/* crypto/des/pcbc_enc.c */

/* 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"

EXPORT_C void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,

		      long length, DES_key_schedule *schedule,

		      DES_cblock *ivec, int enc)

	{

	register DES_LONG sin0,sin1,xor0,xor1,tout0,tout1;

	DES_LONG tin[2];

	const unsigned char *in;

	unsigned char *out,*iv;

	in=input;

	out=output;

	iv = &(*ivec)[0];

	if (enc)

		{

		c2l(iv,xor0);

		c2l(iv,xor1);

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

			{

			if (length >= 8)

				{

				c2l(in,sin0);

				c2l(in,sin1);

				}

			else

				c2ln(in,sin0,sin1,length);

			tin[0]=sin0^xor0;

			tin[1]=sin1^xor1;

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

			tout0=tin[0];

			tout1=tin[1];

			xor0=sin0^tout0;

			xor1=sin1^tout1;

			l2c(tout0,out);

			l2c(tout1,out);

			}

		}

	else

		{

		c2l(iv,xor0); c2l(iv,xor1);

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

			{

			c2l(in,sin0);

			c2l(in,sin1);

			tin[0]=sin0;

			tin[1]=sin1;

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

			tout0=tin[0]^xor0;

			tout1=tin[1]^xor1;

			if (length >= 8)

				{

				l2c(tout0,out);

				l2c(tout1,out);

				}

			else

				l2cn(tout0,tout1,out,length);

			xor0=tout0^sin0;

			xor1=tout1^sin1;

			}

		}

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

	sin0=sin1=xor0=xor1=tout0=tout1=0;

	}