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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: safer.h,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * The SAFER block cipher |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
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30 | /*----- Notes on the SAFER block cipher -----------------------------------* |
31 | * |
32 | * SAFER was designed by James Massey (who also worked on IDEA) for Cylink. |
33 | * It's free -- patents or other silliness. The original key schedule had |
34 | * some weaknesses, and a new one (the SK version) was added. SAFER has a |
35 | * variable number of rounds. The standard interface uses the recommended |
36 | * number for the given key schedule algorithm and key size. |
37 | * |
38 | * SAFER got a bad press in Schneier's book `Applied Cryptography'. I think |
39 | * this is undeserved. SAFER is a well-designed cipher which mostly looks |
40 | * pretty solid. |
41 | */ |
42 | |
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43 | #ifndef CATACOMB_SAFER_H |
44 | #define CATACOMB_SAFER_H |
45 | |
46 | #ifdef __cplusplus |
47 | extern "C" { |
48 | #endif |
49 | |
50 | /*----- Header files ------------------------------------------------------*/ |
51 | |
52 | #include <stddef.h> |
53 | |
54 | #include <mLib/bits.h> |
55 | |
56 | /*----- Magical numbers ---------------------------------------------------*/ |
57 | |
58 | #define SAFER_BLKSZ 8 |
59 | #define SAFER_KEYSZ 8 |
60 | #define SAFER_CLASS (N, B, 64) |
61 | |
62 | #define SAFERSK_BLKSZ SAFER_BLKSZ |
63 | #define SAFERSK_KEYSZ 16 |
64 | #define SAFERSK_CLASS SAFER_CLASS |
65 | |
66 | #define SAFER_MAXROUNDS 12 |
67 | |
68 | extern const octet safer_keysz[]; |
69 | #define safersk_keysz safer_keysz |
70 | |
71 | /*----- Data structures ---------------------------------------------------*/ |
72 | |
73 | typedef struct safer_ctx { |
74 | octet k[8 * (2 * SAFER_MAXROUNDS + 1)]; |
75 | unsigned r; |
76 | } safer_ctx, safersk_ctx; |
77 | |
78 | /*----- Functions provided ------------------------------------------------*/ |
79 | |
80 | /* --- @safer_setup@ --- * |
81 | * |
82 | * Arguments: @safer_ctx *k@ = pointer to context to initialize |
83 | * @unsigned r@ = number of rounds wanted |
84 | * @unsigned f@ = various other flags |
85 | * @const void *buf@ = pointer to key material |
86 | * @size_t sz@ = size of key material in bytes |
87 | * |
88 | * Returns: --- |
89 | * |
90 | * Use: Initializes an SAFER expanded key. A default number of |
91 | * rounds is chosen, based on the key length. |
92 | */ |
93 | |
94 | #define SAFER_SK 1u |
95 | |
96 | extern void safer_setup(safer_ctx */*k*/, unsigned /*r*/, unsigned /*f*/, |
97 | const void */*buf*/, size_t /*sz*/); |
98 | |
99 | /* --- @safer_init@, @safersk_init@ --- * |
100 | * |
101 | * Arguments: @safer_ctx *k@ = pointer to context to initialize |
102 | * @const void *buf@ = pointer to key material |
103 | * @size_t sz@ = size of key material in bytes |
104 | * |
105 | * Returns: --- |
106 | * |
107 | * Use: Initializes an SAFER expanded key. A default number of |
108 | * rounds is chosen, based on the key length. |
109 | */ |
110 | |
111 | extern void safer_init(safer_ctx */*k*/, |
112 | const void */*buf*/, size_t /*sz*/); |
113 | extern void safersk_init(safer_ctx */*k*/, |
114 | const void */*buf*/, size_t /*sz*/); |
115 | |
116 | /* --- @safer_eblk@, @safer_dblk@ --- * |
117 | * |
118 | * Arguments: @const safer_ctx *k@ = pointer to SAFER context |
119 | * @const uint32 s[2]@ = pointer to source block |
120 | * @const uint32 d[2]@ = pointer to destination block |
121 | * |
122 | * Returns: --- |
123 | * |
124 | * Use: Low-level block encryption and decryption. |
125 | */ |
126 | |
127 | extern void safer_eblk(const safer_ctx */*k*/, |
128 | const uint32 */*s*/, uint32 */*dst*/); |
129 | extern void safer_dblk(const safer_ctx */*k*/, |
130 | const uint32 */*s*/, uint32 */*dst*/); |
131 | |
132 | #define safersk_eblk safer_eblk |
133 | #define safersk_dblk safer_dblk |
134 | |
135 | /*----- That's all, folks -------------------------------------------------*/ |
136 | |
137 | #ifdef __cplusplus |
138 | } |
139 | #endif |
140 | |
141 | #endif |