xref: /netbsd-src/external/bsd/openpam/dist/lib/libpam/openpam_restore_cred.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: openpam_restore_cred.c,v 1.3 2017/05/06 19:50:09 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
5  * Copyright (c) 2004-2011 Dag-Erling Smørgrav
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by ThinkSec AS and
9  * Network Associates Laboratories, the Security Research Division of
10  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
11  * ("CBOSS"), as part of the DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The name of the author may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * $OpenPAM: openpam_restore_cred.c 938 2017-04-30 21:34:42Z des $
38  */
39 
40 #ifdef HAVE_CONFIG_H
41 # include "config.h"
42 #endif
43 
44 #include <sys/cdefs.h>
45 __RCSID("$NetBSD: openpam_restore_cred.c,v 1.3 2017/05/06 19:50:09 christos Exp $");
46 
47 #include <sys/param.h>
48 
49 #include <grp.h>
50 #include <limits.h>
51 #include <pwd.h>
52 #include <stdlib.h>
53 #include <unistd.h>
54 
55 #include <security/pam_appl.h>
56 
57 #include "openpam_impl.h"
58 #include "openpam_cred.h"
59 
60 /*
61  * OpenPAM extension
62  *
63  * Restore credentials
64  */
65 
66 int
67 openpam_restore_cred(pam_handle_t *pamh)
68 {
69 	const struct pam_saved_cred *scred;
70 	const void *scredp;
71 	int r;
72 
73 	ENTER();
74 	r = pam_get_data(pamh, PAM_SAVED_CRED, &scredp);
75 	if (r != PAM_SUCCESS)
76 		RETURNC(r);
77 	if (scredp == NULL)
78 		RETURNC(PAM_SYSTEM_ERR);
79 	scred = scredp;
80 	if (scred->euid != geteuid()) {
81 		if (seteuid(scred->euid) < 0 ||
82 		    setgroups(scred->ngroups, scred->groups) < 0 ||
83 		    setegid(scred->egid) < 0)
84 			RETURNC(PAM_SYSTEM_ERR);
85 	}
86 	pam_set_data(pamh, PAM_SAVED_CRED, NULL, NULL);
87 	RETURNC(PAM_SUCCESS);
88 }
89 
90 /*
91  * Error codes:
92  *
93  *	=pam_get_data
94  *	PAM_SYSTEM_ERR
95  */
96 
97 /**
98  * The =openpam_restore_cred function restores the credentials saved by
99  * =openpam_borrow_cred.
100  *
101  * >setegid 2
102  * >seteuid 2
103  * >setgroups 2
104  */
105