Ensure we are sending the right protocol version on second client hello

That is, when we respond to a Hello Retry Request as client, we put
the TLS1.2 version on the second client hello to send a hello that is
as close as possible to the original hello. That effectively separates
the handling of TLS1.2 rehandshake and TLS1.3 hello retry request
when sending a client hello.

Resolves #535

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

diff --git a/lib/handshake.c b/lib/handshake.c
index 7274bafebd56079bc50e2d900eb5fef0eb9967c7..2c7524016e7f4c16b02588629431d5b33e0211c0 100644 (file)
--- a/lib/handshake.c
+++ b/lib/handshake.c
@@ -1991,12 +1991,13 @@ static int send_client_hello(gnutls_session_t session, int again)
        uint8_t session_id_len =
            session->internals.resumed_security_parameters.session_id_size;
 
-       /* note that rehandshake is different than resuming
-        */
-       if (session->security_parameters.session_id_size)
-               rehandshake = 1;
 
        if (again == 0) {
+               /* note that rehandshake is different than resuming
+                */
+               if (session->internals.initial_negotiation_completed)
+                       rehandshake = 1;
+
                ret = _gnutls_buffer_init_handshake_mbuffer(&extdata);
                if (ret < 0)
                        return gnutls_assert_val(ret);

diff --git a/tests/Makefile.am b/tests/Makefile.am
index c9f62f16f0ce337cf2e9a4114c644bfa6952a767..87da31a25d20b33eae71e9b7e0dc6157685597b6 100644 (file)
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -109,6 +109,8 @@ ctests = tls13/supported_versions tls13/tls12-no-tls13-exts \
        tls12-check-rollback-val tls11-check-rollback-val tls13/hello_random_value \
        tls13/post-handshake-with-psk
 
+ctests += tls13/hello_retry_request
+
 ctests += tls13/psk-ext
 
 ctests += tls13/key_update

diff --git a/tests/tls13/hello_retry_request.c b/tests/tls13/hello_retry_request.c
new file mode 100644 (file)
index 0000000..66e4701
--- /dev/null
+++ b/tests/tls13/hello_retry_request.c
@@ -0,0 +1,235 @@
+/*
+ * Copyright (C) 2017-2018 Red Hat, Inc.
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of GnuTLS.
+ *
+ * GnuTLS is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuTLS is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#if defined(_WIN32)
+
+int main()
+{
+       exit(77);
+}
+
+#else
+
+#include <string.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <gnutls/gnutls.h>
+#include <gnutls/dtls.h>
+#include <assert.h>
+#include <signal.h>
+
+#include "cert-common.h"
+#include "utils.h"
+#include "tls13/ext-parse.h"
+
+/* This program tests whether the version in Hello Retry Request message
+ * is the expected */
+
+const char *testname = "";
+
+#define myfail(fmt, ...) \
+       fail("%s: "fmt, testname, ##__VA_ARGS__)
+
+static void server_log_func(int level, const char *str)
+{
+       fprintf(stderr, "server|<%d>| %s", level, str);
+}
+
+static void client_log_func(int level, const char *str)
+{
+       fprintf(stderr, "client|<%d>| %s", level, str);
+}
+
+struct ctx_st {
+       unsigned hrr_seen;
+       unsigned hello_counter;
+};
+
+static int hello_callback(gnutls_session_t session, unsigned int htype,
+                         unsigned post, unsigned int incoming, const gnutls_datum_t *msg)
+{
+       struct ctx_st *ctx = gnutls_session_get_ptr(session);
+       assert(ctx != NULL);
+
+       if (htype == GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST)
+               ctx->hrr_seen = 1;
+
+       if (htype == GNUTLS_HANDSHAKE_CLIENT_HELLO && post == GNUTLS_HOOK_POST) {
+               if (ctx->hello_counter > 0) {
+                       assert(msg->size > 4);
+                       if (msg->data[0] != 0x03 || msg->data[1] != 0x03) {
+                               fail("version is %d.%d expected 3,3\n", (int)msg->data[0], (int)msg->data[1]);
+                       }
+               }
+               ctx->hello_counter++;
+       }
+
+       return 0;
+}
+
+
+static void client(int fd)
+{
+       int ret;
+       gnutls_certificate_credentials_t x509_cred;
+       gnutls_session_t session;
+       struct ctx_st ctx;
+
+       memset(&ctx, 0, sizeof(ctx));
+
+       if (debug) {
+               gnutls_global_set_log_function(client_log_func);
+               gnutls_global_set_log_level(7);
+       }
+
+       assert(gnutls_certificate_allocate_credentials(&x509_cred)>=0);
+
+       assert(gnutls_init(&session, GNUTLS_CLIENT|GNUTLS_KEY_SHARE_TOP)>=0);
+
+       gnutls_handshake_set_timeout(session, 20 * 1000);
+       gnutls_session_set_ptr(session, &ctx);
+
+       ret = gnutls_priority_set_direct(session, "NORMAL:-VERS-ALL:+VERS-TLS1.3:-GROUP-ALL:+GROUP-SECP256R1:+GROUP-X25519", NULL);
+       if (ret < 0)
+               myfail("cannot set TLS 1.3 priorities\n");
+
+       gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
+
+       gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_ANY,
+                                          GNUTLS_HOOK_BOTH,
+                                          hello_callback);
+
+       gnutls_transport_set_int(session, fd);
+
+       do {
+               ret = gnutls_handshake(session);
+       }
+       while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
+
+       assert(ctx.hrr_seen != 0);
+
+       close(fd);
+
+       gnutls_deinit(session);
+
+       gnutls_certificate_free_credentials(x509_cred);
+}
+
+static void server(int fd)
+{
+       int ret;
+       gnutls_session_t session;
+       gnutls_certificate_credentials_t x509_cred;
+
+       if (debug) {
+               gnutls_global_set_log_function(server_log_func);
+               gnutls_global_set_log_level(4711);
+       }
+
+       assert(gnutls_certificate_allocate_credentials(&x509_cred)>=0);
+       assert(gnutls_certificate_set_x509_key_mem(x509_cred, &server_cert,
+                                                  &server_key,
+                                                  GNUTLS_X509_FMT_PEM)>=0);
+
+       gnutls_init(&session, GNUTLS_SERVER);
+
+       gnutls_handshake_set_timeout(session, 20 * 1000);
+
+       /* server only supports x25519, client advertises secp256r1 */
+       assert(gnutls_priority_set_direct(session, "NORMAL:-VERS-ALL:+VERS-TLS1.3:-GROUP-ALL:+GROUP-X25519", NULL)>=0);
+
+       gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
+
+       gnutls_transport_set_int(session, fd);
+
+       do {
+               ret = gnutls_handshake(session);
+               if (ret == GNUTLS_E_INTERRUPTED) { /* expected */
+                       break;
+               }
+       } while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
+
+       if (ret < 0)
+               myfail("handshake error: %s\n", gnutls_strerror(ret));
+
+       if (gnutls_group_get(session) != GNUTLS_GROUP_X25519)
+               myfail("group doesn't match the expected: %s\n", gnutls_group_get_name(gnutls_group_get(session)));
+
+       close(fd);
+       gnutls_deinit(session);
+
+       gnutls_certificate_free_credentials(x509_cred);
+}
+
+static void ch_handler(int sig)
+{
+       int status = 0;
+       wait(&status);
+       check_wait_status(status);
+       return;
+}
+
+void doit(void)
+{
+       int fd[2];
+       int ret;
+       pid_t child;
+
+       signal(SIGCHLD, ch_handler);
+       signal(SIGPIPE, SIG_IGN);
+
+       ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
+       if (ret < 0) {
+               perror("socketpair");
+               exit(1);
+       }
+
+       child = fork();
+       if (child < 0) {
+               perror("fork");
+               fail("fork");
+               exit(1);
+       }
+
+       if (child) {
+               /* parent */
+               close(fd[1]);
+               client(fd[0]);
+               kill(child, SIGTERM);
+       } else {
+               close(fd[0]);
+               server(fd[1]);
+               exit(0);
+       }
+}
+
+#endif                         /* _WIN32 */