xref: /freebsd/lib/libpam/modules/pam_exec/pam_exec.c (revision c98323078dede7579020518ec84cdcb478e5c142)
1 /*-
2  * Copyright (c) 2001,2003 Networks Associates Technology, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by ThinkSec AS and
6  * NAI Labs, the Security Research Division of Network Associates, Inc.
7  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
8  * DARPA CHATS research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote
19  *    products derived from this software without specific prior written
20  *    permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/types.h>
39 #include <sys/wait.h>
40 
41 #include <errno.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #include <security/pam_appl.h>
47 #include <security/pam_modules.h>
48 #include <security/openpam.h>
49 
50 static int
51 _pam_exec(pam_handle_t *pamh __unused, int flags __unused,
52     int argc, const char *argv[])
53 {
54 	int childerr, status;
55 	char **env, **envlist;
56 	pid_t pid;
57 
58 	if (argc < 1)
59 		return (PAM_SERVICE_ERR);
60 
61 	/*
62 	 * XXX For additional credit, divert child's stdin/stdout/stderr
63 	 * to the conversation function.
64 	 */
65 	envlist = pam_getenvlist(pamh);
66 	childerr = 0;
67 	if ((pid = vfork()) == 0) {
68 		execve(argv[0], argv, envlist);
69 		childerr = errno;
70 		_exit(1);
71 	}
72 	for (env = envlist; *env != NULL; ++env)
73 		free(*env);
74 	free(envlist);
75 	if (pid == -1) {
76 		openpam_log(PAM_LOG_ERROR, "vfork(): %m");
77 		return (PAM_SYSTEM_ERR);
78 	}
79 	if (waitpid(pid, &status, 0) == -1) {
80 		openpam_log(PAM_LOG_ERROR, "waitpid(): %m");
81 		return (PAM_SYSTEM_ERR);
82 	}
83 	if (childerr != 0) {
84 		openpam_log(PAM_LOG_ERROR, "execv(): %m");
85 		return (PAM_SYSTEM_ERR);
86 	}
87 	if (WIFSIGNALED(status)) {
88 		openpam_log(PAM_LOG_ERROR, "%s caught signal %d%s",
89 		    argv[0], WTERMSIG(status),
90 		    WCOREDUMP(status) ? " (core dumped)" : "");
91 		return (PAM_SYSTEM_ERR);
92 	}
93 	if (!WIFEXITED(status)) {
94 		openpam_log(PAM_LOG_ERROR, "unknown status 0x%x", status);
95 		return (PAM_SYSTEM_ERR);
96 	}
97 	if (WEXITSTATUS(status) != 0) {
98 		openpam_log(PAM_LOG_ERROR, "%s returned code %d",
99 		    argv[0], WEXITSTATUS(status));
100 		return (PAM_SYSTEM_ERR);
101 	}
102 	return (PAM_SUCCESS);
103 }
104 
105 PAM_EXTERN int
106 pam_sm_authenticate(pam_handle_t *pamh, int flags,
107     int argc, const char *argv[])
108 {
109 
110 	return (_pam_exec(pamh, flags, argc, argv));
111 }
112 
113 PAM_EXTERN int
114 pam_sm_setcred(pam_handle_t *pamh, int flags,
115     int argc, const char *argv[])
116 {
117 
118 	return (_pam_exec(pamh, flags, argc, argv));
119 }
120 
121 PAM_EXTERN int
122 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
123     int argc, const char *argv[])
124 {
125 
126 	return (_pam_exec(pamh, flags, argc, argv));
127 }
128 
129 PAM_EXTERN int
130 pam_sm_open_session(pam_handle_t *pamh, int flags,
131     int argc, const char *argv[])
132 {
133 
134 	return (_pam_exec(pamh, flags, argc, argv));
135 }
136 
137 PAM_EXTERN int
138 pam_sm_close_session(pam_handle_t *pamh, int flags,
139     int argc, const char *argv[])
140 {
141 
142 	return (_pam_exec(pamh, flags, argc, argv));
143 }
144 
145 PAM_EXTERN int
146 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
147     int argc, const char *argv[])
148 {
149 
150 	return (_pam_exec(pamh, flags, argc, argv));
151 }
152 
153 PAM_MODULE_ENTRY("pam_exec");
154