/* 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

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 *    distribution.

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 * 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.

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 * 5. Products derived from this software may not be called "OpenSSL"

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 * 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

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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

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 *

 * 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

*/

#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_DESCBCM is defined */

#ifndef OPENSSL_NO_DESCBCM

#include "des_locl.h"

EXPORT_C 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