/*
 * 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 1.27 2002/01/05 15:41:43 kloczek Exp $")
#include <sys/types.h>
#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#include <ctype.h>
#include <time.h>
#include "prototypes.h"
#include "defines.h"
#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/pam_misc.h>
#endif				/* USE_PAM */
#include <pwd.h>
/*
 * Global variables
 */
static char *Prog;

static int locks;

static long mindays;
static long maxdays;
static long lastday;

#ifdef	SHADOWPWD
static long warndays;
static long inactdays;
static long expdays;
#endif

/*
 * External identifiers
 */

extern long a64l ();
extern char *l64a ();

#include "pwio.h"

#ifdef	SHADOWPWD
#include "shadowio.h"
#endif

#ifdef	NDBM
extern int pw_dbm_mode;

#ifdef	SHADOWPWD
extern int sp_dbm_mode;
#endif
#endif

#define	EPOCH		"1969-12-31"

/* 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)
{
#ifdef SHADOWPWD
	fprintf (stderr,
		 _("Usage: %s [-l] [-m min_days] [-M max_days] [-W warn]\n"
		   "\t[-I inactive] [-E expire] [-d last_day] user\n"),
		 Prog);
#else
	fprintf (stderr,
		 _
		 ("Usage: %s [-l] [-m min_days] [-M max_days] [-d last_day] user\n"),
		 Prog);
#endif
	exit (1);
}

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\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;

#ifdef	SHADOWPWD
	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;
#endif				/* SHADOWPWD */

	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;

	/*
	 * 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:\t%ld\n"), mindays);
	printf (_("Maximum:\t%ld\n"), maxdays);
#ifdef SHADOWPWD
	printf (_("Warning:\t%ld\n"), warndays);
	printf (_("Inactive:\t%ld\n"), inactdays);
#endif

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

#ifdef	SHADOWPWD
	/*
	 * 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"));
	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"));
	if (expdays <= 0) {
		printf (_("Never\n"));
	} else {
		expires = expdays * SCALE;
		print_date (expires);
	}
#endif
}

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

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

int main (int argc, char **argv)
{
	int flag;
	int lflg = 0;
	int mflg = 0;
	int Mflg = 0;
	int dflg = 0;

#ifdef	SHADOWPWD
	int Wflg = 0;
	int Iflg = 0;
	int Eflg = 0;
	const struct spwd *sp;
	struct spwd spwd;
#else
	char new_age[5];
#endif
	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 ();
	amroot = (ruid == 0);

	/*
	 * Get the program name so that error messages can use it.
	 */

	Prog = Basename (argv[0]);

	OPENLOG ("chage");

#ifdef	NDBM
#ifdef	SHADOWPWD
	sp_dbm_mode = O_RDWR;
#endif
	pw_dbm_mode = O_RDWR;
#endif

	/*
	 * Parse the flags. The difference between password file formats
	 * includes the number of fields, and whether the dates are entered
	 * as days or weeks. Shadow password file info =must= be entered in
	 * days, while regular password file info =must= be entered in
	 * weeks.
	 */

#ifdef SHADOWPWD
#define FLAGS "lm:M:W:I:E:d:"
#else
#define FLAGS "lm:M:d:"
#endif
	while ((flag = getopt (argc, argv, FLAGS)) != EOF) {
#undef FLAGS
		switch (flag) {
		case 'l':
			lflg++;
			break;
		case 'm':
			mflg++;
			mindays = strtol (optarg, 0, 10);
			break;
		case 'M':
			Mflg++;
			maxdays = strtol (optarg, 0, 10);
			break;
		case 'd':
			dflg++;
			if (!isnum (optarg))
				lastday = strtoday (optarg);
			else
				lastday = strtol (optarg, 0, 10);
			break;
#ifdef	SHADOWPWD
		case 'W':
			Wflg++;
			warndays = strtol (optarg, 0, 10);
			break;
		case 'I':
			Iflg++;
			inactdays = strtol (optarg, 0, 10);
			break;
		case 'E':
			Eflg++;
			if (!isnum (optarg))
				expdays = strtoday (optarg);
			else
				expdays = strtol (optarg, 0, 10);
			break;
#endif
		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 ();

#ifdef	SHADOWPWD
	if (lflg && (mflg || Mflg || dflg || Wflg || Iflg || Eflg))
#else
	if (lflg && (mflg || Mflg || dflg))
#endif
	{
		fprintf (stderr,
			 _("%s: do not include \"l\" with other flags\n"),
			 Prog);
		closelog ();
		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);
		closelog ();
		exit (1);
	}
#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 (1);
	}

	OPENLOG ("chage");
#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.
	 */
#ifndef SHADOWPWD
	if (locks && !pw_lock ()) {
		fprintf (stderr, _("%s: can't lock password file\n"),
			 Prog);
		SYSLOG ((LOG_ERR, "failed locking %s", PASSWD_FILE));
		closelog ();
		exit (1);
	}
	pwrw = locks;
#else
	pwrw = 0;
#endif
	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 (1);
	}
	if (!(pw = pw_locate (argv[optind]))) {
		fprintf (stderr, _("%s: unknown user: %s\n"), Prog,
			 argv[optind]);
		cleanup (1);
		closelog ();
		exit (1);
	}

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

#ifdef	SHADOWPWD
	/*
	 * 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"), Prog);
		cleanup (1);
		SYSLOG ((LOG_ERR, "failed locking %s", SHADOW_FILE));
		closelog ();
		exit (1);
	}
	if (!spw_open (locks ? O_RDWR : O_RDONLY)) {
		fprintf (stderr,
			 _("%s: can't open shadow password file"), Prog);
		cleanup (2);
		SYSLOG ((LOG_ERR, "failed opening %s", SHADOW_FILE));
		closelog ();
		exit (1);
	}

	if (lflg && (setgid (getgid ()) || setuid (ruid))) {
		fprintf (stderr, "%s: failed to drop privileges (%s)\n",
			 Prog, strerror (errno));
		exit (1);
	}

	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;
	}
#ifdef	ATT_AGE
	else
#endif				/* ATT_AGE */
#endif				/* SHADOWPWD */
#ifdef	ATT_AGE
	{
		if (pwent.pw_age && strlen (pwent.pw_age) >= 2) {
			if (!Mflg)
				maxdays =
				    c64i (pwent.pw_age[0]) * (WEEK /
							      SCALE);
			if (!mflg)
				mindays =
				    c64i (pwent.pw_age[1]) * (WEEK /
							      SCALE);
			if (!dflg && strlen (pwent.pw_age) == 4)
				lastday =
				    a64l (pwent.pw_age +
					  2) * (WEEK / SCALE);
		} else {
			mindays = 0;
			maxdays = 10000L * (DAY / SCALE);
			lastday = -1;
		}
#ifdef	SHADOWPWD
		warndays = inactdays = expdays = -1;
#endif				/* SHADOWPWD */
	}
#endif				/* ATT_AGE */

	/*
	 * 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 (1);
		}
		list_fields ();
		cleanup (2);
		closelog ();
		exit (0);
	}

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

#ifdef	SHADOWPWD
	if (!mflg && !Mflg && !dflg && !Wflg && !Iflg && !Eflg)
#else
	if (!mflg && !Mflg && !dflg)
#endif
	{
		printf (_("Changing the aging information for %s\n"),
			name);
		if (!new_fields ()) {
			fprintf (stderr, _("%s: error changing fields\n"),
				 Prog);
			cleanup (2);
			closelog ();
			exit (1);
		}
	}
#ifdef	SHADOWPWD
	/*
	 * 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 */
#ifdef	ATT_AGE
		pwent.pw_age = "";
#endif
		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 (1);
		}
#ifdef NDBM
		(void) pw_dbm_update (&pwent);
		endpwent ();
#endif
	}
#endif				/* SHADOWPWD */

#ifdef	SHADOWPWD

	/*
	 * 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 (1);
	}
#else				/* !SHADOWPWD */

	/*
	 * fill in the new_age string with the new values
	 */

	if (maxdays > (63 * 7) && mindays == 0) {
		new_age[0] = '\0';
	} else {
		if (maxdays > (63 * 7))
			maxdays = 63 * 7;

		if (mindays > (63 * 7))
			mindays = 63 * 7;

		new_age[0] = i64c (maxdays / 7);
		new_age[1] = i64c ((mindays + 6) / 7);

		if (lastday == 0)
			new_age[2] = '\0';
		else
			strcpy (new_age + 2, l64a (lastday / 7));

	}
	pwent.pw_age = new_age;

	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 (1);
	}
#endif				/* SHADOWPWD */

#ifdef	NDBM
#ifdef	SHADOWPWD

	/*
	 * See if the shadow DBM file exists and try to update it.
	 */

	if (sp_dbm_present () && !sp_dbm_update (&spwd)) {
		fprintf (stderr,
			 _("Error updating the DBM password entry.\n"));
		cleanup (2);
		SYSLOG ((LOG_ERR, "error updating DBM passwd entry"));
		closelog ();
		exit (1);
	}
	endspent ();

#else				/* !SHADOWPWD */

	/*
	 * See if the password DBM file exists and try to update it.
	 */

	if (pw_dbm_present () && !pw_dbm_update (&pwent)) {
		fprintf (stderr,
			 _("Error updating the DBM password entry.\n"));
		cleanup (2);
		SYSLOG ((LOG_ERR, "error updating DBM passwd entry"));
		closelog ();
		exit (1);
	}
	endpwent ();
#endif				/* SHADOWPWD */
#endif				/* NDBM */

#ifdef	SHADOWPWD
	/*
	 * 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 (1);
	}
#endif				/* SHADOWPWD */

	/*
	 * 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 (1);
	}
	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 (1);
		}
	}

	if (retval == PAM_SUCCESS)
		pam_end (pamh, PAM_SUCCESS);
#endif				/* USE_PAM */

	closelog ();
	exit (0);
 /*NOTREACHED*/}

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

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