/* $OpenBSD: xcbc_enc.c,v 1.9 2015/02/07 13:19:15 doug Exp $ */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 * 

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 * 

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from 

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 * 

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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.

 * 

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include "des_locl.h"

/* RSA's DESX */

void DES_xcbc_encrypt(const unsigned char *in, unsigned char *out,

          long length, DES_key_schedule *schedule,

          DES_cblock *ivec, const_DES_cblock *inw,

          const_DES_cblock *outw, int enc)

  {

  DES_LONG tin0,tin1;

  DES_LONG tout0,tout1,xor0,xor1;

  DES_LONG inW0,inW1,outW0,outW1;

  const unsigned char *in2;

  long l=length;

  DES_LONG tin[2];

  unsigned char *iv;

  in2 = &(*inw)[0];

  c2l(in2,inW0);

  c2l(in2,inW1);

  in2 = &(*outw)[0];

  c2l(in2,outW0);

  c2l(in2,outW1);

  iv = &(*ivec)[0];

  if (enc)

    {

    c2l(iv,tout0);

    c2l(iv,tout1);

    for (l-=8; l>=0; l-=8)

      {

      c2l(in,tin0);

      c2l(in,tin1);

      tin0^=tout0^inW0; tin[0]=tin0;

      tin1^=tout1^inW1; tin[1]=tin1;

      DES_encrypt1(tin,schedule,DES_ENCRYPT);

      tout0=tin[0]^outW0; l2c(tout0,out);

      tout1=tin[1]^outW1; l2c(tout1,out);

      }

    if (l != -8)

      {

      c2ln(in,tin0,tin1,l+8);

      tin0^=tout0^inW0; tin[0]=tin0;

      tin1^=tout1^inW1; tin[1]=tin1;

      DES_encrypt1(tin,schedule,DES_ENCRYPT);

      tout0=tin[0]^outW0; l2c(tout0,out);

      tout1=tin[1]^outW1; l2c(tout1,out);

      }

    iv = &(*ivec)[0];

    l2c(tout0,iv);

    l2c(tout1,iv);

    }

  else

    {

    c2l(iv,xor0);

    c2l(iv,xor1);

    for (l-=8; l>0; l-=8)

      {

      c2l(in,tin0); tin[0]=tin0^outW0;

      c2l(in,tin1); tin[1]=tin1^outW1;

      DES_encrypt1(tin,schedule,DES_DECRYPT);

      tout0=tin[0]^xor0^inW0;

      tout1=tin[1]^xor1^inW1;

      l2c(tout0,out);

      l2c(tout1,out);

      xor0=tin0;

      xor1=tin1;

      }

    if (l != -8)

      {

      c2l(in,tin0); tin[0]=tin0^outW0;

      c2l(in,tin1); tin[1]=tin1^outW1;

      DES_encrypt1(tin,schedule,DES_DECRYPT);

      tout0=tin[0]^xor0^inW0;

      tout1=tin[1]^xor1^inW1;

      l2cn(tout0,tout1,out,l+8);

      xor0=tin0;

      xor1=tin1;

      }

    iv = &(*ivec)[0];

    l2c(xor0,iv);

    l2c(xor1,iv);

    }

  tin0=tin1=tout0=tout1=xor0=xor1=0;

  inW0=inW1=outW0=outW1=0;

  tin[0]=tin[1]=0;

  }