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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: safer.h,v 1.2 2001/04/29 18:11:38 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 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: safer.h,v $ |
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33 | * Revision 1.2 2001/04/29 18:11:38 mdw |
34 | * Add some notes. |
35 | * |
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36 | * Revision 1.1 2001/04/29 17:37:35 mdw |
37 | * Added SAFER block cipher. |
38 | * |
39 | */ |
40 | |
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41 | /*----- Notes on the SAFER block cipher -----------------------------------* |
42 | * |
43 | * SAFER was designed by James Massey (who also worked on IDEA) for Cylink. |
44 | * It's free -- patents or other silliness. The original key schedule had |
45 | * some weaknesses, and a new one (the SK version) was added. SAFER has a |
46 | * variable number of rounds. The standard interface uses the recommended |
47 | * number for the given key schedule algorithm and key size. |
48 | * |
49 | * SAFER got a bad press in Schneier's book `Applied Cryptography'. I think |
50 | * this is undeserved. SAFER is a well-designed cipher which mostly looks |
51 | * pretty solid. |
52 | */ |
53 | |
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54 | #ifndef CATACOMB_SAFER_H |
55 | #define CATACOMB_SAFER_H |
56 | |
57 | #ifdef __cplusplus |
58 | extern "C" { |
59 | #endif |
60 | |
61 | /*----- Header files ------------------------------------------------------*/ |
62 | |
63 | #include <stddef.h> |
64 | |
65 | #include <mLib/bits.h> |
66 | |
67 | /*----- Magical numbers ---------------------------------------------------*/ |
68 | |
69 | #define SAFER_BLKSZ 8 |
70 | #define SAFER_KEYSZ 8 |
71 | #define SAFER_CLASS (N, B, 64) |
72 | |
73 | #define SAFERSK_BLKSZ SAFER_BLKSZ |
74 | #define SAFERSK_KEYSZ 16 |
75 | #define SAFERSK_CLASS SAFER_CLASS |
76 | |
77 | #define SAFER_MAXROUNDS 12 |
78 | |
79 | extern const octet safer_keysz[]; |
80 | #define safersk_keysz safer_keysz |
81 | |
82 | /*----- Data structures ---------------------------------------------------*/ |
83 | |
84 | typedef struct safer_ctx { |
85 | octet k[8 * (2 * SAFER_MAXROUNDS + 1)]; |
86 | unsigned r; |
87 | } safer_ctx, safersk_ctx; |
88 | |
89 | /*----- Functions provided ------------------------------------------------*/ |
90 | |
91 | /* --- @safer_setup@ --- * |
92 | * |
93 | * Arguments: @safer_ctx *k@ = pointer to context to initialize |
94 | * @unsigned r@ = number of rounds wanted |
95 | * @unsigned f@ = various other flags |
96 | * @const void *buf@ = pointer to key material |
97 | * @size_t sz@ = size of key material in bytes |
98 | * |
99 | * Returns: --- |
100 | * |
101 | * Use: Initializes an SAFER expanded key. A default number of |
102 | * rounds is chosen, based on the key length. |
103 | */ |
104 | |
105 | #define SAFER_SK 1u |
106 | |
107 | extern void safer_setup(safer_ctx */*k*/, unsigned /*r*/, unsigned /*f*/, |
108 | const void */*buf*/, size_t /*sz*/); |
109 | |
110 | /* --- @safer_init@, @safersk_init@ --- * |
111 | * |
112 | * Arguments: @safer_ctx *k@ = pointer to context to initialize |
113 | * @const void *buf@ = pointer to key material |
114 | * @size_t sz@ = size of key material in bytes |
115 | * |
116 | * Returns: --- |
117 | * |
118 | * Use: Initializes an SAFER expanded key. A default number of |
119 | * rounds is chosen, based on the key length. |
120 | */ |
121 | |
122 | extern void safer_init(safer_ctx */*k*/, |
123 | const void */*buf*/, size_t /*sz*/); |
124 | extern void safersk_init(safer_ctx */*k*/, |
125 | const void */*buf*/, size_t /*sz*/); |
126 | |
127 | /* --- @safer_eblk@, @safer_dblk@ --- * |
128 | * |
129 | * Arguments: @const safer_ctx *k@ = pointer to SAFER context |
130 | * @const uint32 s[2]@ = pointer to source block |
131 | * @const uint32 d[2]@ = pointer to destination block |
132 | * |
133 | * Returns: --- |
134 | * |
135 | * Use: Low-level block encryption and decryption. |
136 | */ |
137 | |
138 | extern void safer_eblk(const safer_ctx */*k*/, |
139 | const uint32 */*s*/, uint32 */*dst*/); |
140 | extern void safer_dblk(const safer_ctx */*k*/, |
141 | const uint32 */*s*/, uint32 */*dst*/); |
142 | |
143 | #define safersk_eblk safer_eblk |
144 | #define safersk_dblk safer_dblk |
145 | |
146 | /*----- That's all, folks -------------------------------------------------*/ |
147 | |
148 | #ifdef __cplusplus |
149 | } |
150 | #endif |
151 | |
152 | #endif |