1/* $Id: audit.c,v 1.6 2011/01/17 10:15:30 dtucker Exp $ */
2
3/*
4 * Copyright (c) 2004, 2005 Darren Tucker.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
28
29#include <stdarg.h>
30#include <string.h>
31
32#ifdef SSH_AUDIT_EVENTS
33
34#include "audit.h"
35#include "log.h"
36#include "key.h"
37#include "hostfile.h"
38#include "auth.h"
39
40/*
41 * Care must be taken when using this since it WILL NOT be initialized when
42 * audit_connection_from() is called and MAY NOT be initialized when
43 * audit_event(CONNECTION_ABANDON) is called.  Test for NULL before using.
44 */
45extern Authctxt *the_authctxt;
46
47/* Maybe add the audit class to struct Authmethod? */
48ssh_audit_event_t
49audit_classify_auth(const char *method)
50{
51	if (strcmp(method, "none") == 0)
52		return SSH_AUTH_FAIL_NONE;
53	else if (strcmp(method, "password") == 0)
54		return SSH_AUTH_FAIL_PASSWD;
55	else if (strcmp(method, "publickey") == 0 ||
56	    strcmp(method, "rsa") == 0)
57		return SSH_AUTH_FAIL_PUBKEY;
58	else if (strncmp(method, "keyboard-interactive", 20) == 0 ||
59	    strcmp(method, "challenge-response") == 0)
60		return SSH_AUTH_FAIL_KBDINT;
61	else if (strcmp(method, "hostbased") == 0 ||
62	    strcmp(method, "rhosts-rsa") == 0)
63		return SSH_AUTH_FAIL_HOSTBASED;
64	else if (strcmp(method, "gssapi-with-mic") == 0)
65		return SSH_AUTH_FAIL_GSSAPI;
66	else
67		return SSH_AUDIT_UNKNOWN;
68}
69
70/* helper to return supplied username */
71const char *
72audit_username(void)
73{
74	static const char unknownuser[] = "(unknown user)";
75	static const char invaliduser[] = "(invalid user)";
76
77	if (the_authctxt == NULL || the_authctxt->user == NULL)
78		return (unknownuser);
79	if (!the_authctxt->valid)
80		return (invaliduser);
81	return (the_authctxt->user);
82}
83
84const char *
85audit_event_lookup(ssh_audit_event_t ev)
86{
87	int i;
88	static struct event_lookup_struct {
89		ssh_audit_event_t event;
90		const char *name;
91	} event_lookup[] = {
92		{SSH_LOGIN_EXCEED_MAXTRIES,	"LOGIN_EXCEED_MAXTRIES"},
93		{SSH_LOGIN_ROOT_DENIED,		"LOGIN_ROOT_DENIED"},
94		{SSH_AUTH_SUCCESS,		"AUTH_SUCCESS"},
95		{SSH_AUTH_FAIL_NONE,		"AUTH_FAIL_NONE"},
96		{SSH_AUTH_FAIL_PASSWD,		"AUTH_FAIL_PASSWD"},
97		{SSH_AUTH_FAIL_KBDINT,		"AUTH_FAIL_KBDINT"},
98		{SSH_AUTH_FAIL_PUBKEY,		"AUTH_FAIL_PUBKEY"},
99		{SSH_AUTH_FAIL_HOSTBASED,	"AUTH_FAIL_HOSTBASED"},
100		{SSH_AUTH_FAIL_GSSAPI,		"AUTH_FAIL_GSSAPI"},
101		{SSH_INVALID_USER,		"INVALID_USER"},
102		{SSH_NOLOGIN,			"NOLOGIN"},
103		{SSH_CONNECTION_CLOSE,		"CONNECTION_CLOSE"},
104		{SSH_CONNECTION_ABANDON,	"CONNECTION_ABANDON"},
105		{SSH_AUDIT_UNKNOWN,		"AUDIT_UNKNOWN"}
106	};
107
108	for (i = 0; event_lookup[i].event != SSH_AUDIT_UNKNOWN; i++)
109		if (event_lookup[i].event == ev)
110			break;
111	return(event_lookup[i].name);
112}
113
114# ifndef CUSTOM_SSH_AUDIT_EVENTS
115/*
116 * Null implementations of audit functions.
117 * These get used if SSH_AUDIT_EVENTS is defined but no audit module is enabled.
118 */
119
120/*
121 * Called after a connection has been accepted but before any authentication
122 * has been attempted.
123 */
124void
125audit_connection_from(const char *host, int port)
126{
127	debug("audit connection from %s port %d euid %d", host, port,
128	    (int)geteuid());
129}
130
131/*
132 * Called when various events occur (see audit.h for a list of possible
133 * events and what they mean).
134 */
135void
136audit_event(ssh_audit_event_t event)
137{
138	debug("audit event euid %d user %s event %d (%s)", geteuid(),
139	    audit_username(), event, audit_event_lookup(event));
140}
141
142/*
143 * Called when a user session is started.  Argument is the tty allocated to
144 * the session, or NULL if no tty was allocated.
145 *
146 * Note that this may be called multiple times if multiple sessions are used
147 * within a single connection.
148 */
149void
150audit_session_open(struct logininfo *li)
151{
152	const char *t = li->line ? li->line : "(no tty)";
153
154	debug("audit session open euid %d user %s tty name %s", geteuid(),
155	    audit_username(), t);
156}
157
158/*
159 * Called when a user session is closed.  Argument is the tty allocated to
160 * the session, or NULL if no tty was allocated.
161 *
162 * Note that this may be called multiple times if multiple sessions are used
163 * within a single connection.
164 */
165void
166audit_session_close(struct logininfo *li)
167{
168	const char *t = li->line ? li->line : "(no tty)";
169
170	debug("audit session close euid %d user %s tty name %s", geteuid(),
171	    audit_username(), t);
172}
173
174/*
175 * This will be called when a user runs a non-interactive command.  Note that
176 * it may be called multiple times for a single connection since SSH2 allows
177 * multiple sessions within a single connection.
178 */
179void
180audit_run_command(const char *command)
181{
182	debug("audit run command euid %d user %s command '%.200s'", geteuid(),
183	    audit_username(), command);
184}
185# endif  /* !defined CUSTOM_SSH_AUDIT_EVENTS */
186#endif /* SSH_AUDIT_EVENTS */
187