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1 | /* -*-c-*- |
2 | * |
a9f7f3b2 |
3 | * $Id: twofish-mktab.c,v 1.3 2000/06/26 17:14:42 mdw Exp $ |
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4 | * |
5 | * Build constant tables for Twofish |
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: twofish-mktab.c,v $ |
a9f7f3b2 |
33 | * Revision 1.3 2000/06/26 17:14:42 mdw |
34 | * (rslog): Ensure that log(1) = 0 (not 255, as previously). While the two |
35 | * are strictly equivalent, it means that the exp table is larger than it |
36 | * otherwise needs to be. |
37 | * |
4d47e157 |
38 | * Revision 1.2 2000/06/18 23:12:15 mdw |
39 | * Change typesetting of Galois Field names. |
40 | * |
8dd8c294 |
41 | * Revision 1.1 2000/06/17 12:10:17 mdw |
42 | * New cipher. |
43 | * |
44 | */ |
45 | |
46 | /*----- Header files ------------------------------------------------------*/ |
47 | |
48 | #include <stdio.h> |
49 | #include <stdlib.h> |
50 | |
51 | #include <mLib/bits.h> |
52 | |
53 | /*----- Data structures ---------------------------------------------------*/ |
54 | |
55 | typedef struct { octet t[4][16]; } t_tab; |
56 | typedef struct { octet q[256]; } q_tab; |
57 | |
58 | /*----- Various Twofish tables --------------------------------------------*/ |
59 | |
60 | /* --- The t-tables --- */ |
61 | |
62 | static const t_tab qt0 = {{ |
63 | { 0x8, 0x1, 0x7, 0xd, 0x6, 0xf, 0x3, 0x2, |
64 | 0x0, 0xb, 0x5, 0x9, 0xe, 0xc, 0xa, 0x4 }, |
65 | { 0xe, 0xc, 0xb, 0x8, 0x1, 0x2, 0x3, 0x5, |
66 | 0xf, 0x4, 0xa, 0x6, 0x7, 0x0, 0x9, 0xd }, |
67 | { 0xb, 0xa, 0x5, 0xe, 0x6, 0xd, 0x9, 0x0, |
68 | 0xc, 0x8, 0xf, 0x3, 0x2, 0x4, 0x7, 0x1 }, |
69 | { 0xd, 0x7, 0xf, 0x4, 0x1, 0x2, 0x6, 0xe, |
70 | 0x9, 0xb, 0x3, 0x0, 0x8, 0x5, 0xc, 0xa } |
71 | }}; |
72 | |
73 | static const t_tab qt1 = {{ |
74 | { 0x2, 0x8, 0xb, 0xd, 0xf, 0x7, 0x6, 0xe, |
75 | 0x3, 0x1, 0x9, 0x4, 0x0, 0xa, 0xc, 0x5 }, |
76 | { 0x1, 0xe, 0x2, 0xb, 0x4, 0xc, 0x3, 0x7, |
77 | 0x6, 0xd, 0xa, 0x5, 0xf, 0x9, 0x0, 0x8 }, |
78 | { 0x4, 0xc, 0x7, 0x5, 0x1, 0x6, 0x9, 0xa, |
79 | 0x0, 0xe, 0xd, 0x8, 0x2, 0xb, 0x3, 0xf }, |
80 | { 0xb, 0x9, 0x5, 0x1, 0xc, 0x3, 0xd, 0xe, |
81 | 0x6, 0x4, 0x7, 0xf, 0x2, 0x0, 0x8, 0xa } |
82 | }}; |
83 | |
84 | static q_tab q0, q1; |
85 | |
86 | /* --- The MDS and Reed-Solomon matrices --- */ |
87 | |
88 | static const octet mds[16] = { |
89 | 0x01, 0xef, 0x5b, 0x5b, |
90 | 0x5b, 0xef, 0xef, 0x01, |
91 | 0xef, 0x5b, 0x01, 0xef, |
92 | 0xef, 0x01, 0xef, 0x5b |
93 | }; |
94 | |
95 | static const octet rs[32] = { |
96 | 0x01, 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, |
97 | 0xa4, 0x56, 0x82, 0xf3, 0x1e, 0xc6, 0x68, 0xe5, |
98 | 0x02, 0xa1, 0xfc, 0xc1, 0x47, 0xae, 0x3d, 0x19, |
99 | 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, 0x03 |
100 | }; |
101 | |
102 | /*----- Magic macros ------------------------------------------------------*/ |
103 | |
104 | #define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15) |
105 | |
106 | /*----- Building and printing @q@ tables ----------------------------------*/ |
107 | |
108 | /* --- @mkq@ --- * |
109 | * |
110 | * Arguments: @q_tab *q@ = pointer to output @q@ table |
111 | * @const t_tab *t@ = pointer to input @t@ table |
112 | * @const char *name@ = name of @q@ table |
113 | * |
114 | * Returns: --- |
115 | * |
116 | * Use: Constructs a 256-entry @q@-table. |
117 | */ |
118 | |
119 | static void mkq(q_tab *q, const t_tab *t, const char *name) |
120 | { |
121 | int i; |
122 | int ok = 1; |
123 | |
124 | /* --- Ensure the t-table is well-formed --- */ |
125 | |
126 | for (i = 0; i < 4; i++) { |
127 | octet f[16] = { 0 }; |
128 | int j; |
129 | |
130 | for (j = 0; j < 16; j++) { |
131 | if (f[t->t[i][j]]) { |
132 | fprintf(stderr, "duplicate %i in %s[%i] (col %i and %i)\n", |
133 | t->t[i][j], name, i, j, f[t->t[i][j]]); |
134 | ok = 0; |
135 | } |
136 | f[t->t[i][j]] = j; |
137 | } |
138 | } |
139 | |
140 | if (!ok) |
141 | exit(EXIT_FAILURE); |
142 | |
143 | /* --- Construct the @q@ table --- */ |
144 | |
145 | for (i = 0; i < 256; i++) { |
146 | int a = i >> 4, b = i & 15; |
147 | int aa = t->t[0][a ^ b], bb = t->t[1][a ^ ((a << 3) & 15) ^ ROR4(b)]; |
148 | a = t->t[2][aa ^ bb], b = t->t[3][aa ^ ((aa << 3) & 15) ^ ROR4(bb)]; |
149 | q->q[i] = a | (b << 4); |
150 | } |
151 | |
152 | /* Consider testing @q@ for linear and differential properties here */ |
153 | } |
154 | |
155 | /* --- @printq@ --- * |
156 | * |
157 | * Arguments: @const q_tab *t@ = pointer to table |
158 | * @const char *name@ = pointer to table name |
159 | * |
160 | * Returns: --- |
161 | * |
162 | * Use: Prints a q table. |
163 | */ |
164 | |
165 | static void printq(const q_tab *q, const char *name) |
166 | { |
167 | int i; |
168 | int j; |
169 | |
170 | printf("\ |
171 | #define TWOFISH_%s { \\\n\ |
172 | ", name); |
173 | j = 0; |
174 | for (i = 0; i < 256; i++) { |
175 | printf("0x%02x", q->q[i]); |
176 | j = (j + 1) & 7; |
177 | if (i == 255) |
178 | fputs(" \\\n}\n\n", stdout); |
179 | else if (j == 0) |
180 | fputs(", \\\n ", stdout); |
181 | else |
182 | fputs(", ", stdout); |
183 | } |
184 | } |
185 | |
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186 | /*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/ |
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187 | |
188 | #define MDS_MOD 0x169 |
189 | #define RS_MOD 0x14d |
190 | |
191 | /* --- @mul@ --- * |
192 | * |
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193 | * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$% |
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194 | * @unsigned m@ = modulus |
195 | * |
196 | * Returns: The product of two polynomials. |
197 | * |
198 | * Use: Computes a product of polynomials, quite slowly. |
199 | */ |
200 | |
201 | static unsigned mul(unsigned x, unsigned y, unsigned m) |
202 | { |
203 | unsigned a = 0; |
204 | unsigned i; |
205 | |
206 | for (i = 0; i < 8; i++) { |
207 | if (y & 1) |
208 | a ^= x; |
209 | y >>= 1; |
210 | x <<= 1; |
211 | if (x & 0x100) |
212 | x ^= m; |
213 | } |
214 | |
215 | return (a); |
216 | } |
217 | |
218 | /* --- @mmul@ --- * |
219 | * |
220 | * Arguments: @octet *d@ = destination vector |
221 | * @const octet *p@ = matrix of bytes |
222 | * @const octet *q@ = vector from somewhere else |
223 | * @size_t r@ = size of destination or number of rows in matrix |
224 | * @size_t n@ = length of row and vector |
225 | * @unsigned m@ = modulus polynomial |
226 | * |
227 | * Returns: --- |
228 | * |
229 | * Use: Computes an inner product of matrices over the finite field |
4d47e157 |
230 | * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid. |
8dd8c294 |
231 | */ |
232 | |
233 | static void mmul(octet *d, const octet *p, const octet *q, |
234 | size_t r, size_t n, unsigned m) |
235 | { |
236 | while (r) { |
237 | const octet *qq = q; |
238 | unsigned a = 0; |
239 | unsigned i; |
240 | |
241 | for (i = 0; i < n; i++) |
242 | a ^= mul(*p++, *qq++, m); |
243 | *d++ = a; |
244 | r--; |
245 | } |
246 | } |
247 | |
248 | /* --- @qrds@ --- * |
249 | * |
250 | * Arguments: --- |
251 | * |
252 | * Returns: --- |
253 | * |
254 | * Use: Prints the MDS/q table. |
255 | */ |
256 | |
257 | static void qmds(void) |
258 | { |
259 | uint32 t[4][256]; |
260 | int i, j; |
261 | static const q_tab *q[4] = { &q1, &q0, &q1, &q0 }; |
262 | |
263 | for (i = 0; i < 4; i++) { |
264 | octet in[4] = { 0, 0, 0, 0 }; |
265 | octet out[4]; |
266 | |
267 | for (j = 0; j < 256; j++) { |
268 | in[i] = q[i]->q[j]; |
269 | mmul(out, mds, in, 4, 4, MDS_MOD); |
270 | t[i][j] = LOAD32_L(out); |
271 | } |
272 | } |
273 | |
274 | puts("\ |
275 | /* --- Expanded MDS tables --- *\n\ |
276 | *\n\ |
277 | * The table contains output vectors for computing the result of pushing\n\ |
278 | * bytes through appropriate @q@ tables and the MDS matrix.\n\ |
279 | */\n\ |
280 | \n\ |
281 | #define TWOFISH_QMDS { \\"); |
282 | for (i = 0; i < 4; i++) { |
283 | fputs(" { ", stdout); |
284 | for (j = 0; j < 256; j++) { |
285 | printf("0x%08lx", (unsigned long)t[i][j]); |
286 | if (j == 255) { |
287 | if (i == 3) |
288 | puts(" } \\\n}"); |
289 | else |
290 | puts(" }, \\\n\ |
291 | \\"); |
292 | } else if (j % 4 == 3) |
293 | fputs(", \\\n ", stdout); |
294 | else |
295 | fputs(", ", stdout); |
296 | } |
297 | } |
298 | |
299 | putchar('\n'); |
300 | } |
301 | |
302 | /* --- @rslog@ --- * |
303 | * |
304 | * Arguments: --- |
305 | * |
306 | * Returns: --- |
307 | * |
308 | * Use: Produces the log and antilog tables for doing the RS |
309 | * arithmetic efficiently. |
310 | */ |
311 | |
312 | static void rslog(void) |
313 | { |
314 | octet rslog[256]; |
315 | octet rsexp[256]; |
316 | |
317 | unsigned x = 1; |
318 | unsigned i; |
319 | |
320 | rslog[0] = 0; |
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321 | for (i = 0; i < 255; i++) { |
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322 | rslog[x] = i; |
323 | rsexp[i] = x; |
324 | x <<= 1; |
325 | if (x & 0x100) |
326 | x ^= RS_MOD; |
327 | } |
328 | |
329 | x = 0; |
330 | for (i = 0; i < 32; i++) { |
331 | if (rslog[rs[i]] > x) |
332 | x = rslog[rs[i]]; |
333 | } |
334 | |
335 | fputs("\ |
336 | /* --- Reed-Solomon log tables --- *\n\ |
337 | *\n\ |
338 | * The Reed-Solomon multiplies are accelerated by using log tables.\n\ |
339 | */\n\ |
340 | \n\ |
341 | #define TWOFISH_RSLOG { \\\n\ |
342 | ", stdout); |
343 | |
344 | for (i = 0; i < 256; i++) { |
345 | printf("0x%02x", rslog[i]); |
346 | if (i == 255) |
347 | puts(" \\\n}\n"); |
348 | else if (i % 8 == 7) |
349 | fputs(", \\\n ", stdout); |
350 | else |
351 | fputs(", ", stdout); |
352 | } |
353 | |
354 | fputs("\ |
355 | #define TWOFISH_RSEXP { \\\n\ |
356 | ", stdout); |
357 | |
358 | for (i = 0; i < 255 + x + 1; i++) { |
359 | printf("0x%02x", rsexp[i % 255]); |
360 | if (i == 255 + x) |
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361 | puts(" \\\n}\n"); |
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362 | else if (i % 8 == 7) |
363 | fputs(", \\\n ", stdout); |
364 | else |
365 | fputs(", ", stdout); |
366 | } |
367 | |
368 | fputs("\ |
369 | /* --- Reed-Solomon matrix with log entries --- */\n\ |
370 | \n\ |
371 | #define TWOFISH_RS { \\\n\ |
372 | ", stdout); |
373 | |
374 | for (i = 0; i < 32; i++) { |
375 | printf("0x%02x", rslog[rs[i]]); |
376 | if (i == 31) |
377 | puts(" \\\n}\n"); |
378 | else if (i % 8 == 7) |
379 | fputs(", \\\n ", stdout); |
380 | else |
381 | fputs(", ", stdout); |
382 | } |
383 | } |
384 | |
385 | /*----- Main program ------------------------------------------------------*/ |
386 | |
387 | /* --- @main@ --- */ |
388 | |
389 | int main(void) |
390 | { |
391 | fputs("\ |
392 | /* -*-c-*- |
393 | * |
394 | * Twofish q tables [generated]\n\ |
395 | */ |
396 | |
397 | #ifndef CATACOMB_TWOFISH_TAB_H |
398 | #define CATACOMB_TWOFISH_TAB_H |
399 | |
400 | ", stdout); |
401 | |
402 | /* --- The q tables --- */ |
403 | |
404 | puts("\ |
405 | /* --- Precomputed @q@ tables --- */\n\ |
406 | "); |
407 | mkq(&q0, &qt0, "qt0"); |
408 | mkq(&q1, &qt1, "qt1"); |
409 | printq(&q0, "Q0"); |
410 | printq(&q1, "Q1"); |
411 | |
412 | /* --- The MDS/q tables --- */ |
413 | |
414 | qmds(); |
415 | rslog(); |
416 | |
417 | /* --- Done --- */ |
418 | |
419 | puts("#endif"); |
420 | |
421 | if (fclose(stdout)) { |
422 | fprintf(stderr, "error writing data\n"); |
423 | exit(EXIT_FAILURE); |
424 | } |
425 | |
426 | return (0); |
427 | } |
428 | |
429 | /*----- That's all, folks -------------------------------------------------*/ |