//Paul Tero, July 2001
//http://www.shopable.co.uk/des.html
//
//Optimised for performance with large blocks by Michael Hayworth, November 2001
//http://www.netdealing.com
//
//THIS SOFTWARE IS PROVIDED "AS IS" AND
//ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
//IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
//ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
//FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
//DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
//OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
//HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
//LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
//OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
//SUCH DAMAGE.

//des
//this performs encryption by calling des_crypt with integer arguments
function DES(key, message, encrypt, mode, iv, k) {
  var result = des_crypt (key, message, encrypt, mode, iv, k); 
  return result;
}


//tripledes
//this performs tripledes, an encryption, decryption and then encryption
function xtripledes (key, message, encrypt, mode, iv, k) {
  var result = des_crypt (key.substr(encrypt?0:16,8), message, encrypt, mode, iv, k); 
  result = des_crypt (key.substr(8,8), result, !encrypt, mode, iv, k); 
  result = des_crypt (key.substr(encrypt?16:0,8), result, encrypt, mode, iv, k); 
  return (result);
}

function TripleDES(sKey, sMessage)
{
	return xtripledes(sKey, sMessage, 1);
}


//des_crypt
//this takes the key, the message, and whether to encrypt or decrypt
function des_crypt (key, message, encrypt, mode, iv, k) {
  //declaring this locally speeds things up a bit
  var spfunction1 = new Array (0x1010400,0,0x10000,0x1010404,0x1010004,0x10404,0x4,0x10000,0x400,0x1010400,0x1010404,0x400,0x1000404,0x1010004,0x1000000,0x4,0x404,0x1000400,0x1000400,0x10400,0x10400,0x1010000,0x1010000,0x1000404,0x10004,0x1000004,0x1000004,0x10004,0,0x404,0x10404,0x1000000,0x10000,0x1010404,0x4,0x1010000,0x1010400,0x1000000,0x1000000,0x400,0x1010004,0x10000,0x10400,0x1000004,0x400,0x4,0x1000404,0x10404,0x1010404,0x10004,0x1010000,0x1000404,0x1000004,0x404,0x10404,0x1010400,0x404,0x1000400,0x1000400,0,0x10004,0x10400,0,0x1010004);
  var spfunction2 = new Array (0x80108020,0x80008000,0x8000,0x108020,0x100000,0x20,0x80100020,0x80008020,0x80000020,0x80108020,0x80108000,0x80000000,0x80008000,0x100000,0x20,0x80100020,0x108000,0x100020,0x80008020,0,0x80000000,0x8000,0x108020,0x80100000,0x100020,0x80000020,0,0x108000,0x8020,0x80108000,0x80100000,0x8020,0,0x108020,0x80100020,0x100000,0x80008020,0x80100000,0x80108000,0x8000,0x80100000,0x80008000,0x20,0x80108020,0x108020,0x20,0x8000,0x80000000,0x8020,0x80108000,0x100000,0x80000020,0x100020,0x80008020,0x80000020,0x100020,0x108000,0,0x80008000,0x8020,0x80000000,0x80100020,0x80108020,0x108000);
  var spfunction3 = new Array (0x208,0x8020200,0,0x8020008,0x8000200,0,0x20208,0x8000200,0x20008,0x8000008,0x8000008,0x20000,0x8020208,0x20008,0x8020000,0x208,0x8000000,0x8,0x8020200,0x200,0x20200,0x8020000,0x8020008,0x20208,0x8000208,0x20200,0x20000,0x8000208,0x8,0x8020208,0x200,0x8000000,0x8020200,0x8000000,0x20008,0x208,0x20000,0x8020200,0x8000200,0,0x200,0x20008,0x8020208,0x8000200,0x8000008,0x200,0,0x8020008,0x8000208,0x20000,0x8000000,0x8020208,0x8,0x20208,0x20200,0x8000008,0x8020000,0x8000208,0x208,0x8020000,0x20208,0x8,0x8020008,0x20200);
  var spfunction4 = new Array (0x802001,0x2081,0x2081,0x80,0x802080,0x800081,0x800001,0x2001,0,0x802000,0x802000,0x802081,0x81,0,0x800080,0x800001,0x1,0x2000,0x800000,0x802001,0x80,0x800000,0x2001,0x2080,0x800081,0x1,0x2080,0x800080,0x2000,0x802080,0x802081,0x81,0x800080,0x800001,0x802000,0x802081,0x81,0,0,0x802000,0x2080,0x800080,0x800081,0x1,0x802001,0x2081,0x2081,0x80,0x802081,0x81,0x1,0x2000,0x800001,0x2001,0x802080,0x800081,0x2001,0x2080,0x800000,0x802001,0x80,0x800000,0x2000,0x802080);
  var spfunction5 = new Array (0x100,0x2080100,0x2080000,0x42000100,0x80000,0x100,0x40000000,0x2080000,0x40080100,0x80000,0x2000100,0x40080100,0x42000100,0x42080000,0x80100,0x40000000,0x2000000,0x40080000,0x40080000,0,0x40000100,0x42080100,0x42080100,0x2000100,0x42080000,0x40000100,0,0x42000000,0x2080100,0x2000000,0x42000000,0x80100,0x80000,0x42000100,0x100,0x2000000,0x40000000,0x2080000,0x42000100,0x40080100,0x2000100,0x40000000,0x42080000,0x2080100,0x40080100,0x100,0x2000000,0x42080000,0x42080100,0x80100,0x42000000,0x42080100,0x2080000,0,0x40080000,0x42000000,0x80100,0x2000100,0x40000100,0x80000,0,0x40080000,0x2080100,0x40000100);
  var spfunction6 = new Array (0x20000010,0x20400000,0x4000,0x20404010,0x20400000,0x10,0x20404010,0x400000,0x20004000,0x404010,0x400000,0x20000010,0x400010,0x20004000,0x20000000,0x4010,0,0x400010,0x20004010,0x4000,0x404000,0x20004010,0x10,0x20400010,0x20400010,0,0x404010,0x20404000,0x4010,0x404000,0x20404000,0x20000000,0x20004000,0x10,0x20400010,0x404000,0x20404010,0x400000,0x4010,0x20000010,0x400000,0x20004000,0x20000000,0x4010,0x20000010,0x20404010,0x404000,0x20400000,0x404010,0x20404000,0,0x20400010,0x10,0x4000,0x20400000,0x404010,0x4000,0x400010,0x20004010,0,0x20404000,0x20000000,0x400010,0x20004010);
  var spfunction7 = new Array (0x200000,0x4200002,0x4000802,0,0x800,0x4000802,0x200802,0x4200800,0x4200802,0x200000,0,0x4000002,0x2,0x4000000,0x4200002,0x802,0x4000800,0x200802,0x200002,0x4000800,0x4000002,0x4200000,0x4200800,0x200002,0x4200000,0x800,0x802,0x4200802,0x200800,0x2,0x4000000,0x200800,0x4000000,0x200800,0x200000,0x4000802,0x4000802,0x4200002,0x4200002,0x2,0x200002,0x4000000,0x4000800,0x200000,0x4200800,0x802,0x200802,0x4200800,0x802,0x4000002,0x4200802,0x4200000,0x200800,0,0x2,0x4200802,0,0x200802,0x4200000,0x800,0x4000002,0x4000800,0x800,0x200002);
  var spfunction8 = new Array (0x10001040,0x1000,0x40000,0x10041040,0x10000000,0x10001040,0x40,0x10000000,0x40040,0x10040000,0x10041040,0x41000,0x10041000,0x41040,0x1000,0x40,0x10040000,0x10000040,0x10001000,0x1040,0x41000,0x40040,0x10040040,0x10041000,0x1040,0,0,0x10040040,0x10000040,0x10001000,0x41040,0x40000,0x41040,0x40000,0x10041000,0x1000,0x40,0x10040040,0x1000,0x41040,0x10001000,0x40,0x10000040,0x10040000,0x10040040,0x10000000,0x40000,0x10001040,0,0x10041040,0x40040,0x10000040,0x10040000,0x10001000,0x10001040,0,0x10041040,0x41000,0x41000,0x1040,0x1040,0x40040,0x10000000,0x10041000);

  //create the 16 subkeys we will need
  var keys = des_createKeys (key);
  var m=0, i, temp, temp2, right1, right2, left, right;
  var cbcleft, cbcleft2, cbcright, cbcright2
  var kcount=0, kbcount=0;
  var startloop = encrypt ? 0 : 30;
  var endloop = encrypt ? 32 : -2;
  var loopinc = encrypt ? 2 : -2;
  var len = message.length;
  var chunk = 0;
  message += "        "; //pad the message out with spaces
  //store the result here
  result = "";
  tempresult = "";

  if (mode == 1) { //CBC mode
    cbcleft = (iv.charCodeAt(m++) << 24) | (iv.charCodeAt(m++) << 16) | (iv.charCodeAt(m++) << 8) | iv.charCodeAt(m++);
    cbcright = (iv.charCodeAt(m++) << 24) | (iv.charCodeAt(m++) << 16) | (iv.charCodeAt(m++) << 8) | iv.charCodeAt(m++);
    m=0;
  }

  //loop through each 64 bit chunk of the message
  while (m < len) {
    left = (message.charCodeAt(m++) << 24) | (message.charCodeAt(m++) << 16) | (message.charCodeAt(m++) << 8) | message.charCodeAt(m++);
    right = (message.charCodeAt(m++) << 24) | (message.charCodeAt(m++) << 16) | (message.charCodeAt(m++) << 8) | message.charCodeAt(m++);

    //for Cipher Block Chaining mode, xor the message with the previous result
    if (mode == 1) {if (encrypt) {left ^= cbcleft; right ^= cbcright;} else {cbcleft2 = cbcleft; cbcright2 = cbcright; cbcleft = left; cbcright = right;}}
    //for Cipher Feedback mode, get k bits from the input
    if (mode == 2) {
      //get k bits from kcount, which is within kbcount
    }

    //first each 64 but chunk of the message must be permuted according to IP
    temp = ((left >>> 4) ^ right) & 0x0f0f0f0f; right ^= temp; left ^= (temp << 4);
    temp = ((left >>> 16) ^ right) & 0x0000ffff; right ^= temp; left ^= (temp << 16);
    temp = ((right >>> 2) ^ left) & 0x33333333; left ^= temp; right ^= (temp << 2);
    temp = ((right >>> 8) ^ left) & 0x00ff00ff; left ^= temp; right ^= (temp << 8);
    temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);

    left = ((left << 1) | (left >>> 31)); 
    right = ((right << 1) | (right >>> 31)); 

    //now go through and perform the encryption or decryption  
    for (i=startloop; i!=endloop; i+=loopinc) {
      right1 = right ^ keys[i]; 
      right2 = ((right >>> 4) | (right << 28)) ^ keys[i+1];
      //the result is attained by passing these bytes through the S selection functions
      temp = left;
      left = right;
      right = temp ^ (spfunction2[(right1 >>> 24) & 0x3f] | spfunction4[(right1 >>> 16) & 0x3f]
            | spfunction6[(right1 >>>  8) & 0x3f] | spfunction8[right1 & 0x3f]
            | spfunction1[(right2 >>> 24) & 0x3f] | spfunction3[(right2 >>> 16) & 0x3f]
            | spfunction5[(right2 >>>  8) & 0x3f] | spfunction7[right2 & 0x3f]);
    }

    //move then each one bit to the right
    right = ((right >>> 1) | (right << 31)); 
    left = ((left >>> 1) | (left << 31)); 

    //now perform IP-1, which is IP in the opposite direction
    temp = ((right >>> 1) ^ left) & 0x55555555; left ^= temp; right ^= (temp << 1);
    temp = ((left >>> 8) ^ right) & 0x00ff00ff; right ^= temp; left ^= (temp << 8);
    temp = ((left >>> 2) ^ right) & 0x33333333; right ^= temp; left ^= (temp << 2);
    temp = ((right >>> 16) ^ left) & 0x0000ffff; left ^= temp; right ^= (temp << 16);
    temp = ((right >>> 4) ^ left) & 0x0f0f0f0f; left ^= temp; right ^= (temp << 4);

    //for Cipher Block Chaining mode, xor the message with the previous result
    if (mode == 1) {if (encrypt) {cbcleft = right; cbcright = left;} else {right ^= cbcleft2; left ^= cbcright2;}}
    tempresult += String.fromCharCode ((right>>>24), ((right>>>16) & 0xff), ((right>>>8) & 0xff), (right & 0xff), (left>>>24), ((left>>>16) & 0xff), ((left>>>8) & 0xff), (left & 0xff));

    chunk += 8;
    if (chunk == 512) {result += tempresult; tempresult = ""; chunk = 0;}
  } //for every 8 characters, or 64 bits in the message

  //return the result as an array
  return result + tempresult;
} //end of des_crypt



//des_createKeys
//this takes as input a 64 bit key (even though only 56 bits are used)
//as an array of 2 integers, and returns 16 48 bit keys
function des_createKeys (key) {
  //declaring this locally speeds things up a bit
  pc2bytes0  = new Array (0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204);
  pc2bytes1  = new Array (0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101);
  pc2bytes2  = new Array (0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808);
  pc2bytes3  = new Array (0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000);
  pc2bytes4  = new Array (0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010);
  pc2bytes5  = new Array (0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420);
  pc2bytes6  = new Array (0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002);
  pc2bytes7  = new Array (0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800);
  pc2bytes8  = new Array (0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002);
  pc2bytes9  = new Array (0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408);
  pc2bytes10 = new Array (0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020);
  pc2bytes11 = new Array (0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200);
  pc2bytes12 = new Array (0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010);
  pc2bytes13 = new Array (0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105);

  //stores the return keys
  var keys = new Array (32);
  //now define the left shifts which need to be done
  var shifts = new Array (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0);
  //other variables
  var lefttemp, righttemp, m=0, temp;

  left = (key.charCodeAt(m++) << 24) | (key.charCodeAt(m++) << 16) | (key.charCodeAt(m++) << 8) | key.charCodeAt(m++);
  right = (key.charCodeAt(m++) << 24) | (key.charCodeAt(m++) << 16) | (key.charCodeAt(m++) << 8) | key.charCodeAt(m++);

  temp = ((left >>> 4) ^ right) & 0x0f0f0f0f; right ^= temp; left ^= (temp << 4);
  temp = ((right >>> -16) ^ left) & 0x0000ffff; left ^= temp; right ^= (temp << -16);
  temp = ((left >>> 2) ^ right) & 0x33333333; right ^= temp; left ^= (temp << 2);
  temp = ((right >>> -16) ^ left) & 0x0000ffff; left ^= temp; right ^= (temp << -16);
  temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);
  temp = ((right >>> 8) ^ left) & 0x00ff00ff; left ^= temp; right ^= (temp << 8);
  temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);

  //the right side needs to be shifted and to get the last four bits of the left side
  temp = (left << 8) | ((right >>> 20) & 0x000000f0);
  //left needs to be put upside down
  left = (right << 24) | ((right << 8) & 0xff0000) | ((right >>> 8) & 0xff00) | ((right >>> 24) & 0xf0);
  right = temp;

  //now go through and perform these shifts on the left and right keys
  m=0;
  for (i=0; i < shifts.length; i++) {
    //shift the keys either one or two bits to the left
    if (shifts[i]) {left = (left << 2) | (left >>> 26); right = (right << 2) | (right >>> 26);}
    else {left = (left << 1) | (left >>> 27); right = (right << 1) | (right >>> 27);}
    left &= 0xfffffff0; right &= 0xfffffff0;

    //now apply PC-2, in such a way that E is easier when encrypting or decrypting
    //this conversion will look like PC-2 except only the last 6 bits of each byte are used
    //rather than 48 consecutive bits and the order of lines will be according to 
    //how the S selection functions will be applied: S2, S4, S6, S8, S1, S3, S5, S7
    lefttemp = pc2bytes0[left >>> 28] | pc2bytes1[(left >>> 24) & 0xf]
            | pc2bytes2[(left >>> 20) & 0xf] | pc2bytes3[(left >>> 16) & 0xf]
            | pc2bytes4[(left >>> 12) & 0xf] | pc2bytes5[(left >>> 8) & 0xf]
            | pc2bytes6[(left >>> 4) & 0xf];
    righttemp = pc2bytes7[right >>> 28] | pc2bytes8[(right >>> 24) & 0xf]
              | pc2bytes9[(right >>> 20) & 0xf] | pc2bytes10[(right >>> 16) & 0xf]
              | pc2bytes11[(right >>> 12) & 0xf] | pc2bytes12[(right >>> 8) & 0xf]
              | pc2bytes13[(right >>> 4) & 0xf];
    temp = ((righttemp >>> 16) ^ lefttemp) & 0x0000ffff; 
    keys[m++] = lefttemp ^ temp; keys[m++] = righttemp ^ (temp << 16);
  }
  //return the keys we've created
  return keys;
} //end of des_createKeys



////////////////////////////// TEST //////////////////////////////
//printHexArray
function printHex (s) {
  var r = "0x";
  var hexes = new Array ("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");
  for (var i=0; i<s.length; i++) {r += hexes [s.charCodeAt(i) >> 4] + hexes [s.charCodeAt(i) & 0xf];}
  return r;
}