usr.bin/passwd/passwd.c

   1 /*-
   2  * Copyright (c) 2002 Networks Associates Technologies, Inc.
   3  * All rights reserved.
   4  *
   5  * This software was developed for the FreeBSD Project by ThinkSec AS and
   6  * NAI Labs, the Security Research Division of Network Associates, Inc.
   7  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
   8  * DARPA CHATS research program.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. The name of the author may not be used to endorse or promote
  19  *    products derived from this software without specific prior written
  20  *    permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include <sys/param.h>
  39
  40 #include <err.h>
  41 #include <pwd.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <syslog.h>
  45 #include <unistd.h>
  46
  47 #include <security/pam_appl.h>
  48 #include <security/openpam.h>
  49
  50 static pam_handle_t *pamh;
  51 static struct pam_conv pamc = {
  52         openpam_ttyconv,
  53         NULL
  54 };
  55
  56 static char     *yp_domain;
  57 static char     *yp_host;
  58
  59 static void
  60 usage(void)
  61 {
  62         fprintf(stderr, "usage: passwd [-ly] [-d domain] [-h host] [user]\n");
  63         exit(1);
  64 }
  65
  66 int
  67 main(int argc, char *argv[])
  68 {
  69         char hostname[MAXHOSTNAMELEN];
  70         struct passwd *pwd;
  71         int o, pam_err;
  72         uid_t uid;
  73
  74         while ((o = getopt(argc, argv, "d:h:loy")) != -1)
  75                 switch (o) {
  76                 case 'd':
  77                         yp_domain = optarg;
  78                         break;
  79                 case 'h':
  80                         yp_host = optarg;
  81                         break;
  82                 case 'l':
  83                 case 'o':
  84                 case 'y':
  85                         /* compatibility */
  86                         break;
  87                 default:
  88                         usage();
  89                 }
  90
  91         argc -= optind;
  92         argv += optind;
  93
  94         uid = getuid();
  95
  96         switch (argc) {
  97         case 0:
  98                 if ((pwd = getpwuid(uid)) == NULL)
  99                         errx(1, "who are you?");
 100                 break;
 101         case 1:
 102                 if ((pwd = getpwnam(*argv)) == NULL)
 103                         errx(1, "%s: no such user", *argv);
 104                 break;
 105         default:
 106                 usage();
 107         }
 108
 109         if (uid != 0 && uid != pwd->pw_uid)
 110                 errx(1, "permission denied");
 111
 112         /* check where the user's from */
 113         switch (pwd->pw_fields & _PWF_SOURCE) {
 114         case _PWF_FILES:
 115                 fprintf(stderr, "Changing local password for %s\n",
 116                     pwd->pw_name);
 117                 break;
 118         case _PWF_NIS:
 119                 fprintf(stderr, "Changing NIS password for %s\n",
 120                     pwd->pw_name);
 121                 break;
 122         default:
 123                 /* XXX: Green men ought to be supported via PAM. */
 124                 errx(1,
 125           "Sorry, `passwd' can only change passwords for local or NIS users.");
 126         }
 127
 128 #define pam_check(func) do { \
 129         if (pam_err != PAM_SUCCESS) { \
 130                 if (pam_err == PAM_AUTH_ERR || pam_err == PAM_PERM_DENIED || \
 131                     pam_err == PAM_AUTHTOK_RECOVERY_ERR) \
 132                         warnx("sorry"); \
 133                 else \
 134                         warnx("%s(): %s", func, pam_strerror(pamh, pam_err)); \
 135                 goto end; \
 136         } \
 137 } while (0)
 138
 139         /* initialize PAM */
 140         pam_err = pam_start("passwd", pwd->pw_name, &pamc, &pamh);
 141         pam_check("pam_start");
 142
 143         pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
 144         pam_check("pam_set_item");
 145         gethostname(hostname, sizeof hostname);
 146         pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
 147         pam_check("pam_set_item");
 148         pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
 149         pam_check("pam_set_item");
 150
 151         /* set YP domain and host */
 152         pam_err = pam_set_data(pamh, "yp_domain", yp_domain, NULL);
 153         pam_check("pam_set_data");
 154         pam_err = pam_set_data(pamh, "yp_server", yp_host, NULL);
 155         pam_check("pam_set_data");
 156
 157         /* set new password */
 158         pam_err = pam_chauthtok(pamh, 0);
 159         pam_check("pam_chauthtok");
 160
 161  end:
 162         pam_end(pamh, pam_err);
 163         exit(pam_err == PAM_SUCCESS ? 0 : 1);
 164 }