1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* This file implements a simple OpenVPN plugin module which
* will test deferred authentication. Will run on Windows or *nix.
*
* See the README file for build instructions.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "openvpn-plugin.h"
/*
* Our context, where we keep our state.
*/
struct plugin_context {
int dummy;
};
/*
* Given an environmental variable name, search
* the envp array for its value, returning it
* if found or NULL otherwise.
*/
static const char *
get_env (const char *name, const char *envp[])
{
if (envp)
{
int i;
const int namelen = strlen (name);
for (i = 0; envp[i]; ++i)
{
if (!strncmp (envp[i], name, namelen))
{
const char *cp = envp[i] + namelen;
if (*cp == '=')
return cp + 1;
}
}
}
return NULL;
}
/* used for safe printf of possible NULL strings */
static const char *
np (const char *str)
{
if (str)
return str;
else
return "[NULL]";
}
OPENVPN_EXPORT openvpn_plugin_handle_t
openvpn_plugin_open_v1 (unsigned int *type_mask, const char *argv[], const char *envp[])
{
struct plugin_context *context;
printf ("FUNC: openvpn_plugin_open_v1\n");
/*
* Allocate our context
*/
context = (struct plugin_context *) calloc (1, sizeof (struct plugin_context));
/*
* Which callbacks to intercept. We are only interested in
* OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, but we intercept all
* the callbacks for illustration purposes, so we can show
* the calling sequence via debug output.
*/
*type_mask =
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_UP) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_DOWN) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_ROUTE_UP) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_IPCHANGE) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_TLS_VERIFY) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_CLIENT_CONNECT_V2) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_CLIENT_DISCONNECT) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_LEARN_ADDRESS) |
OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_TLS_FINAL);
return (openvpn_plugin_handle_t) context;
}
static int
auth_user_pass_verify (struct plugin_context *context, const char *argv[], const char *envp[])
{
/* get username/password from envp string array */
const char *username = get_env ("username", envp);
const char *password = get_env ("password", envp);
/* get auth_control_file filename from envp string array*/
const char *auth_control_file = get_env ("auth_control_file", envp);
printf ("DEFER u='%s' p='%s' acf='%s'\n",
np(username),
np(password),
np(auth_control_file));
/* Authenticate asynchronously in 10 seconds */
if (auth_control_file)
{
char buf[256];
snprintf (buf, sizeof(buf), "( sleep 10 ; echo AUTH %s ; echo 1 >%s ) &",
auth_control_file,
auth_control_file);
printf ("%s\n", buf);
system (buf);
return OPENVPN_PLUGIN_FUNC_DEFERRED;
}
else
return OPENVPN_PLUGIN_FUNC_ERROR;
}
OPENVPN_EXPORT int
openvpn_plugin_func_v1 (openvpn_plugin_handle_t handle, const int type, const char *argv[], const char *envp[])
{
struct plugin_context *context = (struct plugin_context *) handle;
switch (type)
{
case OPENVPN_PLUGIN_UP:
printf ("OPENVPN_PLUGIN_UP\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_DOWN:
printf ("OPENVPN_PLUGIN_DOWN\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_ROUTE_UP:
printf ("OPENVPN_PLUGIN_ROUTE_UP\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_IPCHANGE:
printf ("OPENVPN_PLUGIN_IPCHANGE\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_TLS_VERIFY:
printf ("OPENVPN_PLUGIN_TLS_VERIFY\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY:
printf ("OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY\n");
return auth_user_pass_verify (context, argv, envp);
case OPENVPN_PLUGIN_CLIENT_CONNECT_V2:
printf ("OPENVPN_PLUGIN_CLIENT_CONNECT_V2\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_CLIENT_DISCONNECT:
printf ("OPENVPN_PLUGIN_CLIENT_DISCONNECT\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_LEARN_ADDRESS:
printf ("OPENVPN_PLUGIN_LEARN_ADDRESS\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
case OPENVPN_PLUGIN_TLS_FINAL:
printf ("OPENVPN_PLUGIN_TLS_FINAL\n");
return OPENVPN_PLUGIN_FUNC_SUCCESS;
default:
printf ("OPENVPN_PLUGIN_?\n");
return OPENVPN_PLUGIN_FUNC_ERROR;
}
}
OPENVPN_EXPORT void *
openvpn_plugin_client_constructor_v1 (openvpn_plugin_handle_t handle)
{
printf ("FUNC: openvpn_plugin_client_constructor_v1\n");
return malloc(1);
}
OPENVPN_EXPORT void
openvpn_plugin_client_destructor_v1 (openvpn_plugin_handle_t handle, void *per_client_context)
{
printf ("FUNC: openvpn_plugin_client_destructor_v1\n");
free (per_client_context);
}
OPENVPN_EXPORT void
openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle)
{
struct plugin_context *context = (struct plugin_context *) handle;
printf ("FUNC: openvpn_plugin_close_v1\n");
free (context);
}
|
