/* crypto/des/qud_cksm.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.]

 */

/* From "Message Authentication"  R.R. Jueneman, S.M. Matyas, C.H. Meyer

 * IEEE Communications Magazine Sept 1985 Vol. 23 No. 9 p 29-40

 * This module in only based on the code in this paper and is

 * almost definitely not the same as the MIT implementation.

 */

#include "des_locl.h"

/* bug fix for dos - 7/6/91 - Larry hughes@logos.ucs.indiana.edu */

#define Q_B0(a)	(((DES_LONG)(a)))

#define Q_B1(a)	(((DES_LONG)(a))<<8)

#define Q_B2(a)	(((DES_LONG)(a))<<16)

#define Q_B3(a)	(((DES_LONG)(a))<<24)

/* used to scramble things a bit */

/* Got the value MIT uses via brute force :-) 2/10/90 eay */

#define NOISE	((DES_LONG)83653421L)

EXPORT_C DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],

	     long length, int out_count, DES_cblock *seed)

	{

	DES_LONG z0,z1,t0,t1;

	int i;

	long l;

	const unsigned char *cp;

#ifdef _CRAY

	struct lp_st { int a:32; int b:32; } *lp;

#else

	DES_LONG *lp;

#endif

	if (out_count < 1) out_count=1;

#ifdef _CRAY

	lp = (struct lp_st *) &(output[0])[0];

#else

	lp = (DES_LONG *) &(output[0])[0];

#endif

	z0=Q_B0((*seed)[0])|Q_B1((*seed)[1])|Q_B2((*seed)[2])|Q_B3((*seed)[3]);

	z1=Q_B0((*seed)[4])|Q_B1((*seed)[5])|Q_B2((*seed)[6])|Q_B3((*seed)[7]);

	for (i=0; ((i<4)&&(i<out_count)); i++)

		{

		cp=input;

		l=length;

		while (l > 0)

			{

			if (l > 1)

				{

				t0= (DES_LONG)(*(cp++));

				t0|=(DES_LONG)Q_B1(*(cp++));

				l--;

				}

			else

				t0= (DES_LONG)(*(cp++));

			l--;

			/* add */

			t0+=z0;

			t0&=0xffffffffL;

			t1=z1;

			/* square, well sort of square */

			z0=((((t0*t0)&0xffffffffL)+((t1*t1)&0xffffffffL))

				&0xffffffffL)%0x7fffffffL; 

			z1=((t0*((t1+NOISE)&0xffffffffL))&0xffffffffL)%0x7fffffffL;

			}

		if (lp != NULL)

			{

			/* The MIT library assumes that the checksum is

			 * composed of 2*out_count 32 bit ints */

#ifdef _CRAY

			(*lp).a = z0;

			(*lp).b = z1;

			lp++;

#else

			*lp++ = z0;

			*lp++ = z1;

#endif

			}

		}

	return(z0);

	}