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
|
/*
* 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;
/*
* Allocate our context
*/
context = (struct plugin_context *) calloc (1, sizeof (struct plugin_context));
/*
* We are only interested in intercepting the
* --auth-user-pass-verify callback.
*/
*type_mask = OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY);
return (openvpn_plugin_handle_t) context;
}
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; */
/* 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 void
openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle)
{
struct plugin_context *context = (struct plugin_context *) handle;
free (context);
}
|
