Commit | Line | Data |
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b348397a | 1 | /* -*-c-*- |
b348397a | 2 | * |
3 | * The DESX algorithm | |
4 | * | |
5 | * (c) 2001 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
b348397a | 9 | * |
10 | * This file is part of Catacomb. | |
11 | * | |
12 | * Catacomb is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU Library General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
45c0fd36 | 16 | * |
b348397a | 17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU Library General Public License for more details. | |
45c0fd36 | 21 | * |
b348397a | 22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free | |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
25 | * MA 02111-1307, USA. | |
26 | */ | |
27 | ||
b348397a | 28 | /*----- Notes on DESX -----------------------------------------------------* |
29 | * | |
30 | * DESX was designed by Ron Rivest in 1986 as a simple and cheap way to | |
31 | * strengthen DES against exhaustive search. It also increases the | |
32 | * difficulty of differential and linear attacks. | |
33 | */ | |
34 | ||
35 | #ifndef CATACOMB_DESX_H | |
36 | #define CATACOMB_DESX_H | |
37 | ||
38 | #ifdef __cplusplus | |
39 | extern "C" { | |
40 | #endif | |
41 | ||
42 | /*----- Header files ------------------------------------------------------*/ | |
43 | ||
44 | #include <stddef.h> | |
45 | ||
46 | #include <mLib/bits.h> | |
47 | ||
48 | #ifndef CATACOMB_DES_H | |
49 | # include "des.h" | |
50 | #endif | |
51 | ||
52 | /*----- Magical numbers ---------------------------------------------------*/ | |
53 | ||
54 | #define DESX_BLKSZ 8 | |
55 | #define DESX_KEYSZ 23 | |
56 | #define DESX_CLASS (N, B, 64) | |
57 | ||
58 | extern const octet desx_keysz[]; | |
59 | ||
60 | /*----- Data structures ---------------------------------------------------*/ | |
61 | ||
62 | typedef struct desx_ctx { | |
63 | des_ctx k; | |
64 | uint32 prea, preb; | |
65 | uint32 posta, postb; | |
66 | } desx_ctx; | |
67 | ||
68 | /*----- Functions provided ------------------------------------------------*/ | |
69 | ||
70 | /* --- @desx_init@ --- * | |
71 | * | |
72 | * Arguments: @desx_ctx *k@ = pointer to key block | |
73 | * @const void *buf@ = pointer to key buffer | |
74 | * @size_t sz@ = size of key material | |
75 | * | |
76 | * Returns: --- | |
77 | * | |
78 | * Use: Initializes a DESX key buffer. The key buffer contains, in | |
eea8ea58 MW |
79 | * order, a single-DES key (either 7 or 8 bytes), an optional |
80 | * 8-byte pre-whitening key, and an optional 8-byte | |
81 | * post-whitening key. If no whitening keys are specified, the | |
82 | * algorithm becomes the same as single-DES. | |
b348397a | 83 | */ |
84 | ||
85 | extern void desx_init(desx_ctx */*k*/, const void */*buf*/, size_t /*sz*/); | |
86 | ||
87 | /* --- @desx_eblk@, @desx_dblk@ --- * | |
88 | * | |
89 | * Arguments: @const desx_ctx *k@ = pointer to key block | |
90 | * @const uint32 s[2]@ = pointer to source block | |
91 | * @uint32 d[2]@ = pointer to destination block | |
92 | * | |
93 | * Returns: --- | |
94 | * | |
95 | * Use: Low-level block encryption and decryption. | |
96 | */ | |
97 | ||
98 | extern void desx_eblk(const desx_ctx */*k*/, | |
99 | const uint32 */*s*/, uint32 */*d*/); | |
100 | extern void desx_dblk(const desx_ctx */*k*/, | |
101 | const uint32 */*s*/, uint32 */*d*/); | |
102 | ||
103 | /*----- That's all, folks -------------------------------------------------*/ | |
104 | ||
105 | #ifdef __cplusplus | |
106 | } | |
107 | #endif | |
108 | ||
109 | #endif |