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1 | /* -*-c-*- |
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2 | * |
3 | * The Twofish block cipher |
4 | * |
5 | * (c) 2000 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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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. |
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16 | * |
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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. |
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21 | * |
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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 | |
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28 | /*----- Notes on the Twofish block cipher ---------------------------------* |
29 | * |
30 | * Twofish was designed by Bruce Schneier, John Kelsey, Doug Whiting, David |
31 | * Wagner, Chris Hall and Niels Ferguson. The algorithm is unpatented and |
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32 | * free for anyone to use. It was one of the five AES finalist algorithms. |
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33 | * |
34 | * Twofish is a complex cipher offering various space and time tradeoffs. |
35 | * This implementation has a heavy key schedule and fast bulk encryption. |
36 | */ |
37 | |
38 | #ifndef CATACOMB_TWOFISH_H |
39 | #define CATACOMB_TWOFISH_H |
40 | |
41 | #ifdef __cplusplus |
42 | extern "C" { |
43 | #endif |
44 | |
45 | /*----- Header files ------------------------------------------------------*/ |
46 | |
47 | #include <stddef.h> |
48 | |
49 | #include <mLib/bits.h> |
50 | |
51 | /*----- Magical numbers ---------------------------------------------------*/ |
52 | |
53 | #define TWOFISH_BLKSZ 16 |
54 | #define TWOFISH_KEYSZ 32 |
55 | #define TWOFISH_CLASS (N, L, 128) |
56 | |
57 | extern const octet twofish_keysz[]; |
58 | |
59 | /*----- Data structures ---------------------------------------------------*/ |
60 | |
61 | typedef struct twofish_ctx { |
62 | uint32 k[40]; |
63 | uint32 g[4][256]; |
64 | } twofish_ctx; |
65 | |
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66 | typedef struct twofish_fk { |
67 | uint32 t0[8], t23[8], t4[2]; |
68 | octet t1[32]; |
69 | } twofish_fk; |
70 | |
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71 | /*----- Functions provided ------------------------------------------------*/ |
72 | |
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73 | /* --- @twofish_initfk@ --- * |
74 | * |
75 | * Arguments: @twofish_ctx *k@ = pointer to key block to fill in |
76 | * @const void *buf@ = pointer to buffer of key material |
77 | * @size_t sz@ = size of key material |
78 | * @const twofish_fk *fk@ = family-key information |
79 | * |
80 | * Returns: --- |
81 | * |
82 | * Use: Does the underlying Twofish key initialization with family |
83 | * key. Pass in a family-key structure initialized to |
84 | * all-bits-zero for a standard key schedule. |
85 | */ |
86 | |
87 | extern void twofish_initfk(twofish_ctx */*k*/, const void */*buf*/, |
88 | size_t /*sz*/, const twofish_fk */*fk*/); |
89 | |
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90 | /* --- @twofish_init@ --- * |
91 | * |
92 | * Arguments: @twofish_ctx *k@ = pointer to key block to fill in |
93 | * @const void *buf@ = pointer to buffer of key material |
94 | * @size_t sz@ = size of key material |
95 | * |
96 | * Returns: --- |
97 | * |
98 | * Use: Initializes a Twofish key buffer. Twofish accepts keys of up |
99 | * to 256 bits in length. |
100 | */ |
101 | |
102 | extern void twofish_init(twofish_ctx */*k*/, |
103 | const void */*buf*/, size_t /*sz*/); |
104 | |
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105 | /* --- @twofish_fkinit@ --- * |
106 | * |
107 | * Arguments: @twofish_fk *fk@ = pointer to family key block |
108 | * @const void *buf@ = pointer to buffer of key material |
109 | * @size_t sz@ = size of key material |
110 | * |
111 | * Returns: --- |
112 | * |
113 | * Use: Initializes a family-key buffer. This implementation allows |
114 | * family keys of any size acceptable to the Twofish algorithm. |
115 | */ |
116 | |
117 | extern void twofish_fkinit(twofish_fk */*fk*/, |
118 | const void */*buf*/, size_t /*sz*/); |
119 | |
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120 | /* --- @twofish_eblk@, @twofish_dblk@ --- * |
121 | * |
122 | * Arguments: @const twofish_ctx *k@ = pointer to key block |
123 | * @const uint32 s[4]@ = pointer to source block |
124 | * @uint32 d[4]@ = pointer to destination block |
125 | * |
126 | * Returns: --- |
127 | * |
128 | * Use: Low-level block encryption and decryption. |
129 | */ |
130 | |
131 | extern void twofish_eblk(const twofish_ctx */*k*/, |
132 | const uint32 */*s*/, uint32 */*d*/); |
133 | |
134 | extern void twofish_dblk(const twofish_ctx */*k*/, |
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135 | const uint32 */*s*/, uint32 */*d*/); |
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136 | |
137 | /*----- That's all, folks -------------------------------------------------*/ |
138 | |
139 | #ifdef __cplusplus |
140 | } |
141 | #endif |
142 | |
143 | #endif |