/* crypto/des/ncbc_enc.c */

/*

 * #included by:

 *    cbc_enc.c  (DES_cbc_encrypt)

 *    des_enc.c  (DES_ncbc_encrypt)

 */

/* 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"

#ifdef CBC_ENC_C__DONT_UPDATE_IV

EXPORT_C void DES_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,

		     DES_key_schedule *_schedule, DES_cblock *ivec, int enc)

#else

EXPORT_C void DES_ncbc_encrypt(const unsigned char *in, unsigned char *out, long length,

		     DES_key_schedule *_schedule, DES_cblock *ivec, int enc)

#endif

	{

	register DES_LONG tin0,tin1;

	register DES_LONG tout0,tout1,xor0,xor1;

	register long l=length;

	DES_LONG tin[2];

	unsigned char *iv;

	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; tin[0]=tin0;

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

			DES_encrypt1((DES_LONG *)tin,_schedule,DES_ENCRYPT);

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

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

			}

		if (l != -8)

			{

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

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

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

			DES_encrypt1((DES_LONG *)tin,_schedule,DES_ENCRYPT);

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

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

			}

#ifndef CBC_ENC_C__DONT_UPDATE_IV

		iv = &(*ivec)[0];

		l2c(tout0,iv);

		l2c(tout1,iv);

#endif

		}

	else

		{

		c2l(iv,xor0);

		c2l(iv,xor1);

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

			{

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

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

			DES_encrypt1((DES_LONG *)tin,_schedule,DES_DECRYPT);

			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;

			DES_encrypt1((DES_LONG *)tin,_schedule,DES_DECRYPT);

			tout0=tin[0]^xor0;

			tout1=tin[1]^xor1;

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

#ifndef CBC_ENC_C__DONT_UPDATE_IV

			xor0=tin0;

			xor1=tin1;

#endif

			}

#ifndef CBC_ENC_C__DONT_UPDATE_IV 

		iv = &(*ivec)[0];

		l2c(xor0,iv);

		l2c(xor1,iv);

#endif

		}

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

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

	}