#!/usr/bin/perl
#Perl version
#Paul Tero, July 2001
#http://www.tero.co.uk/des/
#
#Converted from JavaScript to Perl by Chris Drake, July 2002
#
#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.

use strict;

#des
#this takes the key, the message, and whether to encrypt or decrypt
sub TripleDES {
  my($key, $message, $encrypt, $mode, $iv)=@_;

  # declaring this locally speeds things up a bit
  my @spfunction1 = (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);
  my @spfunction2 = (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);
  my @spfunction3 = (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);
  my @spfunction4 = (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);
  my @spfunction5 = (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);
  my @spfunction6 = (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);
  my @spfunction7 = (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);
  my @spfunction8 = (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 or 48 subkeys we will need
  my @keys = &des_createKeys($key);
  my ($m, $i, $j, $temp, $temp2, $right1, $right2, $left, $right, @looping)=(0);
  my ($cbcleft, $cbcleft2, $cbcright, $cbcright2);
  my ($endloop, $loopinc, $result, $tempresult);
  my $len = length($message);
  my $chunk = 0;
  #set up the loops for single and triple des
  my $iterations = $#keys == 32 ? 3 : 9; #single or triple des
  if ($iterations == 3) {@looping = $encrypt ? (0, 32, 2) : (30, -2, -2);}
  else {@looping = $encrypt ? (0, 32, 2, 62, 30, -2, 64, 96, 2) : (94, 62, -2, 32, 64, 2, 30, -2, -2);}

  $message .= "\0\0\0\0\0\0\0\0"; #pad the message out with null bytes
  #store the result here
  $result = "";
  $tempresult = "";

  if ($mode == 1) { #CBC mode
    $cbcleft = (unpack("C",substr($iv,$m++,1)) << 24) | (unpack("C",substr($iv,$m++,1)) << 16) | (unpack("C",substr($iv,$m++,1)) << 8) | unpack("C",substr($iv,$m++,1));
    $cbcright = (unpack("C",substr($iv,$m++,1)) << 24) | (unpack("C",substr($iv,$m++,1)) << 16) | (unpack("C",substr($iv,$m++,1)) << 8) | unpack("C",substr($iv,$m++,1));
    $m=0;
  }

  #loop through each 64 bit chunk of the message
  while ($m < $len) {
    $left = (unpack("C",substr($message,$m++,1)) << 24) | (unpack("C",substr($message,$m++,1)) << 16) | (unpack("C",substr($message,$m++,1)) << 8) | unpack("C",substr($message,$m++,1));
    $right = (unpack("C",substr($message,$m++,1)) << 24) | (unpack("C",substr($message,$m++,1)) << 16) | (unpack("C",substr($message,$m++,1)) << 8) | unpack("C",substr($message,$m++,1));

    #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;}}

    #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)); 

    #do this either 1 or 3 times for each chunk of the message
    for ($j=0; $j<$iterations; $j+=3) {
      $endloop =$looping[$j+1]; $loopinc =$looping[$j+2]; #now go through and perform the encryption or decryption  
      for ($i=$looping[$j]; $i!=$endloop; $i+=$loopinc) { #for efficiency
        $right1 =$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]);
      }
      $temp = $left; $left = $right; $right = $temp; #unreverse left and right
    } #for either 1 or 3 iterations

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

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

    #for Cipher Block Chaining mode, xor the message with the previous result
    if ($mode == 1) {if ($encrypt) {$cbcleft = $left; $cbcright = $right;} else {$left ^= $cbcleft2; $right ^= $cbcright2;}}
    $tempresult .= pack("C*", (($left>>24), (($left>>16) & 0xff), (($left>>8) & 0xff), ($left & 0xff), ($right>>24), (($right>>16) & 0xff), (($right>>8) & 0xff), ($right & 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



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

  #how many iterations (1 for des, 3 for triple des)
  my $iterations = length($key) >= 24 ? 3 : 1;
  #stores the return keys
  my @keys; $#keys=(32 * $iterations);
  #now define the left shifts which need to be done
  my @shifts = (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0);
  #other variables
  my ($m, $n, $lefttemp, $righttemp, $left, $right, $temp)=(0,0);

  for (my $j=0; $j<$iterations; $j++) { #either 1 or 3 iterations
    $left =(unpack("C",substr($key,$m++,1)) << 24) | (unpack("C",substr($key,$m++,1)) << 16) | (unpack("C",substr($key,$m++,1)) << 8) | unpack("C",substr($key,$m++,1));
    $right = (unpack("C",substr($key,$m++,1)) << 24) | (unpack("C",substr($key,$m++,1)) << 16) | (unpack("C",substr($key,$m++,1)) << 8) | unpack("C",substr($key,$m++,1));
 
    $temp = (($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
    for (my $i=0; $i <= $#shifts; $i++) {
      #shift the keys either one or two bits to the left
      if ($shifts[$i]) {
        no integer;
        $left = ($left << 2) | ($left >> 26); 
        $right = ($right << 2) | ($right >> 26);
        use integer;
        $left<<=0;$right<<=0;
      } else {
        no integer;
        $left = ($left << 1) | ($left >> 27); 
        $right = ($right << 1) | ($right >> 27);
        use integer;
        $left<<=0;$right<<=0;
      }
      $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; 
      $keys[$n++] = $lefttemp ^ $temp; $keys[$n++] = $righttemp ^ ($temp << 16);

    }
  } #for each iterations
  #return the keys we've created
  return @keys;
} #end of des_createKeys



#//////////////////////////// TEST //////////////////////////////
#printHexArray
sub printHex {
  my($s)=@_;
  my $r = "0x";
  my @hexes=("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");
  for (my $i=0; $i<length($s); $i++) {$r.=$hexes[unpack("C",substr($s,$i,1)) >> 4] . $hexes[unpack("C",substr($s,$i,1)) & 0xf];}
  return $r;
}



print "3DES in perl\n";

my $K="this is a 24 byte key !!";
my $msg="This is a test message";
my $ciphertext=&TripleDES($K,$msg,1,0);
print "DES Test: " . &printHex($ciphertext) . "\n";
my $plaintext=&TripleDES($K,$ciphertext,0,0);
print "DES Test: " . $plaintext . "\n";

exit(0);