gnutls_init: added flag for automatic re-authentication

This introduces the GNUTLS_AUTO_REAUTH gnutls_init() flag and makes
re-authentication under TLS simpler to enable and use.

Resolves #571

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

1 files changed, 366 insertions, 0 deletions

diff --git a/tests/tls13/post-handshake-with-cert-auto.c b/tests/tls13/post-handshake-with-cert-auto.c
new file mode 100644
index 0000000000..9d920da80c
--- /dev/null
+++ b/tests/tls13/post-handshake-with-cert-auto.c
@@ -0,0 +1,366 @@
+/*
+ * 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 <signal.h>
+#include <assert.h>
+
+#include "cert-common.h"
+#include "tls13/ext-parse.h"
+#include "utils.h"
+
+#define MAX_AUTHS 4
+
+/* This program tests whether the Post Handshake Auth extension is
+ * present in the client hello, and whether it is missing from server
+ * hello. In addition it contains basic functionality test for
+ * post handshake authentication.
+ */
+
+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);
+}
+
+#define MAX_BUF 1024
+#define MAX_APP_DATA 3
+
+static void client(int fd, unsigned send_cert, unsigned max_auths)
+{
+	int ret;
+	gnutls_certificate_credentials_t x509_cred;
+	gnutls_session_t session;
+	char buf[64];
+	unsigned i;
+
+	global_init();
+
+	if (debug) {
+		gnutls_global_set_log_function(client_log_func);
+		gnutls_global_set_log_level(7);
+	}
+
+	assert(gnutls_certificate_allocate_credentials(&x509_cred)>=0);
+
+	/* Initialize TLS session
+	 */
+	assert(gnutls_init(&session, GNUTLS_CLIENT|GNUTLS_POST_HANDSHAKE_AUTH|GNUTLS_AUTO_REAUTH)>=0);
+
+	gnutls_handshake_set_timeout(session, 20 * 1000);
+
+	ret = gnutls_priority_set_direct(session, "NORMAL:-VERS-ALL:+VERS-TLS1.3:+VERS-TLS1.2:+VERS-TLS1.0", NULL);
+	if (ret < 0)
+		fail("cannot set TLS 1.3 priorities\n");
+
+
+	if (send_cert) {
+		assert(gnutls_certificate_set_x509_key_mem(x509_cred, &cli_ca3_cert,
+						    &cli_ca3_key,
+						    GNUTLS_X509_FMT_PEM)>=0);
+	}
+
+	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
+
+	gnutls_transport_set_int(session, fd);
+
+	/* Perform the TLS handshake
+	 */
+	do {
+		ret = gnutls_handshake(session);
+	}
+	while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
+
+	if (ret != 0)
+		fail("handshake failed: %s\n", gnutls_strerror(ret));
+
+	if (debug)
+		success("client handshake completed\n");
+
+	gnutls_record_set_timeout(session, 20 * 1000);
+
+	for (i=0;i<max_auths;i++) {
+		if (debug)
+			success("waiting for auth nr %d\n", i);
+
+		do {
+			ret = gnutls_record_recv(session, buf, sizeof(buf));
+		} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
+
+		if (ret < 0)
+			fail("client: gnutls_record_recv did not succeed as expected: %s\n", gnutls_strerror(ret));
+	}
+
+	assert(ret == 0);
+
+	do {
+		ret = gnutls_bye(session, GNUTLS_SHUT_WR);
+	} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
+
+	close(fd);
+
+	gnutls_deinit(session);
+
+	gnutls_certificate_free_credentials(x509_cred);
+
+	gnutls_global_deinit();
+}
+
+static unsigned client_hello_ok = 0;
+static unsigned server_hello_ok = 0;
+
+#define TLS_EXT_POST_HANDSHAKE 49
+
+static void parse_ext(void *priv, gnutls_datum_t *msg)
+{
+	if (msg->size != 0) {
+		fail("error in extension length: %d\n", (int)msg->size);
+	}
+}
+
+static int hellos_callback(gnutls_session_t session, unsigned int htype,
+	unsigned post, unsigned int incoming, const gnutls_datum_t *msg)
+{
+	if (htype == GNUTLS_HANDSHAKE_SERVER_HELLO && post == GNUTLS_HOOK_POST) {
+		if (find_server_extension(msg, TLS_EXT_POST_HANDSHAKE, NULL, NULL)) {
+			fail("Post handshake extension seen in server hello!\n");
+		}
+		server_hello_ok = 1;
+
+		return GNUTLS_E_INTERRUPTED;
+	}
+
+	if (htype != GNUTLS_HANDSHAKE_CLIENT_HELLO || post != GNUTLS_HOOK_PRE)
+		return 0;
+
+	if (find_client_extension(msg, TLS_EXT_POST_HANDSHAKE, NULL, parse_ext))
+		client_hello_ok = 1;
+	else
+		fail("Post handshake extension NOT seen in client hello!\n");
+
+	return 0;
+}
+
+static void server(int fd, int err, int type, unsigned max_auths)
+{
+	int ret;
+	char buffer[MAX_BUF + 1];
+	gnutls_session_t session;
+	gnutls_certificate_credentials_t x509_cred;
+	unsigned i, retries;
+
+	/* this must be called once in the program
+	 */
+	global_init();
+	memset(buffer, 0, sizeof(buffer));
+
+	if (debug) {
+		gnutls_global_set_log_function(server_log_func);
+		gnutls_global_set_log_level(6);
+	}
+
+	gnutls_certificate_allocate_credentials(&x509_cred);
+	gnutls_certificate_set_x509_key_mem(x509_cred, &server_cert,
+					    &server_key,
+					    GNUTLS_X509_FMT_PEM);
+
+	gnutls_init(&session, GNUTLS_SERVER|GNUTLS_POST_HANDSHAKE_AUTH);
+
+	gnutls_handshake_set_timeout(session, 20 * 1000);
+	gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_ANY,
+					   GNUTLS_HOOK_BOTH,
+					   hellos_callback);
+
+	/* avoid calling all the priority functions, since the defaults
+	 * are adequate.
+	 */
+	gnutls_priority_set_direct(session, "NORMAL:+VERS-TLS1.3", NULL);
+
+	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
+
+	gnutls_transport_set_int(session, fd);
+
+	do {
+		ret = gnutls_handshake(session);
+	} while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
+
+	if (ret != 0)
+		fail("handshake failed: %s\n", gnutls_strerror(ret));
+
+	if (!(gnutls_session_get_flags(session) & GNUTLS_SFLAGS_POST_HANDSHAKE_AUTH)) {
+		fail("server: session flags did not contain GNUTLS_SFLAGS_POST_HANDSHAKE_AUTH\n");
+	}
+
+
+	if (client_hello_ok == 0) {
+		fail("server: did not verify the client hello\n");
+	}
+
+	if (server_hello_ok == 0) {
+		fail("server: did not verify the server hello contents\n");
+	}
+
+	if (debug)
+		success("server handshake completed\n");
+
+	gnutls_certificate_server_set_request(session, type);
+
+	/* i = 0 */
+	/* ask peer for re-authentication */
+	retries = 0;
+	do {
+		do {
+			ret = gnutls_reauth(session, 0);
+		} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
+
+		if (ret == GNUTLS_E_GOT_APPLICATION_DATA) {
+			int ret2;
+			do {
+				ret2 = gnutls_record_recv(session, buffer, sizeof(buffer));
+			} while (ret2 == GNUTLS_E_AGAIN || ret2 == GNUTLS_E_INTERRUPTED);
+
+			if (ret2 < 0)
+				fail("error receiving app data: %s\n", gnutls_strerror(ret2));
+
+			/* sender memsets the message with the retry attempt */
+			assert((uint8_t)buffer[0] == retries);
+			assert(retries < MAX_APP_DATA);
+		}
+
+		retries++;
+	} while (ret == GNUTLS_E_GOT_APPLICATION_DATA);
+
+	if (err) {
+		if (ret != err)
+			fail("server: expected error %s, got: %s\n", gnutls_strerror(err),
+			     gnutls_strerror(ret));
+	} else if (ret != 0)
+		fail("server: gnutls_reauth did not succeed as expected: %s\n", gnutls_strerror(ret));
+
+
+	for (i=1;i<max_auths;i++) {
+		/* ask peer for re-authentication */
+		do {
+			ret = gnutls_reauth(session, 0);
+		} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
+
+		if (err) {
+			if (ret != err)
+				fail("server: expected error %s, got: %s\n", gnutls_strerror(err),
+				     gnutls_strerror(ret));
+		} else if (ret != 0)
+			fail("server: gnutls_reauth did not succeed as expected: %s\n", gnutls_strerror(ret));
+	}
+
+	do {
+		ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
+	} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
+
+	close(fd);
+	gnutls_deinit(session);
+
+	gnutls_certificate_free_credentials(x509_cred);
+
+	gnutls_global_deinit();
+
+	if (debug)
+		success("server: client/server hello were verified\n");
+}
+
+static
+void start(const char *name, int err, int type, unsigned max_auths, unsigned send_cert)
+{
+	int fd[2];
+	int ret;
+	pid_t child;
+	int status = 0;
+
+	success("testing %s\n", name);
+
+	client_hello_ok = 0;
+	server_hello_ok = 0;
+
+	signal(SIGCHLD, SIG_IGN);
+	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]);
+		server(fd[0], err, type, max_auths);
+		kill(child, SIGTERM);
+		wait(&status);
+		check_wait_status(status);
+	} else {
+		close(fd[0]);
+		client(fd[1], send_cert, max_auths);
+		exit(0);
+	}
+
+}
+
+void doit(void)
+{
+	start("multi-reauth", 0, GNUTLS_CERT_REQUIRE, MAX_AUTHS, 1);
+	start("reauth-require with no-cert", GNUTLS_E_NO_CERTIFICATE_FOUND, GNUTLS_CERT_REQUIRE, 1, 0);
+	start("reauth-request with no-cert", 0, GNUTLS_CERT_REQUEST, 1, 0);
+}
+#endif				/* _WIN32 */