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/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* 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.
*/
/*
* DES low level APIs are deprecated for public use, but still ok for internal
* use.
*/
#include "internal/deprecated.h"
#include "des_local.h"
#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;
DES_LONG *lp;
if (out_count < 1)
out_count = 1;
lp = (DES_LONG *)&(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) {
/*
* The MIT library assumes that the checksum is composed of
* 2*out_count 32 bit ints
*/
*lp++ = z0;
*lp++ = z1;
}
}
return z0;
}
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