3 * $Id: idea.h,v 1.3 2000/06/17 11:24:08 mdw Exp $
5 * Implementation of the IDEA cipher
7 * (c) 1999 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 1.3 2000/06/17 11:24:08 mdw
34 * New key size interface.
36 * Revision 1.2 1999/12/10 23:29:48 mdw
37 * Change header file guard names.
39 * Revision 1.1 1999/09/03 08:41:12 mdw
44 /*----- Notes on the IDEA block cipher ------------------------------------*
46 * IDEA was invented by James Massey and Xuejia Lai. The fundamental idea
47 * underlying the cipher is combining incompatible group operations. The
48 * algorithm's main claim to fame is that it is the symmetric cipher in PGP
51 * The IDEA algorithm is allegedly patented by Ascom Tech A.G., even in the
52 * UK and Europe. Ascom are willing to grant licences for use in software
53 * which forbids commercial use, but this is not compatible with Free
54 * Software Foundation ideology. The author recommends against the use of
55 * the IDEA cipher entirely. Blowfish is conceptually simpler, appears more
56 * concervative, offers a larger keyspace, runs faster, and is in the public
60 #ifndef CATACOMB_IDEA_H
61 #define CATACOMB_IDEA_H
67 /*----- Header files ------------------------------------------------------*/
71 #include <mLib/bits.h>
73 /*----- Magical numbers ---------------------------------------------------*/
77 #define IDEA_CLASS (N, B, 64)
79 extern const octet idea_keysz
[];
81 /*----- Data structures ---------------------------------------------------*/
83 typedef struct idea_ctx
{
88 /*----- Functions provided ------------------------------------------------*/
90 /* --- @idea_init@ --- *
92 * Arguments: @idea_ctx *k@ = pointer to key block
93 * @const void *buf@ = pointer to key buffer
94 * @size_t sz@ = size of key material
98 * Use: Initializes an IDEA key buffer. The buffer must be exactly
99 * 16 bytes in size, because IDEA is only defined with a key
103 extern void idea_init(idea_ctx */
*k*/
, const void */
*buf*/
, size_t /*sz*/);
105 /* --- @idea_eblk@, @idea_dblk@ --- *
107 * Arguments: @const idea_ctx *k@ = pointer to a key block
108 * @const uint32 s[2]@ = pointer to source block
109 * @uint32 d[2]@ = pointer to destination block
113 * Use: Low-level block encryption and decryption.
116 extern void idea_eblk(const idea_ctx */
*k*/
,
117 const uint32 */
*s*/
, uint32 */
*d*/
);
118 extern void idea_dblk(const idea_ctx */
*k*/
,
119 const uint32 */
*s*/
, uint32 */
*d*/
);
121 /*----- That's all, folks -------------------------------------------------*/