DES Encrypt/Decrypt ECB/ZeroPadding

des.js

// all functions below accepts input and provide output in big-endian.

var bit_mask = [0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80];

var ip_table =
  [
    [[7,1],[6,1],[5,1],[4,1],[3,1],[2,1],[1,1],[0,1]],
    [[7,3],[6,3],[5,3],[4,3],[3,3],[2,3],[1,3],[0,3]],
    [[7,5],[6,5],[5,5],[4,5],[3,5],[2,5],[1,5],[0,5]],
    [[7,7],[6,7],[5,7],[4,7],[3,7],[2,7],[1,7],[0,7]],

    [[7,0],[6,0],[5,0],[4,0],[3,0],[2,0],[1,0],[0,0]],
    [[7,2],[6,2],[5,2],[4,2],[3,2],[2,2],[1,2],[0,2]],
    [[7,4],[6,4],[5,4],[4,4],[3,4],[2,4],[1,4],[0,4]],
    [[7,6],[6,6],[5,6],[4,6],[3,6],[2,6],[1,6],[0,6]]
  ];

var fp_table =
  [
    [[4,7],[0,7],[5,7],[1,7],[6,7],[2,7],[7,7],[3,7]],
    [[4,6],[0,6],[5,6],[1,6],[6,6],[2,6],[7,6],[3,6]],
    [[4,5],[0,5],[5,5],[1,5],[6,5],[2,5],[7,5],[3,5]],
    [[4,4],[0,4],[5,4],[1,4],[6,4],[2,4],[7,4],[3,4]],

    [[4,3],[0,3],[5,3],[1,3],[6,3],[2,3],[7,3],[3,3]],
    [[4,2],[0,2],[5,2],[1,2],[6,2],[2,2],[7,2],[3,2]],
    [[4,1],[0,1],[5,1],[1,1],[6,1],[2,1],[7,1],[3,1]],
    [[4,0],[0,0],[5,0],[1,0],[6,0],[2,0],[7,0],[3,0]]
  ];

var e_table =
  [
    [[3,7],[0,0],[0,1],[0,2],[0,3],[0,4]],
    [[0,3],[0,4],[0,5],[0,6],[0,7],[1,0]],
    [[0,7],[1,0],[1,1],[1,2],[1,3],[1,4]],
    [[1,3],[1,4],[1,5],[1,6],[1,7],[2,0]],

    [[1,7],[2,0],[2,1],[2,2],[2,3],[2,4]],
    [[2,3],[2,4],[2,5],[2,6],[2,7],[3,0]],
    [[2,7],[3,0],[3,1],[3,2],[3,3],[3,4]],
    [[3,3],[3,4],[3,5],[3,6],[3,7],[0,0]]
  ];

var pc1_table =
  [
    [[7,0],[6,0],[5,0],[4,0],[3,0],[2,0],[1,0]],
    [[0,0],[7,1],[6,1],[5,1],[4,1],[3,1],[2,1]],
    [[1,1],[0,1],[7,2],[6,2],[5,2],[4,2],[3,2]],
    [[2,2],[1,2],[0,2],[7,3],[6,3],[5,3],[4,3]],

    [[7,6],[6,6],[5,6],[4,6],[3,6],[2,6],[1,6]],
    [[0,6],[7,5],[6,5],[5,5],[4,5],[3,5],[2,5]],
    [[1,5],[0,5],[7,4],[6,4],[5,4],[4,4],[3,4]],
    [[2,4],[1,4],[0,4],[3,3],[2,3],[1,3],[0,3]]
  ];

var pc2l_table =
  [
    [[1,6],[2,2],[1,3],[3,2],[0,0],[0,4]],
    [[0,2],[3,6],[2,0],[0,5],[2,6],[1,2]],
    [[3,1],[2,4],[1,4],[0,3],[3,4],[1,0]],
    [[2,1],[0,6],[3,5],[2,5],[1,5],[0,1]]
  ]

var pc2r_table = 
  [
    [[1,5],[3,2],[0,2],[1,1],[2,4],[3,5]],
    [[0,1],[1,4],[3,1],[2,2],[0,4],[2,5]],
    [[2,1],[2,6],[1,3],[3,6],[0,5],[3,3]],
    [[2,3],[1,6],[3,0],[1,0],[0,0],[0,3]]
  ];

var p_table = 
  [
    [[3,3],[1,2],[4,3],[5,0],[7,0],[2,3],[6,3],[4,0]],
    [[0,0],[3,2],[5,2],[6,1],[1,0],[4,1],[7,2],[2,1]],
    [[0,1],[1,3],[5,3],[3,1],[7,3],[6,2],[0,2],[2,0]],
    [[4,2],[3,0],[7,1],[1,1],[5,1],[2,2],[0,3],[6,0]]
  ];

function general_remap(data_in, map)
{
  var data_out = new Array(map.length);

  for (var i=0; i<map.length; i++)
  {
    data_out[i] = 0;
    for (var j=0; j<map[i].length; j++)
    {
      var bit = (data_in[map[i][j][0]] & bit_mask[map[i][j][1]]) != 0;
      data_out[i] = data_out[i] | (bit << j);
    }
  }

  return(data_out);
}

var s_map =
  [
    [0x7,0x2,0xc,0xf,0x4,0xb,0xa,0xc,0xb,0x7,0x6,0x9,0xd,0x4,0x0,0xa,
     0x2,0x8,0x5,0x3,0xf,0x6,0x9,0x5,0x8,0x1,0x3,0xe,0x1,0xd,0xe,0x0,
     0x0,0xf,0x5,0xa,0x7,0x2,0x9,0x5,0xe,0x1,0x3,0xc,0xb,0x8,0xc,0x6,
     0xf,0x3,0x6,0xd,0x4,0x9,0xa,0x0,0x2,0x4,0xd,0x7,0x8,0xe,0x1,0xb],
    [0xf,0x0,0x9,0xa,0x6,0x5,0x3,0x9,0x1,0xe,0x4,0x3,0xc,0xb,0xa,0x4,
     0x8,0x7,0xe,0x1,0xd,0x2,0x0,0xc,0x7,0xd,0xb,0x6,0x2,0x8,0x5,0xf,
     0xc,0xb,0x3,0xd,0xf,0xc,0x6,0x0,0x2,0x5,0x8,0xe,0x1,0x2,0xd,0x7,
     0xb,0x1,0x0,0x6,0x4,0xf,0x9,0xa,0xe,0x8,0x5,0x3,0x7,0x4,0xa,0x9],
    [0x5,0xb,0x8,0xd,0x6,0x1,0xd,0xa,0x9,0x2,0x3,0x4,0xf,0xc,0x4,0x7,
     0x0,0x6,0xb,0x8,0xc,0xf,0x2,0x5,0x7,0x9,0xe,0x3,0xa,0x0,0x1,0xe,
     0xb,0x8,0x4,0x2,0xc,0x6,0x3,0xd,0x0,0xb,0xa,0x7,0x6,0x1,0xf,0x4,
     0xe,0x5,0x1,0xf,0x2,0x9,0xd,0xa,0x9,0x0,0x7,0xc,0x5,0xe,0x8,0x3],
    [0xe,0x5,0x8,0xf,0x0,0x3,0xd,0xa,0x7,0x9,0x1,0xc,0x9,0xe,0x2,0x1,
     0xb,0x6,0x4,0x8,0x6,0xd,0x3,0x4,0xc,0x0,0xa,0x7,0x5,0xb,0xf,0x2,
     0xb,0xc,0x2,0x9,0x6,0x5,0x8,0x3,0xd,0x0,0x4,0xa,0x0,0xb,0x7,0x4,
     0x1,0xf,0xe,0x2,0xf,0x8,0x5,0xe,0xa,0x6,0x3,0xd,0xc,0x1,0x9,0x7],
    [0x4,0x2,0x1,0xf,0xe,0x5,0xb,0x6,0x2,0x8,0xc,0x3,0xd,0xe,0x7,0x0,
     0x3,0x4,0xa,0x9,0x5,0xb,0x0,0xc,0x8,0xd,0xf,0xa,0x6,0x1,0x9,0x7,
     0x7,0xd,0xa,0x6,0x2,0x8,0xc,0x5,0x4,0x3,0xf,0x0,0xb,0x4,0x1,0xa,
     0xd,0x1,0x0,0xf,0xe,0x7,0x9,0x2,0x3,0xe,0x5,0x9,0x8,0xb,0x6,0xc],
    [0x3,0x9,0x0,0xe,0x9,0x4,0x7,0x8,0x5,0xf,0xc,0x2,0x6,0x3,0xa,0xd,
     0x8,0x7,0xb,0x0,0x4,0x1,0xe,0xb,0xf,0xa,0x2,0x5,0x1,0xc,0xd,0x6,
     0x5,0x2,0x6,0xd,0xe,0x9,0x0,0x6,0x2,0x4,0xb,0x8,0x9,0xf,0xc,0x1,
     0xf,0xc,0x8,0x7,0x3,0xa,0xd,0x0,0x4,0x3,0x7,0xe,0xa,0x5,0x1,0xb],
    [0x2,0x8,0xc,0x5,0xf,0x3,0xa,0x0,0x4,0xd,0x9,0x6,0x1,0xe,0x6,0x9,
     0xd,0x2,0x3,0xf,0x0,0xc,0x5,0xa,0x7,0xb,0xe,0x1,0xb,0x7,0x8,0x4,
     0xb,0x6,0x7,0x9,0x2,0x8,0x4,0x7,0xd,0xb,0xa,0x0,0x8,0x5,0x1,0xc,
     0x0,0xd,0xc,0xa,0x9,0x2,0xf,0x4,0xe,0x1,0x3,0xf,0x5,0xe,0x6,0x3],
    [0xb,0xe,0x5,0x0,0x6,0x9,0xa,0xf,0x1,0x2,0xc,0x5,0xd,0x7,0x3,0xa,
     0x4,0xd,0x9,0x6,0xf,0x3,0x0,0xc,0x2,0x8,0x7,0xb,0x8,0x4,0xe,0x1,
     0x8,0x4,0x3,0xf,0x5,0x2,0x0,0xc,0xb,0x7,0x6,0x9,0xe,0x1,0x9,0x6,
     0xf,0x8,0xa,0x3,0xc,0x5,0x7,0xa,0x1,0xe,0xd,0x0,0x2,0xb,0x4,0xd]
  ];

function s_remap(data_in)
{
  var data_out = new Array(8);

  for (var i=0; i<8; i++)
    data_out[i] = s_map[i][data_in[i]];

  return(data_out);
}

var ror_l_mask = [0x00, 0x40, 0x60, 0x70, 0x78, 0x7c, 0x7e, 0x7f];
var ror_r_mask = [0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f];

function subkey_ror(data_in, b)
{
  var data_out = new Array(data_in.length);

  for (var i=0; i<data_in.length; i++)
    data_out[i] = (data_in[i] >> b) | ((data_in[(i+1)%data_in.length] & ror_r_mask[b])<<(7-b));

  return(data_out);
}

function array_swap(data_a, data_b)
{
  var len_a = data_a.length;
  var len_b = data_b.length;
  var len = Math.max(len_a, len_b);
  
  for (var i=i; i<length; i++)
  {
    var tmp = data_a[i];
    data_a[i] = data_b[i];
    data_b[i] = tmp;
  }

  data_a.length = len_b;
  data_b.length = len_a;
}

function array_xor(data_a, data_b)
{
  var len = Math.max(data_a.length,data_b.length);
  var data_out = new Array(len);

  for (var i=0; i<len; i++)
    data_out[i] = data_a[i] ^ data_b[i];

  return(data_out);
}

var ror_table = [1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1];

function des_subkeys(key_in)
{
  // pc1
  var key = general_remap(key_in, pc1_table);
  var key_out = new Array(16);
  
  var key_l = key.slice(0, 4);
  var key_r = key.slice(4, 8);

  for (var i=0; i<16; i++)
  {
    // ror
    key_l = subkey_ror(key_l, ror_table[i]);
    key_r = subkey_ror(key_r, ror_table[i]);

    // pc2
    key_out[i] = general_remap(key_l, pc2l_table);
    key_out[i] = key_out[i].concat(general_remap(key_r, pc2r_table));
  }

  return(key_out);
}

function des_enc_ecb(data_in, subkey)
{
  var data = data_in;
  
  // ip
  data = general_remap(data, ip_table);
  
  var data_l = data.slice(0, 4);
  var data_r = data.slice(4, 8);

  for (var i=0; i<16; i++)
  {
    var data = data_r.slice(0);

    // e
    data = general_remap(data, e_table);

    // mix with key
    data = array_xor(data, subkey[i]);

    // s
    data = s_remap(data);

    // p
    data = general_remap(data, p_table);

    // mix with l
    data_l = array_xor(data_l, data);
    // swap
    data = data_l;
    data_l = data_r;
    data_r = data;

  }
  data = data_l;
  data_l = data_r;
  data_r = data;

  // fp
  var data_out = data_l.concat(data_r);
  data_out = general_remap(data_out, fp_table);

  return(data_out);
}

function des_enc_ecb_zero(data_in, key)
{
  var subkeys = des_subkeys(key);
  var data_out = new Array(0);

  var i = 0;
  while (i<data_in.length)
  {
    data_out =
      data_out.concat(
        des_enc_ecb(
          data_in.slice(i, i+8),
          subkeys
        )
      );
    i += 8;
  }

  return(data_out);
}

function des_dec_ecb(data_in, subkey)
{
  var data = data_in;
  
  // ip
  data = general_remap(data, ip_table);
  
  var data_l = data.slice(0, 4);
  var data_r = data.slice(4, 8);

  for (var i=15; i>=0; i--)
  {
    var data = data_r;
    // e
    data = general_remap(data, e_table);
    // mix with key
    data = array_xor(data, subkey[i]);
    // s
    data = s_remap(data);
    // p
    data = general_remap(data, p_table);
    // mix with l
    data_l = array_xor(data_l, data);
    // swap
    data = data_l;
    data_l = data_r;
    data_r = data;
  }
  data = data_l;
  data_l = data_r;
  data_r = data;

  // fp
  var data_out = data_l.concat(data_r);
  data_out = general_remap(data_out, fp_table);

  return(data_out);
}

function des_dec_ecb_zero(data_in, key)
{
  var subkeys = des_subkeys(key);
  var data_out = new Array(0);

  var i = 0;
  while (i<data_in.length)
  {
    data_out =
      data_out.concat(
        des_dec_ecb(
          data_in.slice(i, i+8),
          subkeys
        )
      );
    i += 8;
  }

  return(data_out);
}

You can use, reuse, abuse, copy, modify, redistribute this file as long as you wish.
Use des_enc_ecb_zero(Array plaintext, Array[8] key) to encrypt, and use des_enc_ecb_zero(Array ciphertext, Array[8] key) to decrypt. All parameters must provide as byte array. plaintext/ciphertext which is longer than
Also you can do instrumentation to see how it works.

Thanks to Wikipedia...
and styere's demo

\sigh ((((( ‾‾.)