#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>

/* A very basic TLS client, with X.509 authentication.
 */

#define MAX_BUF 1024
#define CAFILE \
  "/etc/ssl/certs/Verisign_Class_3_Public_Primary_Certification_Authority.pem"

#define MSG1 "GET / HTTP/1.1 \r\n Accept:*/* \r\n Host: mail.google.com \r\n Connection: Keep-Alive\r\n\r\n"
extern int tcp_connect (void);
extern void tcp_close (int sd);

void mylogfn( int level, const char*ptr)
{
	printf ("Got Logs: ");
	if (ptr)
		printf ("%s", ptr);
}

int
main (void)
{
  int ret, sd, ii;
  gnutls_session_t session;
  char buffer[MAX_BUF + 1];
  const char *err;
  gnutls_certificate_credentials_t xcred;

  gnutls_global_init ();
  
  /* X509 stuff */
  gnutls_certificate_allocate_credentials (&xcred);

  /* Initialize TLS session 
   */
  gnutls_init (&session, GNUTLS_CLIENT);

  /* Use default priorities */
  ret = gnutls_priority_set_direct (session, NULL, &err);
  if (ret < 0) {
    if (ret == GNUTLS_E_INVALID_REQUEST) {
      fprintf(stderr, "Syntax error at: %s\n", err);
    }
    exit(1);
  }
  gnutls_handshake_set_private_extensions (session, 1);
  /* put the x509 credentials to the current session
   */
  gnutls_credentials_set (session, GNUTLS_CRD_CERTIFICATE, xcred);

  /* 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;
    }

  gnutls_record_send (session, MSG1, strlen (MSG1));

  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;
    }

  for (ii = 0; ii < ret; ii++)
    {
      /* fputc (buffer[ii], stdout); */
    }
  fputs ("Finished\n", stdout);

  gnutls_bye (session, GNUTLS_SHUT_RDWR);

end:

  tcp_close (sd);

  gnutls_deinit (session);
  gnutls_global_deinit ();
  return 0;
}