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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include "tls/extensions/s2n_cookie.h"
#include <sys/param.h>
#include "s2n_test.h"
#include "testlib/s2n_testlib.h"
#include "tls/s2n_handshake_type.h"
#include "utils/s2n_random.h"
#include "utils/s2n_safety.h"
#define TEST_COOKIE_COUNT 5
int main()
{
BEGIN_TEST();
if (!s2n_is_tls13_fully_supported()) {
END_TEST();
}
uint16_t test_cookie_sizes[TEST_COOKIE_COUNT] = { 1, UINT8_MAX, UINT8_MAX + 1, UINT16_MAX - 1, UINT16_MAX };
struct s2n_blob test_cookies[TEST_COOKIE_COUNT] = { 0 };
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
EXPECT_SUCCESS(s2n_alloc(&test_cookies[i], test_cookie_sizes[i]));
EXPECT_OK(s2n_get_public_random_data(&test_cookies[i]));
}
/**
* Test: client only sends extension if cookie present
*
*= https://tools.ietf.org/rfc/rfc8446#4.1.2
*= type=test
*# - Including a "cookie" extension if one was provided in the
*# HelloRetryRequest.
**/
{
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(client_conn);
/* Not sent without a cookie */
EXPECT_FALSE(s2n_client_cookie_extension.should_send(client_conn));
/* Sent with a cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[0], &client_conn->cookie));
EXPECT_TRUE(s2n_client_cookie_extension.should_send(client_conn));
};
/* Test: server only sends extension if cookie present
* (cookie will never be present in production)
*/
{
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
/* Not sent without a cookie */
EXPECT_FALSE(s2n_server_cookie_extension.should_send(server_conn));
/* Sent with a cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[0], &server_conn->cookie));
EXPECT_TRUE(s2n_server_cookie_extension.should_send(server_conn));
};
/* Test: client can parse server cookie extension */
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
DEFER_CLEANUP(struct s2n_stuffer server_extension = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&server_extension, 0));
/* Server sends extension with test cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &server_conn->cookie));
EXPECT_SUCCESS(s2n_server_cookie_extension.send(server_conn, &server_extension));
/* Client doesn't parse extension if no retry */
EXPECT_FAILURE_WITH_ERRNO(s2n_server_cookie_extension.recv(client_conn, &server_extension),
S2N_ERR_UNSUPPORTED_EXTENSION);
/* Client parses extension if retry */
client_conn->handshake.handshake_type = HELLO_RETRY_REQUEST;
EXPECT_SUCCESS(s2n_server_cookie_extension.recv(client_conn, &server_extension));
S2N_BLOB_EXPECT_EQUAL(test_cookies[i], client_conn->cookie);
}
/* Test: client sends correctly formatted extension */
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
DEFER_CLEANUP(struct s2n_stuffer client_extension = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&client_extension, 0));
/* Client sends extension with test cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &client_conn->cookie));
EXPECT_SUCCESS(s2n_client_cookie_extension.send(client_conn, &client_extension));
/* Sanity check: Server rejects incorrectly sized cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &server_conn->cookie));
server_conn->cookie.size--;
EXPECT_FAILURE_WITH_ERRNO(s2n_client_cookie_extension.recv(server_conn, &client_extension),
S2N_ERR_BAD_MESSAGE);
EXPECT_SUCCESS(s2n_free(&server_conn->cookie));
EXPECT_SUCCESS(s2n_stuffer_reread(&client_extension));
/* Sanity check: Server rejects incorrect cookie data */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &server_conn->cookie));
server_conn->cookie.data[0] = server_conn->cookie.data[0] + 1;
EXPECT_FAILURE_WITH_ERRNO(s2n_client_cookie_extension.recv(server_conn, &client_extension),
S2N_ERR_BAD_MESSAGE);
EXPECT_SUCCESS(s2n_free(&server_conn->cookie));
EXPECT_SUCCESS(s2n_stuffer_reread(&client_extension));
/* Server accepts correct cookie data */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &server_conn->cookie));
EXPECT_SUCCESS(s2n_client_cookie_extension.recv(server_conn, &client_extension));
}
DEFER_CLEANUP(struct s2n_cert_chain_and_key *chain_and_key = NULL,
s2n_cert_chain_and_key_ptr_free);
EXPECT_SUCCESS(s2n_test_cert_chain_and_key_new(&chain_and_key,
S2N_DEFAULT_ECDSA_TEST_CERT_CHAIN, S2N_DEFAULT_ECDSA_TEST_PRIVATE_KEY));
DEFER_CLEANUP(struct s2n_config *config = s2n_config_new(),
s2n_config_ptr_free);
EXPECT_SUCCESS(s2n_config_add_cert_chain_and_key_to_store(config, chain_and_key));
EXPECT_SUCCESS(s2n_config_set_cipher_preferences(config, "default_tls13"));
EXPECT_SUCCESS(s2n_config_disable_x509_verification(config));
/* Although the cookie is *technically* allowed to be UINT16_MAX,
* in reality it has to share a uint16_t extensions list length
* with other extensions.
*
* So for the self-talk tests, reduce the size of any large test cookies.
*/
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
test_cookies[i].size = MIN(test_cookies[i].size, UINT16_MAX / 2);
}
/* Sanity check: server fails if client does not provide expected cookie */
{
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(server_conn, config));
EXPECT_SUCCESS(s2n_connection_set_blinding(server_conn, S2N_SELF_SERVICE_BLINDING));
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(client_conn, config));
struct s2n_test_io_pair io_pair = { 0 };
EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
EXPECT_SUCCESS(s2n_connections_set_io_pair(client_conn, server_conn, &io_pair));
/* Force the HRR path */
client_conn->security_policy_override = &security_policy_test_tls13_retry;
/* Force the server to send a cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[0], &server_conn->cookie));
/* Begin negotiating handshake.
* The first negotiate_until blocks because the client is looking for a SERVER_HELLO,
* not the HELLO_RETRY_MESSAGE. This is fine; it's in the right place in the handshake.
*/
EXPECT_ERROR_WITH_ERRNO(s2n_negotiate_test_server_and_client_until_message(server_conn, client_conn, HELLO_RETRY_MSG),
S2N_ERR_IO_BLOCKED);
EXPECT_EQUAL(s2n_conn_get_current_message_type(server_conn), HELLO_RETRY_MSG);
EXPECT_EQUAL(s2n_conn_get_current_message_type(client_conn), SERVER_HELLO);
EXPECT_OK(s2n_negotiate_test_server_and_client_until_message(server_conn, client_conn, CLIENT_HELLO));
EXPECT_EQUAL(s2n_conn_get_current_message_type(server_conn), CLIENT_HELLO);
EXPECT_EQUAL(s2n_conn_get_current_message_type(client_conn), CLIENT_HELLO);
/* Verify HRR path */
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(server_conn));
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(client_conn));
/* At this point, the server has already sent its HRR request with a cookie.
* The client has stored the server's cookie, but not responded.
* Wipe the cookie on the client, preventing it from sending the response.
*/
EXPECT_NOT_EQUAL(client_conn->cookie.size, 0);
EXPECT_SUCCESS(s2n_free(&client_conn->cookie));
/* Continue negotiating. We should fail because of the "missing" cookie. */
EXPECT_FAILURE_WITH_ERRNO(s2n_negotiate_test_server_and_client(server_conn, client_conn),
S2N_ERR_MISSING_EXTENSION);
EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
};
/* Self-Talk: Server does NOT use cookies */
{
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(server_conn, config));
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(client_conn, config));
struct s2n_test_io_pair io_pair = { 0 };
EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
EXPECT_SUCCESS(s2n_connections_set_io_pair(client_conn, server_conn, &io_pair));
/* Force the HRR path */
client_conn->security_policy_override = &security_policy_test_tls13_retry;
/* Negotiate handshake */
EXPECT_SUCCESS(s2n_negotiate_test_server_and_client(server_conn, client_conn));
/* Verify HRR path */
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(server_conn));
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(client_conn));
/* Verify no cookies */
EXPECT_EQUAL(client_conn->cookie.size, 0);
EXPECT_EQUAL(server_conn->cookie.size, 0);
EXPECT_SUCCESS(s2n_shutdown_test_server_and_client(server_conn, client_conn));
EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
};
/* Self-Talk: Server does use cookies
*
*= https://tools.ietf.org/rfc/rfc8446#section-4.2.2
*= type=test
*# When sending a HelloRetryRequest, the server MAY provide a "cookie"
*# extension to the client (this is an exception to the usual rule that
*# the only extensions that may be sent are those that appear in the
*# ClientHello). When sending the new ClientHello, the client MUST copy
*# the contents of the extension received in the HelloRetryRequest into
*# a "cookie" extension in the new ClientHello.
*/
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(server_conn, config));
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(client_conn, config));
struct s2n_test_io_pair io_pair = { 0 };
EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
EXPECT_SUCCESS(s2n_connections_set_io_pair(client_conn, server_conn, &io_pair));
/* Force the HRR path */
client_conn->security_policy_override = &security_policy_test_tls13_retry;
/* Force the server to send a cookie */
EXPECT_SUCCESS(s2n_dup(&test_cookies[i], &server_conn->cookie));
/* Negotiate handshake */
EXPECT_SUCCESS(s2n_negotiate_test_server_and_client(server_conn, client_conn));
/* Verify HRR path */
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(server_conn));
EXPECT_TRUE(IS_HELLO_RETRY_HANDSHAKE(client_conn));
/* Verify cookies */
S2N_BLOB_EXPECT_EQUAL(test_cookies[i], client_conn->cookie);
S2N_BLOB_EXPECT_EQUAL(test_cookies[i], server_conn->cookie);
EXPECT_SUCCESS(s2n_shutdown_test_server_and_client(server_conn, client_conn));
EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
}
/* Self-Talk: Full connection lifecycle with cookies
* We try the handshake multiple times with different possible call patterns.
*/
{
DEFER_CLEANUP(struct s2n_connection *server_conn = s2n_connection_new(S2N_SERVER),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(server_conn, config));
DEFER_CLEANUP(struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
EXPECT_NOT_NULL(server_conn);
EXPECT_SUCCESS(s2n_connection_set_config(client_conn, config));
/* We need an arbitrary combination of conditions,
* but consistent across test runs.
*/
srand(0);
for (size_t i = 0; i < 250; i++) {
int r = rand();
bool hrr = (r % 2) == 0;
bool cookie = (r % 3) == 0;
size_t cookie_i = i % TEST_COOKIE_COUNT;
bool free_handshake = (r % 7) == 0;
/* Verify calls to s2n_connection_wipe are safe */
EXPECT_SUCCESS(s2n_connection_wipe(client_conn));
EXPECT_SUCCESS(s2n_connection_wipe(server_conn));
/* Create nonblocking pipes */
struct s2n_test_io_pair io_pair = { 0 };
EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
EXPECT_SUCCESS(s2n_connections_set_io_pair(client_conn, server_conn, &io_pair));
/* Force the HRR path */
if (hrr) {
client_conn->security_policy_override = &security_policy_test_tls13_retry;
}
/* Force the server to send a cookie */
if (cookie) {
EXPECT_SUCCESS(s2n_dup(&test_cookies[cookie_i], &server_conn->cookie));
}
/* Negotiate handshake */
EXPECT_SUCCESS(s2n_negotiate_test_server_and_client(server_conn, client_conn));
/* Verify HRR path */
if (hrr) {
EXPECT_TRUE(s2n_is_hello_retry_handshake(server_conn));
EXPECT_TRUE(s2n_is_hello_retry_handshake(client_conn));
} else {
EXPECT_FALSE(s2n_is_hello_retry_handshake(server_conn));
EXPECT_FALSE(s2n_is_hello_retry_handshake(client_conn));
}
/* Verify cookie data */
if (hrr && cookie) {
S2N_BLOB_EXPECT_EQUAL(test_cookies[cookie_i], client_conn->cookie);
} else {
EXPECT_EQUAL(client_conn->cookie.size, 0);
}
if (free_handshake) {
EXPECT_SUCCESS(s2n_connection_free_handshake(client_conn));
EXPECT_SUCCESS(s2n_connection_free_handshake(server_conn));
}
EXPECT_SUCCESS(s2n_shutdown_test_server_and_client(server_conn, client_conn));
EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
}
};
for (size_t i = 0; i < TEST_COOKIE_COUNT; i++) {
EXPECT_SUCCESS(s2n_free(&test_cookies[i]));
}
END_TEST();
}
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