/*      $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 */