3 * $Id: twofish-mktab.c,v 1.3 2000/06/26 17:14:42 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 /*----- Revision history --------------------------------------------------*
32 * $Log: twofish-mktab.c,v $
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.
38 * Revision 1.2 2000/06/18 23:12:15 mdw
39 * Change typesetting of Galois Field names.
41 * Revision 1.1 2000/06/17 12:10:17 mdw
46 /*----- Header files ------------------------------------------------------*/
51 #include <mLib/bits.h>
53 /*----- Data structures ---------------------------------------------------*/
55 typedef struct { octet t
[4][16]; } t_tab
;
56 typedef struct { octet q
[256]; } q_tab
;
58 /*----- Various Twofish tables --------------------------------------------*/
60 /* --- The t-tables --- */
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 }
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 }
86 /* --- The MDS and Reed-Solomon matrices --- */
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
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
102 /*----- Magic macros ------------------------------------------------------*/
104 #define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15)
106 /*----- Building and printing @q@ tables ----------------------------------*/
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
116 * Use: Constructs a 256-entry @q@-table.
119 static void mkq(q_tab
*q
, const t_tab
*t
, const char *name
)
124 /* --- Ensure the t-table is well-formed --- */
126 for (i
= 0; i
< 4; i
++) {
130 for (j
= 0; j
< 16; 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
]]);
143 /* --- Construct the @q@ table --- */
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);
152 /* Consider testing @q@ for linear and differential properties here */
155 /* --- @printq@ --- *
157 * Arguments: @const q_tab *t@ = pointer to table
158 * @const char *name@ = pointer to table name
162 * Use: Prints a q table.
165 static void printq(const q_tab
*q
, const char *name
)
171 #define TWOFISH_%s { \\\n\
174 for (i
= 0; i
< 256; i
++) {
175 printf("0x%02x", q
->q
[i
]);
178 fputs(" \\\n}\n\n", stdout
);
180 fputs(", \\\n ", stdout
);
186 /*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/
188 #define MDS_MOD 0x169
193 * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$%
194 * @unsigned m@ = modulus
196 * Returns: The product of two polynomials.
198 * Use: Computes a product of polynomials, quite slowly.
201 static unsigned mul(unsigned x
, unsigned y
, unsigned m
)
206 for (i
= 0; i
< 8; i
++) {
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
229 * Use: Computes an inner product of matrices over the finite field
230 * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid.
233 static void mmul(octet
*d
, const octet
*p
, const octet
*q
,
234 size_t r
, size_t n
, unsigned m
)
241 for (i
= 0; i
< n
; i
++)
242 a
^= mul(*p
++, *qq
++, m
);
254 * Use: Prints the MDS/q table.
257 static void qmds(void)
261 static const q_tab
*q
[4] = { &q1
, &q0
, &q1
, &q0
};
263 for (i
= 0; i
< 4; i
++) {
264 octet in
[4] = { 0, 0, 0, 0 };
267 for (j
= 0; j
< 256; j
++) {
269 mmul(out
, mds
, in
, 4, 4, MDS_MOD
);
270 t
[i
][j
] = LOAD32_L(out
);
275 /* --- Expanded MDS tables --- *\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\
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
]);
292 } else if (j
% 4 == 3)
293 fputs(", \\\n ", stdout
);
308 * Use: Produces the log and antilog tables for doing the RS
309 * arithmetic efficiently.
312 static void rslog(void)
321 for (i
= 0; i
< 255; i
++) {
330 for (i
= 0; i
< 32; i
++) {
331 if (rslog
[rs
[i
]] > x
)
336 /* --- Reed-Solomon log tables --- *\n\
338 * The Reed-Solomon multiplies are accelerated by using log tables.\n\
341 #define TWOFISH_RSLOG { \\\n\
344 for (i
= 0; i
< 256; i
++) {
345 printf("0x%02x", rslog
[i
]);
349 fputs(", \\\n ", stdout
);
355 #define TWOFISH_RSEXP { \\\n\
358 for (i
= 0; i
< 255 + x
+ 1; i
++) {
359 printf("0x%02x", rsexp
[i
% 255]);
363 fputs(", \\\n ", stdout
);
369 /* --- Reed-Solomon matrix with log entries --- */\n\
371 #define TWOFISH_RS { \\\n\
374 for (i
= 0; i
< 32; i
++) {
375 printf("0x%02x", rslog
[rs
[i
]]);
379 fputs(", \\\n ", stdout
);
385 /*----- Main program ------------------------------------------------------*/
394 * Twofish q tables [generated]\n\
397 #ifndef CATACOMB_TWOFISH_TAB_H
398 #define CATACOMB_TWOFISH_TAB_H
402 /* --- The q tables --- */
405 /* --- Precomputed @q@ tables --- */\n\
407 mkq(&q0
, &qt0
, "qt0");
408 mkq(&q1
, &qt1
, "qt1");
412 /* --- The MDS/q tables --- */
421 if (fclose(stdout
)) {
422 fprintf(stderr
, "error writing data\n");
429 /*----- That's all, folks -------------------------------------------------*/