util.c

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1988, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 2002 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * Portions of this software were developed for the FreeBSD Project by
 * ThinkSec AS and NAI Labs, the Security Research Division of Network
 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
 * ("CBOSS"), as part of the DARPA CHATS research program.
 *
 * 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. 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
 *    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.
 */

#include <sys/types.h>

#include <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "chpass.h"

static const char *months[] =
	{ "January", "February", "March", "April", "May", "June",
	  "July", "August", "September", "October", "November",
	  "December", NULL };

char *
ttoa(time_t tval)
{
	struct tm *tp;
	static char tbuf[50];

	if (tval) {
		tp = localtime(&tval);
		(void)sprintf(tbuf, "%s %d, %d", months[tp->tm_mon],
		    tp->tm_mday, tp->tm_year + 1900);
	}
	else
		*tbuf = '\0';
	return (tbuf);
}

int
atot(char *p, time_t *store)
{
	static struct tm *lt;
	char *t;
	const char **mp;
	time_t tval;
	int day, month, year;

	if (!*p) {
		*store = 0;
		return (0);
	}
	if (!lt) {
		unsetenv("TZ");
		(void)time(&tval);
		lt = localtime(&tval);
	}
	if (!(t = strtok(p, " \t")))
		goto bad;
	if (isdigit(*t)) {
		month = atoi(t);
	} else {
		for (mp = months;; ++mp) {
			if (!*mp)
				goto bad;
			if (!strncasecmp(*mp, t, 3)) {
				month = mp - months + 1;
				break;
			}
		}
	}
	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
		goto bad;
	day = atoi(t);
	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
		goto bad;
	year = atoi(t);
	if (day < 1 || day > 31 || month < 1 || month > 12)
		goto bad;
	/* Allow two digit years 1969-2068 */
	if (year < 69)
		year += 2000;
	else if (year < 100)
		year += 1900;
	if (year < 1969)
bad:		return (1);
	lt->tm_year = year - 1900;
	lt->tm_mon = month - 1;
	lt->tm_mday = day;
	lt->tm_hour = 0;
	lt->tm_min = 0;
	lt->tm_sec = 0;
	lt->tm_isdst = -1;
	if ((tval = mktime(lt)) < 0)
		return (1);
#ifndef __i386__
	/*
	 * PR227589: The pwd.db and spwd.db files store the change and expire
	 * dates as unsigned 32-bit ints which overflow in 2106, so larger
	 * values must be rejected until the introduction of a v5 password
	 * database.  i386 has 32-bit time_t and so dates beyond y2038 are
	 * already rejected by mktime above.
	 */
	if (tval > UINT32_MAX)
		return (1);
#endif
	*store = tval;
	return (0);
}

int
ok_shell(char *name)
{
	char *p, *sh;

	setusershell();
	while ((sh = getusershell())) {
		if (!strcmp(name, sh)) {
			endusershell();
			return (1);
		}
		/* allow just shell name, but use "real" path */
		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
			endusershell();
			return (1);
		}
	}
	endusershell();
	return (0);
}

char *
dup_shell(char *name)
{
	char *p, *sh, *ret;

	setusershell();
	while ((sh = getusershell())) {
		if (!strcmp(name, sh)) {
			endusershell();
			return (strdup(name));
		}
		/* allow just shell name, but use "real" path */
		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
			ret = strdup(sh);
			endusershell();
			return (ret);
		}
	}
	endusershell();
	return (NULL);
}