1/*
2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10/*
11 * From "Message Authentication" R.R. Jueneman, S.M. Matyas, C.H. Meyer IEEE
12 * Communications Magazine Sept 1985 Vol. 23 No. 9 p 29-40 This module in
13 * only based on the code in this paper and is almost definitely not the same
14 * as the MIT implementation.
15 */
16#include "des_local.h"
17
18#define Q_B0(a) (((DES_LONG)(a)))
19#define Q_B1(a) (((DES_LONG)(a))<<8)
20#define Q_B2(a) (((DES_LONG)(a))<<16)
21#define Q_B3(a) (((DES_LONG)(a))<<24)
22
23/* used to scramble things a bit */
24/* Got the value MIT uses via brute force :-) 2/10/90 eay */
25#define NOISE ((DES_LONG)83653421L)
26
27DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
28 long length, int out_count, DES_cblock *seed)
29{
30 DES_LONG z0, z1, t0, t1;
31 int i;
32 long l;
33 const unsigned char *cp;
34 DES_LONG *lp;
35
36 if (out_count < 1)
37 out_count = 1;
38 lp = (DES_LONG *)&(output[0])[0];
39
40 z0 = Q_B0((*seed)[0]) | Q_B1((*seed)[1]) | Q_B2((*seed)[2]) |
41 Q_B3((*seed)[3]);
42 z1 = Q_B0((*seed)[4]) | Q_B1((*seed)[5]) | Q_B2((*seed)[6]) |
43 Q_B3((*seed)[7]);
44
45 for (i = 0; ((i < 4) && (i < out_count)); i++) {
46 cp = input;
47 l = length;
48 while (l > 0) {
49 if (l > 1) {
50 t0 = (DES_LONG)(*(cp++));
51 t0 |= (DES_LONG)Q_B1(*(cp++));
52 l--;
53 } else
54 t0 = (DES_LONG)(*(cp++));
55 l--;
56 /* add */
57 t0 += z0;
58 t0 &= 0xffffffffL;
59 t1 = z1;
60 /* square, well sort of square */
61 z0 = ((((t0 * t0) & 0xffffffffL) + ((t1 * t1) & 0xffffffffL))
62 & 0xffffffffL) % 0x7fffffffL;
63 z1 = ((t0 * ((t1 + NOISE) & 0xffffffffL)) & 0xffffffffL) %
64 0x7fffffffL;
65 }
66 if (lp != NULL) {
67 /*
68 * The MIT library assumes that the checksum is composed of
69 * 2*out_count 32 bit ints
70 */
71 *lp++ = z0;
72 *lp++ = z1;
73 }
74 }
75 return z0;
76}
77