function showDialogWithText(titleTxt, bodyTxt) { var modalDialog = $('#modalDialog'); var title = modalDialog.find('.modal-title'); var body = modalDialog.find('.modal-body'); title.text(titleTxt); var p = document.createElement("p"); p.innerHTML = bodyTxt; body.empty(); body.append( p ); modalDialog.modal('show'); } // This should stop people ticking more than the maximum permitted function updateCheckboxInteractivity() { var inputs = $("label input[type=checkbox]"); if(selectedCount === MAX_SELECTIONS) { inputs.each(function() { var input = $(this); if(!input.prop('checked')){ input.prop('disabled', true); } }); } else { inputs.each(function() { var input = $(this); if(!input.prop('checked')) { input.prop('disabled', false); } }); } } $("label input[type=checkbox]").change(function() { // Increment the selectedCount counter if a box has been checked if(this.checked) { selectedCount += 1; } else { selectedCount -= 1; // Just incase this falls below zero to avoid any nasty bugs if(selectedCount < 0) { selectedCount = 0; } } updateCheckboxInteractivity(); }); function isVotingInputValid() { var valid = true; // First establish if the user's selection count is valid if(!(selectedCount >= MIN_SELECTIONS && selectedCount <= MAX_SELECTIONS)) { valid = false; } if(selectedCount < MAX_SELECTIONS) { valid = false; } // This will highlight when people haven't selected enough options if(!valid) { let errText = "You've only selected " + selectedCount + " option(s). The minimum number you need to select is " + MIN_SELECTIONS + " and the maximum is " + MAX_SELECTIONS + ". Please go back and correct this."; let titleTxt = 'Voting Error'; showDialogWithText(titleTxt, errText); return; } return valid; } var progressBar = document.getElementById("progress-bar"); $('#gen-ballots-btn').click(function() { // Ensure that the user selections are valid if(isVotingInputValid()) { // Hide the button $(this).toggleClass('hidden'); // Inject the description progress bar which can then be updated by the encrypt btn $('#progress-bar-description').toggleClass('hidden'); $('#progress-bar-container').toggleClass('hidden'); setTimeout(generateBallots, 25); } }); // Based on the user's vote in the current poll, this generates a ballot which // does not leak information about how many options the user has selected function generateBallot() { // Elliptic curve cryptography params used for encryption of encrypted vote // fragments var ctx = new CTX("BN254CX"); var n = new ctx.BIG(); var g1 = new ctx.ECP(); var g2 = new ctx.ECP2(); var parameter = $('#event-param').val(); var tempParams = JSON.parse(JSON.parse(parameter).crypto); //copying the values n.copy(tempParams.n); g1.copy(tempParams.g1); g2.copy(tempParams.g2); var params = { n:n, g1:g1, g2:g2 }; var tempPK = JSON.parse($('#comb_pk').val()); var pk = new ctx.ECP(0); pk.copy(tempPK.PK); // Collect together the unencrypted votes (which correspond to selected options) var checkboxInputs = $("label input[type=checkbox]"); var unencryptedVotes = []; checkboxInputs.each(function() { var checkbox = $(this); // Push the selected option values (ones that have been checked) to an array if(checkbox.prop('checked')) { unencryptedVotes.push(checkbox.val()); } }); // If there is a dif between the num selected and the max allowed, push blank votes to the array to pad this // to prevent information leakage if(unencryptedVotes.length < MAX_SELECTIONS) { let blankVotesToPush = MAX_SELECTIONS - unencryptedVotes.length; for(let i = 0; i < blankVotesToPush; i++) { unencryptedVotes.push(genBlankVote()); } } // Encrypt all of the votes for this ballot var encryptedVotes = []; unencryptedVotes.forEach(function(unencryptedVote) { var encFragments = []; // Encrypt each fragment of the unencrypted vote unencryptedVote.split(',').forEach(function(fragment) { var cipher = encrypt(params, pk, parseInt(fragment)); // Store C1, C2 and r from the cipher in the fragment var c1Bytes = []; cipher.C1.toBytes(c1Bytes); var c2Bytes = []; cipher.C2.toBytes(c2Bytes); var rBytes = []; cipher.r.toBytes(rBytes); encFragments.push({ C1 : c1Bytes.toString(), C2 : c2Bytes.toString(), r : rBytes.toString() }); }); // Store all fragments in a single 'encrypted vote' encryptedVotes.push({ fragments: encFragments }); }); return { encryptedVotes: encryptedVotes }; } // Generates a blank vote as a string using the binary encoding scheme function genBlankVote() { var vote = ""; for(var i = 0; i < OPTION_COUNT; i++) { vote += "0"; if (i !== (OPTION_COUNT - 1)) { vote += ","; } } return vote; } var CSRF = $( "input[name='csrfmiddlewaretoken']" ).val(); function csrfSafeMethod(method) { // these HTTP methods do not require CSRF protection return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method)); } var bytestostring = function(b) { var s = ""; var len = b.length; var ch; for (var i = 0; i < len; i++) { ch = b[i]; s += ((ch >>> 4) & 15).toString(16); s += (ch & 15).toString(16); } return s; }; var stringtobytes = function(s) { var b = []; for (var i = 0; i < s.length; i++) { b.push(s.charCodeAt(i)); } return b; }; function SHA256Hash(bytes, toStr) { var ctx = new CTX(); var R = []; var H = new ctx.HASH256(); H.process_array(bytes); R = H.hash(); if (R.length === 0) { return null; } if(toStr) { // If toStr is true we return the stringified version of the bytes of the hash return bytestostring(R); } else { // If toStr is false we return the bytes of the hash return R; } } function generateBallots() { // Generate Ballot A and Ballot B to be displayed to the user // This fn starts the process var ballotA = generateBallot(); // Update the progress bar once the generation has completed progressBar.setAttribute("style", "width: 50%;"); // This delay allows the execution thread to update the above CSS on the progress bar setTimeout(function () { var ballotB = generateBallot(); progressBar.setAttribute("style", "width: 100%;"); showFirstQRCode(ballotA, ballotB); }, 150); } function showFirstQRCode(ballotA, ballotB) { var ballots = new Array(ballotA, ballotB); var ballotHashes = new Array(2); // Hash both ballots and store for (let i = 0; i <= 1; i++) ballotHashes[i] = SHA256Hash(stringtobytes(JSON.stringify(ballots[i])), true); // With the ballots and their hashes generated, we can display the QR code of both hashes var modalDialog = $('#modalDialog'); var title = modalDialog.find('.modal-title'); var body = modalDialog.find('.modal-body'); var footer = modalDialog.find('.modal-footer'); body.empty(); title.text('Please Scan this QR Code'); var QRCodeImg = document.createElement('img'); QRCodeImg.setAttribute('class', 'QR-code'); new QRCode(QRCodeImg, ballotHashes[0] + ';' + ballotHashes[1]); // ---------------------------------------------- var hashGroupDiv = document.createElement('div'); var br = document.createElement('br'); hashGroupDiv.append( br ); var hashA = document.createElement("span"); hashA.innerHTML = "Hash A: " + ballotHashes[0]; hashGroupDiv.append( hashA ); var br2 = document.createElement('br'); hashGroupDiv.append( br2 ); var hashB = document.createElement("span"); hashB.innerHTML = "Hash B: " + ballotHashes[1]; hashGroupDiv.append( hashB ); // ----------------------------------------------- body.append(QRCodeImg); body.append(hashGroupDiv); var closeButton = $('close-button'); closeButton.removeClass('btn-success'); closeButton.addClass('btn-danger'); closeButton.text("Close without submitting vote"); var nextButton = document.createElement('button'); nextButton.setAttribute('type', 'button'); nextButton.setAttribute('id', 'next-button'); nextButton.setAttribute('class', 'btn btn-default'); nextButton.innerHTML = "Next"; footer.prepend(nextButton); modalDialog.modal('show'); $('#next-button').click(function(e) { showBallotChoiceDialog(ballots); }); } function showBallotChoiceDialog(ballots) { // Display the ballot choice dialog var modalDialog = $('#modalDialog'); var title = modalDialog.find('.modal-title'); var body = modalDialog.find('.modal-body'); body.empty(); title.text('Please Select a Ballot'); // Generate the body of the dialog which consists of a button for A and for B var choiceGroupDiv = document.createElement('div'); choiceGroupDiv.setAttribute('class', 'choice-group'); var btnChoiceA = document.createElement('a'); btnChoiceA.setAttribute('id', 'choice-A'); btnChoiceA.setAttribute('class', 'btn btn-sq btn-primary'); btnChoiceA.innerHTML = 'A'; choiceGroupDiv.append(btnChoiceA); var btnChoiceB = document.createElement('a'); btnChoiceB.setAttribute('id', 'choice-B'); btnChoiceB.setAttribute('class', 'btn btn-sq btn-warning choice'); btnChoiceB.innerHTML = 'B'; choiceGroupDiv.append(btnChoiceB); body.append(choiceGroupDiv); modalDialog.modal('show'); // Register callback functions for the selection of either A or B $('#choice-A').click(function(e) { sendBallotsToServer(ballots[0], ballots[1]); }); $('#choice-B').click(function(e) { sendBallotsToServer(ballots[1], ballots[0]); }); } function sendBallotsToServer(selection, alt) { $.ajaxSetup({ beforeSend: function(xhr, settings) { if (!csrfSafeMethod(settings.type) && !this.crossDomain) { xhr.setRequestHeader("X-CSRFToken", CSRF); } } }); // Elliptic curve cryptography params used for encryption of encrypted vote // fragments var ctx = new CTX("BN254CX"); var n = new ctx.BIG(); var g1 = new ctx.ECP(); var g2 = new ctx.ECP2(); var parameter = $('#event-param').val(); var tempParams = JSON.parse(JSON.parse(parameter).crypto); //copying the values n.copy(tempParams.n); g1.copy(tempParams.g1); g2.copy(tempParams.g2); var params = { n:n, g1:g1, g2:g2 }; var tempPK = JSON.parse($('#comb_pk').val()); var pk = new ctx.ECP(0); pk.copy(tempPK.PK); var voterID = window.location.search.slice(1).split(/=(.+)/)[1];//.slice(0, -2); var eventID = window.location.href.split('/')[4]; var pollNum = $('#poll-num').text(); var ballotID = encodeURIComponent(btoa(JSON.stringify({voterID: voterID, eventID: eventID, pollNum: pollNum}))); var SK = "temporary"; var encAlt = sjcl.encrypt(SK, JSON.stringify(alt)); selection = JSON.stringify(selection); $.ajax({ type : "POST", url : window.location, data : { handle: ballotID, encBallot: encAlt, ballot: selection }, success : function(){ onAfterBallotSend(ballotID, SK); } }); } // Called once the ballot has been sent to the back-end and dialog has closed function onAfterBallotSend(ballotID, SK) { let titleText = 'Vote Successfully Received'; let bodyText = "Thank you for voting! Your secret key is '"+SK+"'. Make sure to scan this QR code with your phone before closing this window."; if(POLL_NUM !== POLL_COUNT) { bodyText += " You can vote on the next poll by closing down this dialog and clicking 'Next Poll'."; } // With one ballot selected, we can display a QR code of the ballot ID var modalDialog = $('#modalDialog'); var title = modalDialog.find('.modal-title'); var body = modalDialog.find('.modal-body'); title.text(titleText); body.empty(); var p = document.createElement("p"); p.innerHTML = bodyText; body.append(p); // Generate the body of the dialog which displays the unselected ballot QR code var QRCodeImg = document.createElement('img'); QRCodeImg.setAttribute('class', 'QR-code'); new QRCode(QRCodeImg, ballotID); body.append(QRCodeImg); var closeButton = $('#close-button'); closeButton.removeClass('btn-danger'); closeButton.addClass('btn-success'); closeButton.text("Close"); modalDialog.modal('show'); }