3 * $Id: cast256.h,v 1.1 2000/06/17 10:49:14 mdw Exp $
5 * The CAST-128 block cipher
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 1.1 2000/06/17 10:49:14 mdw
38 /*----- Notes on the CAST-256 block cipher --------------------------------*
40 * CAST, designed by Carlisle Adams and Stafford Tavares, is a method for
41 * designing block ciphers, based around the concept of `bent functions'. It
42 * is described in the paper `Constructing Symmetric Ciphers using the CAST
43 * Design Procedure' by Carlisle Adams.
45 * CAST-256, defined in RFC2612, is a particular instance of the CAST design
46 * procedure. It is an `incomplete' Feistel network. It uses the same
47 * S-boxes and round functions as CAST-128.
49 * CAST-256 was submitted to the AES contest, but was not selected as one of
50 * the five `finalist' algorithms.
53 #ifndef CATACOMB_CAST256_H
54 #define CATACOMB_CAST256_H
60 /*----- Header files ------------------------------------------------------*/
62 #include <mLib/bits.h>
64 /*----- Magic numbers -----------------------------------------------------*/
66 #define CAST256_BLKSZ 16
67 #define CAST256_KEYSZ 32
68 #define CAST256_CLASS (N, B, 128)
70 extern const octet cast256_keysz
[];
72 /*----- Data structures ---------------------------------------------------*/
74 typedef struct cast256_ctx
{
79 /*----- Functions provided ------------------------------------------------*/
81 /* --- @cast256_init@ --- *
83 * Arguments: @cast256_ctx *k@ = pointer to key block to fill in
84 * @const void *buf@ = pointer to buffer of key material
85 * @size_t sz@ = size of key material
89 * Use: Initializes a CAST-256 key buffer. CAST-256 accepts
90 * 256-bit keys or shorter.
93 extern void cast256_init(cast256_ctx */
*k*/
,
94 const void */
*buf*/
, size_t /*sz*/);
96 /* --- @cast256_eblk@, @cast256_dblk@ --- *
98 * Arguments: @const cast256_ctx *k@ = pointer to key block
99 * @const uint32 s[2]@ = pointer to source block
100 * @uint32 d[2]@ = pointer to destination block
104 * Use: Low-level block encryption and decryption.
107 extern void cast256_eblk(const cast256_ctx */
*k*/
,
108 const uint32 */
*s*/
, uint32 */
*d*/
);
110 extern void cast256_dblk(const cast256_ctx */
*k*/
,
111 const uint32 */
*s*/
, uint32 */
*d*/
);
113 /*----- That's all, folks -------------------------------------------------*/