contrib/openpam/lib/openpam_restore_cred.c

   1 /*-
   2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
   3  * Copyright (c) 2004-2007 Dag-Erling Smørgrav
   4  * All rights reserved.
   5  *
   6  * This software was developed for the FreeBSD Project by ThinkSec AS and
   7  * Network Associates Laboratories, the Security Research Division of
   8  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
   9  * ("CBOSS"), as part of the DARPA CHATS research program.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote
  20  *    products derived from this software without specific prior written
  21  *    permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $Id: openpam_restore_cred.c 408 2007-12-21 11:36:24Z des $
  36  */
  37
  38 #include <sys/param.h>
  39
  40 #include <grp.h>
  41 #include <limits.h>
  42 #include <pwd.h>
  43 #include <stdlib.h>
  44 #include <unistd.h>
  45
  46 #include <security/pam_appl.h>
  47
  48 #include "openpam_impl.h"
  49
  50 /*
  51  * OpenPAM extension
  52  *
  53  * Restore credentials
  54  */
  55
  56 int
  57 openpam_restore_cred(pam_handle_t *pamh)
  58 {
  59         const struct pam_saved_cred *scred;
  60         const void *scredp;
  61         int r;
  62
  63         ENTER();
  64         r = pam_get_data(pamh, PAM_SAVED_CRED, &scredp);
  65         if (r != PAM_SUCCESS)
  66                 RETURNC(r);
  67         if (scredp == NULL)
  68                 RETURNC(PAM_SYSTEM_ERR);
  69         scred = scredp;
  70         if (scred->euid != geteuid()) {
  71                 if (seteuid(scred->euid) < 0 ||
  72                     setgroups(scred->ngroups, scred->groups) < 0 ||
  73                     setegid(scred->egid) < 0)
  74                         RETURNC(PAM_SYSTEM_ERR);
  75         }
  76         pam_set_data(pamh, PAM_SAVED_CRED, NULL, NULL);
  77         RETURNC(PAM_SUCCESS);
  78 }
  79
  80 /*
  81  * Error codes:
  82  *
  83  *      =pam_get_data
  84  *      PAM_SYSTEM_ERR
  85  */
  86
  87 /**
  88  * The =openpam_restore_cred function restores the credentials saved by
  89  * =openpam_borrow_cred.
  90  *
  91  * >setegid 2
  92  * >seteuid 2
  93  * >setgroups 2
  94  */