heimdal/lib/des/qud_cksm.c

/* crypto/des/qud_cksm.c */
/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@mincom.oz.au).
 * 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@mincom.oz.au).
 * 
 * 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@mincom.oz.au)"
 *    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@mincom.oz.au)"
 * 
 * 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)

DES_LONG des_quad_cksum(input, output, length, out_count, seed)
     des_cblock (*input);
     des_cblock (*output);
     long length;
     int out_count;
     des_cblock (*seed);
{
    DES_LONG z0,z1,t0,t1;
    int i;
    long l;
#ifdef _CRAY
    typedef struct {
	unsigned int a:32;
	unsigned int b:32;
    } XXX;
#else
    typedef DES_LONG XXX;
#endif
    unsigned char *cp;
    XXX *lp;

    if (out_count < 1) out_count=1;
    lp=(XXX*)output;

    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=(unsigned char *)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++ = (XXX)z0;
		    *lp++ = (XXX)z1;
#endif
		}
	}
    return(z0);
}