3 * $Id: des.h,v 1.4 2004/04/08 01:36:15 mdw Exp $
5 * The Data Encryption Standard
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 /*----- Notes on the Data Encryption Standard -----------------------------*
32 * Almost twenty years after it was first accepted, DES is still the standard
33 * block cipher. It's showing its age in its small key size and poor
34 * optimiziation for software implementations, but it's not really been badly
35 * dented by the intensive analysis thrown at it.
37 * This interface is here for compatibility with existing protocols, and
38 * because it's a trivial veneer over the base DES code which is used by the
39 * @des3@ interface which implements proper strong triple-DES.
42 #ifndef CATACOMB_DES_H
43 #define CATACOMB_DES_H
49 /*----- Header files ------------------------------------------------------*/
53 #include <mLib/bits.h>
55 /*----- Magical numbers ---------------------------------------------------*/
59 #define DES_CLASS (N, B, 64)
61 extern const octet des_keysz
[];
63 /*----- Data structures ---------------------------------------------------*/
65 typedef struct des_ctx
{
69 /*----- Functions provided ------------------------------------------------*/
71 /* --- @des_init@ --- *
73 * Arguments: @des_ctx *k@ = pointer to key block
74 * @const void *buf@ = pointer to key buffer
75 * @size_t sz@ = size of key material
79 * Use: Initializes a DES key buffer. The key buffer may be either 7
80 * or 8 bytes long. If it's 8 bytes, the key is assumed to be
81 * padded with parity bits in the low order bit of each octet.
82 * These are stripped out without checking prior to the actual
86 extern void des_init(des_ctx */
*k*/
, const void */
*buf*/
, size_t /*sz*/);
88 /* --- @des_eblk@, @des_dblk@ --- *
90 * Arguments: @const des_ctx *k@ = pointer to key block
91 * @const uint32 s[2]@ = pointer to source block
92 * @uint32 d[2]@ = pointer to destination block
96 * Use: Low-level block encryption and decryption.
99 extern void des_eblk(const des_ctx */
*k*/
,
100 const uint32 */
*s*/
, uint32 */
*d*/
);
101 extern void des_dblk(const des_ctx */
*k*/
,
102 const uint32 */
*s*/
, uint32 */
*d*/
);
104 /*----- That's all, folks -------------------------------------------------*/