/*-
 * 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);
}