--- /dev/null
+/* -*-c-*-
+ *
+ * Check the Serpent S-boxes
+ *
+ * (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 <string.h>
+
+#include <mLib/bits.h>
+
+#include "serpent-sbox.h"
+
+/*----- S-box tables ------------------------------------------------------*/
+
+static const octet s[8][16] = {
+ { 3, 8, 15, 1, 10, 6, 5, 11, 14, 13, 4, 2, 7, 0, 9, 12 },
+ { 15, 12, 2, 7, 9, 0, 5, 10, 1, 11, 14, 8, 6, 13, 3, 4 },
+ { 8, 6, 7, 9, 3, 12, 10, 15, 13, 1, 14, 4, 0, 11, 5, 2 },
+ { 0, 15, 11, 8, 12, 9, 6, 3, 13, 1, 2, 4, 10, 7, 5, 14 },
+ { 1, 15, 8, 3, 12, 0, 11, 6, 2, 5, 4, 10, 9, 14, 7, 13 },
+ { 15, 5, 2, 11, 4, 10, 9, 12, 0, 3, 14, 8, 13, 6, 7, 1 },
+ { 7, 2, 12, 5, 8, 4, 6, 11, 14, 9, 1, 15, 13, 3, 10, 0 },
+ { 1, 13, 15, 0, 14, 8, 2, 11, 7, 4, 12, 10, 9, 3, 5, 6 }
+};
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @check@ --- *
+ *
+ * Arguments: @unsigned a, b, c, d@ = four bitslice output registers
+ * @const octet *p@ = pointer to S-box
+ *
+ * Returns: Zero if OK, nonzero on failure.
+ *
+ * Use: Checks that an S-box output is correct.
+ */
+
+static int check(unsigned a, unsigned b, unsigned c, unsigned d,
+ const octet *p)
+{
+ octet buf[16];
+ octet *q = buf;
+ unsigned i;
+
+ for (i = 0; i < 16; i++) {
+ *q++ = (a & 1) | ((b & 1) << 1) | ((c & 1) << 2) | ((d & 1) << 3);
+ a >>= 1; b >>= 1; c >>= 1; d >>= 1;
+ }
+ return (memcmp(buf, p, sizeof(buf)));
+}
+
+#define CHECK(i) do { \
+ unsigned a = 0xaaaa, b = 0xcccc, c = 0xf0f0, d = 0xff00; \
+ S##i(a, b, c, d); \
+ if (check(a, b, c, d, s[i])) { \
+ fprintf(stderr, "failure in S%i\n", i); \
+ rc = EXIT_FAILURE; \
+ } \
+ IS##i(a, b, c, d); \
+ if (a != 0xaaaa || b != 0xcccc || c != 0xf0f0 || d != 0xff00) { \
+ fprintf(stderr, "failure in IS%i\n", i); \
+ rc = EXIT_FAILURE; \
+ } \
+} while (0)
+
+int main(void)
+{
+ int rc = 0;
+ CHECK(0); CHECK(1); CHECK(2); CHECK(3);
+ CHECK(4); CHECK(5); CHECK(6); CHECK(7);
+ return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/