3 * $Id: twofish-mktab.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
5 * Build constant tables for Twofish
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Header files ------------------------------------------------------*/
35 #include <mLib/bits.h>
37 /*----- Data structures ---------------------------------------------------*/
39 typedef struct { octet t
[4][16]; } t_tab
;
40 typedef struct { octet q
[256]; } q_tab
;
42 /*----- Various Twofish tables --------------------------------------------*/
44 /* --- The t-tables --- */
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 }
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 }
70 /* --- The MDS and Reed-Solomon matrices --- */
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
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
86 /*----- Magic macros ------------------------------------------------------*/
88 #define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15)
90 /*----- Building and printing @q@ tables ----------------------------------*/
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
100 * Use: Constructs a 256-entry @q@-table.
103 static void mkq(q_tab
*q
, const t_tab
*t
, const char *name
)
108 /* --- Ensure the t-table is well-formed --- */
110 for (i
= 0; i
< 4; i
++) {
114 for (j
= 0; j
< 16; 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
]]);
127 /* --- Construct the @q@ table --- */
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);
136 /* Consider testing @q@ for linear and differential properties here */
139 /* --- @printq@ --- *
141 * Arguments: @const q_tab *t@ = pointer to table
142 * @const char *name@ = pointer to table name
146 * Use: Prints a q table.
149 static void printq(const q_tab
*q
, const char *name
)
155 #define TWOFISH_%s { \\\n\
158 for (i
= 0; i
< 256; i
++) {
159 printf("0x%02x", q
->q
[i
]);
162 fputs(" \\\n}\n\n", stdout
);
164 fputs(", \\\n ", stdout
);
170 /*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/
172 #define MDS_MOD 0x169
177 * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$%
178 * @unsigned m@ = modulus
180 * Returns: The product of two polynomials.
182 * Use: Computes a product of polynomials, quite slowly.
185 static unsigned mul(unsigned x
, unsigned y
, unsigned m
)
190 for (i
= 0; i
< 8; i
++) {
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
213 * Use: Computes an inner product of matrices over the finite field
214 * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid.
217 static void mmul(octet
*d
, const octet
*p
, const octet
*q
,
218 size_t r
, size_t n
, unsigned m
)
225 for (i
= 0; i
< n
; i
++)
226 a
^= mul(*p
++, *qq
++, m
);
238 * Use: Prints the MDS/q table.
241 static void qmds(void)
245 static const q_tab
*q
[4] = { &q1
, &q0
, &q1
, &q0
};
247 for (i
= 0; i
< 4; i
++) {
248 octet in
[4] = { 0, 0, 0, 0 };
251 for (j
= 0; j
< 256; j
++) {
253 mmul(out
, mds
, in
, 4, 4, MDS_MOD
);
254 t
[i
][j
] = LOAD32_L(out
);
259 /* --- Expanded MDS tables --- *\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\
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
]);
276 } else if (j
% 4 == 3)
277 fputs(", \\\n ", stdout
);
292 * Use: Produces the log and antilog tables for doing the RS
293 * arithmetic efficiently.
296 static void rslog(void)
305 for (i
= 0; i
< 255; i
++) {
314 for (i
= 0; i
< 32; i
++) {
315 if (rslog
[rs
[i
]] > x
)
320 /* --- Reed-Solomon log tables --- *\n\
322 * The Reed-Solomon multiplies are accelerated by using log tables.\n\
325 #define TWOFISH_RSLOG { \\\n\
328 for (i
= 0; i
< 256; i
++) {
329 printf("0x%02x", rslog
[i
]);
333 fputs(", \\\n ", stdout
);
339 #define TWOFISH_RSEXP { \\\n\
342 for (i
= 0; i
< 255 + x
+ 1; i
++) {
343 printf("0x%02x", rsexp
[i
% 255]);
347 fputs(", \\\n ", stdout
);
353 /* --- Reed-Solomon matrix with log entries --- */\n\
355 #define TWOFISH_RS { \\\n\
358 for (i
= 0; i
< 32; i
++) {
359 printf("0x%02x", rslog
[rs
[i
]]);
363 fputs(", \\\n ", stdout
);
369 /*----- Main program ------------------------------------------------------*/
378 * Twofish q tables [generated]\n\
381 #ifndef CATACOMB_TWOFISH_TAB_H\n\
382 #define CATACOMB_TWOFISH_TAB_H\n\
386 /* --- The q tables --- */
389 /* --- Precomputed @q@ tables --- */\n\
391 mkq(&q0
, &qt0
, "qt0");
392 mkq(&q1
, &qt1
, "qt1");
396 /* --- The MDS/q tables --- */
405 if (fclose(stdout
)) {
406 fprintf(stderr
, "error writing data\n");
413 /*----- That's all, folks -------------------------------------------------*/