild(txt);
+					document.getElementById("combinecommands").appendChild(output);
+				}
+				catch (e) {
+					alert(e);
+				}
+		
+			}
+		};
+	</script>
+
 	<script type="text/javascript">
 	(function (ninja) {
 		var ut = ninja.unitTests = {
@@ -7994,4 +8651,4 @@
 		setTimeout(ninja.seeder.forceGenerate, ninja.seeder.seedLimit * 20);
 	</script>
 </body>
-</html>
+</html>