d03ab969 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: des.h,v 1.1 1999/09/03 08:41:11 mdw Exp $ |
4 | * |
5 | * The Data Encryption Standard |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
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. |
18 | * |
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. |
23 | * |
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, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: des.h,v $ |
33 | * Revision 1.1 1999/09/03 08:41:11 mdw |
34 | * Initial import. |
35 | * |
36 | */ |
37 | |
38 | /*----- Notes on the Data Encryption Standard -----------------------------* |
39 | * |
40 | * Almost twenty years after it was first accepted, DES is still the standard |
41 | * block cipher. It's showing its age in its small key size and poor |
42 | * optimiziation for software implementations, but it's not really been badly |
43 | * dented by the intensive analysis thrown at it. |
44 | * |
45 | * This interface is here for compatibility with existing protocols, and |
46 | * because it's a trivial veneer over the base DES code which is used by the |
47 | * @des3@ interface which implements proper strong triple-DES. |
48 | */ |
49 | |
50 | #ifndef DES_H |
51 | #define DES_H |
52 | |
53 | #ifdef __cplusplus |
54 | extern "C" { |
55 | #endif |
56 | |
57 | /*----- Header files ------------------------------------------------------*/ |
58 | |
59 | #include <stddef.h> |
60 | |
61 | #include <mLib/bits.h> |
62 | |
63 | /*----- Magical numbers ---------------------------------------------------*/ |
64 | |
65 | #define DES_BLKSZ 8 |
66 | #define DES_KEYSZ 7 |
67 | #define DES_CLASS (N, B, 64) |
68 | |
69 | /*----- Data structures ---------------------------------------------------*/ |
70 | |
71 | typedef struct des_ctx { |
72 | uint32 k[32]; |
73 | } des_ctx; |
74 | |
75 | /*----- Functions provided ------------------------------------------------*/ |
76 | |
77 | /* --- @des_init@ --- * |
78 | * |
79 | * Arguments: @des_ctx *k@ = pointer to key block |
80 | * @const void *buf@ = pointer to key buffer |
81 | * @size_t sz@ = size of key material |
82 | * |
83 | * Returns: --- |
84 | * |
85 | * Use: Initializes a DES key buffer. The key buffer may be either 7 |
86 | * or 8 bytes long. If it's 8 bytes, the key is assumed to be |
87 | * padded with parity bits in the low order bit of each octet. |
88 | * These are stripped out without checking prior to the actual |
89 | * key scheduling. |
90 | */ |
91 | |
92 | extern void des_init(des_ctx */*k*/, const void */*buf*/, size_t /*sz*/); |
93 | |
94 | /* --- @des_eblk@, @des_dblk@ --- * |
95 | * |
96 | * Arguments: @const des_ctx *k@ = pointer to key block |
97 | * @const uint32 s[2]@ = pointer to source block |
98 | * @uint32 d[2]@ = pointer to destination block |
99 | * |
100 | * Returns: --- |
101 | * |
102 | * Use: Low-level block encryption and decryption. |
103 | */ |
104 | |
105 | extern void des_eblk(const des_ctx */*k*/, |
106 | const uint32 */*s*/, uint32 */*d*/); |
107 | extern void des_dblk(const des_ctx */*k*/, |
108 | const uint32 */*s*/, uint32 */*d*/); |
109 | |
110 | /*----- That's all, folks -------------------------------------------------*/ |
111 | |
112 | #ifdef __cplusplus |
113 | } |
114 | #endif |
115 | |
116 | #endif |