Module Name: src
Committed By: christos
Date: Sat Oct 3 22:27:00 UTC 2020
Modified Files:
src/games/factor: factor.6 factor.c
Log Message:
PR/55693: Andreas Gustafsson: factor(6) lists factors in wrong order
Sync with FreeBSD and change their -h (that printed hex) to -x because
we were already using -h.
To generate a diff of this commit:
cvs rdiff -u -r1.14 -r1.15 src/games/factor/factor.6
cvs rdiff -u -r1.29 -r1.30 src/games/factor/factor.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/games/factor/factor.6
diff -u src/games/factor/factor.6:1.14 src/games/factor/factor.6:1.15
--- src/games/factor/factor.6:1.14 Sat Nov 11 18:48:44 2017
+++ src/games/factor/factor.6 Sat Oct 3 18:27:00 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: factor.6,v 1.14 2017/11/11 23:48:44 rin Exp $
+.\" $NetBSD: factor.6,v 1.15 2020/10/03 22:27:00 christos Exp $
.\"
.\" Copyright (c) 1989, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -35,7 +35,7 @@
.\"
.\" By Landon Curt Noll, http://www.isthe.com/chongo/index.html /\oo/\
.\"
-.Dd Nov 12, 2017
+.Dd October 3, 2020
.Dt FACTOR 6
.Os
.Sh NAME
@@ -43,7 +43,7 @@
.Nd factor a number
.Sh SYNOPSIS
.Nm
-.Op Fl h
+.Op Fl hx
.Op Ar number ...
.Sh DESCRIPTION
The
@@ -98,6 +98,10 @@ If the
.Fl h
flag is specified, factors will be printed in "human-readable" format.
If a factor x divides a value n (>1) times, it will appear as x^n.
+.It Fl x
+If the
+.Fl x
+flag is specified, factors will be printed int hexadecimal format.
.El
.Sh DIAGNOSTICS
Out of range or invalid input results in
Index: src/games/factor/factor.c
diff -u src/games/factor/factor.c:1.29 src/games/factor/factor.c:1.30
--- src/games/factor/factor.c:1.29 Tue Feb 6 11:53:27 2018
+++ src/games/factor/factor.c Sat Oct 3 18:27:00 2020
@@ -1,5 +1,4 @@
-/* $NetBSD: factor.c,v 1.29 2018/02/06 16:53:27 christos Exp $ */
-
+/* $NetBSD: factor.c,v 1.30 2020/10/03 22:27:00 christos Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
@@ -32,29 +31,34 @@
* SUCH DAMAGE.
*/
-#include <sys/cdefs.h>
#ifndef lint
+#include <sys/cdefs.h>
+#ifdef __COPYRIGHT
__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 1.29 2018/02/06 16:53:27 christos Exp $");
+ The Regents of the University of California. All rights reserved.");
+#endif
+#ifdef __SCCSID
+__SCCSID("@(#)factor.c 8.4 (Berkeley) 5/4/95");
+#endif
+#ifdef __RCSID
+__RCSID("$NetBSD: factor.c,v 1.30 2020/10/03 22:27:00 christos Exp $");
+#endif
+#ifdef __FBSDID
+__FBSDID("$FreeBSD: head/usr.bin/factor/factor.c 356666 2020-01-12 20:25:11Z gad $");
#endif
#endif /* not lint */
/*
* factor - factor a number into primes
*
- * By Landon Curt Noll, http://www.isthe.com/chongo/index.html /\oo/\
+ * By: Landon Curt Noll [email protected], ...!{sun,tolsoft}!hoptoad!chongo
+ *
+ * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
*
* usage:
- * factor [-h] [number] ...
+ * factor [-hx] [number] ...
*
- * By Default, the form of the output is:
+ * The form of the output is:
*
* number: factor1 factor1 factor2 factor3 factor3 factor3 ...
*
@@ -63,93 +67,80 @@ __RCSID("$NetBSD: factor.c,v 1.29 2018/0
* If the -h flag is specified, the output is in "human-readable" format.
* Duplicate factors are printed in the form of x^n.
*
+ * If the -x flag is specified numbers are printed in hex.
+ *
* If no number args are given, the list of numbers are read from stdin.
+ * 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 <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
-#include <inttypes.h>
+
+#include "primes.h"
#ifdef HAVE_OPENSSL
+
#include <openssl/bn.h>
+
+#define PRIME_CHECKS 5
+
+static void pollard_pminus1(BIGNUM *, int); /* print factors for big numbers */
+
#else
+
typedef long BIGNUM;
typedef u_long BN_ULONG;
-static int BN_dec2bn(BIGNUM **a, const char *str);
+
+#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))
-#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
- * up to 65537 and 65537^2 > 2^32-1.
- */
-
-#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 *, int); /* 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 int BN_dec2bn(BIGNUM **, const char *);
+static int BN_hex2bn(BIGNUM **, const char *);
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 convert_str2bn(BIGNUM **, char *);
+static bool is_hex_str(char *);
+static void pr_fact(BIGNUM *, int, int); /* print factors of a value */
+static void pr_print(BIGNUM *, int); /* print a prime */
+static void usage(void);
-#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
+static BN_CTX *ctx; /* just use a global context */
int
main(int argc, char *argv[])
{
BIGNUM *val;
- int ch, hflag;
+ int ch, hflag, xflag;
char *p, buf[LINE_MAX]; /* > max number of digits. */
-#ifdef HAVE_OPENSSL
+ hflag = xflag = 0;
ctx = BN_CTX_new();
-#endif
val = BN_new();
if (val == NULL)
errx(1, "can't initialise bignum");
- hflag = 0;
- while ((ch = getopt(argc, argv, "h")) != -1)
+ while ((ch = getopt(argc, argv, "hx")) != -1)
switch (ch) {
case 'h':
- hflag = 1;
+ hflag++;
+ break;
+ case 'x':
+ xflag++;
break;
case '?':
default:
@@ -169,20 +160,14 @@ main(int argc, char *argv[])
for (p = buf; isblank((unsigned char)*p); ++p);
if (*p == '\n' || *p == '\0')
continue;
- if (*p == '-')
- errx(1, "negative numbers aren't permitted.");
- if (BN_dec2bn(&val, buf) == 0)
- errx(1, "%s: illegal numeric format.", argv[0]);
- pr_fact(val, hflag);
+ convert_str2bn(&val, p);
+ pr_fact(val, hflag, xflag);
}
/* Factor the arguments. */
else
- for (; *argv != NULL; ++argv) {
- if (argv[0][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, hflag);
+ for (p = *argv; p != NULL; p = *++argv) {
+ convert_str2bn(&val, p);
+ pr_fact(val, hflag, xflag);
}
exit(0);
}
@@ -190,40 +175,45 @@ main(int argc, char *argv[])
/*
* pr_fact - print the factors of a number
*
- * If the number is 0 or 1, then print the number and return.
- * If the number is < 0, print -1, negate the number and continue
- * processing.
- *
* Print the factors of the number, from the lowest to the highest.
- * By default, a factor will be printed numtiple times if it divides
- * the value multiple times.
+ * A factor will be printed multiple times if it divides the value
+ * multiple times.
*
* If hflag is specified, duplicate factors are printed in "human-
* readable" form of x^n.
*
+ * If the xflag is specified, numbers will be printed in hex.
+ *
* Factors are printed with leading tabs.
*/
static void
-pr_fact(BIGNUM *val, int hflag)
+pr_fact(BIGNUM *val, int hflag, int xflag)
{
- const uint64_t *fact; /* The factor found. */
int i;
+ const uint64_t *fact; /* The factor found. */
/* Firewall - catch 0 and 1. */
- if (BN_is_zero(val) || BN_is_one(val))
- errx(1, "numbers <= 1 aren't permitted.");
+ if (BN_is_zero(val)) /* Historical practice; 0 just exits. */
+ exit(0);
+ if (BN_is_one(val)) {
+ printf("1: 1\n");
+ return;
+ }
/* Factor value. */
- BN_print_dec_fp(stdout, val);
+ if (xflag) {
+ 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. */
- while (fact <= pr_limit) {
+ do {
if (BN_mod_word(val, (BN_ULONG)*fact) == 0)
break;
- fact++;
- }
+ } while (++fact <= pr_limit);
/* Watch for primes larger than the table. */
if (fact > pr_limit) {
@@ -231,17 +221,16 @@ pr_fact(BIGNUM *val, int hflag)
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_ex(val, PRIME_CHECKS, NULL, NULL)
- == 1) {
- putchar(' ');
- BN_print_dec_fp(stdout, val);
- } else
- pollard_rho(val);
+ 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_ex(val, PRIME_CHECKS, NULL, NULL) == 1)
+ pr_print(val, xflag);
+ else
+ pollard_pminus1(val, xflag);
#else
- printf(" %s", BN_bn2dec(val));
+ pr_print(val, xflag);
#endif
break;
}
@@ -251,14 +240,15 @@ pr_fact(BIGNUM *val, int hflag)
do {
i++;
if (!hflag)
- printf(" %" PRIu64, *fact);
+ printf(xflag ? " 0x%" PRIx64 : " %" PRIu64,
+ *fact);
BN_div_word(val, (BN_ULONG)*fact);
} while (BN_mod_word(val, (BN_ULONG)*fact) == 0);
if (hflag) {
- printf(" %" PRIu64, *fact);
+ printf(xflag ? " 0x%" PRIx64 : " %" PRIu64, *fact);
if (i > 1)
- printf("^%d", i);
+ printf(xflag ? "^0x%x" : "^%d", i);
}
/* Let the user know we're doing something. */
@@ -267,121 +257,126 @@ pr_fact(BIGNUM *val, int hflag)
putchar('\n');
}
-/*
- * Sigh.. No _decimal_ output to file functions in BN.
- */
static void
-BN_print_dec_fp(FILE *fp, const BIGNUM *num)
+pr_print(BIGNUM *val, int xflag)
{
- char *buf;
-
- buf = BN_bn2dec(num);
- if (buf == NULL)
- return; /* XXX do anything here? */
- fprintf(fp, "%s", buf);
- free(buf);
+ if (xflag) {
+ fputs(" 0x", stdout);
+ BN_print_fp(stdout, val);
+ } else {
+ putchar(' ');
+ BN_print_dec_fp(stdout, val);
+ }
}
-void
+static void
usage(void)
{
fprintf(stderr, "usage: factor [-h] [value ...]\n");
- exit (0);
+ exit(1);
}
-
-
-
#ifdef HAVE_OPENSSL
+
+/* pollard p-1, algorithm from Jim Gillogly, May 2000 */
static void
-pollard_rho(BIGNUM *val)
+pollard_pminus1(BIGNUM *val, int xflag)
{
- BIGNUM *x, *y, *tmp, *num;
- BN_ULONG a;
- unsigned int steps_taken, steps_limit;
+ BIGNUM *base, *rbase, *num, *i, *x;
- x = BN_new();
- y = BN_new();
- tmp = BN_new();
+ base = BN_new();
+ rbase = BN_new();
num = BN_new();
- a = 1;
-restart:
- steps_taken = 0;
- steps_limit = 2;
- BN_set_word(x, 1);
- BN_copy(y, x);
+ i = BN_new();
+ x = BN_new();
- 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);
+ 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);
- if (!BN_is_one(tmp)) {
- if (BN_is_prime_ex(tmp, PRIME_CHECKS, 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
- }
+ 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_ex(x, PRIME_CHECKS, NULL, NULL) == 1)
+ pr_print(x, xflag);
+ else
+ pollard_pminus1(x, xflag);
fflush(stdout);
- BN_div(num, NULL, val, tmp, ctx);
+ BN_div(num, NULL, val, x, ctx);
if (BN_is_one(num))
return;
- if (BN_is_prime_ex(num, PRIME_CHECKS, NULL, NULL) == 1)
- {
- putchar(' ');
- BN_print_dec_fp(stdout, num);
+ if (BN_is_prime_ex(num, PRIME_CHECKS, NULL,
+ NULL) == 1) {
+ pr_print(num, xflag);
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;
- }
}
+ if (!BN_add_word(i, 1))
+ errx(1, "error in BN_add_word()");
}
}
-#else
-char *
-BN_bn2dec(const BIGNUM *val)
+
+/*
+ * Sigh.. No _decimal_ output to file functions in BN.
+ */
+static void
+BN_print_dec_fp(FILE *fp, const BIGNUM *num)
{
char *buf;
- buf = malloc(100);
- if (!buf)
- return buf;
- snprintf(buf, 100, "%ld", (long)*val);
- return 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 ? 1 : 0); /* OpenSSL returns 0 on error! */
+}
+
+static int
+BN_hex2bn(BIGNUM **a, const char *str)
+{
+ char *p;
+
+ errno = 0;
+ **a = strtoul(str, &p, 16);
+ return (errno == 0 ? 1 : 0); /* OpenSSL returns 0 on error! */
}
static BN_ULONG
@@ -393,4 +388,48 @@ BN_div_word(BIGNUM *a, BN_ULONG b)
*a /= b;
return mod;
}
+
#endif
+
+/*
+ * Scan the string from left-to-right to see if the longest substring
+ * is a valid hexadecimal number.
+ */
+static bool
+is_hex_str(char *str)
+{
+ char c, *p;
+ bool saw_hex = false;
+
+ for (p = str; *p; p++) {
+ if (isdigit((unsigned char)*p))
+ continue;
+ c = tolower((unsigned char)*p);
+ if (c >= 'a' && c <= 'f') {
+ saw_hex = true;
+ continue;
+ }
+ break; /* Not a hexadecimal digit. */
+ }
+ return saw_hex;
+}
+
+/* Convert string pointed to by *str to a bignum. */
+static void
+convert_str2bn(BIGNUM **val, char *p)
+{
+ int n = 0;
+
+ if (*p == '+') p++;
+ if (*p == '-')
+ errx(1, "negative numbers aren't permitted.");
+ if (*p == '0') {
+ p++;
+ if (*p == 'x' || *p == 'X')
+ n = BN_hex2bn(val, ++p);
+ } else {
+ n = is_hex_str(p) ? BN_hex2bn(val, p) : BN_dec2bn(val, p);
+ }
+ if (n == 0)
+ errx(1, "%s: illegal numeric format.", p);
+}
