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
|
/* This example code is placed in the public domain. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <gnutls/gnutls.h>
#define SRP_PASSWD "tpasswd"
#define SRP_PASSWD_CONF "tpasswd.conf"
#define KEYFILE "key.pem"
#define CERTFILE "cert.pem"
#define CAFILE "ca.pem"
/* This is a sample TLS-SRP echo server.
*/
#define SA struct sockaddr
#define SOCKET_ERR(err,s) if(err==-1) {perror(s);return(1);}
#define MAX_BUF 1024
#define PORT 5556 /* listen to 5556 port */
/* These are global */
gnutls_srp_server_credentials_t srp_cred;
gnutls_certificate_credentials_t cert_cred;
static gnutls_session_t
initialize_tls_session (void)
{
gnutls_session_t session;
gnutls_init (&session, GNUTLS_SERVER);
gnutls_priority_set_direct (session, "NORMAL:-KX-ALL:+SRP:+SRP-DSS:+SRP-RSA", NULL);
gnutls_credentials_set (session, GNUTLS_CRD_SRP, srp_cred);
/* for the certificate authenticated ciphersuites.
*/
gnutls_credentials_set (session, GNUTLS_CRD_CERTIFICATE, cert_cred);
/* request client certificate if any.
*/
gnutls_certificate_server_set_request (session, GNUTLS_CERT_IGNORE);
return session;
}
int
main (void)
{
int err, listen_sd;
int sd, ret;
struct sockaddr_in sa_serv;
struct sockaddr_in sa_cli;
int client_len;
char topbuf[512];
gnutls_session_t session;
char buffer[MAX_BUF + 1];
int optval = 1;
char name[256];
strcpy (name, "Echo Server");
gnutls_global_init ();
/* SRP_PASSWD a password file (created with the included srptool utility)
*/
gnutls_srp_allocate_server_credentials (&srp_cred);
gnutls_srp_set_server_credentials_file (srp_cred, SRP_PASSWD,
SRP_PASSWD_CONF);
gnutls_certificate_allocate_credentials (&cert_cred);
gnutls_certificate_set_x509_trust_file (cert_cred, CAFILE,
GNUTLS_X509_FMT_PEM);
gnutls_certificate_set_x509_key_file (cert_cred, CERTFILE, KEYFILE,
GNUTLS_X509_FMT_PEM);
/* TCP socket operations
*/
listen_sd = socket (AF_INET, SOCK_STREAM, 0);
SOCKET_ERR (listen_sd, "socket");
memset (&sa_serv, '\0', sizeof (sa_serv));
sa_serv.sin_family = AF_INET;
sa_serv.sin_addr.s_addr = INADDR_ANY;
sa_serv.sin_port = htons (PORT); /* Server Port number */
setsockopt (listen_sd, SOL_SOCKET, SO_REUSEADDR, (void *) &optval,
sizeof (int));
err = bind (listen_sd, (SA *) & sa_serv, sizeof (sa_serv));
SOCKET_ERR (err, "bind");
err = listen (listen_sd, 1024);
SOCKET_ERR (err, "listen");
printf ("%s ready. Listening to port '%d'.\n\n", name, PORT);
client_len = sizeof (sa_cli);
for (;;)
{
session = initialize_tls_session ();
sd = accept (listen_sd, (SA *) & sa_cli, &client_len);
printf ("- connection from %s, port %d\n",
inet_ntop (AF_INET, &sa_cli.sin_addr, topbuf,
sizeof (topbuf)), ntohs (sa_cli.sin_port));
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) sd);
do
{
ret = gnutls_handshake (session);
}
while (gnutls_error_is_fatal (ret) == 0);
if (ret < 0)
{
close (sd);
gnutls_deinit (session);
fprintf (stderr, "*** Handshake has failed (%s)\n\n",
gnutls_strerror (ret));
continue;
}
printf ("- Handshake was completed\n");
printf ("- User %s was connected\n", gnutls_srp_server_get_username(session));
/* print_info(session); */
for (;;)
{
memset (buffer, 0, MAX_BUF + 1);
ret = gnutls_record_recv (session, buffer, MAX_BUF);
if (ret == 0)
{
printf ("\n- Peer has closed the GnuTLS connection\n");
break;
}
else if (ret < 0)
{
fprintf (stderr, "\n*** Received corrupted "
"data(%d). Closing the connection.\n\n", ret);
break;
}
else if (ret > 0)
{
/* echo data back to the client
*/
gnutls_record_send (session, buffer, strlen (buffer));
}
}
printf ("\n");
/* do not wait for the peer to close the connection. */
gnutls_bye (session, GNUTLS_SHUT_WR);
close (sd);
gnutls_deinit (session);
}
close (listen_sd);
gnutls_srp_free_server_credentials (srp_cred);
gnutls_certificate_free_credentials (cert_cred);
gnutls_global_deinit ();
return 0;
}
|
