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