/* $OpenBSD: rc2_cbc.c,v 1.5 2014/10/28 07:35:59 jsg 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 <openssl/rc2.h>

#include "rc2_locl.h"

void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,

       RC2_KEY *ks, unsigned char *iv, int encrypt)

  {

  unsigned long tin0,tin1;

  unsigned long tout0,tout1,xor0,xor1;

  long l=length;

  unsigned long tin[2];

  if (encrypt)

    {

    c2l(iv,tout0);

    c2l(iv,tout1);

    iv-=8;

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

      {

      c2l(in,tin0);

      c2l(in,tin1);

      tin0^=tout0;

      tin1^=tout1;

      tin[0]=tin0;

      tin[1]=tin1;

      RC2_encrypt(tin,ks);

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

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

      }

    if (l != -8)

      {

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

      tin0^=tout0;

      tin1^=tout1;

      tin[0]=tin0;

      tin[1]=tin1;

      RC2_encrypt(tin,ks);

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

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

      }

    l2c(tout0,iv);

    l2c(tout1,iv);

    }

  else

    {

    c2l(iv,xor0);

    c2l(iv,xor1);

    iv-=8;

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

      {

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

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

      RC2_decrypt(tin,ks);

      tout0=tin[0]^xor0;

      tout1=tin[1]^xor1;

      l2c(tout0,out);

      l2c(tout1,out);

      xor0=tin0;

      xor1=tin1;

      }

    if (l != -8)

      {

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

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

      RC2_decrypt(tin,ks);

      tout0=tin[0]^xor0;

      tout1=tin[1]^xor1;

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

      xor0=tin0;

      xor1=tin1;

      }

    l2c(xor0,iv);

    l2c(xor1,iv);

    }

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

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

  }

void RC2_encrypt(unsigned long *d, RC2_KEY *key)

  {

  int i,n;

  RC2_INT *p0,*p1;

  RC2_INT x0,x1,x2,x3,t;

  unsigned long l;

  l=d[0];

  x0=(RC2_INT)l&0xffff;

  x1=(RC2_INT)(l>>16L);

  l=d[1];

  x2=(RC2_INT)l&0xffff;

  x3=(RC2_INT)(l>>16L);

  n=3;

  i=5;

  p0=p1= &(key->data[0]);

  for (;;)

    {

    t=(x0+(x1& ~x3)+(x2&x3)+ *(p0++))&0xffff;

    x0=(t<<1)|(t>>15);

    t=(x1+(x2& ~x0)+(x3&x0)+ *(p0++))&0xffff;

    x1=(t<<2)|(t>>14);

    t=(x2+(x3& ~x1)+(x0&x1)+ *(p0++))&0xffff;

    x2=(t<<3)|(t>>13);

    t=(x3+(x0& ~x2)+(x1&x2)+ *(p0++))&0xffff;

    x3=(t<<5)|(t>>11);

    if (--i == 0)

      {

      if (--n == 0) break;

      i=(n == 2)?6:5;

      x0+=p1[x3&0x3f];

      x1+=p1[x0&0x3f];

      x2+=p1[x1&0x3f];

      x3+=p1[x2&0x3f];

      }

    }

  d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);

  d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);

  }

void RC2_decrypt(unsigned long *d, RC2_KEY *key)

  {

  int i,n;

  RC2_INT *p0,*p1;

  RC2_INT x0,x1,x2,x3,t;

  unsigned long l;

  l=d[0];

  x0=(RC2_INT)l&0xffff;

  x1=(RC2_INT)(l>>16L);

  l=d[1];

  x2=(RC2_INT)l&0xffff;

  x3=(RC2_INT)(l>>16L);

  n=3;

  i=5;

  p0= &(key->data[63]);

  p1= &(key->data[0]);

  for (;;)

    {

    t=((x3<<11)|(x3>>5))&0xffff;

    x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff;

    t=((x2<<13)|(x2>>3))&0xffff;

    x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff;

    t=((x1<<14)|(x1>>2))&0xffff;

    x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff;

    t=((x0<<15)|(x0>>1))&0xffff;

    x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff;

    if (--i == 0)

      {

      if (--n == 0) break;

      i=(n == 2)?6:5;

      x3=(x3-p1[x2&0x3f])&0xffff;

      x2=(x2-p1[x1&0x3f])&0xffff;

      x1=(x1-p1[x0&0x3f])&0xffff;

      x0=(x0-p1[x3&0x3f])&0xffff;

      }

    }

  d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);

  d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);

  }