--- /dev/null
+/* -*-c-*-
+ *
+ * Build constant tables for Twofish
+ *
+ * (c) 2000 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <mLib/bits.h>
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct { octet t[4][16]; } t_tab;
+typedef struct { octet q[256]; } q_tab;
+
+/*----- Various Twofish tables --------------------------------------------*/
+
+/* --- The t-tables --- */
+
+static const t_tab qt0 = {{
+ { 0x8, 0x1, 0x7, 0xd, 0x6, 0xf, 0x3, 0x2,
+ 0x0, 0xb, 0x5, 0x9, 0xe, 0xc, 0xa, 0x4 },
+ { 0xe, 0xc, 0xb, 0x8, 0x1, 0x2, 0x3, 0x5,
+ 0xf, 0x4, 0xa, 0x6, 0x7, 0x0, 0x9, 0xd },
+ { 0xb, 0xa, 0x5, 0xe, 0x6, 0xd, 0x9, 0x0,
+ 0xc, 0x8, 0xf, 0x3, 0x2, 0x4, 0x7, 0x1 },
+ { 0xd, 0x7, 0xf, 0x4, 0x1, 0x2, 0x6, 0xe,
+ 0x9, 0xb, 0x3, 0x0, 0x8, 0x5, 0xc, 0xa }
+}};
+
+static const t_tab qt1 = {{
+ { 0x2, 0x8, 0xb, 0xd, 0xf, 0x7, 0x6, 0xe,
+ 0x3, 0x1, 0x9, 0x4, 0x0, 0xa, 0xc, 0x5 },
+ { 0x1, 0xe, 0x2, 0xb, 0x4, 0xc, 0x3, 0x7,
+ 0x6, 0xd, 0xa, 0x5, 0xf, 0x9, 0x0, 0x8 },
+ { 0x4, 0xc, 0x7, 0x5, 0x1, 0x6, 0x9, 0xa,
+ 0x0, 0xe, 0xd, 0x8, 0x2, 0xb, 0x3, 0xf },
+ { 0xb, 0x9, 0x5, 0x1, 0xc, 0x3, 0xd, 0xe,
+ 0x6, 0x4, 0x7, 0xf, 0x2, 0x0, 0x8, 0xa }
+}};
+
+static q_tab q0, q1;
+
+/* --- The MDS and Reed-Solomon matrices --- */
+
+static const octet mds[16] = {
+ 0x01, 0xef, 0x5b, 0x5b,
+ 0x5b, 0xef, 0xef, 0x01,
+ 0xef, 0x5b, 0x01, 0xef,
+ 0xef, 0x01, 0xef, 0x5b
+};
+
+static const octet rs[32] = {
+ 0x01, 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e,
+ 0xa4, 0x56, 0x82, 0xf3, 0x1e, 0xc6, 0x68, 0xe5,
+ 0x02, 0xa1, 0xfc, 0xc1, 0x47, 0xae, 0x3d, 0x19,
+ 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, 0x03
+};
+
+/*----- Magic macros ------------------------------------------------------*/
+
+#define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15)
+
+/*----- Building and printing @q@ tables ----------------------------------*/
+
+/* --- @mkq@ --- *
+ *
+ * Arguments: @q_tab *q@ = pointer to output @q@ table
+ * @const t_tab *t@ = pointer to input @t@ table
+ * @const char *name@ = name of @q@ table
+ *
+ * Returns: ---
+ *
+ * Use: Constructs a 256-entry @q@-table.
+ */
+
+static void mkq(q_tab *q, const t_tab *t, const char *name)
+{
+ int i;
+ int ok = 1;
+
+ /* --- Ensure the t-table is well-formed --- */
+
+ for (i = 0; i < 4; i++) {
+ octet f[16] = { 0 };
+ int j;
+
+ for (j = 0; j < 16; j++) {
+ if (f[t->t[i][j]]) {
+ fprintf(stderr, "duplicate %i in %s[%i] (col %i and %i)\n",
+ t->t[i][j], name, i, j, f[t->t[i][j]]);
+ ok = 0;
+ }
+ f[t->t[i][j]] = j;
+ }
+ }
+
+ if (!ok)
+ exit(EXIT_FAILURE);
+
+ /* --- Construct the @q@ table --- */
+
+ for (i = 0; i < 256; i++) {
+ int a = i >> 4, b = i & 15;
+ int aa = t->t[0][a ^ b], bb = t->t[1][a ^ ((a << 3) & 15) ^ ROR4(b)];
+ a = t->t[2][aa ^ bb], b = t->t[3][aa ^ ((aa << 3) & 15) ^ ROR4(bb)];
+ q->q[i] = a | (b << 4);
+ }
+
+ /* Consider testing @q@ for linear and differential properties here */
+}
+
+/* --- @printq@ --- *
+ *
+ * Arguments: @const q_tab *t@ = pointer to table
+ * @const char *name@ = pointer to table name
+ *
+ * Returns: ---
+ *
+ * Use: Prints a q table.
+ */
+
+static void printq(const q_tab *q, const char *name)
+{
+ int i;
+ int j;
+
+ printf("\
+#define TWOFISH_%s { \\\n\
+ ", name);
+ j = 0;
+ for (i = 0; i < 256; i++) {
+ printf("0x%02x", q->q[i]);
+ j = (j + 1) & 7;
+ if (i == 255)
+ fputs(" \\\n}\n\n", stdout);
+ else if (j == 0)
+ fputs(", \\\n ", stdout);
+ else
+ fputs(", ", stdout);
+ }
+}
+
+/*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/
+
+#define MDS_MOD 0x169
+#define RS_MOD 0x14d
+
+/* --- @mul@ --- *
+ *
+ * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$%
+ * @unsigned m@ = modulus
+ *
+ * Returns: The product of two polynomials.
+ *
+ * Use: Computes a product of polynomials, quite slowly.
+ */
+
+static unsigned mul(unsigned x, unsigned y, unsigned m)
+{
+ unsigned a = 0;
+ unsigned i;
+
+ for (i = 0; i < 8; i++) {
+ if (y & 1)
+ a ^= x;
+ y >>= 1;
+ x <<= 1;
+ if (x & 0x100)
+ x ^= m;
+ }
+
+ return (a);
+}
+
+/* --- @mmul@ --- *
+ *
+ * Arguments: @octet *d@ = destination vector
+ * @const octet *p@ = matrix of bytes
+ * @const octet *q@ = vector from somewhere else
+ * @size_t r@ = size of destination or number of rows in matrix
+ * @size_t n@ = length of row and vector
+ * @unsigned m@ = modulus polynomial
+ *
+ * Returns: ---
+ *
+ * Use: Computes an inner product of matrices over the finite field
+ * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid.
+ */
+
+static void mmul(octet *d, const octet *p, const octet *q,
+ size_t r, size_t n, unsigned m)
+{
+ while (r) {
+ const octet *qq = q;
+ unsigned a = 0;
+ unsigned i;
+
+ for (i = 0; i < n; i++)
+ a ^= mul(*p++, *qq++, m);
+ *d++ = a;
+ r--;
+ }
+}
+
+/* --- @qrds@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Prints the MDS/q table.
+ */
+
+static void qmds(void)
+{
+ uint32 t[4][256];
+ int i, j;
+ static const q_tab *q[4] = { &q1, &q0, &q1, &q0 };
+
+ for (i = 0; i < 4; i++) {
+ octet in[4] = { 0, 0, 0, 0 };
+ octet out[4];
+
+ for (j = 0; j < 256; j++) {
+ in[i] = q[i]->q[j];
+ mmul(out, mds, in, 4, 4, MDS_MOD);
+ t[i][j] = LOAD32_L(out);
+ }
+ }
+
+ puts("\
+/* --- Expanded MDS tables --- *\n\
+ *\n\
+ * The table contains output vectors for computing the result of pushing\n\
+ * bytes through appropriate @q@ tables and the MDS matrix.\n\
+ */\n\
+\n\
+#define TWOFISH_QMDS { \\");
+ for (i = 0; i < 4; i++) {
+ fputs(" { ", stdout);
+ for (j = 0; j < 256; j++) {
+ printf("0x%08lx", (unsigned long)t[i][j]);
+ if (j == 255) {
+ if (i == 3)
+ puts(" } \\\n}");
+ else
+ puts(" }, \\\n\
+ \\");
+ } else if (j % 4 == 3)
+ fputs(", \\\n ", stdout);
+ else
+ fputs(", ", stdout);
+ }
+ }
+
+ putchar('\n');
+}
+
+/* --- @rslog@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Produces the log and antilog tables for doing the RS
+ * arithmetic efficiently.
+ */
+
+static void rslog(void)
+{
+ octet rslog[256];
+ octet rsexp[256];
+
+ unsigned x = 1;
+ unsigned i;
+
+ rslog[0] = 0;
+ for (i = 0; i < 255; i++) {
+ rslog[x] = i;
+ rsexp[i] = x;
+ x <<= 1;
+ if (x & 0x100)
+ x ^= RS_MOD;
+ }
+
+ x = 0;
+ for (i = 0; i < 32; i++) {
+ if (rslog[rs[i]] > x)
+ x = rslog[rs[i]];
+ }
+
+ fputs("\
+/* --- Reed-Solomon log tables --- *\n\
+ *\n\
+ * The Reed-Solomon multiplies are accelerated by using log tables.\n\
+ */\n\
+\n\
+#define TWOFISH_RSLOG { \\\n\
+ ", stdout);
+
+ for (i = 0; i < 256; i++) {
+ printf("0x%02x", rslog[i]);
+ if (i == 255)
+ puts(" \\\n}\n");
+ else if (i % 8 == 7)
+ fputs(", \\\n ", stdout);
+ else
+ fputs(", ", stdout);
+ }
+
+ fputs("\
+#define TWOFISH_RSEXP { \\\n\
+ ", stdout);
+
+ for (i = 0; i < 255 + x + 1; i++) {
+ printf("0x%02x", rsexp[i % 255]);
+ if (i == 255 + x)
+ puts(" \\\n}\n");
+ else if (i % 8 == 7)
+ fputs(", \\\n ", stdout);
+ else
+ fputs(", ", stdout);
+ }
+
+ fputs("\
+/* --- Reed-Solomon matrix with log entries --- */\n\
+\n\
+#define TWOFISH_RS { \\\n\
+ ", stdout);
+
+ for (i = 0; i < 32; i++) {
+ printf("0x%02x", rslog[rs[i]]);
+ if (i == 31)
+ puts(" \\\n}\n");
+ else if (i % 8 == 7)
+ fputs(", \\\n ", stdout);
+ else
+ fputs(", ", stdout);
+ }
+}
+
+/*----- Main program ------------------------------------------------------*/
+
+/* --- @main@ --- */
+
+int main(void)
+{
+ fputs("\
+/* -*-c-*-\n\
+ *\n\
+ * Twofish q tables [generated]\n\
+ */\n\
+\n\
+#ifndef CATACOMB_TWOFISH_TAB_H\n\
+#define CATACOMB_TWOFISH_TAB_H\n\
+\n\
+", stdout);
+
+ /* --- The q tables --- */
+
+ puts("\
+/* --- Precomputed @q@ tables --- */\n\
+");
+ mkq(&q0, &qt0, "qt0");
+ mkq(&q1, &qt1, "qt1");
+ printq(&q0, "Q0");
+ printq(&q1, "Q1");
+
+ /* --- The MDS/q tables --- */
+
+ qmds();
+ rslog();
+
+ /* --- Done --- */
+
+ puts("#endif");
+
+ if (fclose(stdout)) {
+ fprintf(stderr, "error writing data\n");
+ exit(EXIT_FAILURE);
+ }
+
+ return (0);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff