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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <gnutls/gnutls.h>
#include <gnutls/extra.h>
/* A basic TLS client, with anonymous authentication and TLS/IA handshake.
*/
#define MAX_BUF 1024
#define SA struct sockaddr
#define MSG "GET / HTTP/1.0\r\n\r\n"
extern int tcp_connect (void);
extern void tcp_close (int sd);
int
client_avp (gnutls_session_t session, void *ptr,
const char *last, size_t lastlen,
char **new, size_t *newlen)
{
if (last)
printf ("- received %d bytes AVP: `%.*s'\n",
lastlen, lastlen, last);
else
printf ("- new application phase\n");
*new = gnutls_strdup ("client avp");
if (!*new)
return -1;
*newlen = strlen (*new);
printf ("- sending %d bytes AVP: `%s'\n", *newlen, *new);
gnutls_ia_permute_inner_secret (session, 3, "foo");
return 0;
}
int
main (void)
{
int ret, sd, ii;
gnutls_session_t session;
char buffer[MAX_BUF + 1];
gnutls_anon_client_credentials_t anoncred;
gnutls_ia_client_credentials_t iacred;
/* Need to enable anonymous KX specifically. */
const int kx_prio[] = { GNUTLS_KX_ANON_DH, 0 };
gnutls_global_init ();
gnutls_anon_allocate_client_credentials (&anoncred);
gnutls_ia_allocate_client_credentials (&iacred);
/* Set TLS/IA stuff
*/
gnutls_ia_set_client_avp_function (iacred, client_avp);
/* Initialize TLS session
*/
gnutls_init (&session, GNUTLS_CLIENT);
/* Use default priorities */
gnutls_set_default_priority (session);
gnutls_kx_set_priority (session, kx_prio);
/* put the anonymous and TLS/IA credentials to the current session
*/
gnutls_credentials_set (session, GNUTLS_CRD_ANON, anoncred);
gnutls_credentials_set (session, GNUTLS_CRD_IA, iacred);
/* connect to the peer
*/
sd = tcp_connect ();
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) sd);
/* Perform the TLS handshake
*/
ret = gnutls_handshake (session);
if (ret < 0)
{
fprintf (stderr, "*** Handshake failed\n");
gnutls_perror (ret);
goto end;
}
else
{
printf ("- Handshake was completed\n");
}
if (!gnutls_ia_handshake_p (session))
{
fprintf (stderr, "*** TLS/IA not negotiated...\n");
goto end;
}
else
{
printf ("- Starting TLS/IA handshake...\n");
ret = gnutls_ia_handshake (session);
if (ret < 0)
{
fprintf (stderr, "*** TLS/IA handshake failed\n");
gnutls_perror (ret);
goto end;
}
else
{
printf ("- TLS/IA Handshake was completed\n");
}
}
gnutls_record_send (session, MSG, strlen (MSG));
ret = gnutls_record_recv (session, buffer, MAX_BUF);
if (ret == 0)
{
printf ("- Peer has closed the TLS connection\n");
goto end;
}
else if (ret < 0)
{
fprintf (stderr, "*** Error: %s\n", gnutls_strerror (ret));
goto end;
}
printf ("- Received %d bytes: ", ret);
for (ii = 0; ii < ret; ii++)
{
fputc (buffer[ii], stdout);
}
fputs ("\n", stdout);
gnutls_bye (session, GNUTLS_SHUT_RDWR);
end:
tcp_close (sd);
gnutls_deinit (session);
gnutls_ia_free_client_credentials (iacred);
gnutls_anon_free_client_credentials (anoncred);
gnutls_global_deinit ();
return 0;
}
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