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1 | /* -*-c-*- |
2 | * |
b817bfc6 |
3 | * $Id: twofish-mktab.c,v 1.5 2004/04/08 01:36:15 mdw Exp $ |
8dd8c294 |
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 | |
8dd8c294 |
30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <stdio.h> |
33 | #include <stdlib.h> |
34 | |
35 | #include <mLib/bits.h> |
36 | |
37 | /*----- Data structures ---------------------------------------------------*/ |
38 | |
39 | typedef struct { octet t[4][16]; } t_tab; |
40 | typedef struct { octet q[256]; } q_tab; |
41 | |
42 | /*----- Various Twofish tables --------------------------------------------*/ |
43 | |
44 | /* --- The t-tables --- */ |
45 | |
46 | static const t_tab qt0 = {{ |
47 | { 0x8, 0x1, 0x7, 0xd, 0x6, 0xf, 0x3, 0x2, |
48 | 0x0, 0xb, 0x5, 0x9, 0xe, 0xc, 0xa, 0x4 }, |
49 | { 0xe, 0xc, 0xb, 0x8, 0x1, 0x2, 0x3, 0x5, |
50 | 0xf, 0x4, 0xa, 0x6, 0x7, 0x0, 0x9, 0xd }, |
51 | { 0xb, 0xa, 0x5, 0xe, 0x6, 0xd, 0x9, 0x0, |
52 | 0xc, 0x8, 0xf, 0x3, 0x2, 0x4, 0x7, 0x1 }, |
53 | { 0xd, 0x7, 0xf, 0x4, 0x1, 0x2, 0x6, 0xe, |
54 | 0x9, 0xb, 0x3, 0x0, 0x8, 0x5, 0xc, 0xa } |
55 | }}; |
56 | |
57 | static const t_tab qt1 = {{ |
58 | { 0x2, 0x8, 0xb, 0xd, 0xf, 0x7, 0x6, 0xe, |
59 | 0x3, 0x1, 0x9, 0x4, 0x0, 0xa, 0xc, 0x5 }, |
60 | { 0x1, 0xe, 0x2, 0xb, 0x4, 0xc, 0x3, 0x7, |
61 | 0x6, 0xd, 0xa, 0x5, 0xf, 0x9, 0x0, 0x8 }, |
62 | { 0x4, 0xc, 0x7, 0x5, 0x1, 0x6, 0x9, 0xa, |
63 | 0x0, 0xe, 0xd, 0x8, 0x2, 0xb, 0x3, 0xf }, |
64 | { 0xb, 0x9, 0x5, 0x1, 0xc, 0x3, 0xd, 0xe, |
65 | 0x6, 0x4, 0x7, 0xf, 0x2, 0x0, 0x8, 0xa } |
66 | }}; |
67 | |
68 | static q_tab q0, q1; |
69 | |
70 | /* --- The MDS and Reed-Solomon matrices --- */ |
71 | |
72 | static const octet mds[16] = { |
73 | 0x01, 0xef, 0x5b, 0x5b, |
74 | 0x5b, 0xef, 0xef, 0x01, |
75 | 0xef, 0x5b, 0x01, 0xef, |
76 | 0xef, 0x01, 0xef, 0x5b |
77 | }; |
78 | |
79 | static const octet rs[32] = { |
80 | 0x01, 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, |
81 | 0xa4, 0x56, 0x82, 0xf3, 0x1e, 0xc6, 0x68, 0xe5, |
82 | 0x02, 0xa1, 0xfc, 0xc1, 0x47, 0xae, 0x3d, 0x19, |
83 | 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, 0x03 |
84 | }; |
85 | |
86 | /*----- Magic macros ------------------------------------------------------*/ |
87 | |
88 | #define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15) |
89 | |
90 | /*----- Building and printing @q@ tables ----------------------------------*/ |
91 | |
92 | /* --- @mkq@ --- * |
93 | * |
94 | * Arguments: @q_tab *q@ = pointer to output @q@ table |
95 | * @const t_tab *t@ = pointer to input @t@ table |
96 | * @const char *name@ = name of @q@ table |
97 | * |
98 | * Returns: --- |
99 | * |
100 | * Use: Constructs a 256-entry @q@-table. |
101 | */ |
102 | |
103 | static void mkq(q_tab *q, const t_tab *t, const char *name) |
104 | { |
105 | int i; |
106 | int ok = 1; |
107 | |
108 | /* --- Ensure the t-table is well-formed --- */ |
109 | |
110 | for (i = 0; i < 4; i++) { |
111 | octet f[16] = { 0 }; |
112 | int j; |
113 | |
114 | for (j = 0; j < 16; j++) { |
115 | if (f[t->t[i][j]]) { |
116 | fprintf(stderr, "duplicate %i in %s[%i] (col %i and %i)\n", |
117 | t->t[i][j], name, i, j, f[t->t[i][j]]); |
118 | ok = 0; |
119 | } |
120 | f[t->t[i][j]] = j; |
121 | } |
122 | } |
123 | |
124 | if (!ok) |
125 | exit(EXIT_FAILURE); |
126 | |
127 | /* --- Construct the @q@ table --- */ |
128 | |
129 | for (i = 0; i < 256; i++) { |
130 | int a = i >> 4, b = i & 15; |
131 | int aa = t->t[0][a ^ b], bb = t->t[1][a ^ ((a << 3) & 15) ^ ROR4(b)]; |
132 | a = t->t[2][aa ^ bb], b = t->t[3][aa ^ ((aa << 3) & 15) ^ ROR4(bb)]; |
133 | q->q[i] = a | (b << 4); |
134 | } |
135 | |
136 | /* Consider testing @q@ for linear and differential properties here */ |
137 | } |
138 | |
139 | /* --- @printq@ --- * |
140 | * |
141 | * Arguments: @const q_tab *t@ = pointer to table |
142 | * @const char *name@ = pointer to table name |
143 | * |
144 | * Returns: --- |
145 | * |
146 | * Use: Prints a q table. |
147 | */ |
148 | |
149 | static void printq(const q_tab *q, const char *name) |
150 | { |
151 | int i; |
152 | int j; |
153 | |
154 | printf("\ |
155 | #define TWOFISH_%s { \\\n\ |
156 | ", name); |
157 | j = 0; |
158 | for (i = 0; i < 256; i++) { |
159 | printf("0x%02x", q->q[i]); |
160 | j = (j + 1) & 7; |
161 | if (i == 255) |
162 | fputs(" \\\n}\n\n", stdout); |
163 | else if (j == 0) |
164 | fputs(", \\\n ", stdout); |
165 | else |
166 | fputs(", ", stdout); |
167 | } |
168 | } |
169 | |
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170 | /*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/ |
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171 | |
172 | #define MDS_MOD 0x169 |
173 | #define RS_MOD 0x14d |
174 | |
175 | /* --- @mul@ --- * |
176 | * |
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177 | * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$% |
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178 | * @unsigned m@ = modulus |
179 | * |
180 | * Returns: The product of two polynomials. |
181 | * |
182 | * Use: Computes a product of polynomials, quite slowly. |
183 | */ |
184 | |
185 | static unsigned mul(unsigned x, unsigned y, unsigned m) |
186 | { |
187 | unsigned a = 0; |
188 | unsigned i; |
189 | |
190 | for (i = 0; i < 8; i++) { |
191 | if (y & 1) |
192 | a ^= x; |
193 | y >>= 1; |
194 | x <<= 1; |
195 | if (x & 0x100) |
196 | x ^= m; |
197 | } |
198 | |
199 | return (a); |
200 | } |
201 | |
202 | /* --- @mmul@ --- * |
203 | * |
204 | * Arguments: @octet *d@ = destination vector |
205 | * @const octet *p@ = matrix of bytes |
206 | * @const octet *q@ = vector from somewhere else |
207 | * @size_t r@ = size of destination or number of rows in matrix |
208 | * @size_t n@ = length of row and vector |
209 | * @unsigned m@ = modulus polynomial |
210 | * |
211 | * Returns: --- |
212 | * |
213 | * Use: Computes an inner product of matrices over the finite field |
4d47e157 |
214 | * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid. |
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215 | */ |
216 | |
217 | static void mmul(octet *d, const octet *p, const octet *q, |
218 | size_t r, size_t n, unsigned m) |
219 | { |
220 | while (r) { |
221 | const octet *qq = q; |
222 | unsigned a = 0; |
223 | unsigned i; |
224 | |
225 | for (i = 0; i < n; i++) |
226 | a ^= mul(*p++, *qq++, m); |
227 | *d++ = a; |
228 | r--; |
229 | } |
230 | } |
231 | |
232 | /* --- @qrds@ --- * |
233 | * |
234 | * Arguments: --- |
235 | * |
236 | * Returns: --- |
237 | * |
238 | * Use: Prints the MDS/q table. |
239 | */ |
240 | |
241 | static void qmds(void) |
242 | { |
243 | uint32 t[4][256]; |
244 | int i, j; |
245 | static const q_tab *q[4] = { &q1, &q0, &q1, &q0 }; |
246 | |
247 | for (i = 0; i < 4; i++) { |
248 | octet in[4] = { 0, 0, 0, 0 }; |
249 | octet out[4]; |
250 | |
251 | for (j = 0; j < 256; j++) { |
252 | in[i] = q[i]->q[j]; |
253 | mmul(out, mds, in, 4, 4, MDS_MOD); |
254 | t[i][j] = LOAD32_L(out); |
255 | } |
256 | } |
257 | |
258 | puts("\ |
259 | /* --- Expanded MDS tables --- *\n\ |
260 | *\n\ |
261 | * The table contains output vectors for computing the result of pushing\n\ |
262 | * bytes through appropriate @q@ tables and the MDS matrix.\n\ |
263 | */\n\ |
264 | \n\ |
265 | #define TWOFISH_QMDS { \\"); |
266 | for (i = 0; i < 4; i++) { |
267 | fputs(" { ", stdout); |
268 | for (j = 0; j < 256; j++) { |
269 | printf("0x%08lx", (unsigned long)t[i][j]); |
270 | if (j == 255) { |
271 | if (i == 3) |
272 | puts(" } \\\n}"); |
273 | else |
274 | puts(" }, \\\n\ |
275 | \\"); |
276 | } else if (j % 4 == 3) |
277 | fputs(", \\\n ", stdout); |
278 | else |
279 | fputs(", ", stdout); |
280 | } |
281 | } |
282 | |
283 | putchar('\n'); |
284 | } |
285 | |
286 | /* --- @rslog@ --- * |
287 | * |
288 | * Arguments: --- |
289 | * |
290 | * Returns: --- |
291 | * |
292 | * Use: Produces the log and antilog tables for doing the RS |
293 | * arithmetic efficiently. |
294 | */ |
295 | |
296 | static void rslog(void) |
297 | { |
298 | octet rslog[256]; |
299 | octet rsexp[256]; |
300 | |
301 | unsigned x = 1; |
302 | unsigned i; |
303 | |
304 | rslog[0] = 0; |
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305 | for (i = 0; i < 255; i++) { |
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306 | rslog[x] = i; |
307 | rsexp[i] = x; |
308 | x <<= 1; |
309 | if (x & 0x100) |
310 | x ^= RS_MOD; |
311 | } |
312 | |
313 | x = 0; |
314 | for (i = 0; i < 32; i++) { |
315 | if (rslog[rs[i]] > x) |
316 | x = rslog[rs[i]]; |
317 | } |
318 | |
319 | fputs("\ |
320 | /* --- Reed-Solomon log tables --- *\n\ |
321 | *\n\ |
322 | * The Reed-Solomon multiplies are accelerated by using log tables.\n\ |
323 | */\n\ |
324 | \n\ |
325 | #define TWOFISH_RSLOG { \\\n\ |
326 | ", stdout); |
327 | |
328 | for (i = 0; i < 256; i++) { |
329 | printf("0x%02x", rslog[i]); |
330 | if (i == 255) |
331 | puts(" \\\n}\n"); |
332 | else if (i % 8 == 7) |
333 | fputs(", \\\n ", stdout); |
334 | else |
335 | fputs(", ", stdout); |
336 | } |
337 | |
338 | fputs("\ |
339 | #define TWOFISH_RSEXP { \\\n\ |
340 | ", stdout); |
341 | |
342 | for (i = 0; i < 255 + x + 1; i++) { |
343 | printf("0x%02x", rsexp[i % 255]); |
344 | if (i == 255 + x) |
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345 | puts(" \\\n}\n"); |
8dd8c294 |
346 | else if (i % 8 == 7) |
347 | fputs(", \\\n ", stdout); |
348 | else |
349 | fputs(", ", stdout); |
350 | } |
351 | |
352 | fputs("\ |
353 | /* --- Reed-Solomon matrix with log entries --- */\n\ |
354 | \n\ |
355 | #define TWOFISH_RS { \\\n\ |
356 | ", stdout); |
357 | |
358 | for (i = 0; i < 32; i++) { |
359 | printf("0x%02x", rslog[rs[i]]); |
360 | if (i == 31) |
361 | puts(" \\\n}\n"); |
362 | else if (i % 8 == 7) |
363 | fputs(", \\\n ", stdout); |
364 | else |
365 | fputs(", ", stdout); |
366 | } |
367 | } |
368 | |
369 | /*----- Main program ------------------------------------------------------*/ |
370 | |
371 | /* --- @main@ --- */ |
372 | |
373 | int main(void) |
374 | { |
375 | fputs("\ |
5292d76e |
376 | /* -*-c-*-\n\ |
377 | *\n\ |
8dd8c294 |
378 | * Twofish q tables [generated]\n\ |
5292d76e |
379 | */\n\ |
380 | \n\ |
381 | #ifndef CATACOMB_TWOFISH_TAB_H\n\ |
382 | #define CATACOMB_TWOFISH_TAB_H\n\ |
383 | \n\ |
8dd8c294 |
384 | ", stdout); |
385 | |
386 | /* --- The q tables --- */ |
387 | |
388 | puts("\ |
389 | /* --- Precomputed @q@ tables --- */\n\ |
390 | "); |
391 | mkq(&q0, &qt0, "qt0"); |
392 | mkq(&q1, &qt1, "qt1"); |
393 | printq(&q0, "Q0"); |
394 | printq(&q1, "Q1"); |
395 | |
396 | /* --- The MDS/q tables --- */ |
397 | |
398 | qmds(); |
399 | rslog(); |
400 | |
401 | /* --- Done --- */ |
402 | |
403 | puts("#endif"); |
404 | |
405 | if (fclose(stdout)) { |
406 | fprintf(stderr, "error writing data\n"); |
407 | exit(EXIT_FAILURE); |
408 | } |
409 | |
410 | return (0); |
411 | } |
412 | |
413 | /*----- That's all, folks -------------------------------------------------*/ |