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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: des.h,v 1.3 2000/06/17 10:52:32 mdw Exp $ |
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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 $ |
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33 | * Revision 1.3 2000/06/17 10:52:32 mdw |
34 | * Support new key size interface. |
35 | * |
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36 | * Revision 1.2 1999/12/10 23:29:48 mdw |
37 | * Change header file guard names. |
38 | * |
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39 | * Revision 1.1 1999/09/03 08:41:11 mdw |
40 | * Initial import. |
41 | * |
42 | */ |
43 | |
44 | /*----- Notes on the Data Encryption Standard -----------------------------* |
45 | * |
46 | * Almost twenty years after it was first accepted, DES is still the standard |
47 | * block cipher. It's showing its age in its small key size and poor |
48 | * optimiziation for software implementations, but it's not really been badly |
49 | * dented by the intensive analysis thrown at it. |
50 | * |
51 | * This interface is here for compatibility with existing protocols, and |
52 | * because it's a trivial veneer over the base DES code which is used by the |
53 | * @des3@ interface which implements proper strong triple-DES. |
54 | */ |
55 | |
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56 | #ifndef CATACOMB_DES_H |
57 | #define CATACOMB_DES_H |
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58 | |
59 | #ifdef __cplusplus |
60 | extern "C" { |
61 | #endif |
62 | |
63 | /*----- Header files ------------------------------------------------------*/ |
64 | |
65 | #include <stddef.h> |
66 | |
67 | #include <mLib/bits.h> |
68 | |
69 | /*----- Magical numbers ---------------------------------------------------*/ |
70 | |
71 | #define DES_BLKSZ 8 |
72 | #define DES_KEYSZ 7 |
73 | #define DES_CLASS (N, B, 64) |
74 | |
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75 | extern const octet des_keysz[]; |
76 | |
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77 | /*----- Data structures ---------------------------------------------------*/ |
78 | |
79 | typedef struct des_ctx { |
80 | uint32 k[32]; |
81 | } des_ctx; |
82 | |
83 | /*----- Functions provided ------------------------------------------------*/ |
84 | |
85 | /* --- @des_init@ --- * |
86 | * |
87 | * Arguments: @des_ctx *k@ = pointer to key block |
88 | * @const void *buf@ = pointer to key buffer |
89 | * @size_t sz@ = size of key material |
90 | * |
91 | * Returns: --- |
92 | * |
93 | * Use: Initializes a DES key buffer. The key buffer may be either 7 |
94 | * or 8 bytes long. If it's 8 bytes, the key is assumed to be |
95 | * padded with parity bits in the low order bit of each octet. |
96 | * These are stripped out without checking prior to the actual |
97 | * key scheduling. |
98 | */ |
99 | |
100 | extern void des_init(des_ctx */*k*/, const void */*buf*/, size_t /*sz*/); |
101 | |
102 | /* --- @des_eblk@, @des_dblk@ --- * |
103 | * |
104 | * Arguments: @const des_ctx *k@ = pointer to key block |
105 | * @const uint32 s[2]@ = pointer to source block |
106 | * @uint32 d[2]@ = pointer to destination block |
107 | * |
108 | * Returns: --- |
109 | * |
110 | * Use: Low-level block encryption and decryption. |
111 | */ |
112 | |
113 | extern void des_eblk(const des_ctx */*k*/, |
114 | const uint32 */*s*/, uint32 */*d*/); |
115 | extern void des_dblk(const des_ctx */*k*/, |
116 | const uint32 */*s*/, uint32 */*d*/); |
117 | |
118 | /*----- That's all, folks -------------------------------------------------*/ |
119 | |
120 | #ifdef __cplusplus |
121 | } |
122 | #endif |
123 | |
124 | #endif |