show.js

/*
 * Anna Dorottya Simon, Márk Szabó
 * Neptun-ID: R48G73, EMX74N
 * Applied cryptography project - a postquantum messenger application
 * January 2017
 * This solution was submitted and prepared by Anna Dorottya Simon(R48G73), Márk Szabó(EMX74N) for the project assignment of the Applied cryptography project seminar course.
 * We declare that this solution is our own work.
 * We have put the necessary references wherever we have used bigger and/or complicated external codes in our project. For shorter code snippets (usually from Stack Overflow) we have put the reference there in most cases.
 * Given the uniqueness of the project (no other student had, have or will have the same project) we have published our code on GitHub with the permission of our professors.
 * Students’ regulation of Eötvös Loránd University (ELTE Regulations Vol. II. 74/C. § ) states that as long as a student presents another student’s work - or at least the significant part of it - as his/her own performance, it will count as a disciplinary fault. The most serious consequence of a disciplinary fault can be dismissal of the student from the University.
 */

function showAddNewFriend() {
  clearTimeout(messageUpdateTimer);
  $('#messagesouter').hide();
  $('#friendRequests').hide();
  $('#alertNewFriend').empty();
  $('.msgtitle').text('Add new friend');
  $('#addnewfriend').show();
  markSelected("menuAddnewfriend");
}

function showFriendRequests() {
  clearTimeout(messageUpdateTimer);
  $('#messagesouter').hide();
  $('#addnewfriend').hide();
  $('.msgtitle').text('Manage friend requests');
  $('#alertFriendRequests').empty();
  $('#friendRequests').show();
  markSelected("menuFriendRequests");
  handleFriendRequests()
}

var user2Id;
var msgSymKey;
var messageUpdateTimer;
var messageTimeout = 5; //in second
var msgId;
var msgIduser2;
const warnSymkeyExchangeEvery = 20 //messages

function showMessages(username, userid, symkey) {
  clearTimeout(messageUpdateTimer); //otherwise problem with switching between chats

  user2Id = userid;
  msgId = 0;
  msgIduser2 = 0;

  //decrypt symmetric key
  msgSymKey = AESdecryptCBC_arr(symkey, decryptionkey);
 
  $.post("getMessages.php", { username: inputEmail, password: authenticationkey, user2Id: user2Id },

  function(data, status){
    $('#messages').empty(); //clear previous messages
    var messages = data.split("\n");
    var signalingMsgs = []
    for(var i=0; i<messages.length; i++) {
      if(messages[i] != "") {
        var fromTo = messages[i].substring(0,1);
        var msgNonce = messages[i].substring(1, messages[i].indexOf(";"));
        var idAndMsg = messages[i].substring(messages[i].indexOf(";")+1);
        var decIdAndMsg = AESdecryptCTR(idAndMsg, msgSymKey, msgNonce);
        if(decIdAndMsg.indexOf(";") == -1) //error decoding or outdated symkey
          continue;
        var decIdAndMsgA = decIdAndMsg.split(";");
        var msg = decIdAndMsgA[1];
        var msgIdi = parseInt(decIdAndMsgA[0]);
        if(msgIdi == 00 && decIdAndMsgA[0].length != 1) //error decoding or outdated symkey
          continue;
        if(fromTo == '1' && msgIdi > msgId) {
          msgId = msgIdi;
          $('#messages').append('<div class="msgFromMe">' + msg + '</div>');
        } else if(fromTo == '0' && msgIdi > msgIduser2){
          msgIduser2 = msgIdi;
          $('#messages').append('<div class="msgToMe">' + msg + '</div>');
        } //handling calls
        else if(fromTo == '0' && msgIdi == 0){
          timestamp=parseInt(decIdAndMsg.split("&")[2])
          if(timestamp+10000>Date.now()){
          msg=decIdAndMsg.split("&")[1]
          signalingMsgs.push(msg)
          }

        }
        if(i != 0 && i % warnSymkeyExchangeEvery == 0)
          $('#messages').append('<div>Reminder: Consider to change secret code.</div>');
      }
    }
    //if call params were recieved
    if (signalingMsgs.length > 2)
    {
      if (!initiator){
      onOfferRecieved(signalingMsgs)
    } else {
      onAnswerRecived(signalingMsgs)
    }

    }

    $('#addnewfriend').hide();
    $('#friendRequests').hide();
    $('.msgtitle').html(username + ' <a href="javascript:changeSymkey(\'' + username + '\', ' + userid + ')"><span class="glyphicon glyphicon-flash" title="Delete all my messages and enforce new secret code"></span></a>');
    $('#messagesouter').show();
    $('#messages').scrollTo("max");
    markSelected("menuMsgs"+userid);
    messageUpdateTimer = setTimeout(function(){showMessages(username, userid, symkey);}, messageTimeout*1000);
  });
}

function changeSymkey(username, userid) {

  $.post("getPublicKey.php", { user: username },
    function(data, status){
      if(data.startsWith("Error")) {
        displayAlert("#alertMessages","danger","Change symkey failed. " + data);
      } else { //no error
        var publicKeyOfFriend = data;
        var encaps = NTRUEncapsulate(publicKeyOfFriend);
        var plainkey = encaps[0];
        var symkeyforfriend = encaps[1];
        var symkeyforme = AESencryptCBC_arr(plainkey, decryptionkey);

        $.post("initChangeSymkey.php", {username: inputEmail, password: authenticationkey, friend: username, symkeyforme: symkeyforme, symkeyforfriend: symkeyforfriend},
          function(data, status){
            if(data == "1") { //success
              send('I changed secret code. All my previous messages were discarded. Please accept a new generated new secret in "Friend requests" to continue conversation. If you send further messages they can not be read by me.');
              displayAlert("#alertMessages","success","Symmetric key changed successfully!");
              showMessages(username, userid, symkeyforme)
            } else {
              displayAlert("#alertMessages","danger",data);
            }
            generateMenu();
          }
        );
      }
    }
  );
}

function markSelected(id) {
  $("li").removeClass("active");
  $("#"+id).addClass("active");
}

//solve the navbar remaining open on mobile after click https://github.com/twbs/bootstrap/issues/12852#issuecomment-39746001
$(document).on('click','.navbar-collapse.in',function(e) {
    if( $(e.target).is('a') ) {
        $(this).collapse('hide');
    }
});