3 * $Id: xtea.h,v 1.2 2000/07/15 13:47:14 mdw Exp $
5 * The Extended 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 2000/07/15 13:47:14 mdw
34 * Whoops. Fix the purpose comment.
36 * Revision 1.1 2000/07/15 13:44:31 mdw
41 /*----- Notes on the Tiny Encryption Algorithm ----------------------------*
43 * XTEA is an amazingly simple 64-round Feistel network. It's tiny, fairly
44 * quick and surprisingly strong. It was invented by David Wheeler and Roger
45 * Needham. It's unpatented. XTEA is a new version of TEA, by the same
46 * designers, which fixes some weaknesses in TEA's key schedule.
48 * This implementation uses big-endian byte order, following SCAN.
51 #ifndef CATACOMB_XTEA_H
52 #define CATACOMB_XTEA_H
58 /*----- Header files ------------------------------------------------------*/
62 #include <mLib/bits.h>
64 /*----- Magical numbers ---------------------------------------------------*/
68 #define XTEA_CLASS (N, B, 64)
70 extern const octet xtea_keysz
[];
72 /*----- Data structures ---------------------------------------------------*/
74 typedef struct xtea_ctx
{
78 /*----- Functions provided ------------------------------------------------*/
80 /* --- @xtea_init@ --- *
82 * Arguments: @xtea_ctx *k@ = pointer to key block
83 * @const void *buf@ = pointer to key buffer
84 * @size_t sz@ = size of key material
88 * Use: Initializes an XTEA key buffer. The key buffer may be up to
92 extern void xtea_init(xtea_ctx */
*k*/
, const void */
*buf*/
, size_t /*sz*/);
94 /* --- @xtea_eblk@, @xtea_dblk@ --- *
96 * Arguments: @const xtea_ctx *k@ = pointer to key block
97 * @const uint32 s[2]@ = pointer to source block
98 * @uint32 d[2]@ = pointer to xteatination block
102 * Use: Low-level block encryption and decryption.
105 extern void xtea_eblk(const xtea_ctx */
*k*/
,
106 const uint32 */
*s*/
, uint32 */
*d*/
);
107 extern void xtea_dblk(const xtea_ctx */
*k*/
,
108 const uint32 */
*s*/
, uint32 */
*d*/
);
110 /*----- That's all, folks -------------------------------------------------*/