1 /*
2 * Copyright 1995-2020 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
17 /*
18 * DES low level APIs are deprecated for public use, but still ok for internal
19 * use.
20 */
21 #include "internal/deprecated.h"
22
23 #include "des_local.h"
24
25 #define Q_B0(a) (((DES_LONG)(a)))
26 #define Q_B1(a) (((DES_LONG)(a)) << 8)
27 #define Q_B2(a) (((DES_LONG)(a)) << 16)
28 #define Q_B3(a) (((DES_LONG)(a)) << 24)
29
30 /* used to scramble things a bit */
31 /* Got the value MIT uses via brute force :-) 2/10/90 eay */
32 #define NOISE ((DES_LONG)83653421L)
33
DES_quad_cksum(const unsigned char * input,DES_cblock output[],long length,int out_count,DES_cblock * seed)34 DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
35 long length, int out_count, DES_cblock *seed)
36 {
37 DES_LONG z0, z1, t0, t1;
38 int i;
39 long l;
40 const unsigned char *cp;
41 DES_LONG *lp;
42
43 if (out_count < 1)
44 out_count = 1;
45 lp = (DES_LONG *)&(output[0])[0];
46
47 z0 = Q_B0((*seed)[0]) | Q_B1((*seed)[1]) | Q_B2((*seed)[2]) | Q_B3((*seed)[3]);
48 z1 = Q_B0((*seed)[4]) | Q_B1((*seed)[5]) | Q_B2((*seed)[6]) | Q_B3((*seed)[7]);
49
50 for (i = 0; ((i < 4) && (i < out_count)); i++) {
51 cp = input;
52 l = length;
53 while (l > 0) {
54 if (l > 1) {
55 t0 = (DES_LONG)(*(cp++));
56 t0 |= (DES_LONG)Q_B1(*(cp++));
57 l--;
58 } else
59 t0 = (DES_LONG)(*(cp++));
60 l--;
61 /* add */
62 t0 += z0;
63 t0 &= 0xffffffffL;
64 t1 = z1;
65 /* square, well sort of square */
66 z0 = ((((t0 * t0) & 0xffffffffL) + ((t1 * t1) & 0xffffffffL))
67 & 0xffffffffL)
68 % 0x7fffffffL;
69 z1 = ((t0 * ((t1 + NOISE) & 0xffffffffL)) & 0xffffffffL) % 0x7fffffffL;
70 }
71 if (lp != NULL) {
72 /*
73 * The MIT library assumes that the checksum is composed of
74 * 2*out_count 32 bit ints
75 */
76 *lp++ = z0;
77 *lp++ = z1;
78 }
79 }
80 return z0;
81 }
82