des.c

/*
 *  FIPS-46-3 compliant 3DES implementation
 *
 *  Copyright (C) 2001-2003  Christophe Devine
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "memory.h"
#include "des.h"

/* the eight DES S-boxes */

static uint32 SB1[64] = {
  0x01010400, 0x00000000, 0x00010000, 0x01010404,
  0x01010004, 0x00010404, 0x00000004, 0x00010000,
  0x00000400, 0x01010400, 0x01010404, 0x00000400,
  0x01000404, 0x01010004, 0x01000000, 0x00000004,
  0x00000404, 0x01000400, 0x01000400, 0x00010400,
  0x00010400, 0x01010000, 0x01010000, 0x01000404,
  0x00010004, 0x01000004, 0x01000004, 0x00010004,
  0x00000000, 0x00000404, 0x00010404, 0x01000000,
  0x00010000, 0x01010404, 0x00000004, 0x01010000,
  0x01010400, 0x01000000, 0x01000000, 0x00000400,
  0x01010004, 0x00010000, 0x00010400, 0x01000004,
  0x00000400, 0x00000004, 0x01000404, 0x00010404,
  0x01010404, 0x00010004, 0x01010000, 0x01000404,
  0x01000004, 0x00000404, 0x00010404, 0x01010400,
  0x00000404, 0x01000400, 0x01000400, 0x00000000,
  0x00010004, 0x00010400, 0x00000000, 0x01010004
};

static uint32 SB2[64] = {
  0x80108020, 0x80008000, 0x00008000, 0x00108020,
  0x00100000, 0x00000020, 0x80100020, 0x80008020,
  0x80000020, 0x80108020, 0x80108000, 0x80000000,
  0x80008000, 0x00100000, 0x00000020, 0x80100020,
  0x00108000, 0x00100020, 0x80008020, 0x00000000,
  0x80000000, 0x00008000, 0x00108020, 0x80100000,
  0x00100020, 0x80000020, 0x00000000, 0x00108000,
  0x00008020, 0x80108000, 0x80100000, 0x00008020,
  0x00000000, 0x00108020, 0x80100020, 0x00100000,
  0x80008020, 0x80100000, 0x80108000, 0x00008000,
  0x80100000, 0x80008000, 0x00000020, 0x80108020,
  0x00108020, 0x00000020, 0x00008000, 0x80000000,
  0x00008020, 0x80108000, 0x00100000, 0x80000020,
  0x00100020, 0x80008020, 0x80000020, 0x00100020,
  0x00108000, 0x00000000, 0x80008000, 0x00008020,
  0x80000000, 0x80100020, 0x80108020, 0x00108000
};

static uint32 SB3[64] = {
  0x00000208, 0x08020200, 0x00000000, 0x08020008,
  0x08000200, 0x00000000, 0x00020208, 0x08000200,
  0x00020008, 0x08000008, 0x08000008, 0x00020000,
  0x08020208, 0x00020008, 0x08020000, 0x00000208,
  0x08000000, 0x00000008, 0x08020200, 0x00000200,
  0x00020200, 0x08020000, 0x08020008, 0x00020208,
  0x08000208, 0x00020200, 0x00020000, 0x08000208,
  0x00000008, 0x08020208, 0x00000200, 0x08000000,
  0x08020200, 0x08000000, 0x00020008, 0x00000208,
  0x00020000, 0x08020200, 0x08000200, 0x00000000,
  0x00000200, 0x00020008, 0x08020208, 0x08000200,
  0x08000008, 0x00000200, 0x00000000, 0x08020008,
  0x08000208, 0x00020000, 0x08000000, 0x08020208,
  0x00000008, 0x00020208, 0x00020200, 0x08000008,
  0x08020000, 0x08000208, 0x00000208, 0x08020000,
  0x00020208, 0x00000008, 0x08020008, 0x00020200
};

static uint32 SB4[64] = {
  0x00802001, 0x00002081, 0x00002081, 0x00000080,
  0x00802080, 0x00800081, 0x00800001, 0x00002001,
  0x00000000, 0x00802000, 0x00802000, 0x00802081,
  0x00000081, 0x00000000, 0x00800080, 0x00800001,
  0x00000001, 0x00002000, 0x00800000, 0x00802001,
  0x00000080, 0x00800000, 0x00002001, 0x00002080,
  0x00800081, 0x00000001, 0x00002080, 0x00800080,
  0x00002000, 0x00802080, 0x00802081, 0x00000081,
  0x00800080, 0x00800001, 0x00802000, 0x00802081,
  0x00000081, 0x00000000, 0x00000000, 0x00802000,
  0x00002080, 0x00800080, 0x00800081, 0x00000001,
  0x00802001, 0x00002081, 0x00002081, 0x00000080,
  0x00802081, 0x00000081, 0x00000001, 0x00002000,
  0x00800001, 0x00002001, 0x00802080, 0x00800081,
  0x00002001, 0x00002080, 0x00800000, 0x00802001,
  0x00000080, 0x00800000, 0x00002000, 0x00802080
};

static uint32 SB5[64] = {
  0x00000100, 0x02080100, 0x02080000, 0x42000100,
  0x00080000, 0x00000100, 0x40000000, 0x02080000,
  0x40080100, 0x00080000, 0x02000100, 0x40080100,
  0x42000100, 0x42080000, 0x00080100, 0x40000000,
  0x02000000, 0x40080000, 0x40080000, 0x00000000,
  0x40000100, 0x42080100, 0x42080100, 0x02000100,
  0x42080000, 0x40000100, 0x00000000, 0x42000000,
  0x02080100, 0x02000000, 0x42000000, 0x00080100,
  0x00080000, 0x42000100, 0x00000100, 0x02000000,
  0x40000000, 0x02080000, 0x42000100, 0x40080100,
  0x02000100, 0x40000000, 0x42080000, 0x02080100,
  0x40080100, 0x00000100, 0x02000000, 0x42080000,
  0x42080100, 0x00080100, 0x42000000, 0x42080100,
  0x02080000, 0x00000000, 0x40080000, 0x42000000,
  0x00080100, 0x02000100, 0x40000100, 0x00080000,
  0x00000000, 0x40080000, 0x02080100, 0x40000100
};

static uint32 SB6[64] = {
  0x20000010, 0x20400000, 0x00004000, 0x20404010,
  0x20400000, 0x00000010, 0x20404010, 0x00400000,
  0x20004000, 0x00404010, 0x00400000, 0x20000010,
  0x00400010, 0x20004000, 0x20000000, 0x00004010,
  0x00000000, 0x00400010, 0x20004010, 0x00004000,
  0x00404000, 0x20004010, 0x00000010, 0x20400010,
  0x20400010, 0x00000000, 0x00404010, 0x20404000,
  0x00004010, 0x00404000, 0x20404000, 0x20000000,
  0x20004000, 0x00000010, 0x20400010, 0x00404000,
  0x20404010, 0x00400000, 0x00004010, 0x20000010,
  0x00400000, 0x20004000, 0x20000000, 0x00004010,
  0x20000010, 0x20404010, 0x00404000, 0x20400000,
  0x00404010, 0x20404000, 0x00000000, 0x20400010,
  0x00000010, 0x00004000, 0x20400000, 0x00404010,
  0x00004000, 0x00400010, 0x20004010, 0x00000000,
  0x20404000, 0x20000000, 0x00400010, 0x20004010
};

static uint32 SB7[64] = {
  0x00200000, 0x04200002, 0x04000802, 0x00000000,
  0x00000800, 0x04000802, 0x00200802, 0x04200800,
  0x04200802, 0x00200000, 0x00000000, 0x04000002,
  0x00000002, 0x04000000, 0x04200002, 0x00000802,
  0x04000800, 0x00200802, 0x00200002, 0x04000800,
  0x04000002, 0x04200000, 0x04200800, 0x00200002,
  0x04200000, 0x00000800, 0x00000802, 0x04200802,
  0x00200800, 0x00000002, 0x04000000, 0x00200800,
  0x04000000, 0x00200800, 0x00200000, 0x04000802,
  0x04000802, 0x04200002, 0x04200002, 0x00000002,
  0x00200002, 0x04000000, 0x04000800, 0x00200000,
  0x04200800, 0x00000802, 0x00200802, 0x04200800,
  0x00000802, 0x04000002, 0x04200802, 0x04200000,
  0x00200800, 0x00000000, 0x00000002, 0x04200802,
  0x00000000, 0x00200802, 0x04200000, 0x00000800,
  0x04000002, 0x04000800, 0x00000800, 0x00200002
};

static uint32 SB8[64] = {
  0x10001040, 0x00001000, 0x00040000, 0x10041040,
  0x10000000, 0x10001040, 0x00000040, 0x10000000,
  0x00040040, 0x10040000, 0x10041040, 0x00041000,
  0x10041000, 0x00041040, 0x00001000, 0x00000040,
  0x10040000, 0x10000040, 0x10001000, 0x00001040,
  0x00041000, 0x00040040, 0x10040040, 0x10041000,
  0x00001040, 0x00000000, 0x00000000, 0x10040040,
  0x10000040, 0x10001000, 0x00041040, 0x00040000,
  0x00041040, 0x00040000, 0x10041000, 0x00001000,
  0x00000040, 0x10040040, 0x00001000, 0x00041040,
  0x10001000, 0x00000040, 0x10000040, 0x10040000,
  0x10040040, 0x10000000, 0x00040000, 0x10001040,
  0x00000000, 0x10041040, 0x00040040, 0x10000040,
  0x10040000, 0x10001000, 0x10001040, 0x00000000,
  0x10041040, 0x00041000, 0x00041000, 0x00001040,
  0x00001040, 0x00040040, 0x10000000, 0x10041000
};

/* PC1: left and right halves bit-swap */

static uint32 LHs[16] = {
  0x00000000, 0x00000001, 0x00000100, 0x00000101,
  0x00010000, 0x00010001, 0x00010100, 0x00010101,
  0x01000000, 0x01000001, 0x01000100, 0x01000101,
  0x01010000, 0x01010001, 0x01010100, 0x01010101
};

static uint32 RHs[16] = {
  0x00000000, 0x01000000, 0x00010000, 0x01010000,
  0x00000100, 0x01000100, 0x00010100, 0x01010100,
  0x00000001, 0x01000001, 0x00010001, 0x01010001,
  0x00000101, 0x01000101, 0x00010101, 0x01010101,
};

/* platform-independant 32-bit integer manipulation macros */

#define GET_UINT32(n,b,i)                       \
{                                               \
	(n) = ( (uint32) (b)[(i)    ] << 24 )       \
        | ( (uint32) (b)[(i) + 1] << 16 )       \
        | ( (uint32) (b)[(i) + 2] <<  8 )       \
        | ( (uint32) (b)[(i) + 3]       );      \
}

#define PUT_UINT32(n,b,i)                       \
{                                               \
    (b)[(i)    ] = (uint8) ( (n) >> 24 );       \
    (b)[(i) + 1] = (uint8) ( (n) >> 16 );       \
    (b)[(i) + 2] = (uint8) ( (n) >>  8 );       \
    (b)[(i) + 3] = (uint8) ( (n)       );       \
}

/* Initial Permutation macro */

#define DES_IP(X,Y)                                             \
{                                                               \
    T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);   \
    T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);   \
    T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);   \
    T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);   \
    Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF;                    \
    T = (X ^ Y) & 0xAAAAAAAA; Y ^= T; X ^= T;                   \
    X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF;                    \
}

/* Final Permutation macro */

#define DES_FP(X,Y)                                             \
{                                                               \
    X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF;                    \
    T = (X ^ Y) & 0xAAAAAAAA; X ^= T; Y ^= T;                   \
    Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF;                    \
    T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);   \
    T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);   \
    T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);   \
    T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);   \
}

/* DES round macro */

#define DES_ROUND(X,Y)                          \
{                                               \
    T = *SK++ ^ X;                              \
    Y ^= SB8[ (T      ) & 0x3F ] ^              \
         SB6[ (T >>  8) & 0x3F ] ^              \
         SB4[ (T >> 16) & 0x3F ] ^              \
         SB2[ (T >> 24) & 0x3F ];               \
                                                \
    T = *SK++ ^ ((X << 28) | (X >> 4));         \
    Y ^= SB7[ (T      ) & 0x3F ] ^              \
		 SB5[ (T >>  8) & 0x3F ] ^              \
		 SB3[ (T >> 16) & 0x3F ] ^              \
		 SB1[ (T >> 24) & 0x3F ];               \
}

/* DES key schedule */

static inline int
des_main_ks (uint32 SK[32], const uint8 key[8])
{
  int i;
  uint32 X, Y, T;

  GET_UINT32 (X, key, 0);
  GET_UINT32 (Y, key, 4);

  /* Permuted Choice 1 */

  T = ((Y >> 4) ^ X) & 0x0F0F0F0F;
  X ^= T;
  Y ^= (T << 4);
  T = ((Y) ^ X) & 0x10101010;
  X ^= T;
  Y ^= (T);

  X = (LHs[(X) & 0xF] << 3) | (LHs[(X >> 8) & 0xF] << 2)
    | (LHs[(X >> 16) & 0xF] << 1) | (LHs[(X >> 24) & 0xF])
    | (LHs[(X >> 5) & 0xF] << 7) | (LHs[(X >> 13) & 0xF] << 6)
    | (LHs[(X >> 21) & 0xF] << 5) | (LHs[(X >> 29) & 0xF] << 4);

  Y = (RHs[(Y >> 1) & 0xF] << 3) | (RHs[(Y >> 9) & 0xF] << 2)
    | (RHs[(Y >> 17) & 0xF] << 1) | (RHs[(Y >> 25) & 0xF])
    | (RHs[(Y >> 4) & 0xF] << 7) | (RHs[(Y >> 12) & 0xF] << 6)
    | (RHs[(Y >> 20) & 0xF] << 5) | (RHs[(Y >> 28) & 0xF] << 4);

  X &= 0x0FFFFFFF;
  Y &= 0x0FFFFFFF;

  /* calculate subkeys */

  for (i = 0; i < 16; i++)
    {
      if (i < 2 || i == 8 || i == 15)
	{
	  X = ((X << 1) | (X >> 27)) & 0x0FFFFFFF;
	  Y = ((Y << 1) | (Y >> 27)) & 0x0FFFFFFF;
	}
      else
	{
	  X = ((X << 2) | (X >> 26)) & 0x0FFFFFFF;
	  Y = ((Y << 2) | (Y >> 26)) & 0x0FFFFFFF;
	}

      *SK++ = ((X << 4) & 0x24000000) | ((X << 28) & 0x10000000)
	| ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000)
	| ((X << 6) & 0x01000000) | ((X << 9) & 0x00200000)
	| ((X >> 1) & 0x00100000) | ((X << 10) & 0x00040000)
	| ((X << 2) & 0x00020000) | ((X >> 10) & 0x00010000)
	| ((Y >> 13) & 0x00002000) | ((Y >> 4) & 0x00001000)
	| ((Y << 6) & 0x00000800) | ((Y >> 1) & 0x00000400)
	| ((Y >> 14) & 0x00000200) | ((Y) & 0x00000100)
	| ((Y >> 5) & 0x00000020) | ((Y >> 10) & 0x00000010)
	| ((Y >> 3) & 0x00000008) | ((Y >> 18) & 0x00000004)
	| ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001);

      *SK++ = ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000)
	| ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000)
	| ((X >> 2) & 0x02000000) | ((X << 1) & 0x01000000)
	| ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000)
	| ((X << 3) & 0x00080000) | ((X >> 6) & 0x00040000)
	| ((X << 15) & 0x00020000) | ((X >> 4) & 0x00010000)
	| ((Y >> 2) & 0x00002000) | ((Y << 8) & 0x00001000)
	| ((Y >> 14) & 0x00000808) | ((Y >> 9) & 0x00000400)
	| ((Y) & 0x00000200) | ((Y << 7) & 0x00000100)
	| ((Y >> 7) & 0x00000020) | ((Y >> 3) & 0x00000011)
	| ((Y << 2) & 0x00000004) | ((Y >> 21) & 0x00000002);
    }

  return (0);
}


int
des_set_key (des_context * ctx, const uint8 key[8])
{
  int i;

  // setup encryption subkeys

  des_main_ks (ctx->esk, key);

  // setup decryption subkeys

  for (i = 0; i < 32; i += 2)
    {
      ctx->dsk[i] = ctx->esk[30 - i];
      ctx->dsk[i + 1] = ctx->esk[31 - i];
    }

  return (0);
}


// DES 64-bit block encryption/decryption

static void
des_crypt (const uint32 SK[32], const uint8 input[8], uint8 output[8])
{
  uint32 X, Y, T;

  GET_UINT32 (X, input, 0);
  GET_UINT32 (Y, input, 4);

  DES_IP (X, Y);

  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);

  DES_FP (Y, X);

  PUT_UINT32 (Y, output, 0);
  PUT_UINT32 (X, output, 4);
}


void
des_encrypt (des_context * ctx, const uint8 input[8], uint8 output[8])
{
  des_crypt (ctx->esk, input, output);
}

void
des_decrypt (des_context * ctx, const uint8 input[8], uint8 output[8])
{
  des_crypt (ctx->dsk, input, output);
}

// Triple-DES key schedule

int
des3_set_2keys (des3_context * ctx, const uint8 key1[8], const uint8 key2[8])
{
  int i;

  des_main_ks (ctx->esk, key1);
  des_main_ks (ctx->dsk + 32, key2);

  for (i = 0; i < 32; i += 2)
    {
      ctx->dsk[i] = ctx->esk[30 - i];
      ctx->dsk[i + 1] = ctx->esk[31 - i];

      ctx->esk[i + 32] = ctx->dsk[62 - i];
      ctx->esk[i + 33] = ctx->dsk[63 - i];

      ctx->esk[i + 64] = ctx->esk[i];
      ctx->esk[i + 65] = ctx->esk[1 + i];

      ctx->dsk[i + 64] = ctx->dsk[i];
      ctx->dsk[i + 65] = ctx->dsk[1 + i];
    }

  return (0);
}

// Triple-DES 64-bit block encryption/decryption

void
des3_crypt (uint32 SK[96], uint8 input[8], uint8 output[8])
{
  uint32 X, Y, T;

  GET_UINT32 (X, input, 0);
  GET_UINT32 (Y, input, 4);

  DES_IP (X, Y);

  // encrypt
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);

  // decrypt
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);

  // encrypt
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);
  DES_ROUND (Y, X);
  DES_ROUND (X, Y);

  DES_FP (Y, X);

  PUT_UINT32 (Y, output, 0);
  PUT_UINT32 (X, output, 4);
}

void
des3_encrypt (des3_context * ctx, uint8 input[8], uint8 output[8])
{
  des3_crypt (ctx->esk, input, output);
}

void
des3_decrypt (des3_context * ctx, uint8 input[8], uint8 output[8])
{
  des3_crypt (ctx->dsk, input, output);
}

void
encrypt_3des (const unsigned char *key, unsigned char *input, int inputLength,
	      unsigned char **output, int *outputLength)
{
  unsigned char in[8], out[8];
  des3_context ctx3;
  int i;
  int j;
  unsigned char *temp;

  temp = *output;

  // Set encryption keys
  //des3_set_2keys( &ctx3, DES3_keys[0], DES3_keys[1] );
  des3_set_2keys (&ctx3, &key[0], &key[8]);

  // clear buffers
  memset (in, 0x00, 8);
  memset (out, 0x00, 8);

  // do for each 8 byte block of input
  for (i = 0; i < inputLength / 8; i++)
    {
      // copy 8 bytes from input buffer to in
      memcpy (in, &input[i * 8], 8);

      // xor with ciphered block -1 
      for (j = 0; j < 8; j++)
	in[j] = in[j] ^ out[j];

      // 3DES encryption
      des3_encrypt (&ctx3, in, out);

      // copy encrypted block to output
      memcpy (&temp[i * 8], out, 8);
    }
  *outputLength = inputLength;
}

void
decrypt_3des (const unsigned char *key, unsigned char *input, int inputLength,
	      unsigned char **output, int *outputLength)
{
  des3_context ctx3;
  unsigned char in[8], out[8], in2[8];

  unsigned char *temp;

  int i;
  int j;

  temp = *output;

  // Set encryption keys
  //des3_set_2keys( &ctx3, DES3_keys[0], DES3_keys[1] );
  des3_set_2keys (&ctx3, &key[0], &key[8]);

  // clear buffers
  memset (in, 0x00, 8);
  memset (out, 0x00, 8);
  memset (in2, 0x00, 8);

  // do for each 8 byte block of input
  for (i = 0; i < inputLength / 8; i++)
    {
      // copy 8 bytes from input buffer to in
      memcpy (in, &input[i * 8], 8);

      // 3DES encryption
      des3_decrypt (&ctx3, in, out);

      // xor with ciphered block -1 
      for (j = 0; j < 8; j++)
	out[j] = out[j] ^ in2[j];

      memcpy (in2, &input[i * 8], 8);

      // copy decrypted block to output
      memcpy (&temp[i * 8], out, 8);
    }
}

void
encrypt_des (const unsigned char *key, unsigned char *input, int inputLength,
	     unsigned char **output, int *outputLength)
{
  unsigned char in[8], out[8];
  des_context ctx;
  int i, j;
  unsigned char *temp;

  temp = *output;

  // Set encryption keys
  //des3_set_2keys( &ctx3, DES3_keys[0], DES3_keys[1] );
  des_set_key (&ctx, &key[0]);

  // clear buffers
  memset (in, 0x00, 8);
  memset (out, 0x00, 8);

  // do for each 8 byte block of input
  for (i = 0; i < inputLength / 8; i++)
    {
      // copy 8 bytes from input buffer to in
      memcpy (in, &input[i * 8], 8);

      // xor with ciphered block -1 
      for (j = 0; j < 8; j++)
	in[j] = in[j] ^ out[j];

      // 3DES encryption
      des_encrypt (&ctx, in, out);

      // copy encrypted block to output
      memcpy (&temp[i * 8], out, 8);
    }
  *outputLength = inputLength;
}

void
decrypt_des (const unsigned char *key, unsigned char *input, int inputLength,
	     unsigned char **output, int *outputLength)
{
  des_context ctx;
  unsigned char in[8], out[8], in2[8];

  unsigned char *temp;

  int i, j;

  temp = *output;

  // Set encryption keys
  //des3_set_2keys( &ctx3, DES3_keys[0], DES3_keys[1] );
  des_set_key (&ctx, &key[0]);

  // clear buffers
  memset (in, 0x00, 8);
  memset (out, 0x00, 8);
  memset (in2, 0x00, 8);

  // do for each 8 byte block of input
  for (i = 0; i < inputLength / 8; i++)
    {
      // copy 8 bytes from input buffer to in
      memcpy (in, &input[i * 8], 8);

      // 3DES encryption
      des_decrypt (&ctx, in, out);

      // xor with ciphered block -1 
      for (j = 0; j < 8; j++)
	out[j] = out[j] ^ in2[j];

      memcpy (in2, &input[i * 8], 8);

      // copy decrypted block to output
      memcpy (&temp[i * 8], out, 8);
    }
}