Commit | Line | Data |
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8b3d7f30 | 1 | /* -*-c-*- |
2 | * | |
8b3d7f30 | 3 | * Low-level stuff for all Rijndael block sizes |
4 | * | |
5 | * (c) 2001 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
8b3d7f30 | 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 | * |
8b3d7f30 | 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 | * |
8b3d7f30 | 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 | ||
8b3d7f30 | 28 | /*----- Header files ------------------------------------------------------*/ |
29 | ||
30 | #include <assert.h> | |
31 | #include <stdio.h> | |
32 | ||
33 | #include <mLib/bits.h> | |
34 | ||
35 | #include "blkc.h" | |
36 | #include "gcipher.h" | |
37 | #include "rijndael.h" | |
38 | #include "rijndael-base.h" | |
8b3d7f30 | 39 | |
40 | /*----- Global variables --------------------------------------------------*/ | |
41 | ||
42 | const octet rijndael_keysz[] = { KSZ_RANGE, RIJNDAEL_KEYSZ, 4, 32, 4 }; | |
43 | ||
8b3d7f30 | 44 | /*----- Main code ---------------------------------------------------------*/ |
45 | ||
46 | /* --- @rijndael_setup@ --- * | |
47 | * | |
48 | * Arguments: @rijndael_ctx *k@ = pointer to context to initialize | |
49 | * @unsigned nb@ = number of words in the block | |
50 | * @const void *buf@ = pointer to buffer of key material | |
51 | * @size_t sz@ = size of the key material | |
52 | * | |
53 | * Returns: --- | |
54 | * | |
55 | * Use: Low-level key-scheduling. | |
56 | */ | |
57 | ||
58 | void rijndael_setup(rijndael_ctx *k, unsigned nb, const void *buf, size_t sz) | |
59 | { | |
60 | unsigned nk, nr, nw; | |
61 | unsigned i, j, jj; | |
62 | const octet *p; | |
63 | uint32 ww; | |
64 | ||
65 | /* --- Sort out the key size --- */ | |
66 | ||
67 | KSZ_ASSERT(rijndael, sz); | |
68 | nk = sz / 4; | |
69 | ||
70 | /* --- Select the number of rounds --- */ | |
71 | ||
72 | nr = (nk > nb ? nk : nb) + 6; | |
73 | if (nr < 10) | |
74 | nr = 10; | |
75 | k->nr = nr; | |
76 | ||
77 | /* --- Fetch the first key words out --- */ | |
78 | ||
79 | p = buf; | |
80 | for (i = 0; i < nk; i++) { | |
38333dc2 | 81 | k->w[i] = LOAD32_B(p); |
8b3d7f30 | 82 | p += 4; |
83 | } | |
84 | ||
85 | /* --- Expand this material to fill the rest of the table --- */ | |
86 | ||
87 | nw = (nr + 1) * nb; | |
88 | ww = k->w[i - 1]; | |
89 | p = RCON; | |
90 | for (; i < nw; i++) { | |
91 | uint32 w = k->w[i - nk]; | |
92 | if (i % nk == 0) { | |
38333dc2 MW |
93 | ww = ROL32(ww, 8); |
94 | w ^= SUB(S, ww, ww, ww, ww) ^ (*p++ << 24); | |
8b3d7f30 | 95 | } else if (nk > 6 && i % nk == 4) |
96 | w ^= SUB(S, ww, ww, ww, ww); | |
97 | else | |
98 | w ^= ww; | |
99 | k->w[i] = ww = w; | |
100 | } | |
101 | ||
102 | /* --- Make the decryption keys --- */ | |
103 | ||
104 | j = nw; i = 0; | |
105 | ||
106 | j -= nb; jj = 0; | |
107 | for (; i < nb; i++) | |
108 | k->wi[i] = k->w[j + jj++]; | |
109 | ||
110 | for (; i < nw - nb; i += nb) { | |
111 | j -= nb; | |
112 | for (jj = 0; jj < nb; jj++) { | |
113 | uint32 w = k->w[j + jj]; | |
114 | k->wi[i + jj] = MIX(U, w, w, w, w); | |
115 | } | |
116 | } | |
117 | ||
118 | j -= nb; jj = 0; | |
119 | for (; i < nw; i++) | |
120 | k->wi[i] = k->w[j + jj++]; | |
121 | } | |
122 | ||
123 | /*----- That's all, folks -------------------------------------------------*/ |