des-64.js

// Information Security
// Waseda University 2016-1
// Evandro Sasse - 1W15C902-3

function pad(bits, size){
  while(bits.length < size)
    bits = "0"+bits;
  return bits;
}

function hexToBin(hex){
  return hex.split('').reduce((prv,cur)=>{
    return prv+pad(parseInt(cur,16).toString(2),4);
  },"")
}

function binToHex(bin){
  var hex = "";
  for(var i = 0; i < bin.length/4; i++){
    hex += parseInt(bin.slice(i*4,i*4+4),2).toString(16);
  }
  return hex.toUpperCase();
}

function xor(bits1, bits2){
  bits1 = bits1.split('');
  bits2 = bits2.split('');
  return bits1.reduce((prv,cur,ind)=>{
    switch(cur+bits2[ind]){
      case "00":
      case "11":
        return prv + "0";
      case "01":
      case "10":
        return prv + "1";
    }
  },"")
}

function permutation(bits, order){
  bits = bits.split('');
  var reorder = order.reduce((prv,cur)=>prv+bits[cur-1],"");
  return reorder;
}

function circularshift(bits,amount){
  var [first, ...left] = bits;
  bits = [...left, first].join('');
  if(amount === 1) return bits;
  return circularshift(bits, amount-1);
}

const _IP = [58, 50, 42, 34, 26, 18, 10, 2,
           60, 52, 44, 36, 28, 20, 12, 4,
           62, 54, 46, 38, 30, 22, 14, 6,
           64, 56, 48, 40, 32, 24, 16, 8,
           57, 49, 41, 33, 25, 17, 9, 1,
           59, 51, 43, 35, 27, 19, 11, 3,
           61, 53, 45, 37, 29, 21, 13, 5,
           63, 55, 47, 39, 31, 23, 15, 7]
function IP(bits){
  return permutation(bits,_IP);
}
const _FP = [40, 8, 48, 16, 56, 24, 64, 32,
           39, 7, 47, 15, 55, 23, 63, 31,
           38, 6, 46, 14, 54, 22, 62, 30,
           37, 5, 45, 13, 53, 21, 61, 29,
           36, 4, 44, 12, 52, 20, 60, 28,
           35, 3, 43, 11, 51, 19, 59, 27,
           34, 2, 42, 10, 50, 18, 58, 26,
           33, 1, 41, 9, 49, 17, 57, 25]
function FP(bits){
  return permutation(bits,_FP);
}

const _E = [32, 1, 2, 3, 4, 5,
           4, 5, 6, 7, 8, 9,
           8, 9, 10, 11, 12, 13,
           12, 13, 14, 15, 16, 17,
           16, 17, 18, 19, 20, 21,
           20, 21, 22, 23, 24, 25,
           24, 25, 26, 27, 28, 29,
           28, 29, 30, 31, 32, 1]
function E(bits){
  return permutation(bits,_E);
}
const _P = [16, 7, 20, 21, 29, 12, 28, 17,
           1, 15, 23, 26, 5, 18, 31, 10,
           2, 8, 24, 14, 32, 27, 3, 9,
           19, 13, 30, 6, 22, 11, 4, 25]
function P(bits){
  return permutation(bits,_P);
}

const _S = [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
            0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
            4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
            15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13],
           [15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
            3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
            0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
            13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9],
           [10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
            13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
            13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
            1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12],
           [7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
            13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
            10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
            3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14],
           [2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
            14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
            4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
            11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3],
           [12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
            10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
            9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
            4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13],
           [4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
            13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
            1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
            6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12],
           [13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
            1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
            7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
            2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]

const _PC1 = [57, 49, 41, 33, 25, 17, 9,
              1, 58, 50, 42, 34, 26, 18,
              10, 2, 59, 51, 43, 35, 27,
              19, 11, 3, 60, 52, 44, 36,
              63, 55, 47, 39, 31, 23, 15,
              7, 62, 54, 46, 38, 30, 22,
              14, 6, 61, 53, 45, 37, 29,
              21, 13, 5, 28, 20, 12, 4]
function PC1(bits){
  return permutation(bits,_PC1);
}
const _PC2 = [14, 17, 11, 24, 1, 5,
              3, 28, 15, 6, 21, 10,
              23, 19, 12, 4, 26, 8,
              16, 7, 27, 20, 13, 2,
              41, 52, 31, 37, 47, 55,
              30, 40, 51, 45, 33, 48,
              44, 49, 39, 56, 34, 53,
              46, 42, 50, 36, 29, 32]
function PC2(bits){
  return permutation(bits,_PC2);
}
const rotations = [1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1];

function K(key){
  key = PC1(key);
  var left = key.slice(0,28);
  var right = key.slice(28,56);
  
  var k = [];
  for(var i = 0; i < 16; i++){
    //console.log(left,right);
    left = circularshift(left,rotations[i]);
    right = circularshift(right,rotations[i]);
    k[i] = PC2(left+right);
  }
  
  return k;
}

function SBox(ind,bits){
  var box = _S[ind];
  var y = parseInt(bits.slice(1,5),2);
  var x = parseInt(bits[0]+bits[5],2);
  return pad(Number(box[x*16+y]).toString(2),4);
}
function S(bits){
  var s = [];
  for(var i = 0; i < 8; i++){
    s[i] = SBox(i,bits.slice(i*6,i*6+6));
  }
  return s.reduce((prv,cur)=>prv+cur,"");
}

function F(ri, ki){
  var bits = xor(E(ri),ki);
  bits = S(bits);
  return P(bits);
}

function DES(plaintext,key){
  var bits = IP(plaintext);
  var l = [];
  var r = [];
  l[0] = bits.slice(0,32);
  r[0] = bits.slice(32);
  
  var k = K(key);
  //console.log(k);
  
  for(var i = 0; i < 16; i++){
    l[i+1] = r[i];
    r[i+1] = xor(l[i],F(r[i],k[i]))
    //console.log(l,r);
  }
  
  return FP(r[16]+l[16]);
}