Commit | Line | Data |
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ea937a0e | 1 | /* -*-c-*- |
ea937a0e | 2 | * |
3 | * The Tiny Encryption Algorithm | |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
ea937a0e | 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. | |
45c0fd36 | 16 | * |
ea937a0e | 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. | |
45c0fd36 | 21 | * |
ea937a0e | 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 | ||
ea937a0e | 28 | /*----- Notes on the Tiny Encryption Algorithm ----------------------------* |
29 | * | |
30 | * TEA is an amazingly simple 64-round Feistel network. It's tiny, fairly | |
31 | * quick and surprisingly strong. It was invented by David Wheeler and Roger | |
32 | * Needham. It's unpatented. The keyspace is has only 126 effective bits, | |
33 | * and there are related-key attacks. If you want these fixed, use XTEA. | |
34 | * | |
35 | * This implementation uses big-endian byte order, following SCAN. | |
36 | */ | |
37 | ||
38 | #ifndef CATACOMB_TEA_H | |
39 | #define CATACOMB_TEA_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 TEA_BLKSZ 8 | |
54 | #define TEA_KEYSZ 16 | |
55 | #define TEA_CLASS (N, B, 64) | |
56 | ||
57 | extern const octet tea_keysz[]; | |
58 | ||
59 | /*----- Data structures ---------------------------------------------------*/ | |
60 | ||
61 | typedef struct tea_ctx { | |
d36cd240 | 62 | unsigned r; |
ea937a0e | 63 | uint32 ka, kb, kc, kd; |
64 | } tea_ctx; | |
65 | ||
66 | /*----- Functions provided ------------------------------------------------*/ | |
67 | ||
68 | /* --- @tea_init@ --- * | |
69 | * | |
45c0fd36 MW |
70 | * Arguments: @tea_ctx *k@ = pointer to key block |
71 | * @const void *buf@ = pointer to key buffer | |
72 | * @size_t sz@ = size of key material | |
ea937a0e | 73 | * |
45c0fd36 | 74 | * Returns: --- |
ea937a0e | 75 | * |
45c0fd36 | 76 | * Use: Initializes a TEA key buffer. The key buffer may be up to 16 |
ea937a0e | 77 | * bytes long. |
78 | */ | |
79 | ||
80 | extern void tea_init(tea_ctx */*k*/, const void */*buf*/, size_t /*sz*/); | |
81 | ||
82 | /* --- @tea_eblk@, @tea_dblk@ --- * | |
83 | * | |
45c0fd36 MW |
84 | * Arguments: @const tea_ctx *k@ = pointer to key block |
85 | * @const uint32 s[2]@ = pointer to source block | |
86 | * @uint32 d[2]@ = pointer to teatination block | |
ea937a0e | 87 | * |
45c0fd36 | 88 | * Returns: --- |
ea937a0e | 89 | * |
45c0fd36 | 90 | * Use: Low-level block encryption and decryption. |
ea937a0e | 91 | */ |
92 | ||
93 | extern void tea_eblk(const tea_ctx */*k*/, | |
45c0fd36 | 94 | const uint32 */*s*/, uint32 */*d*/); |
ea937a0e | 95 | extern void tea_dblk(const tea_ctx */*k*/, |
45c0fd36 | 96 | const uint32 */*s*/, uint32 */*d*/); |
ea937a0e | 97 | |
98 | /*----- That's all, folks -------------------------------------------------*/ | |
99 | ||
100 | #ifdef __cplusplus | |
101 | } | |
102 | #endif | |
103 | ||
104 | #endif |