/*
 * Copyright 1989 - 1994, Julianne Frances Haugh
 * All rights reserved.
 *
 * 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 Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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 <config.h>

#include "rcsid.h"
RCSID (PKG_VER "$Id: chage.c,v 1.49 2005/07/11 16:12:38 kloczek Exp $")
#include <ctype.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <time.h>
#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/pam_misc.h>
#endif				/* USE_PAM */
#include <pwd.h>
#ifdef WITH_SELINUX
#include <selinux/selinux.h>
#include <selinux/av_permissions.h>
#endif
#include "prototypes.h"
#include "defines.h"
#include "pwio.h"
#include "shadowio.h"
/*
 * Global variables
 */
static char *Prog;

static int
 dflg = 0,			/* set last password change date */
    Eflg = 0,			/* set account expiration date */
    Iflg = 0,			/* set password inactive after expiration */
    lflg = 0,			/* show account aging information */
    mflg = 0,			/* set minimum number of days before password change */
    Mflg = 0,			/* set maximim number of days before password change */
    Wflg = 0;			/* set expiration warning days */

static int locks;

static long mindays;
static long maxdays;
static long lastday;
static long warndays;
static long inactdays;
static long expdays;

#define	EPOCH		"1969-12-31"


/*
 * exit status values
 */
#define E_SUCCESS	0	/* success */
#define E_NOPERM	1	/* permission denied */
#define E_USAGE 	2	/* invalid command syntax */

/* local function prototypes */
static void usage (void);
static void date_to_str (char *, size_t, time_t);
static int new_fields (void);
static void print_date (time_t);
static void list_fields (void);
static void cleanup (int);

/*
 * isnum - determine whether or not a string is a number
 */
int isnum (const char *s)
{
	while (*s) {
		if (!isdigit (*s))
			return 0;
		s++;
	}
	return 1;
}

/*
 * usage - print command line syntax and exit
 */

static void usage (void)
{
	fprintf (stderr, _("Usage: chage [options] user\n"
			   "\n"
			   "Options:\n"
			   "  -d, --lastday LAST_DAY	set last password change to LAST_DAY\n"
			   "  -E, --expiredate EXPIRE_DATE	set account expiration date to EXPIRE_DATE\n"
			   "  -h, --help			display this help message and exit\n"
			   "  -I, --inactive INACTIVE	set password inactive after expiration\n"
			   "				to INACTIVE\n"
			   "  -l, --list			show account aging information\n"
			   "  -m, --mindays MIN_DAYS	set minimum number of days before password\n"
			   "				change to MIN_DAYS\n"
			   "  -M, --maxdays MAX_DAYS	set maximim number of days before password\n"
			   "				change to MAX_DAYS\n"
			   "  -W, --warndays WARN_DAYS	set expiration warning days to WARN_DAYS\n"));
	exit (E_USAGE);
}

static void date_to_str (char *buf, size_t maxsize, time_t date)
{
	struct tm *tp;

	tp = gmtime (&date);
#ifdef HAVE_STRFTIME
	strftime (buf, maxsize, "%Y-%m-%d", tp);
#else
	snprintf (buf, maxsize, "%04d-%02d-%02d",
		  tp->tm_year + 1900, tp->tm_mon + 1, tp->tm_mday);
#endif				/* HAVE_STRFTIME */
}

/*
 * new_fields - change the user's password aging information interactively.
 *
 * prompt the user for all of the password age values. set the fields
 * from the user's response, or leave alone if nothing was entered. The
 * value (-1) is used to indicate the field should be removed if possible.
 * any other negative value is an error. very large positive values will
 * be handled elsewhere.
 */

static int new_fields (void)
{
	char buf[200];
	char *cp;

	printf (_("Enter the new value, or press ENTER for the default\n"));
	printf ("\n");

	snprintf (buf, sizeof buf, "%ld", mindays);
	change_field (buf, sizeof buf, _("Minimum Password Age"));
	if (((mindays = strtol (buf, &cp, 10)) == 0 && *cp)
	    || mindays < -1)
		return 0;

	snprintf (buf, sizeof buf, "%ld", maxdays);
	change_field (buf, sizeof buf, _("Maximum Password Age"));
	if (((maxdays = strtol (buf, &cp, 10)) == 0 && *cp)
	    || maxdays < -1)
		return 0;

	date_to_str (buf, sizeof buf, lastday * SCALE);

	change_field (buf, sizeof buf, _("Last Password Change (YYYY-MM-DD)"));

	if (strcmp (buf, EPOCH) == 0)
		lastday = -1;
	else if ((lastday = strtoday (buf)) == -1)
		return 0;

	snprintf (buf, sizeof buf, "%ld", warndays);
	change_field (buf, sizeof buf, _("Password Expiration Warning"));
	if (((warndays = strtol (buf, &cp, 10)) == 0 && *cp)
	    || warndays < -1)
		return 0;

	snprintf (buf, sizeof buf, "%ld", inactdays);
	change_field (buf, sizeof buf, _("Password Inactive"));
	if (((inactdays = strtol (buf, &cp, 10)) == 0 && *cp)
	    || inactdays < -1)
		return 0;

	date_to_str (buf, sizeof buf, expdays * SCALE);

	change_field (buf, sizeof buf,
		      _("Account Expiration Date (YYYY-MM-DD)"));

	if (strcmp (buf, EPOCH) == 0)
		expdays = -1;
	else if ((expdays = strtoday (buf)) == -1)
		return 0;

	return 1;
}

static void print_date (time_t date)
{
#ifdef HAVE_STRFTIME
	struct tm *tp;
	char buf[80];

	tp = gmtime (&date);
	strftime (buf, sizeof buf, "%b %d, %Y", tp);
	puts (buf);
#else
	struct tm *tp;
	char *cp;

	tp = gmtime (&date);
	cp = asctime (tp);
	printf ("%6.6s, %4.4s\n", cp + 4, cp + 20);
#endif
}

/*
 * list_fields - display the current values of the expiration fields
 *
 * display the password age information from the password fields. Date
 * values will be displayed as a calendar date, or the word "never" if
 * the date is 1/1/70, which is day number 0.
 */

static void list_fields (void)
{
	long changed = 0;
	long expires;

	/*
	 * The "last change" date is either "never" or the date the password
	 * was last modified. The date is the number of days since 1/1/1970.
	 */

	printf (_("Last password change\t\t\t\t\t: "));
	if (lastday <= 0) {
		printf (_("never\n"));
	} else {
		changed = lastday * SCALE;
		print_date (changed);
	}

	/*
	 * The password expiration date is determined from the last change
	 * date plus the number of days the password is valid for.
	 */

	printf (_("Password expires\t\t\t\t\t: "));
	if (lastday <= 0 || maxdays >= 10000 * (DAY / SCALE)
	    || maxdays <= 0) {
		printf (_("never\n"));
	} else {
		expires = changed + maxdays * SCALE;
		print_date (expires);
	}

	/*
	 * The account becomes inactive if the password is expired for more
	 * than "inactdays". The expiration date is calculated and the
	 * number of inactive days is added. The resulting date is when the
	 * active will be disabled.
	 */

	printf (_("Password inactive\t\t\t\t\t: "));
	if (lastday <= 0 || inactdays <= 0 ||
	    maxdays >= 10000 * (DAY / SCALE) || maxdays <= 0) {
		printf (_("never\n"));
	} else {
		expires = changed + (maxdays + inactdays) * SCALE;
		print_date (expires);
	}

	/*
	 * The account will expire on the given date regardless of the
	 * password expiring or not.
	 */

	printf (_("Account expires\t\t\t\t\t\t: "));
	if (expdays <= 0) {
		printf (_("never\n"));
	} else {
		expires = expdays * SCALE;
		print_date (expires);
	}

	/*
	 * Start with the easy numbers - the number of days before the
	 * password can be changed, the number of days after which the
	 * password must be chaged, the number of days before the password
	 * expires that the user is told, and the number of days after the
	 * password expires that the account becomes unusable.
	 */

	printf (_("Minimum number of days between password change\t\t: %ld\n"),
		mindays);
	printf (_("Maximum number of days between password change\t\t: %ld\n"),
		maxdays);
	printf (_("Number of days of warning before password expires\t: %ld\n"),
		warndays);
}

#ifdef USE_PAM
static struct pam_conv conv = {
	misc_conv,
	NULL
};
#endif				/* USE_PAM */

/*
 * cleanup - unlock any locked password files
 */

static void cleanup (int state)
{
	switch (state) {
	case 2:
		if (locks)
			spw_unlock ();
	case 1:
		if (locks)
			pw_unlock ();
	case 0:
		break;
	}
}

/*
 * chage - change a user's password aging information
 *
 *	This command controls the password aging information.
 *
 *	The valid options are
 *
 *	-d	set last password change date (*)
 *	-E	set account expiration date (*)
 *	-I	set password inactive after expiration (*)
 *	-l	show account aging information
 *	-M	set maximim number of days before password change (*)
 *	-m	set minimum number of days before password change (*)
 *	-W	set expiration warning days (*)
 *
 *	(*) requires root permission to execute.
 *
 *	All of the time fields are entered in the internal format which is
 *	either seconds or days.
 */

int main (int argc, char **argv)
{
	int flag;
	const struct spwd *sp;
	struct spwd spwd;
	uid_t ruid;
	int amroot, pwrw;
	const struct passwd *pw;
	struct passwd pwent;
	char name[BUFSIZ];

#ifdef USE_PAM
	pam_handle_t *pamh = NULL;
	struct passwd *pampw;
	int retval;
#endif

	sanitize_env ();
	setlocale (LC_ALL, "");
	bindtextdomain (PACKAGE, LOCALEDIR);
	textdomain (PACKAGE);

	ruid = getuid ();
#ifdef WITH_SELINUX
	amroot = (ruid == 0 && checkPasswdAccess (PASSWD__ROOTOK) == 0);
#else
	amroot = (ruid == 0);
#endif

	/*
	 * Get the program name so that error messages can use it.
	 */
	Prog = Basename (argv[0]);

	{
		/*
		 * Parse the command line options.
		 */
		int option_index = 0;
		int c;
		static struct option long_options[] = {
			{"lastday", required_argument, NULL, 'd'},
			{"expiredate", required_argument, NULL, 'E'},
			{"help", no_argument, NULL, 'h'},
			{"inactive", required_argument, NULL, 'I'},
			{"list", no_argument, NULL, 'l'},
			{"mindays", required_argument, NULL, 'm'},
			{"maxdays", required_argument, NULL, 'M'},
			{"warndays", required_argument, NULL, 'W'},
			{NULL, 0, NULL, '\0'}
		};

		while ((c =
			getopt_long (argc, argv, "d:E:hI:lm:M:W:", long_options,
				     &option_index)) != -1) {
			switch (c) {
			case 'd':
				dflg++;
				if (!isnum (optarg))
					lastday = strtoday (optarg);
				else
					lastday = strtol (optarg, 0, 10);
				break;
			case 'E':
				Eflg++;
				if (!isnum (optarg))
					expdays = strtoday (optarg);
				else
					expdays = strtol (optarg, 0, 10);
				break;
			case 'h':
				usage ();
				break;
			case 'I':
				Iflg++;
				inactdays = strtol (optarg, 0, 10);
				break;
			case 'l':
				lflg++;
				break;
			case 'm':
				mflg++;
				mindays = strtol (optarg, 0, 10);
				break;
			case 'M':
				Mflg++;
				maxdays = strtol (optarg, 0, 10);
				break;
			case 'W':
				Wflg++;
				warndays = strtol (optarg, 0, 10);
				break;
			default:
				usage ();
			}
		}
	}

	/*
	 * Make certain the flags do not conflict and that there is a user
	 * name on the command line.
	 */

	if (argc != optind + 1)
		usage ();

	if (lflg && (mflg || Mflg || dflg || Wflg || Iflg || Eflg)) {
		fprintf (stderr,
			 _("%s: do not include \"l\" with other flags\n"),
			 Prog);
		usage ();
	}

	/*
	 * An unprivileged user can ask for their own aging information, but
	 * only root can change it, or list another user's aging
	 * information.
	 */

	if (!amroot && !lflg) {
		fprintf (stderr, _("%s: Permission denied.\n"), Prog);
		exit (E_NOPERM);
	}

	OPENLOG ("chage");

#ifdef USE_PAM
	retval = PAM_SUCCESS;

	pampw = getpwuid (getuid ());
	if (pampw == NULL) {
		retval = PAM_USER_UNKNOWN;
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_start ("chage", pampw->pw_name, &conv, &pamh);
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_authenticate (pamh, 0);
		if (retval != PAM_SUCCESS) {
			pam_end (pamh, retval);
		}
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_acct_mgmt (pamh, 0);
		if (retval != PAM_SUCCESS) {
			pam_end (pamh, retval);
		}
	}

	if (retval != PAM_SUCCESS) {
		fprintf (stderr, _("%s: PAM authentication failed\n"), Prog);
		exit (E_NOPERM);
	}
#endif				/* USE_PAM */

	/*
	 * We use locks for read-write accesses only (locks implies amroot,
	 * but amroot doesn't imply locks).
	 */
	locks = !lflg;

	/*
	 * Lock and open the password file. This loads all of the password
	 * file entries into memory. Then we get a pointer to the password
	 * file entry for the requested user.
	 */
	pwrw = 0;
	if (!pw_open (pwrw ? O_RDWR : O_RDONLY)) {
		fprintf (stderr, _("%s: can't open password file\n"), Prog);
		cleanup (1);
		SYSLOG ((LOG_ERR, "failed opening %s", PASSWD_FILE));
		closelog ();
		exit (E_NOPERM);
	}
	if (!(pw = pw_locate (argv[optind]))) {
		fprintf (stderr, _("%s: unknown user %s\n"), Prog,
			 argv[optind]);
		cleanup (1);
		closelog ();
		exit (E_NOPERM);
	}

	pwent = *pw;
	STRFCPY (name, pwent.pw_name);

	/*
	 * For shadow password files we have to lock the file and read in
	 * the entries as was done for the password file. The user entries
	 * does not have to exist in this case; a new entry will be created
	 * for this user if one does not exist already.
	 */
	if (locks && !spw_lock ()) {
		fprintf (stderr,
			 _("%s: can't lock shadow password file\n"), Prog);
		cleanup (1);
		SYSLOG ((LOG_ERR, "failed locking %s", SHADOW_FILE));
		closelog ();
		exit (E_NOPERM);
	}
	if (!spw_open (locks ? O_RDWR : O_RDONLY)) {
		fprintf (stderr,
			 _("%s: can't open shadow password file\n"), Prog);
		cleanup (2);
		SYSLOG ((LOG_ERR, "failed opening %s", SHADOW_FILE));
		closelog ();
		exit (E_NOPERM);
	}

	if (lflg && (setgid (getgid ()) || setuid (ruid))) {
		fprintf (stderr, "%s: failed to drop privileges (%s)\n",
			 Prog, strerror (errno));
		exit (E_NOPERM);
	}

	sp = spw_locate (argv[optind]);

	/*
	 * Set the fields that aren't being set from the command line from
	 * the password file.
	 */

	if (sp) {
		spwd = *sp;

		if (!Mflg)
			maxdays = spwd.sp_max;
		if (!mflg)
			mindays = spwd.sp_min;
		if (!dflg)
			lastday = spwd.sp_lstchg;
		if (!Wflg)
			warndays = spwd.sp_warn;
		if (!Iflg)
			inactdays = spwd.sp_inact;
		if (!Eflg)
			expdays = spwd.sp_expire;
	}

	/*
	 * Print out the expiration fields if the user has requested the
	 * list option.
	 */

	if (lflg) {
		if (!amroot && (ruid != pwent.pw_uid)) {
			fprintf (stderr, _("%s: Permission denied.\n"), Prog);
			closelog ();
			exit (E_NOPERM);
		}
		list_fields ();
		cleanup (2);
		closelog ();
		exit (E_SUCCESS);
	}

	/*
	 * If none of the fields were changed from the command line, let the
	 * user interactively change them.
	 */

	if (!mflg && !Mflg && !dflg && !Wflg && !Iflg && !Eflg) {
		printf (_("Changing the aging information for %s\n"), name);
		if (!new_fields ()) {
			fprintf (stderr, _("%s: error changing fields\n"),
				 Prog);
			cleanup (2);
			closelog ();
			exit (E_NOPERM);
		}
	}
	/*
	 * There was no shadow entry. The new entry will have the encrypted
	 * password transferred from the normal password file along with the
	 * aging information.
	 */

	if (sp == 0) {
		sp = &spwd;
		memzero (&spwd, sizeof spwd);

		spwd.sp_namp = xstrdup (pwent.pw_name);
		spwd.sp_pwdp = xstrdup (pwent.pw_passwd);
		spwd.sp_flag = -1;

		pwent.pw_passwd = SHADOW_PASSWD_STRING;	/* XXX warning: const */
		if (!pw_update (&pwent)) {
			fprintf (stderr,
				 _("%s: can't update password file\n"), Prog);
			cleanup (2);
			SYSLOG ((LOG_ERR, "failed updating %s", PASSWD_FILE));
			closelog ();
			exit (E_NOPERM);
		}
	}

	/*
	 * Copy the fields back to the shadow file entry and write the
	 * modified entry back to the shadow file. Closing the shadow and
	 * password files will commit any changes that have been made.
	 */

	spwd.sp_max = maxdays;
	spwd.sp_min = mindays;
	spwd.sp_lstchg = lastday;
	spwd.sp_warn = warndays;
	spwd.sp_inact = inactdays;
	spwd.sp_expire = expdays;

	if (!spw_update (&spwd)) {
		fprintf (stderr,
			 _("%s: can't update shadow password file\n"), Prog);
		cleanup (2);
		SYSLOG ((LOG_ERR, "failed updating %s", SHADOW_FILE));
		closelog ();
		exit (E_NOPERM);
	}

	/*
	 * Now close the shadow password file, which will cause all of the
	 * entries to be re-written.
	 */
	if (!spw_close ()) {
		fprintf (stderr,
			 _("%s: can't rewrite shadow password file\n"), Prog);
		cleanup (2);
		SYSLOG ((LOG_ERR, "failed rewriting %s", SHADOW_FILE));
		closelog ();
		exit (E_NOPERM);
	}
#ifdef USE_PAM
	retval = PAM_SUCCESS;

	pampw = getpwuid (getuid ());
	if (pampw == NULL) {
		retval = PAM_USER_UNKNOWN;
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_start ("chage", pampw->pw_name, &conv, &pamh);
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_authenticate (pamh, 0);
		if (retval != PAM_SUCCESS) {
			pam_end (pamh, retval);
		}
	}

	if (retval == PAM_SUCCESS) {
		retval = pam_acct_mgmt (pamh, 0);
		if (retval != PAM_SUCCESS) {
			pam_end (pamh, retval);
		}
	}

	if (retval != PAM_SUCCESS) {
		fprintf (stderr, _("%s: PAM authentication failed\n"), Prog);
		exit (E_NOPERM);
	}
#endif				/* USE_PAM */

	/*
	 * Close the password file. If any entries were modified, the file
	 * will be re-written.
	 */

	if (!pw_close ()) {
		fprintf (stderr, _("%s: can't rewrite password file\n"), Prog);
		cleanup (2);
		SYSLOG ((LOG_ERR, "failed rewriting %s", PASSWD_FILE));
		closelog ();
		exit (E_NOPERM);
	}
	cleanup (2);
	SYSLOG ((LOG_INFO, "changed password expiry for %s", name));

#ifdef USE_PAM
	if (!lflg) {
		if (retval == PAM_SUCCESS) {
			retval = pam_chauthtok (pamh, 0);
			if (retval != PAM_SUCCESS) {
				pam_end (pamh, retval);
			}
		}

		if (retval != PAM_SUCCESS) {
			fprintf (stderr, _("%s: PAM chauthtok failed\n"), Prog);
			exit (E_NOPERM);
		}
	}

	if (retval == PAM_SUCCESS)
		pam_end (pamh, PAM_SUCCESS);

#endif				/* USE_PAM */

	closelog ();
	exit (E_SUCCESS);
}