2 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3 * Copyright (c) 2004-2007 Dag-Erling Smørgrav
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.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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
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
35 * $Id: openpam_borrow_cred.c 408 2007-12-21 11:36:24Z des $
38 #include <sys/param.h>
46 #include <security/pam_appl.h>
48 #include "openpam_impl.h"
53 * Temporarily borrow user credentials
57 openpam_borrow_cred(pam_handle_t *pamh,
58 const struct passwd *pwd)
60 struct pam_saved_cred *scred;
65 r = pam_get_data(pamh, PAM_SAVED_CRED, &scredp);
66 if (r == PAM_SUCCESS && scredp != NULL) {
67 openpam_log(PAM_LOG_DEBUG,
68 "already operating under borrowed credentials");
69 RETURNC(PAM_SYSTEM_ERR);
71 if (geteuid() != 0 && geteuid() != pwd->pw_uid) {
72 openpam_log(PAM_LOG_DEBUG, "called with non-zero euid: %d",
74 RETURNC(PAM_PERM_DENIED);
76 scred = calloc(1, sizeof *scred);
79 scred->euid = geteuid();
80 scred->egid = getegid();
81 r = getgroups(NGROUPS_MAX, scred->groups);
84 RETURNC(PAM_SYSTEM_ERR);
87 r = pam_set_data(pamh, PAM_SAVED_CRED, scred, &openpam_free_data);
88 if (r != PAM_SUCCESS) {
92 if (geteuid() == pwd->pw_uid)
94 if (initgroups(pwd->pw_name, pwd->pw_gid) < 0 ||
95 setegid(pwd->pw_gid) < 0 || seteuid(pwd->pw_uid) < 0) {
96 openpam_restore_cred(pamh);
97 RETURNC(PAM_SYSTEM_ERR);
112 * The =openpam_borrow_cred function saves the current credentials and
113 * switches to those of the user specified by its =pwd argument.
114 * The affected credentials are the effective UID, the effective GID, and
115 * the group access list.
116 * The original credentials can be restored using =openpam_restore_cred.