/* Copyright 2000 Free Software Foundation, Inc. This file is part of the GNU MP Library test suite. The GNU MP Library test suite is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. The GNU MP Library test suite 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 General Public License for more details. You should have received a copy of the GNU General Public License along with the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */ #include #include #include #include #include #include "gmpstat.h" #define RCSID(msg) \ static /**/const char *const rcsid[] = { (char *)rcsid, "\100(#)" msg } RCSID("$Id: findlc.c,v 1.1.1.4 2020/09/27 00:27:04 mrg Exp $"); int g_debug = 0; static mpz_t a; static void sh_status (int sig) { printf ("sh_status: signal %d caught. dumping status.\n", sig); printf (" a = "); mpz_out_str (stdout, 10, a); printf ("\n"); fflush (stdout); if (SIGSEGV == sig) /* remove SEGV handler */ signal (SIGSEGV, SIG_DFL); } /* Input is a modulus (m). We shall find multiplier (a) and adder (c) conforming to the rules found in the first comment block in file mpz/urandom.c. Then run a spectral test on the generator and discard any multipliers not passing. */ /* TODO: . find a better algorithm than a+=8; bigger jumps perhaps? */ void mpz_true_random (mpz_t s, unsigned long int nbits) { #if __FreeBSD__ FILE *fs; char c[1]; int i; mpz_set_ui (s, 0); for (i = 0; i < nbits; i += 8) { for (;;) { int nread; fs = fopen ("/dev/random", "r"); nread = fread (c, 1, 1, fs); fclose (fs); if (nread != 0) break; sleep (1); } mpz_mul_2exp (s, s, 8); mpz_add_ui (s, s, ((unsigned long int) c[0]) & 0xff); printf ("%d random bits\n", i + 8); } if (nbits % 8 != 0) mpz_mod_2exp (s, s, nbits); #endif } int main (int argc, char *argv[]) { const char usage[] = "usage: findlc [-dv] m2exp [low_merit [high_merit]]\n"; int f; int v_lose, m_lose, v_best, m_best; int c; int debug = 1; int cnt_high_merit; mpz_t m; unsigned long int m2exp; #define DIMS 6 /* dimensions run in spectral test */ mpf_t v[DIMS-1]; /* spectral test result (there's no v for 1st dimension */ mpf_t f_merit, low_merit, high_merit; mpz_t acc, minus8; mpz_t min, max; mpz_t s; mpz_init (m); mpz_init (a); for (f = 0; f < DIMS-1; f++) mpf_init (v[f]); mpf_init (f_merit); mpf_init_set_d (low_merit, .1); mpf_init_set_d (high_merit, .1); while ((c = getopt (argc, argv, "a:di:hv")) != -1) switch (c) { case 'd': /* debug */ g_debug++; break; case 'v': /* print version */ puts (rcsid[1]); exit (0); case 'h': case '?': default: fputs (usage, stderr); exit (1); } argc -= optind; argv += optind; if (argc < 1) { fputs (usage, stderr); exit (1); } /* Install signal handler. */ if (SIG_ERR == signal (SIGSEGV, sh_status)) { perror ("signal (SIGSEGV)"); exit (1); } if (SIG_ERR == signal (SIGHUP, sh_status)) { perror ("signal (SIGHUP)"); exit (1); } printf ("findlc: version: %s\n", rcsid[1]); m2exp = atol (argv[0]); mpz_init_set_ui (m, 1); mpz_mul_2exp (m, m, m2exp); printf ("m = 0x"); mpz_out_str (stdout, 16, m); puts (""); if (argc > 1) /* have low_merit */ mpf_set_str (low_merit, argv[1], 0); if (argc > 2) /* have high_merit */ mpf_set_str (high_merit, argv[2], 0); if (debug) { fprintf (stderr, "low_merit = "); mpf_out_str (stderr, 10, 2, low_merit); fprintf (stderr, "; high_merit = "); mpf_out_str (stderr, 10, 2, high_merit); fputs ("\n", stderr); } mpz_init (minus8); mpz_set_si (minus8, -8L); mpz_init_set_ui (acc, 0); mpz_init (s); mpz_init_set_d (min, 0.01 * pow (2.0, (double) m2exp)); mpz_init_set_d (max, 0.99 * pow (2.0, (double) m2exp)); mpz_true_random (s, m2exp); /* Start. */ mpz_setbit (s, 0); /* Make it odd. */ v_best = m_best = 2*(DIMS-1); for (;;) { mpz_add (acc, acc, s); mpz_mod_2exp (acc, acc, m2exp); #if later mpz_and_si (a, acc, -8L); #else mpz_and (a, acc, minus8); #endif mpz_add_ui (a, a, 5); if (mpz_cmp (a, min) <= 0 || mpz_cmp (a, max) >= 0) continue; spectral_test (v, DIMS, a, m); for (f = 0, v_lose = m_lose = 0, cnt_high_merit = DIMS-1; f < DIMS-1; f++) { merit (f_merit, f + 2, v[f], m); if (mpf_cmp_ui (v[f], 1 << (30 / (f + 2) + (f == 2))) < 0) v_lose++; if (mpf_cmp (f_merit, low_merit) < 0) m_lose++; if (mpf_cmp (f_merit, high_merit) >= 0) cnt_high_merit--; } if (0 == v_lose && 0 == m_lose) { mpz_out_str (stdout, 10, a); puts (""); fflush (stdout); if (0 == cnt_high_merit) break; /* leave loop */ } if (v_lose < v_best) { v_best = v_lose; printf ("best (v_lose=%d; m_lose=%d): ", v_lose, m_lose); mpz_out_str (stdout, 10, a); puts (""); fflush (stdout); } if (m_lose < m_best) { m_best = m_lose; printf ("best (v_lose=%d; m_lose=%d): ", v_lose, m_lose); mpz_out_str (stdout, 10, a); puts (""); fflush (stdout); } } mpz_clear (m); mpz_clear (a); for (f = 0; f < DIMS-1; f++) mpf_clear (v[f]); mpf_clear (f_merit); mpf_clear (low_merit); mpf_clear (high_merit); printf ("done.\n"); return 0; }