/*      $NetBSD: local_passwd.c,v 1.37 2024/05/18 19:03:31 andvar Exp $ */

/*-
 * Copyright (c) 1990, 1993, 1994
 *      The Regents of the University of California.  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 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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)local_passwd.c    8.3 (Berkeley) 4/2/94";
#else
__RCSID("$NetBSD: local_passwd.c,v 1.37 2024/05/18 19:03:31 andvar Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <time.h>
#include <unistd.h>
#include <util.h>
#include <login_cap.h>
#include <syslog.h>

#include "extern.h"

static uid_t uid;

static char *
getnewpasswd(struct passwd *pw, int min_pw_len)
{
        int tries;
        char *p, *t;
        char buf[_PASSWORD_LEN+1], salt[_PASSWORD_LEN+1];
        char option[LINE_MAX], *key, *opt;
        
        (void)printf("Changing local password for %s.\n", pw->pw_name);

        if (uid && pw->pw_passwd[0] &&
            strcmp(crypt(getpass("Old password:"), pw->pw_passwd),
            pw->pw_passwd)) {
                errno = EACCES;
                syslog(LOG_AUTH | LOG_NOTICE,
                       "user %s (UID %lu) failed to change the "
                       "local password of user %s: %m",
                       pw->pw_name, (unsigned long)uid, pw->pw_name);
                pw_error(NULL, 1, 1);
        }

        for (buf[0] = '\0', tries = 0;;) {
                p = getpass("New password:");
                if (!*p) {
                        (void)printf("Password unchanged.\n");
                        pw_error(NULL, 0, 0);
                }
                if (min_pw_len > 0 && (int)strlen(p) < min_pw_len) {
                        (void) printf("Password is too short.\n");
                        continue;
                }
                if (strlen(p) <= 5 && ++tries < 2) {
                        (void)printf("Please enter a longer password.\n");
                        continue;
                }
                for (t = p; *t && islower((unsigned char)*t); ++t);
                if (!*t && ++tries < 2) {
                        (void)printf("Please don't use an all-lower case "
                                     "password.\nUnusual capitalization, "
                                     "control characters or digits are "
                                     "suggested.\n");
                        continue;
                }
                (void)strlcpy(buf, p, sizeof(buf));
                if (!strcmp(buf, getpass("Retype new password:")))
                        break;
                (void)printf("Mismatch; try again, EOF to quit.\n");
        }

        pw_getpwconf(option, sizeof(option), pw, "localcipher");
        opt = option;
        key = strsep(&opt, ",");
        if(pw_gensalt(salt, _PASSWORD_LEN, key, opt) == -1) {
                warn("Couldn't generate salt");
                pw_error(NULL, 0, 0);
        }
        return(crypt(buf, salt));
}

#ifdef USE_PAM

void
pwlocal_usage(const char *prefix)
{

        (void) fprintf(stderr, "%s %s [-d files | -l] [user]\n",
            prefix, getprogname());
}

void
pwlocal_process(const char *username, int argc, char **argv)
{
        struct passwd *pw;
        struct passwd old_pw;
        time_t old_change;
        int pfd, tfd;
        int min_pw_len = 0;
        int pw_expiry  = 0;
        int ch;
#ifdef LOGIN_CAP
        login_cap_t *lc;
#endif

        while ((ch = getopt(argc, argv, "l")) != -1) {
                switch (ch) {
                case 'l':
                        /*
                         * Absorb the -l that may have gotten us here.
                         */
                        break;

                default:
                        usage();
                        /* NOTREACHED */
                }
        }

        argc -= optind;
        argv += optind;

        switch (argc) {
        case 0:
                /* username already provided */
                break;
        case 1:
                username = argv[0];
                break;
        default:
                usage();
                /* NOTREACHED */
        }

        if (!(pw = getpwnam(username)))
                errx(1, "unknown user %s", username);

        uid = getuid();
        if (uid && uid != pw->pw_uid)
                errx(1, "%s", strerror(EACCES));

        /* Save the old pw information for comparing on pw_copy(). */
        old_pw = *pw;

        /*
         * Get class restrictions for this user, then get the new password. 
         */
#ifdef LOGIN_CAP
        if((lc = login_getclass(pw->pw_class)) != NULL) {
                min_pw_len = (int) login_getcapnum(lc, "minpasswordlen", 0, 0);
                pw_expiry  = (int) login_getcaptime(lc, "passwordtime", 0, 0);
                login_close(lc);
        }
#endif

        pw->pw_passwd = getnewpasswd(pw, min_pw_len);
        old_change = pw->pw_change;
        pw->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0;

        /*
         * Now that the user has given us a new password, let us
         * change the database.
         */
        pw_init();
        tfd = pw_lock(0);
        if (tfd < 0) {
                warnx ("The passwd file is busy, waiting...");
                tfd = pw_lock(10);
                if (tfd < 0)
                        errx(1, "The passwd file is still busy, "
                             "try again later.");
        }

        pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
        if (pfd < 0)
                pw_error(_PATH_MASTERPASSWD, 1, 1);

        pw_copy(pfd, tfd, pw, &old_pw);

        if (pw_mkdb(username, old_change == pw->pw_change) < 0)
                pw_error(NULL, 0, 1);

        syslog(LOG_AUTH | LOG_INFO,
               "user %s (UID %lu) successfully changed "
               "the local password of user %s",
               uid ? username : "root", (unsigned long)uid, username);
}

#else /* ! USE_PAM */

static int force_local;

int
local_init(const char *progname)
{
        force_local = 0;
        return (0);
}

int
local_arg(char ch, const char *arg)
{
        switch (ch) {
        case 'l':
                force_local = 1;
                break;
        default:
                return(0);
        }
        return(1);
}

int
local_arg_end(void)
{
        if (force_local)
                return(PW_USE_FORCE);
        return(PW_USE);
}

void
local_end(void)
{
        /* NOOP */
}

int
local_chpw(const char *uname)
{
        struct passwd *pw;
        struct passwd old_pw;
        time_t old_change;
        int pfd, tfd;
        int min_pw_len = 0;
        int pw_expiry  = 0;
#ifdef LOGIN_CAP
        login_cap_t *lc;
#endif
        
        if (!(pw = getpwnam(uname))) {
                warnx("unknown user %s", uname);
                return (1);
        }

        uid = getuid();
        if (uid && uid != pw->pw_uid) {
                warnx("%s", strerror(EACCES));
                return (1);
        }

        /* Save the old pw information for comparing on pw_copy(). */
        old_pw = *pw;

        /*
         * Get class restrictions for this user, then get the new password. 
         */
#ifdef LOGIN_CAP
        if((lc = login_getclass(pw->pw_class))) {
                min_pw_len = (int) login_getcapnum(lc, "minpasswordlen", 0, 0);
                pw_expiry  = (int) login_getcaptime(lc, "passwordtime", 0, 0);
                login_close(lc);
        }
#endif

        pw->pw_passwd = getnewpasswd(pw, min_pw_len);
        old_change = pw->pw_change;
        pw->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0;

        /*
         * Now that the user has given us a new password, let us
         * change the database.
         */
        pw_init();
        tfd = pw_lock(0);
        if (tfd < 0) {
                warnx ("The passwd file is busy, waiting...");
                tfd = pw_lock(10);
                if (tfd < 0)
                        errx(1, "The passwd file is still busy, "
                             "try again later.");
        }

        pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
        if (pfd < 0)
                pw_error(_PATH_MASTERPASSWD, 1, 1);

        pw_copy(pfd, tfd, pw, &old_pw);

        if (pw_mkdb(uname, old_change == pw->pw_change) < 0)
                pw_error(NULL, 0, 1);

        syslog(LOG_AUTH | LOG_INFO,
               "user %s (UID %lu) successfully changed "
               "the local password of user %s",
               uid ? uname : "root", (unsigned long)uid, uname);

        return (0);
}

#endif /* USE_PAM */