xref: /freebsd/contrib/openpam/lib/libpam/openpam_restore_cred.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2011 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 
36 #ifdef HAVE_CONFIG_H
37 # include "config.h"
38 #endif
39 
40 #include <sys/param.h>
41 
42 #include <grp.h>
43 #include <limits.h>
44 #include <pwd.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 
48 #include <security/pam_appl.h>
49 
50 #include "openpam_impl.h"
51 #include "openpam_cred.h"
52 
53 /*
54  * OpenPAM extension
55  *
56  * Restore credentials
57  */
58 
59 int
60 openpam_restore_cred(pam_handle_t *pamh)
61 {
62 	const struct pam_saved_cred *scred;
63 	const void *scredp;
64 	int r;
65 
66 	ENTER();
67 	r = pam_get_data(pamh, PAM_SAVED_CRED, &scredp);
68 	if (r != PAM_SUCCESS)
69 		RETURNC(r);
70 	if (scredp == NULL)
71 		RETURNC(PAM_SYSTEM_ERR);
72 	scred = scredp;
73 	if (scred->euid != geteuid()) {
74 		if (seteuid(scred->euid) < 0 ||
75 		    setgroups(scred->ngroups, scred->groups) < 0 ||
76 		    setegid(scred->egid) < 0)
77 			RETURNC(PAM_SYSTEM_ERR);
78 	}
79 	pam_set_data(pamh, PAM_SAVED_CRED, NULL, NULL);
80 	RETURNC(PAM_SUCCESS);
81 }
82 
83 /*
84  * Error codes:
85  *
86  *	=pam_get_data
87  *	PAM_SYSTEM_ERR
88  */
89 
90 /**
91  * The =openpam_restore_cred function restores the credentials saved by
92  * =openpam_borrow_cred.
93  *
94  * >setegid 2
95  * >seteuid 2
96  * >setgroups 2
97  */
98