1 files changed, 143 insertions, 0 deletions
diff --git a/doc/examples/ex-client-x509.c b/doc/examples/ex-client-x509.c
new file mode 100644
index 0000000..07abcf0
--- /dev/null
+++ b/doc/examples/ex-client-x509.c
@@ -0,0 +1,143 @@
+/* This example code is placed in the public domain. */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+#include "examples.h"
+
+/* A very basic TLS client, with X.509 authentication and server certificate
+ * verification. Note that error recovery is minimal for simplicity.
+ */
+
+#define CHECK(x) assert((x)>=0)
+#define LOOP_CHECK(rval, cmd) \
+        do { \
+                rval = cmd; \
+        } while(rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED); \
+        assert(rval >= 0)
+
+#define MAX_BUF 1024
+#define MSG "GET / HTTP/1.0\r\n\r\n"
+
+extern int tcp_connect(void);
+extern void tcp_close(int sd);
+
+int main(void)
+{
+        int ret, sd, ii;
+        gnutls_session_t session;
+        char buffer[MAX_BUF + 1], *desc;
+        gnutls_datum_t out;
+        int type;
+        unsigned status;
+        gnutls_certificate_credentials_t xcred;
+
+        if (gnutls_check_version("3.4.6") == NULL) {
+                fprintf(stderr, "GnuTLS 3.4.6 or later is required for this example\n");
+                exit(1);
+        }
+
+        /* for backwards compatibility with gnutls < 3.3.0 */
+        CHECK(gnutls_global_init());
+
+        /* X509 stuff */
+        CHECK(gnutls_certificate_allocate_credentials(&xcred));
+
+        /* sets the system trusted CAs for Internet PKI */
+        CHECK(gnutls_certificate_set_x509_system_trust(xcred));
+
+        /* If client holds a certificate it can be set using the following:
+         *
+         gnutls_certificate_set_x509_key_file (xcred, "cert.pem", "key.pem", 
+         GNUTLS_X509_FMT_PEM); 
+         */
+
+        /* Initialize TLS session */
+        CHECK(gnutls_init(&session, GNUTLS_CLIENT));
+
+        CHECK(gnutls_server_name_set(session, GNUTLS_NAME_DNS, "www.example.com",
+                                     strlen("www.example.com")));
+
+        /* It is recommended to use the default priorities */
+        CHECK(gnutls_set_default_priority(session));
+
+        /* put the x509 credentials to the current session
+         */
+        CHECK(gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred));
+        gnutls_session_set_verify_cert(session, "www.example.com", 0);
+
+        /* connect to the peer
+         */
+        sd = tcp_connect();
+
+        gnutls_transport_set_int(session, sd);
+        gnutls_handshake_set_timeout(session,
+                                     GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
+
+        /* Perform the TLS handshake
+         */
+        do {
+                ret = gnutls_handshake(session);
+        }
+        while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
+        if (ret < 0) {
+                if (ret == GNUTLS_E_CERTIFICATE_VERIFICATION_ERROR) {
+                        /* check certificate verification status */
+                        type = gnutls_certificate_type_get(session);
+                        status = gnutls_session_get_verify_cert_status(session);
+                        CHECK(gnutls_certificate_verification_status_print(status,
+                              type, &out, 0));
+                        printf("cert verify output: %s\n", out.data);
+                        gnutls_free(out.data);
+                }
+                fprintf(stderr, "*** Handshake failed: %s\n", gnutls_strerror(ret));
+                goto end;
+        } else {
+                desc = gnutls_session_get_desc(session);
+                printf("- Session info: %s\n", desc);
+                gnutls_free(desc);
+        }
+
+	/* send data */
+        LOOP_CHECK(ret, gnutls_record_send(session, MSG, strlen(MSG)));
+
+        LOOP_CHECK(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 && gnutls_error_is_fatal(ret) == 0) {
+                fprintf(stderr, "*** Warning: %s\n", gnutls_strerror(ret));
+        } else if (ret < 0) {
+                fprintf(stderr, "*** Error: %s\n", gnutls_strerror(ret));
+                goto end;
+        }
+
+        if (ret > 0) {
+                printf("- Received %d bytes: ", ret);
+                for (ii = 0; ii < ret; ii++) {
+                        fputc(buffer[ii], stdout);
+                }
+                fputs("\n", stdout);
+        }
+
+        CHECK(gnutls_bye(session, GNUTLS_SHUT_RDWR));
+
+      end:
+
+        tcp_close(sd);
+
+        gnutls_deinit(session);
+
+        gnutls_certificate_free_credentials(xcred);
+
+        gnutls_global_deinit();
+
+        return 0;
+}