xref: /freebsd/crypto/openssh/audit-linux.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /* $Id: audit-linux.c,v 1.1 2011/01/17 10:15:30 dtucker Exp $ */
2 
3 /*
4  * Copyright 2010 Red Hat, Inc.  All rights reserved.
5  * Use is subject to license terms.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * Red Hat author: Jan F. Chadima <jchadima@redhat.com>
28  */
29 
30 #include "includes.h"
31 #if defined(USE_LINUX_AUDIT)
32 #include <libaudit.h>
33 #include <unistd.h>
34 #include <string.h>
35 
36 #include "log.h"
37 #include "audit.h"
38 #include "canohost.h"
39 
40 const char* audit_username(void);
41 
42 int
43 linux_audit_record_event(int uid, const char *username,
44     const char *hostname, const char *ip, const char *ttyn, int success)
45 {
46 	int audit_fd, rc, saved_errno;
47 
48 	audit_fd = audit_open();
49 	if (audit_fd < 0) {
50 		if (errno == EINVAL || errno == EPROTONOSUPPORT ||
51 		    errno == EAFNOSUPPORT)
52 			return 1; /* No audit support in kernel */
53 		else
54 			return 0; /* Must prevent login */
55 	}
56 	rc = audit_log_acct_message(audit_fd, AUDIT_USER_LOGIN,
57 	    NULL, "login", username ? username : "(unknown)",
58 	    username == NULL ? uid : -1, hostname, ip, ttyn, success);
59 	saved_errno = errno;
60 	close(audit_fd);
61 	/*
62 	 * Do not report error if the error is EPERM and sshd is run as non
63 	 * root user.
64 	 */
65 	if ((rc == -EPERM) && (geteuid() != 0))
66 		rc = 0;
67 	errno = saved_errno;
68 	return (rc >= 0);
69 }
70 
71 /* Below is the sshd audit API code */
72 
73 void
74 audit_connection_from(const char *host, int port)
75 {
76 }
77 	/* not implemented */
78 
79 void
80 audit_run_command(const char *command)
81 {
82 	/* not implemented */
83 }
84 
85 void
86 audit_session_open(struct logininfo *li)
87 {
88 	if (linux_audit_record_event(li->uid, NULL, li->hostname,
89 	    NULL, li->line, 1) == 0)
90 		fatal("linux_audit_write_entry failed: %s", strerror(errno));
91 }
92 
93 void
94 audit_session_close(struct logininfo *li)
95 {
96 	/* not implemented */
97 }
98 
99 void
100 audit_event(ssh_audit_event_t event)
101 {
102 	switch(event) {
103 	case SSH_AUTH_SUCCESS:
104 	case SSH_CONNECTION_CLOSE:
105 	case SSH_NOLOGIN:
106 	case SSH_LOGIN_EXCEED_MAXTRIES:
107 	case SSH_LOGIN_ROOT_DENIED:
108 		break;
109 
110 	case SSH_AUTH_FAIL_NONE:
111 	case SSH_AUTH_FAIL_PASSWD:
112 	case SSH_AUTH_FAIL_KBDINT:
113 	case SSH_AUTH_FAIL_PUBKEY:
114 	case SSH_AUTH_FAIL_HOSTBASED:
115 	case SSH_AUTH_FAIL_GSSAPI:
116 	case SSH_INVALID_USER:
117 		linux_audit_record_event(-1, audit_username(), NULL,
118 			get_remote_ipaddr(), "sshd", 0);
119 		break;
120 
121 	default:
122 		debug("%s: unhandled event %d", __func__, event);
123 	}
124 }
125 
126 #endif /* USE_LINUX_AUDIT */
127