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1 | /* -*-c-*- |
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2 | * |
3 | * Implementation of double- and triple-DES |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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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. |
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16 | * |
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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. |
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21 | * |
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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 | |
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28 | #ifndef CATACOMB_DES3_H |
29 | #define CATACOMB_DES3_H |
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30 | |
31 | #ifdef __cplusplus |
32 | extern "C" { |
33 | #endif |
34 | |
35 | /*----- Notes on double- and triple-DES -----------------------------------* |
36 | * |
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). |
42 | */ |
43 | |
44 | /*----- Header files ------------------------------------------------------*/ |
45 | |
46 | #include <stddef.h> |
47 | |
48 | #include <mLib/bits.h> |
49 | |
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50 | #ifndef CATACOMB_DES_H |
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51 | # include "des.h" |
52 | #endif |
53 | |
54 | /*----- Magical numbers ---------------------------------------------------*/ |
55 | |
56 | #define DES3_BLKSZ 8 |
57 | #define DES3_KEYSZ 21 |
58 | #define DES3_CLASS (N, B, 64) |
59 | |
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60 | extern const octet des3_keysz[]; |
61 | |
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62 | /*----- Data structures ---------------------------------------------------*/ |
63 | |
64 | typedef struct des3_ctx { |
65 | des_ctx a, b, c; |
66 | } des3_ctx; |
67 | |
68 | /*----- Functions provided ------------------------------------------------*/ |
69 | |
70 | /* --- @des3_init@ --- * |
71 | * |
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 |
75 | * |
76 | * Returns: --- |
77 | * |
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). |
82 | */ |
83 | |
84 | extern void des3_init(des3_ctx */*k*/, const void */*buf*/, size_t /*sz*/); |
85 | |
86 | /* --- @des3_eblk@, @des_dblk@ --- * |
87 | * |
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 |
91 | * |
92 | * Returns: --- |
93 | * |
94 | * Use: Low-level block encryption and decryption. |
95 | */ |
96 | |
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*/); |
101 | |
102 | /*----- That's all, folks -------------------------------------------------*/ |
103 | |
104 | #ifdef __cplusplus |
105 | } |
106 | #endif |
107 | |
108 | #endif |