--- /dev/null
+/* -*-c-*-
+ *
+ * FIPS140 randomness tests
+ *
+ * (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 <mLib/bits.h>
+
+#include "fipstest.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @monobit@ --- *
+ *
+ * Arguments: @const octet *p@ = pointer to buffer
+ *
+ * Returns: Zero if OK, @FIPSTEST_MONOBIT@ on failure.
+ *
+ * Use: Performs the monobit test on a buffer of data. If %$n_1$% is
+ * the number of 1 bits in the buffer, then the monobit test is
+ * passed when %$9654 < n_1 < 10346$%.
+ */
+
+static unsigned monobit(const octet *p)
+{
+ unsigned n1 = 0;
+ unsigned i, j;
+
+ for (i = 0; i < FIPSTEST_BUFSZ; i++) {
+ octet x = p[i];
+ for (j = 0; j < 8; j++) {
+ if (x & 1)
+ n1++;
+ x >>= 1;
+ }
+ }
+
+ if (9725 >= n1 || n1 >= 10275)
+ return (FIPSTEST_MONOBIT);
+ return (0);
+}
+
+/* --- @poker@ --- *
+ *
+ * Arguments: @const octet *p@ = pointer to buffer
+ *
+ * Returns: Zero if OK, @FIPSTEST_POKER@ on failure.
+ *
+ * Use: Performs the poker test on a buffer of data. The buffer is
+ * divided into 4-bit nibbles %$x_i$%. If
+ * %$f(x) = \sum_{x_i = x} 1$% is the frequency of each nibble,
+ * then the test is passed if
+ * %$2.16 < 16/5000 \sum_i f(i)^2 - 5000 < 46.17$%.
+ */
+
+static unsigned poker(const octet *p)
+{
+ unsigned long f[16] = { 0 };
+ unsigned i;
+ unsigned long q = 0;
+
+ /* --- Compute the frequencies --- */
+
+ for (i = 0; i < FIPSTEST_BUFSZ; i++) {
+ octet x = p[i];
+ f[x & 0xf]++;
+ f[(x >> 4) & 0xf]++;
+ }
+
+ /* --- Now do the comparison --- *
+ *
+ * This can be simplified. Multiply through the inequality by 5000 and
+ * we get %$5150 < 16 \sum_i f(i)^2 - 5000^2 < 287000$%.
+ */
+
+ for (i = 0; i < 16; i++)
+ q += f[i] * f[i];
+ q <<= 4;
+ q -= 5000ul * 5000ul;
+
+ if (10800 >= q || q >= 230850)
+ return (FIPSTEST_POKER);
+ return (0);
+}
+
+/* --- @runs@ --- *
+ *
+ * Arguments: @const octet *p@ = pointer to buffer
+ *
+ * Returns: Zero for success, @FIPSTEST_RUNS@ or @FIPSTEST_LONGRUNS@ on
+ * failure.
+ *
+ * Use: Performs the runs and long runs tests. The frequency of each
+ * `run', or sequence of equal bits, is counted and tested.
+ */
+
+static unsigned runs(const octet *p)
+{
+ unsigned rc = 0;
+ unsigned i, j;
+ unsigned r = 0;
+ unsigned bb = 0;
+ unsigned f[2][6] = { { 0 } };
+
+ /* --- Count the run lengths --- */
+
+ for (i = 0; i < FIPSTEST_BUFSZ; i++) {
+ octet x = p[i];
+ for (j = 0; j < 8; j++) {
+ unsigned b = x & 1;
+ x >>= 1;
+ if (b == bb)
+ r++;
+ else {
+ if (r) {
+ if (r >= 34)
+ rc |= FIPSTEST_LONGRUNS;
+ if (r > 6)
+ r = 6;
+ f[bb][r - 1]++;
+ }
+ r = 1;
+ bb = b;
+ }
+ }
+ }
+
+ if (r >= 26)
+ rc |= FIPSTEST_LONGRUNS;
+ if (r > 6)
+ r = 6;
+ f[bb][r - 1]++;
+
+ /* --- Check the results --- */
+
+ if (2343 > f[0][0] || f[0][0] > 2657 || 2343 > f[1][0] || f[1][0] > 2657 ||
+ 1135 > f[0][1] || f[0][1] > 1365 || 1135 > f[1][1] || f[1][1] > 1365 ||
+ 542 > f[0][2] || f[0][2] > 708 || 542 > f[1][2] || f[1][2] > 708 ||
+ 251 > f[0][3] || f[0][3] > 373 || 251 > f[1][3] || f[1][3] > 373 ||
+ 111 > f[0][4] || f[0][4] > 201 || 111 > f[1][4] || f[1][4] > 201 ||
+ 111 > f[0][5] || f[0][5] > 201 || 111 > f[1][5] || f[1][5] > 201)
+ rc |= FIPSTEST_RUNS;
+
+ return (rc);
+}
+
+/* --- @fipstest@ --- *
+ *
+ * Arguments: @const octet *p@ = pointer to a buffer of @FIPSTEST_BUFSZ@
+ * bytes
+ *
+ * Returns: Zero if OK, or a bitmask of failed tests.
+ *
+ * Use: Performs the FIPS140 randomness tests on a block of data.
+ */
+
+unsigned fipstest(const octet *p)
+{
+ unsigned rc = 0;
+ rc |= monobit(p);
+ rc |= poker(p);
+ rc |= runs(p);
+ return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/