+ struct tcpip_state *sp = (struct tcpip_state *) cs->cprivate;
+ if (sp->session)
+ {
+ const gnutls_datum_t *cert_list;
+ unsigned i, cert_list_size;
+ if (gnutls_certificate_type_get(sp->session) != GNUTLS_CRT_X509)
+ return;
+ printf("X509 certificate\n");
+ cert_list = gnutls_certificate_get_peers(sp->session,
+ &cert_list_size);
+ printf("Peer provided %u certificates\n", cert_list_size);
+ for (i = 0; i < cert_list_size; i++)
+ {
+ gnutls_x509_crt_t cert;
+ gnutls_datum_t cinfo;
+ int ret;
+ time_t expiration_time, activation_time;
+ size_t size;
+ char serial[40];
+ char dn[256];
+ unsigned int algo, bits;
+
+ /* we only print information about the first certificate. */
+ gnutls_x509_crt_init(&cert);
+ gnutls_x509_crt_import(cert, &cert_list[i], GNUTLS_X509_FMT_DER);
+ printf("Certificate info %d:\n", i + 1);
+ /* This is the preferred way of printing short information about
+ a certificate. */
+ ret = gnutls_x509_crt_print(cert, GNUTLS_CRT_PRINT_ONELINE, &cinfo);
+ if (ret == 0)
+ {
+ printf("\t%s\n", cinfo.data);
+ gnutls_free(cinfo.data);
+ }
+
+ /* If you want to extract fields manually for some other reason,
+ below are popular example calls. */
+
+ expiration_time = gnutls_x509_crt_get_expiration_time(cert);
+ activation_time = gnutls_x509_crt_get_activation_time(cert);
+
+ printf("\tCertificate is valid since: %s", ctime(&activation_time));
+ printf("\tCertificate expires: %s", ctime(&expiration_time));
+
+ /* Print the serial number of the certificate. */
+ size = sizeof(serial);
+ gnutls_x509_crt_get_serial(cert, serial, &size);
+
+ printf("\tCertificate serial number: %s\n",
+ bin2hex(serial, size));
+
+ /* Extract some of the public key algorithm's parameters
+ */
+ algo = gnutls_x509_crt_get_pk_algorithm(cert, &bits);
+
+ printf("Certificate public key: %s",
+ gnutls_pk_algorithm_get_name(algo));
+
+ /* Print the version of the X.509 certificate. */
+ printf("\tCertificate version: #%d\n",
+ gnutls_x509_crt_get_version(cert));
+
+ size = sizeof(dn);
+ gnutls_x509_crt_get_dn(cert, dn, &size);
+ printf("\tDN: %s\n", dn);
+
+ size = sizeof(dn);
+ gnutls_x509_crt_get_issuer_dn(cert, dn, &size);
+ printf("\tIssuer's DN: %s\n", dn);
+
+ gnutls_x509_crt_deinit(cert);
+
+ }
+ }