lib/pam_module/pam_group/pam_group.c

   1 /*-
   2  * Copyright (c) 2003 Networks Associates Technology, Inc.
   3  * All rights reserved.
   4  *
   5  * Portions of this software were developed for the FreeBSD Project by
   6  * ThinkSec AS and NAI Labs, the Security Research Division of Network
   7  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
   8  * ("CBOSS"), as part of the 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  * $FreeBSD: src/lib/libpam/modules/pam_group/pam_group.c,v 1.4 2003/12/11 13:55:15 des Exp $
  35  */
  36
  37 #include <sys/types.h>
  38
  39 #include <grp.h>
  40 #include <pwd.h>
  41 #include <stdarg.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <syslog.h>
  45 #include <unistd.h>
  46
  47 #define PAM_SM_AUTH
  48
  49 #include <security/pam_appl.h>
  50 #include <security/pam_modules.h>
  51 #include <security/openpam.h>
  52
  53
  54 PAM_EXTERN int
  55 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
  56                     int argc __unused, const char *argv[] __unused)
  57 {
  58         const char *group, *user;
  59         const void *ruser;
  60         char *const *list;
  61         struct passwd *pwd;
  62         struct group *grp;
  63
  64         /* get target account */
  65         if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
  66             user == NULL || (pwd = getpwnam(user)) == NULL)
  67                 return (PAM_AUTH_ERR);
  68         if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
  69                 return (PAM_IGNORE);
  70
  71         /* get applicant */
  72         if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS
  73             || ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
  74                 return (PAM_AUTH_ERR);
  75
  76         /* get regulating group */
  77         if ((group = openpam_get_option(pamh, "group")) == NULL)
  78                 group = "wheel";
  79         if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
  80                 goto failed;
  81
  82         /* check if the group is empty */
  83         if (*grp->gr_mem == NULL)
  84                 goto failed;
  85
  86         /* check membership */
  87         if (pwd->pw_gid == grp->gr_gid)
  88                 goto found;
  89         for (list = grp->gr_mem; *list != NULL; ++list)
  90                 if (strcmp(*list, pwd->pw_name) == 0)
  91                         goto found;
  92
  93  not_found:
  94         if (openpam_get_option(pamh, "deny"))
  95                 return (PAM_SUCCESS);
  96         return (PAM_AUTH_ERR);
  97  found:
  98         if (openpam_get_option(pamh, "deny"))
  99                 return (PAM_AUTH_ERR);
 100         return (PAM_SUCCESS);
 101  failed:
 102         if (openpam_get_option(pamh, "fail_safe"))
 103                 goto found;
 104         else
 105                 goto not_found;
 106 }
 107
 108 PAM_EXTERN int
 109 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
 110                int argc __unused, const char *argv[] __unused)
 111 {
 112
 113         return (PAM_SUCCESS);
 114 }
 115
 116 PAM_MODULE_ENTRY("pam_group");