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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: des3.c,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * Implementation of double- and triple-DES |
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 | |
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30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <assert.h> |
33 | #include <stdio.h> |
34 | #include <stdlib.h> |
35 | #include <string.h> |
36 | |
37 | #include <mLib/bits.h> |
38 | |
39 | #include "blkc.h" |
40 | #include "des-base.h" |
41 | #include "des.h" |
42 | #include "des3.h" |
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43 | #include "gcipher.h" |
44 | |
45 | /*----- Global variables --------------------------------------------------*/ |
46 | |
47 | const octet des3_keysz[] = { KSZ_SET, 21, 7, 8, 14, 16, 24, 0 }; |
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48 | |
49 | /*----- Main code ---------------------------------------------------------*/ |
50 | |
51 | /* --- @des3_init@ --- * |
52 | * |
53 | * Arguments: @des3_ctx *k@ = pointer to key block |
54 | * @const void *buf@ = pointer to key buffer |
55 | * @size_t sz@ = size of key material |
56 | * |
57 | * Returns: --- |
58 | * |
59 | * Use: Initializes a DES key buffer. The key buffer may have length |
60 | * 7, 8, 14, 16, 21, or 24. These correspond to one, two or |
61 | * three DES keys, either packed or unpacked (i.e., still |
62 | * containing parity bits). |
63 | */ |
64 | |
65 | void des3_init(des3_ctx *k, const void *buf, size_t sz) |
66 | { |
67 | size_t step; |
68 | const octet *p = buf; |
69 | |
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70 | KSZ_ASSERT(des3, sz); |
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71 | |
72 | if (sz % 7 == 0) |
73 | step = 7; |
74 | else |
75 | step = 8; |
76 | |
77 | des_init(&k->a, p, step); |
78 | if (sz > 8) p += step; |
79 | des_init(&k->b, p, step); |
80 | if (sz > 16) p += step; else p = buf; |
81 | des_init(&k->c, p, step); |
82 | } |
83 | |
84 | /* --- @des3_eblk@, @des3_dblk@ --- * |
85 | * |
86 | * Arguments: @const des3_ctx *k@ = pointer to key block |
87 | * @const uint32 s[2]@ = pointer to source block |
88 | * @uint32 d[2]@ = pointer to destination block |
89 | * |
90 | * Returns: --- |
91 | * |
92 | * Use: Low-level block encryption and decryption. |
93 | */ |
94 | |
95 | void des3_eblk(const des3_ctx *k, const uint32 *s, uint32 *d) |
96 | { |
97 | uint32 x = s[0], y = s[1]; |
98 | DES_IP(x, y); |
99 | DES_EBLK(k->a.k, x, y, x, y); |
100 | DES_DBLK(k->b.k, x, y, x, y); |
101 | DES_EBLK(k->c.k, x, y, x, y); |
102 | DES_IPINV(x, y); |
103 | d[0] = x, d[1] = y; |
104 | } |
105 | |
106 | void des3_dblk(const des3_ctx *k, const uint32 *s, uint32 *d) |
107 | { |
108 | uint32 x = s[0], y = s[1]; |
109 | DES_IP(x, y); |
110 | DES_DBLK(k->c.k, x, y, x, y); |
111 | DES_EBLK(k->b.k, x, y, x, y); |
112 | DES_DBLK(k->a.k, x, y, x, y); |
113 | DES_IPINV(x, y); |
114 | d[0] = x, d[1] = y; |
115 | } |
116 | |
117 | BLKC_TEST(DES3, des3) |
118 | |
119 | /*----- That's all, folks -------------------------------------------------*/ |