Commit | Line | Data |
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8b3d7f30 | 1 | /* -*-c-*- |
2 | * | |
b817bfc6 | 3 | * $Id: rijndael-base.c,v 1.2 2004/04/08 01:36:15 mdw Exp $ |
8b3d7f30 | 4 | * |
5 | * Low-level stuff for all Rijndael block sizes | |
6 | * | |
7 | * (c) 2001 Straylight/Edgeware | |
8 | */ | |
9 | ||
45c0fd36 | 10 | /*----- Licensing notice --------------------------------------------------* |
8b3d7f30 | 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. | |
45c0fd36 | 18 | * |
8b3d7f30 | 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. | |
45c0fd36 | 23 | * |
8b3d7f30 | 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 | ||
8b3d7f30 | 30 | /*----- Header files ------------------------------------------------------*/ |
31 | ||
32 | #include <assert.h> | |
33 | #include <stdio.h> | |
34 | ||
35 | #include <mLib/bits.h> | |
36 | ||
37 | #include "blkc.h" | |
38 | #include "gcipher.h" | |
39 | #include "rijndael.h" | |
40 | #include "rijndael-base.h" | |
41 | #include "rijndael-tab.h" | |
42 | ||
43 | /*----- Global variables --------------------------------------------------*/ | |
44 | ||
45 | const octet rijndael_keysz[] = { KSZ_RANGE, RIJNDAEL_KEYSZ, 4, 32, 4 }; | |
46 | ||
47 | /*----- Constant tables ---------------------------------------------------*/ | |
48 | ||
49 | const octet rijndael_s[256] = RIJNDAEL_S; | |
50 | const octet rijndael_si[256] = RIJNDAEL_SI; | |
51 | const uint32 rijndael_t[4][256] = RIJNDAEL_T; | |
52 | const uint32 rijndael_ti[4][256] = RIJNDAEL_TI; | |
53 | const uint32 rijndael_u[4][256] = RIJNDAEL_U; | |
54 | const octet rijndael_rcon[] = RIJNDAEL_RCON; | |
55 | ||
56 | /*----- Main code ---------------------------------------------------------*/ | |
57 | ||
58 | /* --- @rijndael_setup@ --- * | |
59 | * | |
60 | * Arguments: @rijndael_ctx *k@ = pointer to context to initialize | |
61 | * @unsigned nb@ = number of words in the block | |
62 | * @const void *buf@ = pointer to buffer of key material | |
63 | * @size_t sz@ = size of the key material | |
64 | * | |
65 | * Returns: --- | |
66 | * | |
67 | * Use: Low-level key-scheduling. | |
68 | */ | |
69 | ||
70 | void rijndael_setup(rijndael_ctx *k, unsigned nb, const void *buf, size_t sz) | |
71 | { | |
72 | unsigned nk, nr, nw; | |
73 | unsigned i, j, jj; | |
74 | const octet *p; | |
75 | uint32 ww; | |
76 | ||
77 | /* --- Sort out the key size --- */ | |
78 | ||
79 | KSZ_ASSERT(rijndael, sz); | |
80 | nk = sz / 4; | |
81 | ||
82 | /* --- Select the number of rounds --- */ | |
83 | ||
84 | nr = (nk > nb ? nk : nb) + 6; | |
85 | if (nr < 10) | |
86 | nr = 10; | |
87 | k->nr = nr; | |
88 | ||
89 | /* --- Fetch the first key words out --- */ | |
90 | ||
91 | p = buf; | |
92 | for (i = 0; i < nk; i++) { | |
38333dc2 | 93 | k->w[i] = LOAD32_B(p); |
8b3d7f30 | 94 | p += 4; |
95 | } | |
96 | ||
97 | /* --- Expand this material to fill the rest of the table --- */ | |
98 | ||
99 | nw = (nr + 1) * nb; | |
100 | ww = k->w[i - 1]; | |
101 | p = RCON; | |
102 | for (; i < nw; i++) { | |
103 | uint32 w = k->w[i - nk]; | |
104 | if (i % nk == 0) { | |
38333dc2 MW |
105 | ww = ROL32(ww, 8); |
106 | w ^= SUB(S, ww, ww, ww, ww) ^ (*p++ << 24); | |
8b3d7f30 | 107 | } else if (nk > 6 && i % nk == 4) |
108 | w ^= SUB(S, ww, ww, ww, ww); | |
109 | else | |
110 | w ^= ww; | |
111 | k->w[i] = ww = w; | |
112 | } | |
113 | ||
114 | /* --- Make the decryption keys --- */ | |
115 | ||
116 | j = nw; i = 0; | |
117 | ||
118 | j -= nb; jj = 0; | |
119 | for (; i < nb; i++) | |
120 | k->wi[i] = k->w[j + jj++]; | |
121 | ||
122 | for (; i < nw - nb; i += nb) { | |
123 | j -= nb; | |
124 | for (jj = 0; jj < nb; jj++) { | |
125 | uint32 w = k->w[j + jj]; | |
126 | k->wi[i + jj] = MIX(U, w, w, w, w); | |
127 | } | |
128 | } | |
129 | ||
130 | j -= nb; jj = 0; | |
131 | for (; i < nw; i++) | |
132 | k->wi[i] = k->w[j + jj++]; | |
133 | } | |
134 | ||
135 | /*----- That's all, folks -------------------------------------------------*/ |