3 * Implementation of double- and triple-DES
5 * (c) 1999 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
28 #ifndef CATACOMB_DES3_H
29 #define CATACOMB_DES3_H
35 /*----- Notes on double- and triple-DES -----------------------------------*
37 * The normal recommendation for using DES now is `triple DES'.
38 * Conventionally, this involves an encrypt-decrypt-encrypt sequence,
39 * although whether the first and last operations use the same key is
40 * unfortunately not agreed upon. This interface handles both cases (and the
41 * single-key one too, although the simple @des@ calls are quicker for that).
44 /*----- Header files ------------------------------------------------------*/
48 #include <mLib/bits.h>
50 #ifndef CATACOMB_DES_H
54 /*----- Magical numbers ---------------------------------------------------*/
58 #define DES3_CLASS (N, B, 64)
60 extern const octet des3_keysz[];
62 /*----- Data structures ---------------------------------------------------*/
64 typedef struct des3_ctx {
68 /*----- Functions provided ------------------------------------------------*/
70 /* --- @des3_init@ --- *
72 * Arguments: @des3_ctx *k@ = pointer to key block
73 * @const void *buf@ = pointer to key buffer
74 * @size_t sz@ = size of key material
78 * Use: Initializes a DES key buffer. The key buffer may have length
79 * 7, 8, 14, 16, 21, or 24. These correspond to one, two or
80 * three DES keys, either packed or unpacked (i.e., still
81 * containing parity bits).
84 extern void des3_init(des3_ctx */*k*/, const void */*buf*/, size_t /*sz*/);
86 /* --- @des3_eblk@, @des_dblk@ --- *
88 * Arguments: @const des3_ctx *k@ = pointer to key block
89 * @const uint32 s[2]@ = pointer to source block
90 * @uint32 d[2]@ = pointer to destination block
94 * Use: Low-level block encryption and decryption.
97 extern void des3_eblk(const des3_ctx */*k*/,
98 const uint32 */*s*/, uint32 */*d*/);
99 extern void des3_dblk(const des3_ctx */*k*/,
100 const uint32 */*s*/, uint32 */*d*/);
102 /*----- That's all, folks -------------------------------------------------*/