3 * $Id: tea.h,v 1.2 2000/07/29 09:56:47 mdw Exp $
5 * The Tiny Encryption Algorithm
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.2 2000/07/29 09:56:47 mdw
34 * Allow the number of rounds to be configured. This isn't exported
35 * through the gcipher interface, but it may be useful anyway.
37 * Revision 1.1 2000/07/15 13:44:31 mdw
42 /*----- Notes on the Tiny Encryption Algorithm ----------------------------*
44 * TEA is an amazingly simple 64-round Feistel network. It's tiny, fairly
45 * quick and surprisingly strong. It was invented by David Wheeler and Roger
46 * Needham. It's unpatented. The keyspace is has only 126 effective bits,
47 * and there are related-key attacks. If you want these fixed, use XTEA.
49 * This implementation uses big-endian byte order, following SCAN.
52 #ifndef CATACOMB_TEA_H
53 #define CATACOMB_TEA_H
59 /*----- Header files ------------------------------------------------------*/
63 #include <mLib/bits.h>
65 /*----- Magical numbers ---------------------------------------------------*/
69 #define TEA_CLASS (N, B, 64)
71 extern const octet tea_keysz
[];
73 /*----- Data structures ---------------------------------------------------*/
75 typedef struct tea_ctx
{
77 uint32 ka
, kb
, kc
, kd
;
80 /*----- Functions provided ------------------------------------------------*/
82 /* --- @tea_init@ --- *
84 * Arguments: @tea_ctx *k@ = pointer to key block
85 * @const void *buf@ = pointer to key buffer
86 * @size_t sz@ = size of key material
90 * Use: Initializes a TEA key buffer. The key buffer may be up to 16
94 extern void tea_init(tea_ctx */
*k*/
, const void */
*buf*/
, size_t /*sz*/);
96 /* --- @tea_eblk@, @tea_dblk@ --- *
98 * Arguments: @const tea_ctx *k@ = pointer to key block
99 * @const uint32 s[2]@ = pointer to source block
100 * @uint32 d[2]@ = pointer to teatination block
104 * Use: Low-level block encryption and decryption.
107 extern void tea_eblk(const tea_ctx */
*k*/
,
108 const uint32 */
*s*/
, uint32 */
*d*/
);
109 extern void tea_dblk(const tea_ctx */
*k*/
,
110 const uint32 */
*s*/
, uint32 */
*d*/
);
112 /*----- That's all, folks -------------------------------------------------*/