xref: /dflybsd-src/contrib/openpam/lib/libpam/openpam_restore_cred.c (revision 7031abe4d1ef8c309d4113438494530b74f3f3fe)
1*10b5fe87SSascha Wildner /*-
2*10b5fe87SSascha Wildner  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3*10b5fe87SSascha Wildner  * Copyright (c) 2004-2011 Dag-Erling Smørgrav
4*10b5fe87SSascha Wildner  * All rights reserved.
5*10b5fe87SSascha Wildner  *
6*10b5fe87SSascha Wildner  * This software was developed for the FreeBSD Project by ThinkSec AS and
7*10b5fe87SSascha Wildner  * Network Associates Laboratories, the Security Research Division of
8*10b5fe87SSascha Wildner  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9*10b5fe87SSascha Wildner  * ("CBOSS"), as part of the DARPA CHATS research program.
10*10b5fe87SSascha Wildner  *
11*10b5fe87SSascha Wildner  * Redistribution and use in source and binary forms, with or without
12*10b5fe87SSascha Wildner  * modification, are permitted provided that the following conditions
13*10b5fe87SSascha Wildner  * are met:
14*10b5fe87SSascha Wildner  * 1. Redistributions of source code must retain the above copyright
15*10b5fe87SSascha Wildner  *    notice, this list of conditions and the following disclaimer.
16*10b5fe87SSascha Wildner  * 2. Redistributions in binary form must reproduce the above copyright
17*10b5fe87SSascha Wildner  *    notice, this list of conditions and the following disclaimer in the
18*10b5fe87SSascha Wildner  *    documentation and/or other materials provided with the distribution.
19*10b5fe87SSascha Wildner  * 3. The name of the author may not be used to endorse or promote
20*10b5fe87SSascha Wildner  *    products derived from this software without specific prior written
21*10b5fe87SSascha Wildner  *    permission.
22*10b5fe87SSascha Wildner  *
23*10b5fe87SSascha Wildner  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24*10b5fe87SSascha Wildner  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25*10b5fe87SSascha Wildner  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26*10b5fe87SSascha Wildner  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27*10b5fe87SSascha Wildner  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28*10b5fe87SSascha Wildner  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29*10b5fe87SSascha Wildner  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30*10b5fe87SSascha Wildner  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31*10b5fe87SSascha Wildner  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32*10b5fe87SSascha Wildner  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33*10b5fe87SSascha Wildner  * SUCH DAMAGE.
34*10b5fe87SSascha Wildner  *
35*10b5fe87SSascha Wildner  * $OpenPAM: openpam_restore_cred.c 938 2017-04-30 21:34:42Z des $
36*10b5fe87SSascha Wildner  */
37*10b5fe87SSascha Wildner 
38*10b5fe87SSascha Wildner #ifdef HAVE_CONFIG_H
39*10b5fe87SSascha Wildner # include "config.h"
40*10b5fe87SSascha Wildner #endif
41*10b5fe87SSascha Wildner 
42*10b5fe87SSascha Wildner #include <sys/param.h>
43*10b5fe87SSascha Wildner 
44*10b5fe87SSascha Wildner #include <grp.h>
45*10b5fe87SSascha Wildner #include <limits.h>
46*10b5fe87SSascha Wildner #include <pwd.h>
47*10b5fe87SSascha Wildner #include <stdlib.h>
48*10b5fe87SSascha Wildner #include <unistd.h>
49*10b5fe87SSascha Wildner 
50*10b5fe87SSascha Wildner #include <security/pam_appl.h>
51*10b5fe87SSascha Wildner 
52*10b5fe87SSascha Wildner #include "openpam_impl.h"
53*10b5fe87SSascha Wildner #include "openpam_cred.h"
54*10b5fe87SSascha Wildner 
55*10b5fe87SSascha Wildner /*
56*10b5fe87SSascha Wildner  * OpenPAM extension
57*10b5fe87SSascha Wildner  *
58*10b5fe87SSascha Wildner  * Restore credentials
59*10b5fe87SSascha Wildner  */
60*10b5fe87SSascha Wildner 
61*10b5fe87SSascha Wildner int
openpam_restore_cred(pam_handle_t * pamh)62*10b5fe87SSascha Wildner openpam_restore_cred(pam_handle_t *pamh)
63*10b5fe87SSascha Wildner {
64*10b5fe87SSascha Wildner 	const struct pam_saved_cred *scred;
65*10b5fe87SSascha Wildner 	const void *scredp;
66*10b5fe87SSascha Wildner 	int r;
67*10b5fe87SSascha Wildner 
68*10b5fe87SSascha Wildner 	ENTER();
69*10b5fe87SSascha Wildner 	r = pam_get_data(pamh, PAM_SAVED_CRED, &scredp);
70*10b5fe87SSascha Wildner 	if (r != PAM_SUCCESS)
71*10b5fe87SSascha Wildner 		RETURNC(r);
72*10b5fe87SSascha Wildner 	if (scredp == NULL)
73*10b5fe87SSascha Wildner 		RETURNC(PAM_SYSTEM_ERR);
74*10b5fe87SSascha Wildner 	scred = scredp;
75*10b5fe87SSascha Wildner 	if (scred->euid != geteuid()) {
76*10b5fe87SSascha Wildner 		if (seteuid(scred->euid) < 0 ||
77*10b5fe87SSascha Wildner 		    setgroups(scred->ngroups, scred->groups) < 0 ||
78*10b5fe87SSascha Wildner 		    setegid(scred->egid) < 0)
79*10b5fe87SSascha Wildner 			RETURNC(PAM_SYSTEM_ERR);
80*10b5fe87SSascha Wildner 	}
81*10b5fe87SSascha Wildner 	pam_set_data(pamh, PAM_SAVED_CRED, NULL, NULL);
82*10b5fe87SSascha Wildner 	RETURNC(PAM_SUCCESS);
83*10b5fe87SSascha Wildner }
84*10b5fe87SSascha Wildner 
85*10b5fe87SSascha Wildner /*
86*10b5fe87SSascha Wildner  * Error codes:
87*10b5fe87SSascha Wildner  *
88*10b5fe87SSascha Wildner  *	=pam_get_data
89*10b5fe87SSascha Wildner  *	PAM_SYSTEM_ERR
90*10b5fe87SSascha Wildner  */
91*10b5fe87SSascha Wildner 
92*10b5fe87SSascha Wildner /**
93*10b5fe87SSascha Wildner  * The =openpam_restore_cred function restores the credentials saved by
94*10b5fe87SSascha Wildner  * =openpam_borrow_cred.
95*10b5fe87SSascha Wildner  *
96*10b5fe87SSascha Wildner  * >setegid 2
97*10b5fe87SSascha Wildner  * >seteuid 2
98*10b5fe87SSascha Wildner  * >setgroups 2
99*10b5fe87SSascha Wildner  */
100