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
38 #include <sys/types.h>
39
40 #include <grp.h>
41 #include <pwd.h>
42 #include <stdarg.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <syslog.h>
46 #include <unistd.h>
47
48 #define PAM_SM_AUTH
49 #define PAM_SM_ACCOUNT
50
51 #include <security/pam_appl.h>
52 #include <security/pam_modules.h>
53 #include <security/openpam.h>
54
55 static int
pam_group(pam_handle_t * pamh)56 pam_group(pam_handle_t *pamh)
57 {
58 int local, remote;
59 const char *group, *user;
60 const void *ruser;
61 char *const *list;
62 struct passwd *pwd;
63 struct group *grp;
64
65 /* get target account */
66 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
67 user == NULL || (pwd = getpwnam(user)) == NULL)
68 return (PAM_AUTH_ERR);
69 if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
70 return (PAM_IGNORE);
71
72 /* check local / remote */
73 local = openpam_get_option(pamh, "luser") ? 1 : 0;
74 remote = openpam_get_option(pamh, "ruser") ? 1 : 0;
75 if (local && remote) {
76 openpam_log(PAM_LOG_ERROR, "(pam_group) "
77 "the luser and ruser options are mutually exclusive");
78 return (PAM_SERVICE_ERR);
79 } else if (local) {
80 /* we already have the correct struct passwd */
81 } else {
82 if (!remote)
83 openpam_log(PAM_LOG_NOTICE, "(pam_group) "
84 "neither luser nor ruser specified, assuming ruser");
85 /* default / historical behavior */
86 if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
87 ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
88 return (PAM_AUTH_ERR);
89 }
90
91 /* get regulating group */
92 if ((group = openpam_get_option(pamh, "group")) == NULL)
93 group = "wheel";
94 if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
95 goto failed;
96
97 /* check if user's own primary group */
98 if (pwd->pw_gid == grp->gr_gid)
99 goto found;
100
101 /* iterate over members */
102 for (list = grp->gr_mem; list != NULL && *list != NULL; ++list)
103 if (strcmp(*list, pwd->pw_name) == 0)
104 goto found;
105
106 not_found:
107 if (openpam_get_option(pamh, "deny"))
108 return (PAM_SUCCESS);
109 return (PAM_AUTH_ERR);
110 found:
111 if (openpam_get_option(pamh, "deny"))
112 return (PAM_AUTH_ERR);
113 return (PAM_SUCCESS);
114 failed:
115 if (openpam_get_option(pamh, "fail_safe"))
116 goto found;
117 else
118 goto not_found;
119 }
120
121 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)122 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
123 int argc __unused, const char *argv[] __unused)
124 {
125
126 return (pam_group(pamh));
127 }
128
129 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)130 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
131 int argc __unused, const char *argv[] __unused)
132 {
133
134 return (PAM_SUCCESS);
135 }
136
137 PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)138 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
139 int argc __unused, const char *argv[] __unused)
140 {
141
142 return (pam_group(pamh));
143 }
144
145 PAM_MODULE_ENTRY("pam_group");
146