/*      $NetBSD: yp_passwd.c,v 1.38 2024/05/18 19:28:36 andvar Exp $    */

/*
 * Copyright (c) 1988, 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: yp_passwd.c,v 1.38 2024/05/18 19:28:36 andvar Exp $");
#endif
#endif /* not lint */

#ifdef  YP

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <limits.h>
#include <util.h>

#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>

#include "extern.h"

#define passwd yp_passwd_rec
#include <rpcsvc/yppasswd.h>
#undef passwd

#ifndef _PASSWORD_LEN
#define _PASSWORD_LEN PASS_MAX
#endif

static uid_t uid;
static char *domain;

__dead static void
pwerror(const char *name, int show_err, int eval)
{

        if (show_err)
                warn("%s", name);
        errx(eval, "NIS passwd database unchanged");
}

static char *
getnewpasswd(struct passwd *pw, char **old_pass)
{
        int tries;
        const char *p, *t;
        char *result;
        static char buf[_PASSWORD_LEN + 1];
        char salt[_PASSWORD_LEN + 1];
        char option[LINE_MAX], *key, *opt;

        (void)printf("Changing NIS password for %s.\n", pw->pw_name);

        if (old_pass) {
                *old_pass = NULL;
        
                if (pw->pw_passwd[0]) {
                        if (strcmp(crypt(p = getpass("Old password:"),
                            pw->pw_passwd),  pw->pw_passwd)) {
                                (void)printf("Sorry.\n");
                                pwerror(NULL, 0, 1);
                        }
                } else {
                        p = "";
                }

                *old_pass = strdup(p);
                if (!*old_pass) {
                        (void)printf("not enough core.\n");
                        pwerror(NULL, 0, 1);
                }
        }
        for (buf[0] = '\0', tries = 0;;) {
                p = getpass("New password:");
                if (!*p) {
                        (void)printf("Password unchanged.\n");
                        pwerror(NULL, 0, 0);
                }
                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, "ypcipher");
        opt = option;
        key = strsep(&opt, ",");
        if (pw_gensalt(salt, _PASSWORD_LEN, key, opt) == -1) {
                warn("Couldn't generate salt");
                pwerror(NULL, 0, 0);
        }
        result = strdup(crypt(buf, salt));
        if (!result) {
                (void)printf("not enough core.\n");
                pwerror(NULL, 0, 0);
        }
        return result;
}

static void
makeypp(struct yppasswd *ypp, struct passwd *pw)
{
        /* prompt for new password */
        ypp->newpw.pw_passwd = getnewpasswd(pw, &ypp->oldpass);

        /* tell rpc.yppasswdd */
        ypp->newpw.pw_name      = estrdup(pw->pw_name);
        ypp->newpw.pw_uid       = pw->pw_uid;
        ypp->newpw.pw_gid       = pw->pw_gid;
        ypp->newpw.pw_gecos     = estrdup(pw->pw_gecos);
        ypp->newpw.pw_dir       = estrdup(pw->pw_dir);
        ypp->newpw.pw_shell     = estrdup(pw->pw_shell);
}

static int
ypgetpwnam(const char *nam, struct passwd *pwd)
{
        char *val;
        int reason, vallen, namlen = (int)strlen(nam);
        int flags;
        int ok;
        
        flags = ok = 0;
        val = NULL;
        reason = yp_match(domain, "master.passwd.byname", nam, namlen,
            &val, &vallen);
        if (reason == YPERR_MAP) {
                reason = yp_match(domain, "passwd.byname", nam, namlen,
                    &val, &vallen);
                flags = _PASSWORD_OLDFMT;
        }
        if (reason != 0)
                goto out;

        if (pw_scan(val, pwd, &flags) == 0)
                goto out;

        ok = 1;
        val = NULL;     /* Don't free the memory, it is still in use */
out:
        if (val)
                free(val);
        return ok;
}

#ifdef USE_PAM

void
pwyp_usage(const char *prefix)
{

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

void
pwyp_argv0_usage(const char *prefix)
{

        (void)fprintf(stderr, "%s %s [user]\n",
            prefix, getprogname());
}

void
pwyp_process(const char *username, int argc, char **argv)
{
        char *master;
        int ch, r, rpcport, status;
        enum clnt_stat yr;
        struct yppasswd ypp;
        struct passwd pwb, pwb2, *pw;
        char pwbuf[1024];
        struct timeval tv;
        CLIENT *client;

        while ((ch = getopt(argc, argv, "y")) != -1) {
                switch (ch) {
                case 'y':
                        /*
                         * Absorb the -y 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 (_yp_check(NULL) == 0) {
                /* can't use YP. */
                errx(EXIT_FAILURE, "NIS not in use.");
        }

        uid = getuid();

        /*
         * Get local domain
         */
        if ((r = yp_get_default_domain(&domain)) != 0)
                errx(EXIT_FAILURE, "Can't get local NIS domain (%s)",
                    yperr_string(r));

        /*
         * Find the host for the passwd map; it should be running
         * the daemon.
         */
        if ((r = yp_master(domain, "passwd.byname", &master)) != 0)
                errx(EXIT_FAILURE, "Can't find the master NIS server (%s)",
                    yperr_string(r));

        /*
         * Ask the portmapper for the port of the daemon.
         */
        if ((rpcport = getrpcport(master, YPPASSWDPROG,
            YPPASSWDPROC_UPDATE, IPPROTO_UDP)) == 0)
                errx(EXIT_FAILURE, "Master NIS server not running yppasswd "
                    "daemon");

        /*
         * Be sure the port is privileged
         */
        if (rpcport >= IPPORT_RESERVED)
                errx(EXIT_FAILURE, "Yppasswd daemon is on an invalid port");

        /* Bail out if this is a local (non-yp) user, */
        /* then get user's login identity */
        if (!ypgetpwnam(username, &pwb) ||
            getpwnam_r(username, &pwb2, pwbuf, sizeof(pwbuf), &pw) ||
            pw == NULL)
                errx(EXIT_FAILURE, "NIS unknown user %s", username);

        if (uid && uid != pwb.pw_uid) {
                errno = EACCES;
                err(EXIT_FAILURE, "You may only change your own password");
        }

        makeypp(&ypp, &pwb);

        client = clnt_create(master, YPPASSWDPROG, YPPASSWDVERS, "udp");
        if (client == NULL)
                errx(EXIT_FAILURE, "Cannot contact yppasswdd on %s (%s)",
                    master, yperr_string(YPERR_YPBIND));

        client->cl_auth = authunix_create_default();
        tv.tv_sec = 2;
        tv.tv_usec = 0;
        yr = clnt_call(client, YPPASSWDPROC_UPDATE,
            xdr_yppasswd, &ypp, xdr_int, &status, tv);
        if (yr != RPC_SUCCESS)
                errx(EXIT_FAILURE, "RPC to yppasswdd failed (%s)",
                    clnt_sperrno(yr));
        else if (status)
                printf("Couldn't change NIS password.\n");
        else
                printf("The NIS password has been changed on %s, %s\n",
                    master, "the master NIS passwd server.");
}

#else /* ! USE_PAM */

static  int yflag;

int
yp_init(const char *progname)
{
        int yppwd;

        if (strcmp(progname, "yppasswd") == 0) {
                yppwd = 1;
        } else
                yppwd = 0;
        yflag = 0;
        if (_yp_check(NULL) == 0) {
                /* can't use YP. */
                if (yppwd)
                        errx(EXIT_FAILURE, "NIS not in use");
                return -1;
        }
        return 0;
}

int
yp_arg(char ch, const char *arg)
{
        switch (ch) {
        case 'y':
                yflag = 1;
                break;
        default:
                return 0;
        }
        return 1;
}

int
yp_arg_end(void)
{
        if (yflag)
                return PW_USE_FORCE;
        return PW_USE;
}

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

int
yp_chpw(const char *username)
{
        char *master;
        int r, rpcport, status;
        enum clnt_stat yr;
        struct yppasswd ypp;
        struct passwd *pw, pwb;
        char pwbuf[1024];
        struct timeval tv;
        CLIENT *client;

        uid = getuid();

        /*
         * Get local domain
         */
        if ((r = yp_get_default_domain(&domain)) != 0)
                errx(EXIT_FAILURE, "can't get local NIS domain.  Reason: %s",
                    yperr_string(r));

        /*
         * Find the host for the passwd map; it should be running
         * the daemon.
         */
        if ((r = yp_master(domain, "passwd.byname", &master)) != 0) {
                warnx("can't find the master NIS server.  Reason: %s",
                    yperr_string(r));
                /* continuation */
                return -1;
        }

        /*
         * Ask the portmapper for the port of the daemon.
         */
        if ((rpcport = getrpcport(master, YPPASSWDPROG,
            YPPASSWDPROC_UPDATE, IPPROTO_UDP)) == 0) {
                warnx("Master NIS server not running yppasswd daemon");
                /* continuation */
                return -1;
        }

        /*
         * Be sure the port is privileged
         */
        if (rpcport >= IPPORT_RESERVED)
                errx(EXIT_FAILURE, "Yppasswd daemon is on an invalid port");

        /* Bail out if this is a local (non-yp) user, */
        /* then get user's login identity */
        if (!ypgetpwnam(username, pw = &pwb) ||
            getpwnam_r(username, &pwb, pwbuf, sizeof(pwbuf), &pw) ||
            pw == NULL) {
                warnx("NIS unknown user %s", username);
                /* continuation */
                return -1;
        }

        if (uid && uid != pw->pw_uid) {
                errno = EACCES;
                err(EXIT_FAILURE, "You may only change your own password");
        }

        makeypp(&ypp, pw);

        client = clnt_create(master, YPPASSWDPROG, YPPASSWDVERS, "udp");
        if (client == NULL) {
                warnx("Cannot contact yppasswdd on %s (%s)",
                    master, yperr_string(YPERR_YPBIND));
                return YPERR_YPBIND;
        }

        client->cl_auth = authunix_create_default();
        tv.tv_sec = 2;
        tv.tv_usec = 0;
        yr = clnt_call(client, YPPASSWDPROC_UPDATE,
            xdr_yppasswd, &ypp, xdr_int, &status, tv);
        if (yr != RPC_SUCCESS)
                errx(EXIT_FAILURE, "RPC to yppasswdd failed (%s)",
                    clnt_sperrno(yr));
        else if (status)
                printf("Couldn't change NIS password.\n");
        else
                printf("The NIS password has been changed on %s, %s\n",
                    master, "the master NIS passwd server.");
        return 0;
}

#endif /* USE_PAM */

#endif  /* YP */