-/* $NetBSD: factor.c,v 1.9 1999/09/08 21:17:48 jsm Exp $ */
+/* $NetBSD: factor.c,v 1.24 2010/05/15 21:22:39 joerg Exp $ */
/*
* Copyright (c) 1989, 1993
* 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 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.
*
#include <sys/cdefs.h>
#ifndef lint
-__COPYRIGHT("@(#) Copyright (c) 1989, 1993\n\
- The Regents of the University of California. All rights reserved.\n");
+__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
+ The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)factor.c 8.4 (Berkeley) 5/4/95";
#else
-__RCSID("$NetBSD: factor.c,v 1.9 1999/09/08 21:17:48 jsm Exp $");
+__RCSID("$NetBSD: factor.c,v 1.24 2010/05/15 21:22:39 joerg Exp $");
#endif
#endif /* not lint */
*
* number: factor1 factor1 factor2 factor3 factor3 factor3 ...
*
- * where factor1 < factor2 < factor3 < ...
+ * where factor1 <= factor2 <= factor3 <= ...
*
* If no args are given, the list of numbers are read from stdin.
*/
-#include <err.h>
#include <ctype.h>
+#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
+#ifdef HAVE_OPENSSL
+#include <openssl/bn.h>
+#else
+typedef long BIGNUM;
+typedef u_long BN_ULONG;
+static int BN_dec2bn(BIGNUM **a, const char *str);
+#define BN_new() ((BIGNUM *)calloc(sizeof(BIGNUM), 1))
+#define BN_is_zero(v) (*(v) == 0)
+#define BN_is_one(v) (*(v) == 1)
+#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))
+#endif
+
#include "primes.h"
/*
* prime[i] is the (i-1)th prime.
*
- * We are able to sieve 2^32-1 because this byte table yields all primes
+ * We are able to sieve 2^32-1 because this byte table yields all primes
* up to 65537 and 65537^2 > 2^32-1.
*/
extern const ubig prime[];
extern const ubig *pr_limit; /* largest prime in the prime array */
+#if 0 /* debugging: limit table use to stress the "pollard" code */
+#define pr_limit &prime[0]
+#endif
+
+#define PRIME_CHECKS 5
+
+#ifdef HAVE_OPENSSL
+static BN_CTX *ctx; /* just use a global context */
+#endif
+
+static void pr_fact(BIGNUM *); /* print factors of a value */
+static void BN_print_dec_fp(FILE *, const BIGNUM *);
+static void usage(void) __dead;
+#ifdef HAVE_OPENSSL
+static void pollard_rho(BIGNUM *); /* print factors for big numbers */
+#else
+static char *BN_bn2dec(const BIGNUM *);
+static BN_ULONG BN_div_word(BIGNUM *, BN_ULONG);
+#endif
-int main __P((int, char *[]));
-void pr_fact __P((ubig)); /* print factors of a value */
-void usage __P((void)) __attribute__((__noreturn__));
+
+#ifndef HAVE_OPENSSL
+static int
+BN_dec2bn(BIGNUM **a, const char *str)
+{
+ char *p;
+
+ errno = 0;
+ **a = strtoul(str, &p, 10);
+ if (errno)
+ err(1, "%s", str);
+ return (*p == '\n' || *p == '\0');
+}
+#endif
int
-main(argc, argv)
- int argc;
- char *argv[];
+main(int argc, char *argv[])
{
- ubig val;
+ BIGNUM *val;
int ch;
- char *p, buf[100]; /* > max number of digits. */
+ char *p, buf[LINE_MAX]; /* > max number of digits. */
+
+#ifdef HAVE_OPENSSL
+ ctx = BN_CTX_new();
+#endif
+ val = BN_new();
+ if (val == NULL)
+ errx(1, "can't initialise bignum");
while ((ch = getopt(argc, argv, "")) != -1)
switch (ch) {
err(1, "stdin");
exit (0);
}
- for (p = buf; isblank(*p); ++p);
+ for (p = buf; isblank((unsigned char)*p); ++p);
if (*p == '\n' || *p == '\0')
continue;
if (*p == '-')
errx(1, "negative numbers aren't permitted.");
- errno = 0;
- val = strtoul(buf, &p, 10);
- if (errno)
- err(1, "%s", buf);
- if (*p != '\n')
- errx(1, "%s: illegal numeric format.", buf);
+ if (BN_dec2bn(&val, buf) == 0)
+ errx(1, "%s: illegal numeric format.", argv[0]);
pr_fact(val);
}
/* Factor the arguments. */
else
for (; *argv != NULL; ++argv) {
if (argv[0][0] == '-')
- errx(1, "negative numbers aren't permitted.");
- errno = 0;
- val = strtoul(argv[0], &p, 10);
- if (errno)
- err(1, "%s", argv[0]);
- if (*p != '\0')
+ errx(1, "numbers <= 1 aren't permitted.");
+ if (BN_dec2bn(&val, argv[0]) == 0)
errx(1, "%s: illegal numeric format.", argv[0]);
pr_fact(val);
}
*
* Factors are printed with leading tabs.
*/
-void
-pr_fact(val)
- ubig val; /* Factor this value. */
+static void
+pr_fact(BIGNUM *val)
{
const ubig *fact; /* The factor found. */
/* Firewall - catch 0 and 1. */
- if (val == 0) /* Historical practice; 0 just exits. */
- exit(0);
- if (val == 1) {
- (void)printf("1: 1\n");
- return;
- }
+ if (BN_is_zero(val) || BN_is_one(val))
+ errx(1, "numbers <= 1 aren't permitted.");
/* Factor value. */
- (void)printf("%lu:", val);
- for (fact = &prime[0]; val > 1; ++fact) {
+
+ BN_print_dec_fp(stdout, val);
+ putchar(':');
+ for (fact = &prime[0]; !BN_is_one(val); ++fact) {
/* Look for the smallest factor. */
- do {
- if (val % (long)*fact == 0)
+ while (fact <= pr_limit) {
+ if (BN_mod_word(val, (BN_ULONG)*fact) == 0)
break;
- } while (++fact <= pr_limit);
+ fact++;
+ }
/* Watch for primes larger than the table. */
if (fact > pr_limit) {
- (void)printf(" %lu", val);
+#ifdef HAVE_OPENSSL
+ BIGNUM *bnfact;
+
+ bnfact = BN_new();
+ BN_set_word(bnfact, (BN_ULONG)*(fact - 1));
+ BN_sqr(bnfact, bnfact, ctx);
+ if (BN_cmp(bnfact, val) > 0
+ || BN_is_prime(val, PRIME_CHECKS, NULL, NULL,
+ NULL) == 1) {
+ putchar(' ');
+ BN_print_dec_fp(stdout, val);
+ } else
+ pollard_rho(val);
+#else
+ printf(" %s", BN_bn2dec(val));
+#endif
break;
}
/* Divide factor out until none are left. */
do {
- (void)printf(" %lu", *fact);
- val /= (long)*fact;
- } while ((val % (long)*fact) == 0);
+ printf(" %lu", *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. */
- (void)fflush(stdout);
+ fflush(stdout);
}
- (void)putchar('\n');
+ putchar('\n');
+}
+
+/*
+ * 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, buf);
+ free(buf);
}
void
-usage()
+usage(void)
{
- (void)fprintf(stderr, "usage: factor [value ...]\n");
+ fprintf(stderr, "usage: factor [value ...]\n");
exit (0);
}
+
+
+
+
+#ifdef HAVE_OPENSSL
+static void
+pollard_rho(BIGNUM *val)
+{
+ BIGNUM *x, *y, *tmp, *num;
+ BN_ULONG a;
+ unsigned int steps_taken, steps_limit;
+
+ x = BN_new();
+ y = BN_new();
+ tmp = BN_new();
+ num = BN_new();
+ a = 1;
+restart:
+ steps_taken = 0;
+ steps_limit = 2;
+ BN_set_word(x, 1);
+ BN_copy(y, x);
+
+ for (;;) {
+ BN_sqr(tmp, x, ctx);
+ BN_add_word(tmp, a);
+ BN_mod(x, tmp, val, ctx);
+ BN_sub(tmp, x, y);
+ if (BN_is_zero(tmp)) {
+#ifdef DEBUG
+ printf(" (loop)");
+#endif
+ a++;
+ goto restart;
+ }
+ BN_gcd(tmp, tmp, val, ctx);
+
+ if (!BN_is_one(tmp)) {
+ if (BN_is_prime(tmp, PRIME_CHECKS, NULL, NULL,
+ NULL) == 1) {
+ putchar(' ');
+ BN_print_dec_fp(stdout, tmp);
+ } else {
+#ifdef DEBUG
+ printf(" (recurse for ");
+ BN_print_dec_fp(stdout, tmp);
+ putchar(')');
+#endif
+ pollard_rho(BN_dup(tmp));
+#ifdef DEBUG
+ printf(" (back)");
+#endif
+ }
+ fflush(stdout);
+
+ BN_div(num, NULL, val, tmp, ctx);
+ if (BN_is_one(num))
+ return;
+ if (BN_is_prime(num, PRIME_CHECKS, NULL, NULL,
+ NULL) == 1) {
+ putchar(' ');
+ BN_print_dec_fp(stdout, num);
+ fflush(stdout);
+ return;
+ }
+ BN_copy(val, num);
+ goto restart;
+ }
+ steps_taken++;
+ if (steps_taken == steps_limit) {
+ BN_copy(y, x); /* teleport the turtle */
+ steps_taken = 0;
+ steps_limit *= 2;
+ if (steps_limit == 0) {
+#ifdef DEBUG
+ printf(" (overflow)");
+#endif
+ a++;
+ goto restart;
+ }
+ }
+ }
+}
+#else
+char *
+BN_bn2dec(const BIGNUM *val)
+{
+ char *buf;
+
+ buf = malloc(100);
+ if (!buf)
+ return buf;
+ snprintf(buf, 100, "%ld", (long)*val);
+ return buf;
+}
+
+static BN_ULONG
+BN_div_word(BIGNUM *a, BN_ULONG b)
+{
+ BN_ULONG mod;
+
+ mod = *a % b;
+ *a /= b;
+ return mod;
+}
+#endif
git.ckatri.com / bsdgames-darwin.git / blobdiff