usr.bin/passwd/pam_passwd.c

   1 /*      $NetBSD: pam_passwd.c,v 1.6 2010/03/09 16:14:08 joerg Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2002 Networks Associates Technologies, Inc.
   5  * All rights reserved.
   6  *
   7  * This software was developed for the FreeBSD Project by ThinkSec AS and
   8  * NAI Labs, the Security Research Division of Network Associates, Inc.
   9  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
  10  * DARPA CHATS research program.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. The name of the author may not be used to endorse or promote
  21  *    products derived from this software without specific prior written
  22  *    permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #include <sys/cdefs.h>
  38 #ifdef __FreeBSD__
  39 __FBSDID("$FreeBSD: src/usr.bin/passwd/passwd.c,v 1.23 2003/04/18 21:27:09 nectar Exp $");
  40 #else
  41 __RCSID("$NetBSD: pam_passwd.c,v 1.6 2010/03/09 16:14:08 joerg Exp $");
  42 #endif
  43
  44 #include <sys/param.h>
  45
  46 #include <err.h>
  47 #include <pwd.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <syslog.h>
  51 #include <unistd.h>
  52
  53 #include "extern.h"
  54
  55 #include <security/pam_appl.h>
  56 #include <security/openpam.h>
  57
  58 static pam_handle_t *pamh;
  59 static struct pam_conv pamc = {
  60         openpam_ttyconv,
  61         NULL
  62 };
  63
  64 #define pam_check(msg)                                                  \
  65 do {                                                                    \
  66         if (pam_err != PAM_SUCCESS) {                                   \
  67                 warnx("%s: %s", (msg), pam_strerror(pamh, pam_err));    \
  68                 goto end;                                               \
  69         }                                                               \
  70 } while (/*CONSTCOND*/0)
  71
  72 void
  73 pwpam_process(const char *username, int argc, char **argv)
  74 {
  75         int ch, pam_err;
  76         char hostname[MAXHOSTNAMELEN + 1];
  77
  78         /* details about the invoking user for logging */
  79         const uid_t i_uid = getuid();
  80         const struct passwd *const i_pwd = getpwuid(i_uid);
  81         const char *const i_username = (i_pwd && i_pwd->pw_name)
  82                 ? i_pwd->pw_name : "(null)";
  83
  84         while ((ch = getopt(argc, argv, "")) != -1) {
  85                 switch (ch) {
  86                 default:
  87                         usage();
  88                         /* NOTREACHED */
  89                 }
  90         }
  91
  92         argc -= optind;
  93         argv += optind;
  94
  95         switch (argc) {
  96         case 0:
  97                 /* username already provided */
  98                 break;
  99         case 1:
 100                 username = argv[0];
 101                 break;
 102         default:
 103                 usage();
 104                 /* NOTREACHED */
 105         }
 106
 107         (void)printf("Changing password for %s.\n", username);
 108
 109         /* initialize PAM -- always use the program name "passwd" */
 110         pam_err = pam_start("passwd", username, &pamc, &pamh);
 111         if (pam_err != PAM_SUCCESS)
 112                 errx(1, "unable to start PAM session: %s",
 113                     pam_strerror(NULL, pam_err));
 114
 115         pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
 116         pam_check("unable to set TTY");
 117
 118         (void)gethostname(hostname, sizeof hostname);
 119         pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
 120         pam_check("unable to set RHOST");
 121
 122         pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
 123         pam_check("unable to set RUSER");
 124
 125         /* set new password */
 126         pam_err = pam_chauthtok(pamh, 0);
 127         if (pam_err != PAM_SUCCESS) {
 128                 if (pam_err == PAM_PERM_DENIED) {
 129                         syslog(LOG_AUTH | LOG_NOTICE,
 130                                "user %s (UID %lu) failed to change the "
 131                                "PAM authentication token of user %s: %s",
 132                                i_username, (unsigned long)i_uid, username,
 133                                pam_strerror(pamh, pam_err));
 134                 }
 135                 printf("Unable to change auth token: %s\n",
 136                     pam_strerror(pamh, pam_err));
 137         } else {
 138                 syslog(LOG_AUTH | LOG_INFO,
 139                        "user %s (UID %lu) successfully changed the "
 140                        "PAM authentication token of user %s",
 141                        i_username, (unsigned long)i_uid, username);
 142         }
 143
 144  end:
 145         pam_end(pamh, pam_err);
 146         if (pam_err == PAM_SUCCESS)
 147                 return;
 148         exit(1);
 149 }