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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: rijndael.c,v 1.2 2000/12/06 20:32:59 mdw Exp $ |
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4 | * |
5 | * The Rijndael block cipher |
6 | * |
7 | * (c) 2000 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 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: rijndael.c,v $ |
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33 | * Revision 1.2 2000/12/06 20:32:59 mdw |
34 | * Fix round count for weird key sizes. |
35 | * |
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36 | * Revision 1.1 2000/06/17 11:56:07 mdw |
37 | * New cipher. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <assert.h> |
44 | #include <stdio.h> |
45 | |
46 | #include <mLib/bits.h> |
47 | |
48 | #include "blkc.h" |
49 | #include "gcipher.h" |
50 | #include "rijndael.h" |
51 | #include "rijndael-tab.h" |
52 | |
53 | /*----- Global variables --------------------------------------------------*/ |
54 | |
55 | const octet rijndael_keysz[] = { KSZ_RANGE, RIJNDAEL_KEYSZ, 4, 32, 4 }; |
56 | |
57 | /*----- Constant tables ---------------------------------------------------*/ |
58 | |
59 | static const octet S[256] = RIJNDAEL_S, SI[256] = RIJNDAEL_SI; |
60 | static const uint32 T[4][256] = RIJNDAEL_T, TI[4][256] = RIJNDAEL_TI; |
61 | static const uint32 U[4][256] = RIJNDAEL_U; |
62 | static const octet rcon[] = RIJNDAEL_RCON; |
63 | |
64 | /*----- Main code ---------------------------------------------------------*/ |
65 | |
66 | #define BYTESUB(x, s) \ |
67 | (s[U8((x) >> 24)] << 24 | s[U8((x) >> 16)] << 16 | \ |
68 | s[U8((x) >> 8)] << 8 | s[U8((x) >> 0)] << 0) |
69 | |
70 | /* --- @rijndael_init@ --- * |
71 | * |
72 | * Arguments: @rijndael_ctx *k@ = pointer to context to initialize |
73 | * @const void *buf@ = pointer to buffer of key material |
74 | * @size_t sz@ = size of the key material |
75 | * |
76 | * Returns: --- |
77 | * |
78 | * Use: Initializes a Rijndael context with a particular key. This |
79 | * implementation of Rijndael doesn't impose any particular |
80 | * limits on the key size except that it must be multiple of 4 |
81 | * bytes long. 256 bits seems sensible, though. |
82 | */ |
83 | |
84 | void rijndael_init(rijndael_ctx *k, const void *buf, size_t sz) |
85 | { |
86 | unsigned nk, nr, nw; |
87 | unsigned i, j, jj; |
88 | const octet *p; |
89 | uint32 ww; |
90 | |
91 | /* --- Sort out the key size --- */ |
92 | |
93 | KSZ_ASSERT(rijndael, sz); |
94 | nk = sz / 4; |
95 | |
96 | /* --- Select the number of rounds --- */ |
97 | |
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98 | nr = nk + 6; |
99 | if (nr < 10) |
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100 | nr = 10; |
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101 | k->nr = nr; |
102 | |
103 | /* --- Fetch the first key words out --- */ |
104 | |
105 | p = buf; |
106 | for (i = 0; i < nk; i++) { |
107 | k->w[i] = LOAD32_L(p); |
108 | p += 4; |
109 | } |
110 | |
111 | /* --- Expand this material to fill the rest of the table --- */ |
112 | |
113 | nw = (nr + 1) * (RIJNDAEL_BLKSZ / 4); |
114 | ww = k->w[i - 1]; |
115 | p = rcon; |
116 | for (; i < nw; i++) { |
117 | uint32 w = k->w[i - nk]; |
118 | if (i % nk == 0) { |
119 | ww = ROR32(ww, 8); |
120 | w ^= BYTESUB(ww, S) ^ *p++; |
121 | } else if (nk > 6 && i % nk == 4) |
122 | w ^= BYTESUB(ww, S); |
123 | else |
124 | w ^= ww; |
125 | k->w[i] = ww = w; |
126 | } |
127 | |
128 | /* --- Make the decryption keys --- */ |
129 | |
130 | j = nw; |
131 | |
132 | j -= RIJNDAEL_BLKSZ / 4; jj = 0; |
133 | for (i = 0; i < RIJNDAEL_BLKSZ / 4; i++) |
134 | k->wi[i] = k->w[j + jj++]; |
135 | |
136 | for (; i < nw - RIJNDAEL_BLKSZ / 4; i += RIJNDAEL_BLKSZ / 4) { |
137 | j -= RIJNDAEL_BLKSZ / 4; |
138 | for (jj = 0; jj < RIJNDAEL_BLKSZ / 4; jj++) { |
139 | uint32 w = k->w[j + jj]; |
140 | k->wi[i + jj] = (U[0][U8(w >> 0)] ^ U[1][U8(w >> 8)] ^ |
141 | U[2][U8(w >> 16)] ^ U[3][U8(w >> 24)]); |
142 | } |
143 | } |
144 | |
145 | j -= RIJNDAEL_BLKSZ / 4; jj = 0; |
146 | for (; i < nw; i++) |
147 | k->wi[i] = k->w[j + jj++]; |
148 | } |
149 | |
150 | /* --- @rijndael_eblk@, @rijndael_dblk@ --- * |
151 | * |
152 | * Arguments: @const rijndael_ctx *k@ = pointer to Rijndael context |
153 | * @const uint32 s[4]@ = pointer to source block |
154 | * @uint32 d[4]@ = pointer to destination block |
155 | * |
156 | * Returns: --- |
157 | * |
158 | * Use: Low-level block encryption and decryption. |
159 | */ |
160 | |
161 | #define EROUND(aa, bb, cc, dd, a, b, c, d, w) do { \ |
162 | aa = (T[0][U8(a >> 0)] ^ T[1][U8(b >> 8)] ^ \ |
163 | T[2][U8(c >> 16)] ^ T[3][U8(d >> 24)]) ^ *w++; \ |
164 | bb = (T[0][U8(b >> 0)] ^ T[1][U8(c >> 8)] ^ \ |
165 | T[2][U8(d >> 16)] ^ T[3][U8(a >> 24)]) ^ *w++; \ |
166 | cc = (T[0][U8(c >> 0)] ^ T[1][U8(d >> 8)] ^ \ |
167 | T[2][U8(a >> 16)] ^ T[3][U8(b >> 24)]) ^ *w++; \ |
168 | dd = (T[0][U8(d >> 0)] ^ T[1][U8(a >> 8)] ^ \ |
169 | T[2][U8(b >> 16)] ^ T[3][U8(c >> 24)]) ^ *w++; \ |
170 | } while (0) |
171 | |
172 | #define DROUND(aa, bb, cc, dd, a, b, c, d, w) do { \ |
173 | aa = (TI[0][U8(a >> 0)] ^ TI[1][U8(d >> 8)] ^ \ |
174 | TI[2][U8(c >> 16)] ^ TI[3][U8(b >> 24)]) ^ *w++; \ |
175 | bb = (TI[0][U8(b >> 0)] ^ TI[1][U8(a >> 8)] ^ \ |
176 | TI[2][U8(d >> 16)] ^ TI[3][U8(c >> 24)]) ^ *w++; \ |
177 | cc = (TI[0][U8(c >> 0)] ^ TI[1][U8(b >> 8)] ^ \ |
178 | TI[2][U8(a >> 16)] ^ TI[3][U8(d >> 24)]) ^ *w++; \ |
179 | dd = (TI[0][U8(d >> 0)] ^ TI[1][U8(c >> 8)] ^ \ |
180 | TI[2][U8(b >> 16)] ^ TI[3][U8(a >> 24)]) ^ *w++; \ |
181 | } while (0) |
182 | |
183 | void rijndael_eblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst) |
184 | { |
185 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; |
186 | uint32 aa, bb, cc, dd; |
187 | uint32 *w = k->w; |
188 | |
189 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; |
190 | |
191 | switch (k->nr) { |
192 | case 14: |
193 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
194 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
195 | case 12: |
196 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
197 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
198 | case 10: |
199 | default: |
200 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
201 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
202 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
203 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
204 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
205 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
206 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
207 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
208 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
209 | } |
210 | |
211 | a = ((S[U8(aa >> 0)] << 0) ^ (S[U8(bb >> 8)] << 8) ^ |
212 | (S[U8(cc >> 16)] << 16) ^ (S[U8(dd >> 24)] << 24)) ^ *w++; |
213 | b = ((S[U8(bb >> 0)] << 0) ^ (S[U8(cc >> 8)] << 8) ^ |
214 | (S[U8(dd >> 16)] << 16) ^ (S[U8(aa >> 24)] << 24)) ^ *w++; |
215 | c = ((S[U8(cc >> 0)] << 0) ^ (S[U8(dd >> 8)] << 8) ^ |
216 | (S[U8(aa >> 16)] << 16) ^ (S[U8(bb >> 24)] << 24)) ^ *w++; |
217 | d = ((S[U8(dd >> 0)] << 0) ^ (S[U8(aa >> 8)] << 8) ^ |
218 | (S[U8(bb >> 16)] << 16) ^ (S[U8(cc >> 24)] << 24)) ^ *w++; |
219 | |
220 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; |
221 | } |
222 | |
223 | void rijndael_dblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst) |
224 | { |
225 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; |
226 | uint32 aa, bb, cc, dd; |
227 | uint32 *w = k->wi; |
228 | |
229 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; |
230 | |
231 | switch (k->nr) { |
232 | case 14: |
233 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
234 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
235 | case 12: |
236 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
237 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
238 | case 10: |
239 | default: |
240 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
241 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
242 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
243 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
244 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
245 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
246 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
247 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
248 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
249 | } |
250 | |
251 | a = ((SI[U8(aa >> 0)] << 0) ^ (SI[U8(dd >> 8)] << 8) ^ |
252 | (SI[U8(cc >> 16)] << 16) ^ (SI[U8(bb >> 24)] << 24)) ^ *w++; |
253 | b = ((SI[U8(bb >> 0)] << 0) ^ (SI[U8(aa >> 8)] << 8) ^ |
254 | (SI[U8(dd >> 16)] << 16) ^ (SI[U8(cc >> 24)] << 24)) ^ *w++; |
255 | c = ((SI[U8(cc >> 0)] << 0) ^ (SI[U8(bb >> 8)] << 8) ^ |
256 | (SI[U8(aa >> 16)] << 16) ^ (SI[U8(dd >> 24)] << 24)) ^ *w++; |
257 | d = ((SI[U8(dd >> 0)] << 0) ^ (SI[U8(cc >> 8)] << 8) ^ |
258 | (SI[U8(bb >> 16)] << 16) ^ (SI[U8(aa >> 24)] << 24)) ^ *w++; |
259 | |
260 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; |
261 | } |
262 | |
263 | BLKC_TEST(RIJNDAEL, rijndael) |
264 | |
265 | /*----- That's all, folks -------------------------------------------------*/ |