lib/libpam/modules/pam_securetty/pam_securetty.c

   1 /*      $NetBSD: pam_securetty.c,v 1.6 2006/11/03 18:04:20 christos Exp $       */
   2
   3 /*-
   4  * Copyright (c) 2001 Mark R V Murray
   5  * All rights reserved.
   6  * Copyright (c) 2001 Networks Associates Technology, Inc.
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed for the FreeBSD Project by
  10  * ThinkSec AS and NAI Labs, the Security Research Division of Network
  11  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
  12  * ("CBOSS"), as part of the DARPA CHATS research program.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  * 3. The name of the author may not be used to endorse or promote
  23  *    products derived from this software without specific prior written
  24  *    permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <sys/cdefs.h>
  40 #ifdef __FreeBSD__
  41 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_securetty/pam_securetty.c,v 1.13 2004/02/10 10:13:21 des Exp $");
  42 #else
  43 __RCSID("$NetBSD: pam_securetty.c,v 1.6 2006/11/03 18:04:20 christos Exp $");
  44 #endif
  45
  46 #include <sys/types.h>
  47 #include <sys/stat.h>
  48 #include <pwd.h>
  49 #include <ttyent.h>
  50 #include <string.h>
  51 #include <syslog.h>
  52
  53 #define PAM_SM_ACCOUNT
  54
  55 #include <security/pam_appl.h>
  56 #include <security/pam_modules.h>
  57 #include <security/pam_mod_misc.h>
  58
  59 #define TTY_PREFIX      "/dev/"
  60
  61 PAM_EXTERN int
  62 pam_sm_acct_mgmt(pam_handle_t *pamh __unused, int flags __unused,
  63     int argc __unused, const char *argv[] __unused)
  64 {
  65         struct passwd *pwd, pwres;
  66         struct ttyent *ty;
  67         const char *user;
  68         const void *tty;
  69         const void *hostname;
  70         int pam_err;
  71         char pwbuf[1024];
  72         struct syslog_data data = SYSLOG_DATA_INIT;
  73
  74         pam_err = pam_get_user(pamh, &user, NULL);
  75         if (pam_err != PAM_SUCCESS)
  76                 return (pam_err);
  77         if (user == NULL ||
  78             getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
  79             pwd == NULL)
  80                 return (PAM_SERVICE_ERR);
  81
  82         PAM_LOG("Got user: %s", user);
  83
  84         /* If the user is not root, secure ttys do not apply */
  85         if (pwd->pw_uid != 0)
  86                 return (PAM_SUCCESS);
  87
  88         pam_err = pam_get_item(pamh, PAM_TTY, &tty);
  89         if (pam_err != PAM_SUCCESS)
  90                 return (pam_err);
  91
  92         PAM_LOG("Got TTY: %s", (const char *)tty);
  93
  94         /* Ignore any "/dev/" on the PAM_TTY item */
  95         if (tty != NULL && strncmp(TTY_PREFIX, tty, sizeof(TTY_PREFIX)) == 0) {
  96                 PAM_LOG("WARNING: PAM_TTY starts with " TTY_PREFIX);
  97                 tty = (const char *)tty + sizeof(TTY_PREFIX) - 1;
  98         }
  99
 100         if (tty != NULL && (ty = getttynam(tty)) != NULL &&
 101             (ty->ty_status & TTY_SECURE) != 0)
 102                 return (PAM_SUCCESS);
 103
 104         pam_err = pam_get_item(pamh, PAM_RHOST, &hostname);
 105         if (pam_err != PAM_SUCCESS)
 106                 hostname = NULL;
 107
 108         openlog_r("pam_securetty", LOG_PID, LOG_AUTHPRIV, &data);
 109         if (hostname)
 110                 syslog_r(LOG_NOTICE, &data,
 111                     "LOGIN %s REFUSED FROM %s ON TTY %s",
 112                      pwd->pw_name, (const char *)hostname,
 113                      (const char *)tty);
 114         else
 115                 syslog_r(LOG_NOTICE, &data,
 116                     "LOGIN %s REFUSED ON TTY %s",
 117                      pwd->pw_name, (const char *)tty);
 118         closelog_r(&data);
 119
 120
 121         PAM_VERBOSE_ERROR("Not on secure TTY");
 122         return (PAM_AUTH_ERR);
 123 }
 124
 125 PAM_MODULE_ENTRY("pam_securetty");