xref: /netbsd-src/lib/libpam/modules/pam_exec/pam_exec.c (revision fd5cb0acea84d278e04e640d37ca2398f894991f)
1 /*	$NetBSD: pam_exec.c,v 1.2 2004/12/12 08:18:44 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001,2003 Networks Associates Technology, Inc.
5  * All rights reserved.
6  *
7  * This software was developed for the FreeBSD Project by ThinkSec AS and
8  * NAI Labs, the Security Research Division of Network Associates, Inc.
9  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
10  * DARPA CHATS research program.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. The name of the author may not be used to endorse or promote
21  *    products derived from this software without specific prior written
22  *    permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #ifdef __FreeBSD__
39 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_exec/pam_exec.c,v 1.3 2003/02/06 12:56:51 des Exp $");
40 #else
41 __RCSID("$NetBSD: pam_exec.c,v 1.2 2004/12/12 08:18:44 christos Exp $");
42 #endif
43 
44 #include <sys/types.h>
45 #include <sys/wait.h>
46 
47 #include <errno.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 #include <security/pam_appl.h>
53 #include <security/pam_modules.h>
54 #include <security/openpam.h>
55 
56 static int
57 _pam_exec(pam_handle_t *pamh __unused, int flags __unused,
58     int argc, const char *argv[])
59 {
60 	int childerr, status;
61 	char **env, **envlist;
62 	pid_t pid;
63 
64 	if (argc < 1)
65 		return (PAM_SERVICE_ERR);
66 
67 	/*
68 	 * XXX For additional credit, divert child's stdin/stdout/stderr
69 	 * to the conversation function.
70 	 */
71 	envlist = pam_getenvlist(pamh);
72 	childerr = 0;
73 	if ((pid = vfork()) == 0) {
74 		/*LINTED const cast*/
75 		execve(argv[0], (char **)__UNCONST(argv), envlist);
76 		childerr = errno;
77 		_exit(1);
78 	}
79 	for (env = envlist; *env != NULL; ++env)
80 		free(*env);
81 	free(envlist);
82 	if (pid == -1) {
83 		openpam_log(PAM_LOG_ERROR, "vfork(): %m");
84 		return (PAM_SYSTEM_ERR);
85 	}
86 	if (waitpid(pid, &status, 0) == -1) {
87 		openpam_log(PAM_LOG_ERROR, "waitpid(): %m");
88 		return (PAM_SYSTEM_ERR);
89 	}
90 	if (childerr != 0) {
91 		openpam_log(PAM_LOG_ERROR, "execv(): %m");
92 		return (PAM_SYSTEM_ERR);
93 	}
94 	if (WIFSIGNALED(status)) {
95 		openpam_log(PAM_LOG_ERROR, "%s caught signal %d%s",
96 		    argv[0], WTERMSIG(status),
97 		    WCOREDUMP(status) ? " (core dumped)" : "");
98 		return (PAM_SYSTEM_ERR);
99 	}
100 	if (!WIFEXITED(status)) {
101 		openpam_log(PAM_LOG_ERROR, "unknown status 0x%x", status);
102 		return (PAM_SYSTEM_ERR);
103 	}
104 	if (WEXITSTATUS(status) != 0) {
105 		openpam_log(PAM_LOG_ERROR, "%s returned code %d",
106 		    argv[0], WEXITSTATUS(status));
107 		return (PAM_SYSTEM_ERR);
108 	}
109 	return (PAM_SUCCESS);
110 }
111 
112 PAM_EXTERN int
113 pam_sm_authenticate(pam_handle_t *pamh, int flags,
114     int argc, const char *argv[])
115 {
116 
117 	return (_pam_exec(pamh, flags, argc, argv));
118 }
119 
120 PAM_EXTERN int
121 pam_sm_setcred(pam_handle_t *pamh, int flags,
122     int argc, const char *argv[])
123 {
124 
125 	return (_pam_exec(pamh, flags, argc, argv));
126 }
127 
128 PAM_EXTERN int
129 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
130     int argc, const char *argv[])
131 {
132 
133 	return (_pam_exec(pamh, flags, argc, argv));
134 }
135 
136 PAM_EXTERN int
137 pam_sm_open_session(pam_handle_t *pamh, int flags,
138     int argc, const char *argv[])
139 {
140 
141 	return (_pam_exec(pamh, flags, argc, argv));
142 }
143 
144 PAM_EXTERN int
145 pam_sm_close_session(pam_handle_t *pamh, int flags,
146     int argc, const char *argv[])
147 {
148 
149 	return (_pam_exec(pamh, flags, argc, argv));
150 }
151 
152 PAM_EXTERN int
153 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
154     int argc, const char *argv[])
155 {
156 
157 	return (_pam_exec(pamh, flags, argc, argv));
158 }
159 
160 PAM_MODULE_ENTRY("pam_exec");
161