d03ab969 |
1 | /* -*-c-*- |
d03ab969 |
2 | * |
3 | * The Data Encryption Standard |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
45c0fd36 |
8 | /*----- Licensing notice --------------------------------------------------* |
d03ab969 |
9 | * |
10 | * This file is part of Catacomb. |
11 | * |
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. |
45c0fd36 |
16 | * |
d03ab969 |
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. |
45c0fd36 |
21 | * |
d03ab969 |
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, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
d03ab969 |
28 | /*----- Notes on the Data Encryption Standard -----------------------------* |
29 | * |
30 | * Almost twenty years after it was first accepted, DES is still the standard |
31 | * block cipher. It's showing its age in its small key size and poor |
32 | * optimiziation for software implementations, but it's not really been badly |
33 | * dented by the intensive analysis thrown at it. |
34 | * |
35 | * This interface is here for compatibility with existing protocols, and |
36 | * because it's a trivial veneer over the base DES code which is used by the |
37 | * @des3@ interface which implements proper strong triple-DES. |
38 | */ |
39 | |
b3f05084 |
40 | #ifndef CATACOMB_DES_H |
41 | #define CATACOMB_DES_H |
d03ab969 |
42 | |
43 | #ifdef __cplusplus |
44 | extern "C" { |
45 | #endif |
46 | |
47 | /*----- Header files ------------------------------------------------------*/ |
48 | |
49 | #include <stddef.h> |
50 | |
51 | #include <mLib/bits.h> |
52 | |
53 | /*----- Magical numbers ---------------------------------------------------*/ |
54 | |
55 | #define DES_BLKSZ 8 |
56 | #define DES_KEYSZ 7 |
57 | #define DES_CLASS (N, B, 64) |
58 | |
89ae755d |
59 | extern const octet des_keysz[]; |
60 | |
d03ab969 |
61 | /*----- Data structures ---------------------------------------------------*/ |
62 | |
63 | typedef struct des_ctx { |
64 | uint32 k[32]; |
65 | } des_ctx; |
66 | |
67 | /*----- Functions provided ------------------------------------------------*/ |
68 | |
986527ae |
69 | /* --- @des_expand@ --- * |
70 | * |
71 | * Arguments: @const octet *k@ = pointer to key material |
72 | * @size_t n@ = number of octets of key material (7 or 8) |
73 | * @uint32 *xx, *yy@ = where to put the results |
74 | * |
75 | * Returns: --- |
76 | * |
77 | * Use: Extracts 64 bits of key material from the given buffer, |
78 | * possibly expanding it from 56 to 64 bits on the way. |
79 | * Parity is set correctly if the key is expanded. |
80 | */ |
81 | |
82 | extern void des_expand(const octet */*k*/, size_t /*n*/, |
83 | uint32 */*xx*/, uint32 */*yy*/); |
84 | |
d03ab969 |
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 |