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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>
#include <assert.h>
#define CAFILE "ca-cert.pem"
#define KEYFILE "server-key.pem"
#define CERTFILE "server-cert.pem"
#define CRLFILE "crl.pem"
#define CHECK(x) assert((x) >= 0)
#define LOOP_CHECK(rval, cmd) \
do \
{ \
rval = cmd; \
} while (rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED)
#define MAX_BUF 16
#define PORT 5556 /* listen to 5556 port */
int main(void)
{
int listen_sd;
int sd, ret;
gnutls_certificate_credentials_t x509_cred;
gnutls_priority_t priority_cache;
struct sockaddr_in sa_serv;
struct sockaddr_in sa_cli;
socklen_t client_len;
char topbuf[512];
gnutls_session_t session;
char buffer[MAX_BUF + 1];
int optval = 1;
/* for backwards compatibility with gnutls < 3.3.0 */
CHECK(gnutls_global_init());
CHECK(gnutls_certificate_allocate_credentials(&x509_cred));
CHECK(gnutls_certificate_set_x509_crl_file(x509_cred, CRLFILE, GNUTLS_X509_FMT_PEM));
CHECK(gnutls_certificate_set_x509_key_file(x509_cred, CERTFILE, KEYFILE, GNUTLS_X509_FMT_PEM));
CHECK(gnutls_certificate_set_x509_trust_file(x509_cred, CAFILE, GNUTLS_X509_FMT_PEM));
CHECK(gnutls_priority_init(&priority_cache, NULL, NULL));
#if GNUTLS_VERSION_NUMBER >= 0x030506
/* only available since GnuTLS 3.5.6, on previous versions see
* gnutls_certificate_set_dh_params(). */
gnutls_certificate_set_known_dh_params(x509_cred, GNUTLS_SEC_PARAM_HIGH);
#endif
/* Socket operations */
listen_sd = socket(AF_INET, SOCK_STREAM, 0);
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));
bind(listen_sd, (struct sockaddr *)&sa_serv, sizeof(sa_serv));
listen(listen_sd, 1024);
printf("Server ready. Listening to port '%d'.\n", PORT);
client_len = sizeof(sa_cli);
for (;;)
{
CHECK(gnutls_init(&session, GNUTLS_SERVER));
CHECK(gnutls_priority_set(session, priority_cache));
CHECK(gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred));
gnutls_session_set_verify_cert(session, NULL, 0);
gnutls_certificate_server_set_request(session, GNUTLS_CERT_REQUIRE);
gnutls_certificate_send_x509_rdn_sequence(session, 1);
gnutls_handshake_set_timeout(session, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
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", gnutls_strerror(ret));
continue;
}
printf("- Handshake was completed\n");
for (;;)
{
LOOP_CHECK(ret, gnutls_record_recv(session, buffer, MAX_BUF));
if (ret == 0)
{
printf("- 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",
ret);
break;
}
else if (ret > 0 && ret < MAX_BUF - 1)
{
buffer[ret] = '$';
CHECK(gnutls_record_send(session, buffer, ret + 1));
}
}
LOOP_CHECK(ret, gnutls_bye(session, GNUTLS_SHUT_WR));
close(sd);
gnutls_deinit(session);
}
close(listen_sd);
gnutls_certificate_free_credentials(x509_cred);
gnutls_priority_deinit(priority_cache);
gnutls_global_deinit();
return 0;
}
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