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DEMOS2/static/js/event_vote.js
Rumperuu 08b5985396 ajg
2018-09-19 08:38:50 +01:00

705 lines
No EOL
22 KiB
JavaScript

var dialogOpen = false;
var DIALOG_BTN_STATES = {
STEP_1: 1,
STEP_2: 2,
STEP_3: 3,
VOTE_SUCCESS: 4,
VOTE_ERROR: 5
};
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);
if (!dialogOpen) {
modalDialog.modal('toggle');
dialogOpen = true;
}
}
function updateDialogButtons(state) {
// Trigger the btn selectors once here
let nextDialogBtn = $('#nextDialogBtn');
let cancelDialogBtn = $('#cancelDialogBtn');
let closeDialogBtn = $('#closeDialogBtn');
let startOverDialogBtn = $('#startOverDialogBtn');
let submitDialogBtn = $('#submitDialogBtn');
switch(state) {
case DIALOG_BTN_STATES.STEP_1:
nextDialogBtn.removeClass("hidden");
cancelDialogBtn.removeClass("hidden");
closeDialogBtn.addClass("hidden");
startOverDialogBtn.addClass("hidden");
submitDialogBtn.addClass("hidden");
break;
case DIALOG_BTN_STATES.STEP_2:
nextDialogBtn.addClass("hidden");
cancelDialogBtn.removeClass("hidden");
closeDialogBtn.addClass("hidden");
startOverDialogBtn.addClass("hidden");
submitDialogBtn.addClass("hidden");
break;
case DIALOG_BTN_STATES.STEP_3:
nextDialogBtn.addClass("hidden");
cancelDialogBtn.addClass("hidden");
closeDialogBtn.addClass("hidden");
startOverDialogBtn.removeClass("hidden");
submitDialogBtn.removeClass("hidden");
break;
case DIALOG_BTN_STATES.VOTE_SUCCESS:
case DIALOG_BTN_STATES.VOTE_ERROR:
nextDialogBtn.addClass("hidden");
cancelDialogBtn.addClass("hidden");
closeDialogBtn.removeClass("hidden");
startOverDialogBtn.addClass("hidden");
submitDialogBtn.addClass("hidden");
break;
}
}
// 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;
}
// This will highlight when people haven't selected enough options
if(!valid) {
let errText = "You've only selected " + selectedCount;
if(selectedCount > 1) {
errText += " options.";
} else {
errText = " You haven't selected any options.";
}
errText += " 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);
updateDialogButtons(DIALOG_BTN_STATES.VOTE_ERROR);
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() {
// Get the user's selected option
let inputs = $("label input[type=checkbox]");
let selectedOption = "";
inputs.each(function() {
let input = $(this);
if(input.prop('checked')) {
selectedOption = input.val();
selectedOption = document.getElementById(selectedOption).innerText;
}
});
// 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%;");
showIDsQRCode(ballotA, ballotB, selectedOption);
}, 150);
}
function showIDsQRCode(ballotA, ballotB, selectedOption) {
var voterID = window.location.search.slice(1).split(/=(.+)/)[1];
var eventID = window.location.href.split('/')[4];
var pollID = $('#poll-num').text();
// Display a QR code with ID details
var modalDialog = $('#modalDialog');
var title = modalDialog.find('.modal-title');
var body = modalDialog.find('.modal-body');
body.empty();
title.text('Step 0 of 3: Scan this');
let pleaseScanP = document.createElement('p');
pleaseScanP.innerHTML = "Please scan the following QR code from your DEMOS 2 mobile application:";
let QRDiv = document.createElement('div');
var QRCodeImg = document.createElement('img');
QRCodeImg.setAttribute('class', 'QR-code');
QRCodeImg.setAttribute('id', "qr-img");
new QRCode(QRCodeImg, voterID+";"+eventID+";"+pollID);
QRDiv.append(QRCodeImg);
body.append(pleaseScanP);
body.append(QRDiv);
// Prepare the appropriate dialog buttons
updateDialogButtons(DIALOG_BTN_STATES.STEP_1);
if(!dialogOpen) {
modalDialog.modal('toggle');
dialogOpen = true;
}
$('#nextDialogBtn').click(function(e) {
showHashQRCode(ballotA, ballotB, selectedOption);
});
};
// Called in stage 1 of 3 in the voting process
function showHashQRCode(ballotA, ballotB, selectedOption) {
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');
body.empty();
title.text('Step 1 of 3: Link Your Vote');
let pleaseScanP = document.createElement('p');
pleaseScanP.innerHTML = "Please scan the following QR code from your DEMOS 2 auditor:";
let QRDiv = document.createElement('div');
var QRCodeImg = document.createElement('img');
QRCodeImg.setAttribute('class', 'QR-code');
QRCodeImg.setAttribute('id', "qr-img");
new QRCode(QRCodeImg, ballotHashes[0] + ';' + ballotHashes[1]);
QRDiv.append(QRCodeImg);
// ----------------------------------------------
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(pleaseScanP);
body.append(QRDiv);
body.append(hashGroupDiv);
// Prepare the appropriate dialog buttons
updateDialogButtons(DIALOG_BTN_STATES.STEP_1);
if(!dialogOpen) {
modalDialog.modal('toggle');
dialogOpen = true;
}
$('#nextDialogBtn').click(function(e) {
showBallotChoiceDialog(ballots, ballotHashes, selectedOption, modalDialog);
});
}
// Called in stage 2 of 3 in the voting process
function showBallotChoiceDialog(ballots, ballotHashes, selectedOption, dialog) {
// Display the ballot choice dialog
var title = dialog.find('.modal-title');
var body = dialog.find('.modal-body');
body.empty();
title.text('Step 2 of 3: 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);
// ----------------------------------------------
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(choiceGroupDiv);
body.append(hashGroupDiv);
// Register callback functions for the selection of either A or B
$('#choice-A').click(function(e) {
showSelectionConfirmationDialog("A", ballots[0], ballotHashes[0], ballots[1], selectedOption, dialog);
});
$('#choice-B').click(function(e) {
showSelectionConfirmationDialog("B", ballots[1], ballotHashes[1], ballots[0], selectedOption, dialog);
});
updateDialogButtons(DIALOG_BTN_STATES.STEP_2);
if(!dialogOpen) {
modalDialog.modal('toggle');
dialogOpen = true;
}
}
// Called in stage 3 of 3 in the voting process
function showSelectionConfirmationDialog(selection, selectedBallot, selectedBallotHash,
otherBallot, selectedOption, dialog) {
let title = dialog.find('.modal-title');
let body = dialog.find('.modal-body');
body.empty();
title.text("Step 3 of 3: Confirm Ballot Selection");
// Ballot detail section
let selectedInfoSecDiv = document.createElement('div');
let detailsP = document.createElement('p');
detailsP.innerHTML = "Please check the following details are correct: ";
selectedInfoSecDiv.append(detailsP);
let ul = document.createElement('ul');
let selectedOptionLi = document.createElement('li');
selectedOptionLi.innerHTML = "Selected Option: " + selectedOption;
let ballotSelectionLi = document.createElement('li');
ballotSelectionLi.innerHTML = "Selected Ballot: " + selection;
let ballotHashLi = document.createElement('li');
ballotHashLi.innerHTML = "SHA256 Ballot Fingerprint: " + selectedBallotHash;
ul.append(selectedOptionLi);
ul.append(ballotSelectionLi);
ul.append(ballotHashLi);
selectedInfoSecDiv.append(ul);
// Instruction section
let instructionsP = document.createElement('p');
instructionsP.innerHTML = "If you are happy with your selection you can click on the 'Submit' button below to store"
+ " your vote. Otherwise you can select 'Start Over' to go through the voting process again.";
selectedInfoSecDiv.append(instructionsP);
let additionalInstructionsP = document.createElement('p');
additionalInstructionsP.innerHTML = "You can overwrite your vote later by re-visiting this page and voting again.";
selectedInfoSecDiv.append(additionalInstructionsP);
body.append(selectedInfoSecDiv);
// Update the dialog buttons accordingly
updateDialogButtons(DIALOG_BTN_STATES.STEP_3);
$('#submitDialogBtn').click(function() {
// Dispatch the ballot to the server
sendBallotsToServer(selection, selectedBallot, otherBallot);
});
if(!dialogOpen) {
modalDialog.modal('toggle');
dialogOpen = true;
}
}
function sendBallotsToServer(selection, selectedBallot, otherBallot) {
$.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);
// Prepares the unselected ballot to send, encrypted, to the server.
// Creates the unique ballot ID for the unselected ballot
var voterID = window.location.search.slice(1).split(/=(.+)/)[1];
var eventID = window.location.href.split('/')[4];
var pollNum = $('#poll-num').text();
var ballotID = encodeURIComponent(btoa(JSON.stringify({voterID: voterID, eventID: eventID, pollNum: pollNum})));
// TODO: Generate a SK rather than using a static one. UUID generated server side and then injected JS side?
var SK = "temporary";
var encAlt = sjcl.encrypt(SK, JSON.stringify({ballotID: ballotID, ballot: otherBallot}));
// Generates an HMAC to protect the encrypted ballot from tampering.
var out = (new sjcl.misc.hmac(key, sjcl.hash.sha256)).mac(encAlt);
var hmac = sjcl.codec.hex.fromBits(out);
// Prepares the selected ballot to submit to the server.
let selectedBallotAsStr = JSON.stringify(selectedBallot);
$.ajax({
type : "POST",
url : window.location,
data : { handle: ballotID, encBallot: encAlt, ballot: selectedBallotAsStr, selection: selection },
success : function(){
onAfterBallotSend(ballotID, SK, hmac);
}
});
}
// Called once the ballot has been sent to the back-end and dialog has closed
function onAfterBallotSend(ballotID, SK, hmac) {
// 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');
body.empty();
let titleText = 'Vote Successfully Received';
title.text(titleText);
// Add the first section: Instructions on next steps
let instructions1Txt = "Thank you for voting! Please note down the ballot identifier by scanning " +
"this QR code using the DEMOS2 mobile application: ";
var instructions1P = document.createElement("p");
instructions1P.innerHTML = instructions1Txt;
body.append(instructions1P);
// Add the second section: QR code that contains the ballot identifier and HMAC
var QRCodeImg = document.createElement('img');
QRCodeImg.setAttribute('class', 'QR-code');
new QRCode(QRCodeImg, ballotID+";"+btoa(hmac));
body.append(QRCodeImg);
// Add the third section: instructions on Ballot ID and SK
let instructions2Div = document.createElement('div');
instructions2Div.setAttribute('class', 'containerMarginTop');
let instructions2Txt = "You will also be emailed the ballot identifier. However, you will need to note down the following " +
"secret in order to later verify your ballot was cast as recorded: ";
let instructions2P = document.createElement('p');
instructions2P.innerHTML = instructions2Txt;
instructions2Div.append(instructions2P);
body.append(instructions2Div);
// Add the fourth section: SK plain text
let SKContainerDiv = document.createElement('div');
SKContainerDiv.setAttribute("class", "containerMarginTop");
let SKDiv = document.createElement('div');
SKDiv.setAttribute("class", "skDIV");
let SKP = document.createElement('p');
SKP.innerHTML = SK;
SKDiv.append(SKP);
SKContainerDiv.append(SKDiv);
body.append(SKContainerDiv);
// Conditional fifth section: Instructions on how to vote on the next poll for the event
if(POLL_NUM !== POLL_COUNT) {
let instructions3Txt = "You can vote on the next poll by closing down this dialog and clicking 'Next Poll'.";
let instructions3P = document.createElement('p');
instructions3P.innerHTML = instructions3Txt;
body.append(instructions3P);
}
updateDialogButtons(DIALOG_BTN_STATES.VOTE_SUCCESS);
}
$('#modalDialog').on('hide.bs.modal', function (e) {
var titleText = $(this).find('.modal-title').text();
if(titleText.indexOf("Received") > -1) {
// Update page to reflect the fact that a vote has taken place
location.reload();
} else if (titleText.indexOf("Error") === -1) {
// Reset poll voting to allow user to vote again
progressBar.setAttribute("style", "width: 0%;");
$('#gen-ballots-btn').toggleClass("hidden");
$('#progress-bar-description').toggleClass('hidden');
$('#progress-bar-container').toggleClass('hidden');
var inputs = $("label input[type=checkbox]");
inputs.each(function () {
var input = $(this);
input.prop('checked', false);
input.prop('disabled', false);
});
selectedCount = 0;
}
dialogOpen = false;
});