lib/libpam/modules/pam_guest/pam_guest.c

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c) 2003 Networks Associates Technology, Inc.
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed for the FreeBSD Project by
   8  * ThinkSec AS and NAI Labs, the Security Research Division of Network
   9  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
  10  * ("CBOSS"), as part of the 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/lib/libpam/modules/pam_guest/pam_guest.c,v 1.1 2003/05/31 16:52:58 des Exp $");
  40 #else
  41 __RCSID("$NetBSD$");
  42 #endif
  43
  44 #include <string.h>
  45
  46 #define PAM_SM_AUTH
  47
  48 #include <security/pam_appl.h>
  49 #include <security/pam_modules.h>
  50 #include <security/openpam.h>
  51
  52 #define DEFAULT_GUESTS  "guest"
  53
  54 static int
  55 lookup(const char *str, const char *list)
  56 {
  57         const char *next;
  58         size_t len;
  59
  60         len = strlen(str);
  61         while (*list != '\0') {
  62                 while (*list == ',')
  63                         ++list;
  64                 if ((next = strchr(list, ',')) == NULL)
  65                         next = strchr(list, '\0');
  66                 if (next - list == (ptrdiff_t)len &&
  67                     strncmp(list, str, len) == 0)
  68                         return (1);
  69                 list = next;
  70         }
  71         return (0);
  72 }
  73
  74 PAM_EXTERN int
  75 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
  76     int argc __unused, const char *argv[] __unused)
  77 {
  78         const char *authtok, *guests, *user;
  79         int err, is_guest;
  80
  81         /* get target account */
  82         if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL)
  83                 return (PAM_AUTH_ERR);
  84
  85         /* get list of guest logins */
  86         if ((guests = openpam_get_option(pamh, "guests")) == NULL)
  87                 guests = DEFAULT_GUESTS;
  88
  89         /* check if the target account is on the list */
  90         is_guest = lookup(user, guests);
  91
  92         /* check password */
  93         if (!openpam_get_option(pamh, "nopass")) {
  94                 err = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL);
  95                 if (err != PAM_SUCCESS)
  96                         return (err);
  97                 if (openpam_get_option(pamh, "pass_is_user") &&
  98                     strcmp(user, authtok) != 0)
  99                         return (PAM_AUTH_ERR);
 100                 if (openpam_get_option(pamh, "pass_as_ruser"))
 101                         pam_set_item(pamh, PAM_RUSER, authtok);
 102         }
 103
 104         /* done */
 105         if (is_guest) {
 106                 pam_setenv(pamh, "GUEST", user, 1);
 107                 return (PAM_SUCCESS);
 108         }
 109         return (PAM_AUTH_ERR);
 110 }
 111
 112 PAM_EXTERN int
 113 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
 114     int argc __unused, const char *argv[] __unused)
 115 {
 116
 117         return (PAM_SUCCESS);
 118 }
 119
 120 PAM_MODULE_ENTRY("pam_guest");