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ede_cbcm_enc.c

/* ede_cbcm_enc.c */
/* Written by Ben Laurie <ben@algroup.co.uk> for the OpenSSL
 * project 13 Feb 1999.
 */
/* ====================================================================
 * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

/*

This is an implementation of Triple DES Cipher Block Chaining with Output
Feedback Masking, by Coppersmith, Johnson and Matyas, (IBM and Certicom).

Note that there is a known attack on this by Biham and Knudsen but it takes
a lot of work:

http://www.cs.technion.ac.il/users/wwwb/cgi-bin/tr-get.cgi/1998/CS/CS0928.ps.gz

*/

#ifndef OPENSSL_NO_DESCBCM
#include "des_locl.h"

void DES_ede3_cbcm_encrypt(const unsigned char *in, unsigned char *out,
           long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
           DES_key_schedule *ks3, DES_cblock *ivec1, DES_cblock *ivec2,
           int enc)
    {
    register DES_LONG tin0,tin1;
    register DES_LONG tout0,tout1,xor0,xor1,m0,m1;
    register long l=length;
    DES_LONG tin[2];
    unsigned char *iv1,*iv2;

    iv1 = &(*ivec1)[0];
    iv2 = &(*ivec2)[0];

    if (enc)
      {
      c2l(iv1,m0);
      c2l(iv1,m1);
      c2l(iv2,tout0);
      c2l(iv2,tout1);
      for (l-=8; l>=-7; l-=8)
          {
          tin[0]=m0;
          tin[1]=m1;
          DES_encrypt1(tin,ks3,1);
          m0=tin[0];
          m1=tin[1];

          if(l < 0)
            {
            c2ln(in,tin0,tin1,l+8);
            }
          else
            {
            c2l(in,tin0);
            c2l(in,tin1);
            }
          tin0^=tout0;
          tin1^=tout1;

          tin[0]=tin0;
          tin[1]=tin1;
          DES_encrypt1(tin,ks1,1);
          tin[0]^=m0;
          tin[1]^=m1;
          DES_encrypt1(tin,ks2,0);
          tin[0]^=m0;
          tin[1]^=m1;
          DES_encrypt1(tin,ks1,1);
          tout0=tin[0];
          tout1=tin[1];

          l2c(tout0,out);
          l2c(tout1,out);
          }
      iv1=&(*ivec1)[0];
      l2c(m0,iv1);
      l2c(m1,iv1);

      iv2=&(*ivec2)[0];
      l2c(tout0,iv2);
      l2c(tout1,iv2);
      }
    else
      {
      register DES_LONG t0,t1;

      c2l(iv1,m0);
      c2l(iv1,m1);
      c2l(iv2,xor0);
      c2l(iv2,xor1);
      for (l-=8; l>=-7; l-=8)
          {
          tin[0]=m0;
          tin[1]=m1;
          DES_encrypt1(tin,ks3,1);
          m0=tin[0];
          m1=tin[1];

          c2l(in,tin0);
          c2l(in,tin1);

          t0=tin0;
          t1=tin1;

          tin[0]=tin0;
          tin[1]=tin1;
          DES_encrypt1(tin,ks1,0);
          tin[0]^=m0;
          tin[1]^=m1;
          DES_encrypt1(tin,ks2,1);
          tin[0]^=m0;
          tin[1]^=m1;
          DES_encrypt1(tin,ks1,0);
          tout0=tin[0];
          tout1=tin[1];

          tout0^=xor0;
          tout1^=xor1;
          if(l < 0)
            {
            l2cn(tout0,tout1,out,l+8);
            }
          else
            {
            l2c(tout0,out);
            l2c(tout1,out);
            }
          xor0=t0;
          xor1=t1;
          }

      iv1=&(*ivec1)[0];
      l2c(m0,iv1);
      l2c(m1,iv1);

      iv2=&(*ivec2)[0];
      l2c(xor0,iv2);
      l2c(xor1,iv2);
      }
    tin0=tin1=tout0=tout1=xor0=xor1=0;
    tin[0]=tin[1]=0;
    }
#endif

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