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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: square.h,v 1.2 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * The Square block cipher |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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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. |
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18 | * |
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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. |
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23 | * |
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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 Square block cipher ----------------------------------* |
31 | * |
32 | * Invented by Joan Daemen and Vincent Rijmen, Square is a fast and |
33 | * relatively simple 128-bit block cipher. It is the predecessor to |
34 | * Rijndael. I have grave doubts about the security of Square, though: a |
35 | * dedicated attack against Square's structure by Knudsen has been extended |
36 | * by the Twofish team against Rijndael, and I believe that this extended |
37 | * attack is also effective against Square. This is a shame: the structure |
38 | * of Square (and Rijndael) is extremely elegant, and has some extremely nice |
39 | * properties. |
40 | */ |
41 | |
42 | #ifndef CATACOMB_SQUARE_H |
43 | #define CATACOMB_SQUARE_H |
44 | |
45 | #ifdef __cplusplus |
46 | extern "C" { |
47 | #endif |
48 | |
49 | /*----- Header files ------------------------------------------------------*/ |
50 | |
51 | #include <stddef.h> |
52 | |
53 | #include <mLib/bits.h> |
54 | |
55 | /*----- Magical numbers ---------------------------------------------------*/ |
56 | |
57 | #define SQUARE_BLKSZ 16 |
58 | #define SQUARE_KEYSZ 16 |
59 | #define SQUARE_CLASS (N, L, 128) |
60 | |
61 | extern const octet square_keysz[]; |
62 | |
63 | /*----- Data structures ---------------------------------------------------*/ |
64 | |
65 | #define SQUARE_MAXROUNDS 8 |
66 | #define SQUARE_KWORDS ((SQUARE_MAXROUNDS + 1) * (SQUARE_BLKSZ / 4)) |
67 | |
68 | typedef struct square_ctx { |
69 | uint32 w[SQUARE_KWORDS]; |
70 | uint32 wi[SQUARE_KWORDS]; |
71 | } square_ctx; |
72 | |
73 | /*----- Functions provided ------------------------------------------------*/ |
74 | |
75 | /* --- @square_init@ --- * |
76 | * |
77 | * Arguments: @square_ctx *k@ = pointer to context to initialize |
78 | * @const void *buf@ = pointer to buffer of key material |
79 | * @size_t sz@ = size of the key material |
80 | * |
81 | * Returns: --- |
82 | * |
83 | * Use: Initializes a Square context with a particular key. This |
84 | * implementation of Square doesn't impose any particular |
85 | * limits on the key size except that it must be multiple of 4 |
86 | * bytes long. 256 bits seems sensible, though. |
87 | */ |
88 | |
89 | extern void square_init(square_ctx */*k*/, |
90 | const void */*buf*/, size_t /*sz*/); |
91 | |
92 | /* --- @square_eblk@, @square_dblk@ --- * |
93 | * |
94 | * Arguments: @const square_ctx *k@ = pointer to Square context |
95 | * @const uint32 s[4]@ = pointer to source block |
96 | * @uint32 d[4]@ = pointer to destination block |
97 | * |
98 | * Returns: --- |
99 | * |
100 | * Use: Low-level block encryption and decryption. |
101 | */ |
102 | |
103 | extern void square_eblk(const square_ctx */*k*/, |
104 | const uint32 */*s*/, uint32 */*dst*/); |
105 | extern void square_dblk(const square_ctx */*k*/, |
106 | const uint32 */*s*/, uint32 */*dst*/); |
107 | |
108 | /*----- That's all, folks -------------------------------------------------*/ |
109 | |
110 | #ifdef __cplusplus |
111 | } |
112 | #endif |
113 | |
114 | #endif |