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mirror of https://git.FreeBSD.org/src.git synced 2024-12-22 11:17:19 +00:00
freebsd/crypto/libdes/qud_cksm.c
1999-09-04 12:45:43 +00:00

141 lines
5.1 KiB
C

/* 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)
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;
unsigned char *lp;
if (out_count < 1) out_count=1;
lp = &(output[0])[0];
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)
{
/* I believe I finally have things worked out.
* The MIT library assumes that the checksum
* is one huge number and it is returned in a
* host dependant byte order.
*/
static DES_LONG ltmp=1;
static unsigned char *c=(unsigned char *)&ltmp;
if (c[0])
{
l2c(z0,lp);
l2c(z1,lp);
}
else
{
lp = &(output[out_count-i-1])[0];
l2n(z1,lp);
l2n(z0,lp);
}
}
}
return(z0);
}