3 * $Id: cast128.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-128 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-128, defined in RFC2144, is a particular instance of the CAST design
46 * procedure, The cipher seems strong and fairly quick. The design procedure
47 * itself is patented, although the cipher CAST-128 is free to use.
49 * Although CAST ciphers are resistant to differential and linear
50 * cryptanalysis, some instances have been broken by more advanced techniques
51 * -- the CAST procedure does not guarantee a strong cipher. However,
52 * CAST-128 has so far resisted all attacks against it, and has now been
53 * accepted by the Canadian government for protection of all `Designated'
57 #ifndef CATACOMB_CAST128_H
58 #define CATACOMB_CAST128_H
64 /*----- Header files ------------------------------------------------------*/
66 #include <mLib/bits.h>
68 /*----- Magic numbers -----------------------------------------------------*/
70 #define CAST128_BLKSZ 8
71 #define CAST128_KEYSZ 16
72 #define CAST128_CLASS (N, B, 64)
74 extern const octet cast128_keysz
[];
76 /*----- Data structures ---------------------------------------------------*/
78 typedef struct cast128_ctx
{
84 /*----- Functions provided ------------------------------------------------*/
86 /* --- @cast128_init@ --- *
88 * Arguments: @cast128_ctx *k@ = pointer to key block to fill in
89 * @const void *buf@ = pointer to buffer of key material
90 * @size_t sz@ = size of key material
94 * Use: Initializes a CAST-128 key buffer. CAST-128 accepts
95 * 128-bit keys or shorter.
98 extern void cast128_init(cast128_ctx */
*k*/
,
99 const void */
*buf*/
, size_t /*sz*/);
101 /* --- @cast128_eblk@, @cast128_dblk@ --- *
103 * Arguments: @const cast128_ctx *k@ = pointer to key block
104 * @const uint32 s[2]@ = pointer to source block
105 * @uint32 d[2]@ = pointer to destination block
109 * Use: Low-level block encryption and decryption.
112 extern void cast128_eblk(const cast128_ctx */
*k*/
,
113 const uint32 */
*s*/
, uint32 */
*d*/
);
115 extern void cast128_dblk(const cast128_ctx */
*k*/
,
116 const uint32 */
*s*/
, uint32 */
*d*/
);
118 /*----- That's all, folks -------------------------------------------------*/