1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2004-2011 Dag-Erling Smørgrav
6 * All rights reserved.
7 *
8 * Portions of this software were developed for the FreeBSD Project by
9 * ThinkSec AS and NAI Labs, the Security Research Division of Network
10 * 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 * $FreeBSD: head/lib/libpam/modules/pam_group/pam_group.c 326219 2017-11-26 02:00:33Z pfg $
38 */
39
40 #include <sys/types.h>
41
42 #include <grp.h>
43 #include <pwd.h>
44 #include <stdarg.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <syslog.h>
48 #include <unistd.h>
49
50 #define PAM_SM_AUTH
51 #define PAM_SM_ACCOUNT
52
53 #include <security/pam_appl.h>
54 #include <security/pam_modules.h>
55 #include <security/openpam.h>
56
57 static int
pam_group(pam_handle_t * pamh)58 pam_group(pam_handle_t *pamh)
59 {
60 int local, remote;
61 const char *group, *user;
62 const void *ruser;
63 char *const *list;
64 struct passwd *pwd;
65 struct group *grp;
66
67 /* get target account */
68 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
69 user == NULL || (pwd = getpwnam(user)) == NULL)
70 return (PAM_AUTH_ERR);
71 if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
72 return (PAM_IGNORE);
73
74 /* check local / remote */
75 local = openpam_get_option(pamh, "luser") ? 1 : 0;
76 remote = openpam_get_option(pamh, "ruser") ? 1 : 0;
77 if (local && remote) {
78 openpam_log(PAM_LOG_ERROR, "(pam_group) "
79 "the luser and ruser options are mutually exclusive");
80 return (PAM_SERVICE_ERR);
81 } else if (local) {
82 /* we already have the correct struct passwd */
83 } else {
84 if (!remote)
85 openpam_log(PAM_LOG_NOTICE, "(pam_group) "
86 "neither luser nor ruser specified, assuming ruser");
87 /* default / historical behavior */
88 if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
89 ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
90 return (PAM_AUTH_ERR);
91 }
92
93 /* get regulating group */
94 if ((group = openpam_get_option(pamh, "group")) == NULL)
95 group = "wheel";
96 if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
97 goto failed;
98
99 /* check if user's own primary group */
100 if (pwd->pw_gid == grp->gr_gid)
101 goto found;
102
103 /* iterate over members */
104 for (list = grp->gr_mem; list != NULL && *list != NULL; ++list)
105 if (strcmp(*list, pwd->pw_name) == 0)
106 goto found;
107
108 not_found:
109 if (openpam_get_option(pamh, "deny"))
110 return (PAM_SUCCESS);
111 return (PAM_AUTH_ERR);
112 found:
113 if (openpam_get_option(pamh, "deny"))
114 return (PAM_AUTH_ERR);
115 return (PAM_SUCCESS);
116 failed:
117 if (openpam_get_option(pamh, "fail_safe"))
118 goto found;
119 else
120 goto not_found;
121 }
122
123 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)124 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
125 int argc __unused, const char *argv[] __unused)
126 {
127
128 return (pam_group(pamh));
129 }
130
131 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)132 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
133 int argc __unused, const char *argv[] __unused)
134 {
135
136 return (PAM_SUCCESS);
137 }
138
139 PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)140 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
141 int argc __unused, const char *argv[] __unused)
142 {
143
144 return (pam_group(pamh));
145 }
146
147 PAM_MODULE_ENTRY("pam_group");
148