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 | |
27 | DES_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 | |