/*----------------------------------------------------------------------------+
 |                                                                            |
 |   Package: krypto                                                          |
 |                                                                            |
 |      This code is based on code in Eric Young's blowfish implementation    |
 |   and was slightly modified to conform with libkrypto's interface.         |
 |   See copyright notice below.                                              |
 |                                                                            |
 +----------------------------------------------------------------------------*/

/* crypto/bf/bf_cbc.c */
/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@mincom.oz.au).
 * 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@mincom.oz.au).
 * 
 * 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@mincom.oz.au)"
 *    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@mincom.oz.au)"
 * 
 * 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 "krypto.h"
#include "krypto_locl.h"

void
cipher_crypt_cbc (c, in, out, length)
cipher *c;
unsigned char *in;
unsigned char *out;
long length;
{
  register CIPHER_LONG tin0, tin1;
  register CIPHER_LONG tout0, tout1, xor0, xor1;
  register long l = length;
  CIPHER_LONG tin[2];
  unsigned char *iv = c->iv;

  if (c->state == CIPHER_STATE_ENCRYPT)
  {
    n2l(iv,tout0);
    n2l(iv,tout1);
    iv-=8;

    for (l-=8; l>=0; l-=8)
    {
      n2l(in,tin0);
      n2l(in,tin1);
      tin0^=tout0;
      tin1^=tout1;
      tin[0]=tin0;
      tin[1]=tin1;
      c->cipher->crypt (c->context, (unsigned char *) tin, 8, c->state);
      tout0=tin[0];
      tout1=tin[1];
      l2n(tout0,out);
      l2n(tout1,out);
    }

    if (l != -8)
    {
      n2ln(in,tin0,tin1,l+8);
      tin0^=tout0;
      tin1^=tout1;
      tin[0]=tin0;
      tin[1]=tin1;
      c->cipher->crypt (c->context, (unsigned char *) tin, 8, c->state);
      tout0=tin[0];
      tout1=tin[1];
      l2n(tout0,out);
      l2n(tout1,out);
    }

    l2n(tout0,iv);
    l2n(tout1,iv);
  }
  else
  {
    n2l(iv,xor0);
    n2l(iv,xor1);
    iv-=8;

    for (l-=8; l>=0; l-=8)
    {
      n2l(in,tin0);
      n2l(in,tin1);
      tin[0]=tin0;
      tin[1]=tin1;
      c->cipher->crypt (c->context, (unsigned char *) tin, 8, c->state);
      tout0=tin[0]^xor0;
      tout1=tin[1]^xor1;
      l2n(tout0,out);
      l2n(tout1,out);
      xor0=tin0;
      xor1=tin1;
    }

    if (l != -8)
    {
      n2l(in,tin0);
      n2l(in,tin1);
      tin[0]=tin0;
      tin[1]=tin1;
      c->cipher->crypt (c->context, (unsigned char *) tin, 8, c->state);
      tout0=tin[0]^xor0;
      tout1=tin[1]^xor1;
      l2nn(tout0,tout1,out,l+8);
      xor0=tin0;
      xor1=tin1;
    }

    l2n(xor0,iv);
    l2n(xor1,iv);
  }

  tin0=tin1=tout0=tout1=xor0=xor1=0;
  tin[0]=tin[1]=0;
}

