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/* 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 KEYFILE "key.pem"
#define CERTFILE "cert.pem"
#define CAFILE "/etc/ssl/certs/ca-certificates.crt"
#define CRLFILE "crl.pem"
#define LOOP_CHECK(rval, cmd) \
do { \
rval = cmd; \
} while(rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED)
/* This is a sample TLS echo server, supporting X.509 and PSK
authentication.
*/
#define SOCKET_ERR(err,s) if(err==-1) {perror(s);return(1);}
#define MAX_BUF 1024
#define PORT 5556 /* listen to 5556 port */
static int
pskfunc(gnutls_session_t session, const char *username, gnutls_datum_t * key)
{
printf("psk: username %s\n", username);
key->data = gnutls_malloc(4);
key->data[0] = 0xDE;
key->data[1] = 0xAD;
key->data[2] = 0xBE;
key->data[3] = 0xEF;
key->size = 4;
return 0;
}
int main(void)
{
int err, listen_sd;
int sd, ret;
struct sockaddr_in sa_serv;
struct sockaddr_in sa_cli;
socklen_t client_len;
char topbuf[512];
gnutls_session_t session;
gnutls_certificate_credentials_t x509_cred;
gnutls_psk_server_credentials_t psk_cred;
gnutls_priority_t priority_cache;
char buffer[MAX_BUF + 1];
int optval = 1;
int kx;
if (gnutls_check_version("3.1.4") == NULL) {
fprintf(stderr,
"GnuTLS 3.1.4 or later is required for this example\n");
exit(1);
}
/* for backwards compatibility with gnutls < 3.3.0 */
gnutls_global_init();
gnutls_certificate_allocate_credentials(&x509_cred);
gnutls_certificate_set_x509_trust_file(x509_cred, CAFILE,
GNUTLS_X509_FMT_PEM);
gnutls_certificate_set_x509_crl_file(x509_cred, CRLFILE,
GNUTLS_X509_FMT_PEM);
gnutls_certificate_set_x509_key_file(x509_cred, CERTFILE, KEYFILE,
GNUTLS_X509_FMT_PEM);
gnutls_psk_allocate_server_credentials(&psk_cred);
gnutls_psk_set_server_credentials_function(psk_cred, pskfunc);
/* pre-3.6.3 equivalent:
* gnutls_priority_init(&priority_cache,
* "NORMAL:+PSK:+ECDHE-PSK:+DHE-PSK",
* NULL);
*/
gnutls_priority_init2(&priority_cache,
"+ECDHE-PSK:+DHE-PSK:+PSK",
NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND);
gnutls_certificate_set_known_dh_params(x509_cred,
GNUTLS_SEC_PARAM_MEDIUM);
/* 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, (struct sockaddr *)&sa_serv, sizeof(sa_serv));
SOCKET_ERR(err, "bind");
err = listen(listen_sd, 1024);
SOCKET_ERR(err, "listen");
printf("Server ready. Listening to port '%d'.\n\n", PORT);
client_len = sizeof(sa_cli);
for (;;) {
gnutls_init(&session, GNUTLS_SERVER);
gnutls_priority_set(session, priority_cache);
gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE,
x509_cred);
gnutls_credentials_set(session, GNUTLS_CRD_PSK, psk_cred);
/* request client certificate if any.
*/
gnutls_certificate_server_set_request(session,
GNUTLS_CERT_REQUEST);
sd = accept(listen_sd, (struct sockaddr *)&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_int(session, sd);
LOOP_CHECK(ret, gnutls_handshake(session));
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");
kx = gnutls_kx_get(session);
if (kx == GNUTLS_KX_PSK || kx == GNUTLS_KX_DHE_PSK ||
kx == GNUTLS_KX_ECDHE_PSK) {
printf("- User %s was connected\n",
gnutls_psk_server_get_username(session));
}
/* see the Getting peer's information example */
/* print_info(session); */
for (;;) {
LOOP_CHECK(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 && gnutls_error_is_fatal(ret) == 0) {
fprintf(stderr, "*** Warning: %s\n",
gnutls_strerror(ret));
} 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, ret);
}
}
printf("\n");
/* do not wait for the peer to close the connection.
*/
LOOP_CHECK(ret, gnutls_bye(session, GNUTLS_SHUT_WR));
close(sd);
gnutls_deinit(session);
}
close(listen_sd);
gnutls_certificate_free_credentials(x509_cred);
gnutls_psk_free_server_credentials(psk_cred);
gnutls_priority_deinit(priority_cache);
gnutls_global_deinit();
return 0;
}
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