-
Notifications
You must be signed in to change notification settings - Fork 46
/
duo_openvpn.c
191 lines (162 loc) · 3.97 KB
/
duo_openvpn.c
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
#include <sys/stat.h>
#include <sys/wait.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <unistd.h>
#include <syslog.h>
#include "openvpn-plugin.h"
#ifndef USE_PERL
#define DUO_SCRIPT_PATH PREFIX "/duo_openvpn.py"
#else
#define DUO_SCRIPT_PATH PREFIX "/duo_openvpn.pl"
#endif
struct context {
char *ikey;
char *skey;
char *host;
char *proxy_host;
char *proxy_port;
};
static const char *
get_env(const char *name, const char *envp[])
{
int i, namelen;
const char *cp;
if (envp) {
namelen = strlen(name);
for (i = 0; envp[i]; ++i) {
if (!strncmp(envp[i], name, namelen)) {
cp = envp[i] + namelen;
if (*cp == '=') {
return cp + 1;
}
}
}
}
return NULL;
}
static int
auth_user_pass_verify(struct context *ctx, const char *args[], const char *envp[])
{
int pid;
const char *control, *username, *password, *ipaddr;
char *argv[] = { DUO_SCRIPT_PATH, NULL };
control = get_env("auth_control_file", envp);
username = get_env("common_name", envp);
password = get_env("password", envp);
ipaddr = get_env("untrusted_ip", envp);
if (!control || !username || !password || !ipaddr) {
return OPENVPN_PLUGIN_FUNC_ERROR;
}
pid = fork();
if (pid < 0) {
return OPENVPN_PLUGIN_FUNC_ERROR;
}
if (pid > 0) {
int status;
/* openvpn process forked ok, wait for first child to exit and return its status */
pid = waitpid(pid, &status, 0);
if (pid < 0) {
return OPENVPN_PLUGIN_FUNC_ERROR;
}
if (WIFEXITED(status)) {
return WEXITSTATUS(status);
}
return OPENVPN_PLUGIN_FUNC_ERROR;
}
pid = fork();
if (pid < 0) {
exit(OPENVPN_PLUGIN_FUNC_ERROR);
}
if (pid > 0) {
/* first child forked ok, pass deferred return up to parent openvpn process */
exit(OPENVPN_PLUGIN_FUNC_DEFERRED);
}
/* second child daemonizes so PID 1 can reap */
umask(0);
setsid();
chdir("/");
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
if (ctx->ikey && ctx->skey && ctx->host) {
setenv("ikey", ctx->ikey, 1);
setenv("skey", ctx->skey, 1);
setenv("host", ctx->host, 1);
if (ctx->proxy_host) {
setenv("proxy_host", ctx->proxy_host, 1);
}
else {
unsetenv("proxy_host");
}
if (ctx->proxy_port) {
setenv("proxy_port", ctx->proxy_port, 1);
}
else {
unsetenv("proxy_port");
}
}
setenv("control", control, 1);
setenv("username", username, 1);
setenv("password", password, 1);
setenv("ipaddr", ipaddr, 1);
execvp(argv[0], argv);
exit(1);
}
OPENVPN_EXPORT int
openvpn_plugin_func_v2(openvpn_plugin_handle_t handle, const int type, const char *argv[], const char *envp[], void *per_client_context, struct openvpn_plugin_string_list **return_list)
{
struct context *ctx = (struct context *) handle;
if (type == OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY) {
return auth_user_pass_verify(ctx, argv, envp);
} else {
return OPENVPN_PLUGIN_FUNC_ERROR;
}
}
OPENVPN_EXPORT openvpn_plugin_handle_t
openvpn_plugin_open_v2(unsigned int *type_mask, const char *argv[], const char *envp[], struct openvpn_plugin_string_list **return_list)
{
struct context *ctx;
ctx = (struct context *) calloc(1, sizeof(struct context));
if (argv[1] && argv[2] && argv[3]) {
ctx->ikey = strdup(argv[1]);
ctx->skey = strdup(argv[2]);
ctx->host = strdup(argv[3]);
}
/* Passing proxy_host even if proxy_port is not present
* generates a more informative log message.
*/
if (argv[4]) {
ctx->proxy_host = strdup(argv[4]);
if (argv[5]) {
ctx->proxy_port = strdup(argv[5]);
}
else {
ctx->proxy_port = NULL;
}
}
else {
ctx->proxy_host = NULL;
ctx->proxy_port = NULL;
}
*type_mask = OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY);
return (openvpn_plugin_handle_t) ctx;
}
OPENVPN_EXPORT void
openvpn_plugin_close_v1(openvpn_plugin_handle_t handle)
{
struct context *ctx = (struct context *) handle;
free(ctx->ikey);
free(ctx->skey);
free(ctx->host);
if (ctx->proxy_host) {
free(ctx->proxy_host);
}
if (ctx->proxy_port) {
free(ctx->proxy_port);
}
free(ctx);
}