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1 | /* -*-c-*- |
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2 | * |
3 | * The Square 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 Square block cipher ----------------------------------* |
29 | * |
30 | * Invented by Joan Daemen and Vincent Rijmen, Square is a fast and |
31 | * relatively simple 128-bit block cipher. It is the predecessor to |
32 | * Rijndael. I have grave doubts about the security of Square, though: a |
33 | * dedicated attack against Square's structure by Knudsen has been extended |
34 | * by the Twofish team against Rijndael, and I believe that this extended |
35 | * attack is also effective against Square. This is a shame: the structure |
36 | * of Square (and Rijndael) is extremely elegant, and has some extremely nice |
37 | * properties. |
38 | */ |
39 | |
40 | #ifndef CATACOMB_SQUARE_H |
41 | #define CATACOMB_SQUARE_H |
42 | |
43 | #ifdef __cplusplus |
44 | extern "C" { |
45 | #endif |
46 | |
47 | /*----- Header files ------------------------------------------------------*/ |
48 | |
49 | #include <stddef.h> |
50 | |
51 | #include <mLib/bits.h> |
52 | |
53 | /*----- Magical numbers ---------------------------------------------------*/ |
54 | |
55 | #define SQUARE_BLKSZ 16 |
56 | #define SQUARE_KEYSZ 16 |
57 | #define SQUARE_CLASS (N, L, 128) |
58 | |
59 | extern const octet square_keysz[]; |
60 | |
61 | /*----- Data structures ---------------------------------------------------*/ |
62 | |
63 | #define SQUARE_MAXROUNDS 8 |
64 | #define SQUARE_KWORDS ((SQUARE_MAXROUNDS + 1) * (SQUARE_BLKSZ / 4)) |
65 | |
66 | typedef struct square_ctx { |
67 | uint32 w[SQUARE_KWORDS]; |
68 | uint32 wi[SQUARE_KWORDS]; |
69 | } square_ctx; |
70 | |
71 | /*----- Functions provided ------------------------------------------------*/ |
72 | |
73 | /* --- @square_init@ --- * |
74 | * |
75 | * Arguments: @square_ctx *k@ = pointer to context to initialize |
76 | * @const void *buf@ = pointer to buffer of key material |
77 | * @size_t sz@ = size of the key material |
78 | * |
79 | * Returns: --- |
80 | * |
81 | * Use: Initializes a Square context with a particular key. This |
82 | * implementation of Square doesn't impose any particular |
83 | * limits on the key size except that it must be multiple of 4 |
84 | * bytes long. 256 bits seems sensible, though. |
85 | */ |
86 | |
87 | extern void square_init(square_ctx */*k*/, |
88 | const void */*buf*/, size_t /*sz*/); |
89 | |
90 | /* --- @square_eblk@, @square_dblk@ --- * |
91 | * |
92 | * Arguments: @const square_ctx *k@ = pointer to Square context |
93 | * @const uint32 s[4]@ = pointer to source block |
94 | * @uint32 d[4]@ = pointer to destination block |
95 | * |
96 | * Returns: --- |
97 | * |
98 | * Use: Low-level block encryption and decryption. |
99 | */ |
100 | |
101 | extern void square_eblk(const square_ctx */*k*/, |
102 | const uint32 */*s*/, uint32 */*dst*/); |
103 | extern void square_dblk(const square_ctx */*k*/, |
104 | const uint32 */*s*/, uint32 */*dst*/); |
105 | |
106 | /*----- That's all, folks -------------------------------------------------*/ |
107 | |
108 | #ifdef __cplusplus |
109 | } |
110 | #endif |
111 | |
112 | #endif |