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authorcperciva <cperciva@FreeBSD.org>2015-10-02 10:08:11 +0000
committercperciva <cperciva@FreeBSD.org>2015-10-02 10:08:11 +0000
commit8cc71b38c27f2be8ba4c227078a51c63847a89de (patch)
tree0bbcb3f392def57bae56978c0da09362f7d6b426 /usr.bin/factor/factor.c
parent0c2e89c50542aa374d776ce0787b4a06e0de1be2 (diff)
downloadFreeBSD-src-8cc71b38c27f2be8ba4c227078a51c63847a89de.zip
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Final step of eliminating the "games" distribution: Merge src/games
(or what's left of it, at least) into src/usr.bin. This change will not be MFCed. Discussed at: EuroBSDCon 2014 Committed from: EuroBSDCon 2015
Diffstat (limited to 'usr.bin/factor/factor.c')
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diff --git a/usr.bin/factor/factor.c b/usr.bin/factor/factor.c
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+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Landon Curt Noll.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+#include <sys/cdefs.h>
+#ifdef __COPYRIGHT
+__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
+ The Regents of the University of California. All rights reserved.");
+#endif
+#ifdef __SCCSID
+__SCCSID("@(#)factor.c 8.4 (Berkeley) 5/4/95");
+#endif
+#ifdef __RCSID
+__RCSID("$NetBSD: factor.c,v 1.19 2009/08/12 05:54:31 dholland Exp $");
+#endif
+#ifdef __FBSDID
+__FBSDID("$FreeBSD$");
+#endif
+#endif /* not lint */
+
+/*
+ * factor - factor a number into primes
+ *
+ * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
+ *
+ * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
+ *
+ * usage:
+ * factor [-h] [number] ...
+ *
+ * The form of the output is:
+ *
+ * number: factor1 factor1 factor2 factor3 factor3 factor3 ...
+ *
+ * where factor1 <= factor2 <= factor3 <= ...
+ *
+ * If no args are given, the list of numbers are read from stdin.
+ */
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "primes.h"
+
+#ifdef HAVE_OPENSSL
+
+#include <openssl/bn.h>
+
+#define PRIME_CHECKS 5
+
+static void pollard_pminus1(BIGNUM *); /* print factors for big numbers */
+
+#else
+
+typedef ubig BIGNUM;
+typedef u_long BN_ULONG;
+
+#define BN_CTX int
+#define BN_CTX_new() NULL
+#define BN_new() ((BIGNUM *)calloc(sizeof(BIGNUM), 1))
+#define BN_is_zero(v) (*(v) == 0)
+#define BN_is_one(v) (*(v) == 1)
+#define BN_mod_word(a, b) (*(a) % (b))
+
+static int BN_dec2bn(BIGNUM **a, const char *str);
+static int BN_hex2bn(BIGNUM **a, const char *str);
+static BN_ULONG BN_div_word(BIGNUM *, BN_ULONG);
+static void BN_print_fp(FILE *, const BIGNUM *);
+
+#endif
+
+static void BN_print_dec_fp(FILE *, const BIGNUM *);
+
+static void pr_fact(BIGNUM *); /* print factors of a value */
+static void pr_print(BIGNUM *); /* print a prime */
+static void usage(void);
+
+static BN_CTX *ctx; /* just use a global context */
+static int hflag;
+
+int
+main(int argc, char *argv[])
+{
+ BIGNUM *val;
+ int ch;
+ char *p, buf[LINE_MAX]; /* > max number of digits. */
+
+ ctx = BN_CTX_new();
+ val = BN_new();
+ if (val == NULL)
+ errx(1, "can't initialise bignum");
+
+ while ((ch = getopt(argc, argv, "h")) != -1)
+ switch (ch) {
+ case 'h':
+ hflag++;
+ break;
+ case '?':
+ default:
+ usage();
+ }
+ argc -= optind;
+ argv += optind;
+
+ /* No args supplied, read numbers from stdin. */
+ if (argc == 0)
+ for (;;) {
+ if (fgets(buf, sizeof(buf), stdin) == NULL) {
+ if (ferror(stdin))
+ err(1, "stdin");
+ exit (0);
+ }
+ for (p = buf; isblank(*p); ++p);
+ if (*p == '\n' || *p == '\0')
+ continue;
+ if (*p == '-')
+ errx(1, "negative numbers aren't permitted.");
+ if (BN_dec2bn(&val, buf) == 0 &&
+ BN_hex2bn(&val, buf) == 0)
+ errx(1, "%s: illegal numeric format.", buf);
+ pr_fact(val);
+ }
+ /* Factor the arguments. */
+ else
+ for (; *argv != NULL; ++argv) {
+ if (argv[0][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+ if (BN_dec2bn(&val, argv[0]) == 0 &&
+ BN_hex2bn(&val, argv[0]) == 0)
+ errx(1, "%s: illegal numeric format.", argv[0]);
+ pr_fact(val);
+ }
+ exit(0);
+}
+
+/*
+ * pr_fact - print the factors of a number
+ *
+ * Print the factors of the number, from the lowest to the highest.
+ * A factor will be printed multiple times if it divides the value
+ * multiple times.
+ *
+ * Factors are printed with leading tabs.
+ */
+static void
+pr_fact(BIGNUM *val)
+{
+ const ubig *fact; /* The factor found. */
+
+ /* Firewall - catch 0 and 1. */
+ if (BN_is_zero(val)) /* Historical practice; 0 just exits. */
+ exit(0);
+ if (BN_is_one(val)) {
+ printf("1: 1\n");
+ return;
+ }
+
+ /* Factor value. */
+
+ if (hflag) {
+ fputs("0x", stdout);
+ BN_print_fp(stdout, val);
+ } else
+ BN_print_dec_fp(stdout, val);
+ putchar(':');
+ for (fact = &prime[0]; !BN_is_one(val); ++fact) {
+ /* Look for the smallest factor. */
+ do {
+ if (BN_mod_word(val, (BN_ULONG)*fact) == 0)
+ break;
+ } while (++fact <= pr_limit);
+
+ /* Watch for primes larger than the table. */
+ if (fact > pr_limit) {
+#ifdef HAVE_OPENSSL
+ BIGNUM *bnfact;
+
+ bnfact = BN_new();
+ BN_set_word(bnfact, *(fact - 1));
+ if (!BN_sqr(bnfact, bnfact, ctx))
+ errx(1, "error in BN_sqr()");
+ if (BN_cmp(bnfact, val) > 0 ||
+ BN_is_prime(val, PRIME_CHECKS,
+ NULL, NULL, NULL) == 1)
+ pr_print(val);
+ else
+ pollard_pminus1(val);
+#else
+ pr_print(val);
+#endif
+ break;
+ }
+
+ /* Divide factor out until none are left. */
+ do {
+ printf(hflag ? " 0x%" PRIx64 "" : " %" PRIu64 "", *fact);
+ BN_div_word(val, (BN_ULONG)*fact);
+ } while (BN_mod_word(val, (BN_ULONG)*fact) == 0);
+
+ /* Let the user know we're doing something. */
+ fflush(stdout);
+ }
+ putchar('\n');
+}
+
+static void
+pr_print(BIGNUM *val)
+{
+ if (hflag) {
+ fputs(" 0x", stdout);
+ BN_print_fp(stdout, val);
+ } else {
+ putchar(' ');
+ BN_print_dec_fp(stdout, val);
+ }
+}
+
+static void
+usage(void)
+{
+ fprintf(stderr, "usage: factor [-h] [value ...]\n");
+ exit(1);
+}
+
+#ifdef HAVE_OPENSSL
+
+/* pollard p-1, algorithm from Jim Gillogly, May 2000 */
+static void
+pollard_pminus1(BIGNUM *val)
+{
+ BIGNUM *base, *rbase, *num, *i, *x;
+
+ base = BN_new();
+ rbase = BN_new();
+ num = BN_new();
+ i = BN_new();
+ x = BN_new();
+
+ BN_set_word(rbase, 1);
+newbase:
+ if (!BN_add_word(rbase, 1))
+ errx(1, "error in BN_add_word()");
+ BN_set_word(i, 2);
+ BN_copy(base, rbase);
+
+ for (;;) {
+ BN_mod_exp(base, base, i, val, ctx);
+ if (BN_is_one(base))
+ goto newbase;
+
+ BN_copy(x, base);
+ BN_sub_word(x, 1);
+ if (!BN_gcd(x, x, val, ctx))
+ errx(1, "error in BN_gcd()");
+
+ if (!BN_is_one(x)) {
+ if (BN_is_prime(x, PRIME_CHECKS, NULL, NULL,
+ NULL) == 1)
+ pr_print(x);
+ else
+ pollard_pminus1(x);
+ fflush(stdout);
+
+ BN_div(num, NULL, val, x, ctx);
+ if (BN_is_one(num))
+ return;
+ if (BN_is_prime(num, PRIME_CHECKS, NULL, NULL,
+ NULL) == 1) {
+ pr_print(num);
+ fflush(stdout);
+ return;
+ }
+ BN_copy(val, num);
+ }
+ if (!BN_add_word(i, 1))
+ errx(1, "error in BN_add_word()");
+ }
+}
+
+/*
+ * Sigh.. No _decimal_ output to file functions in BN.
+ */
+static void
+BN_print_dec_fp(FILE *fp, const BIGNUM *num)
+{
+ char *buf;
+
+ buf = BN_bn2dec(num);
+ if (buf == NULL)
+ return; /* XXX do anything here? */
+ fprintf(fp, "%s", buf);
+ free(buf);
+}
+
+#else
+
+static void
+BN_print_fp(FILE *fp, const BIGNUM *num)
+{
+ fprintf(fp, "%lx", (unsigned long)*num);
+}
+
+static void
+BN_print_dec_fp(FILE *fp, const BIGNUM *num)
+{
+ fprintf(fp, "%lu", (unsigned long)*num);
+}
+
+static int
+BN_dec2bn(BIGNUM **a, const char *str)
+{
+ char *p;
+
+ errno = 0;
+ **a = strtoul(str, &p, 10);
+ return (errno == 0 && (*p == '\n' || *p == '\0'));
+}
+
+static int
+BN_hex2bn(BIGNUM **a, const char *str)
+{
+ char *p;
+
+ errno = 0;
+ **a = strtoul(str, &p, 16);
+ return (errno == 0 && (*p == '\n' || *p == '\0'));
+}
+
+static BN_ULONG
+BN_div_word(BIGNUM *a, BN_ULONG b)
+{
+ BN_ULONG mod;
+
+ mod = *a % b;
+ *a /= b;
+ return mod;
+}
+
+#endif
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