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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 <stdint.h>
#include "api/s2n.h"
#include "crypto/s2n_pq.h"
#include "s2n_test.h"
#include "stuffer/s2n_stuffer.h"
#include "testlib/s2n_nist_kats.h"
#include "testlib/s2n_testlib.h"
#include "tls/extensions/s2n_client_key_share.h"
#include "tls/extensions/s2n_server_key_share.h"
#include "tls/s2n_security_policies.h"
#include "tls/s2n_tls13.h"
#include "utils/s2n_bitmap.h"
#include "utils/s2n_safety.h"
#define HELLO_RETRY_MSG_NO 1
int s2n_server_key_share_send_check_pq_hybrid(struct s2n_connection *conn);
int s2n_server_key_share_send_check_ecdhe(struct s2n_connection *conn);
static int s2n_read_server_key_share_hybrid_test_vectors(const struct s2n_kem_group *kem_group, struct s2n_blob *pq_private_key,
struct s2n_stuffer *pq_shared_secret, struct s2n_stuffer *key_share_payload);
int main(int argc, char **argv)
{
BEGIN_TEST();
EXPECT_SUCCESS(s2n_enable_tls13_in_test());
/* Test s2n_server_key_share_send_check_ecdhe */
{
struct s2n_security_policy test_security_policy_no_x25519 = {
.minimum_protocol_version = S2N_TLS10,
.cipher_preferences = &cipher_preferences_test_all_tls13,
.kem_preferences = &kem_preferences_null,
.signature_preferences = &s2n_signature_preferences_20200207,
.ecc_preferences = &s2n_ecc_preferences_20140601,
};
struct s2n_connection *conn = NULL;
EXPECT_FAILURE(s2n_server_key_share_send_check_ecdhe(conn));
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
conn->security_policy_override = &test_security_policy_no_x25519;
EXPECT_FAILURE(s2n_server_key_share_send_check_ecdhe(conn));
if (s2n_is_evp_apis_supported()) {
conn->kex_params.server_ecc_evp_params.negotiated_curve = &s2n_ecc_curve_x25519;
EXPECT_FAILURE(s2n_server_key_share_send_check_ecdhe(conn));
}
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_ecdhe(conn), S2N_ERR_BAD_KEY_SHARE);
conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_ecdhe(conn), S2N_ERR_BAD_KEY_SHARE);
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&conn->kex_params.client_ecc_evp_params));
EXPECT_SUCCESS(s2n_server_key_share_send_check_ecdhe(conn));
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_extensions_server_key_share_send_size */
{
struct s2n_connection *conn;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
EXPECT_EQUAL(0, s2n_extensions_server_key_share_send_size(conn));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
EXPECT_EQUAL(ecc_pref->ecc_curves[0]->share_size + 8, s2n_extensions_server_key_share_send_size(conn));
conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[1];
EXPECT_EQUAL(ecc_pref->ecc_curves[1]->share_size + 8, s2n_extensions_server_key_share_send_size(conn));
conn->kex_params.server_ecc_evp_params.negotiated_curve = NULL;
EXPECT_EQUAL(0, s2n_extensions_server_key_share_send_size(conn));
/* A HelloRetryRequest only requires a Selected Group, not a key share */
EXPECT_SUCCESS(s2n_connection_set_all_protocol_versions(conn, S2N_TLS13));
EXPECT_OK(s2n_conn_choose_state_machine(conn, S2N_TLS13));
EXPECT_SUCCESS(s2n_set_connection_hello_retry_flags(conn));
conn->kex_params.server_ecc_evp_params.negotiated_curve = s2n_all_supported_curves_list[0];
EXPECT_EQUAL(6, s2n_extensions_server_key_share_send_size(conn));
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.send sends key share success (ECDHE) */
{
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
EXPECT_NULL(conn->kex_params.server_kem_group_params.kem_group);
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 1024));
for (size_t i = 0; i < ecc_pref->count; i++) {
const struct s2n_ecc_named_curve *curve = ecc_pref->ecc_curves[i];
conn->kex_params.server_ecc_evp_params.negotiated_curve = curve;
conn->kex_params.client_ecc_evp_params.negotiated_curve = curve;
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&conn->kex_params.client_ecc_evp_params));
EXPECT_SUCCESS(s2n_server_key_share_extension.send(conn, &stuffer));
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, curve->iana_id, uint16);
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, curve->share_size, uint16);
S2N_STUFFER_LENGTH_WRITTEN_EXPECT_EQUAL(&stuffer, curve->share_size);
EXPECT_NULL(conn->kex_params.server_kem_group_params.kem_group);
EXPECT_EQUAL(conn->kex_params.server_ecc_evp_params.negotiated_curve, curve);
EXPECT_SUCCESS(s2n_ecc_evp_params_free(&conn->kex_params.server_ecc_evp_params));
EXPECT_SUCCESS(s2n_ecc_evp_params_free(&conn->kex_params.client_ecc_evp_params));
}
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.send sends IANA ID for HRR (ECDHE) */
{
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
conn->actual_protocol_version = S2N_TLS13;
EXPECT_OK(s2n_conn_choose_state_machine(conn, S2N_TLS13));
conn->handshake.handshake_type = HELLO_RETRY_REQUEST;
conn->handshake.message_number = HELLO_RETRY_MSG_NO;
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
EXPECT_NULL(conn->kex_params.server_kem_group_params.kem_group);
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 1024));
for (size_t i = 0; i < ecc_pref->count; i++) {
const struct s2n_ecc_named_curve *curve = ecc_pref->ecc_curves[i];
conn->kex_params.server_ecc_evp_params.negotiated_curve = curve;
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.evp_pkey);
EXPECT_SUCCESS(s2n_server_key_share_extension.send(conn, &stuffer));
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, curve->iana_id, uint16);
EXPECT_EQUAL(0, s2n_stuffer_data_available(&stuffer));
EXPECT_EQUAL(conn->kex_params.server_ecc_evp_params.negotiated_curve, curve);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.evp_pkey);
}
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.send for failures */
{
EXPECT_FAILURE(s2n_server_key_share_extension.send(NULL, NULL));
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
EXPECT_FAILURE(s2n_server_key_share_extension.send(conn, NULL));
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 0));
/* Error if both curve and kem_group are NULL */
conn->kex_params.server_ecc_evp_params.negotiated_curve = NULL;
conn->kex_params.server_kem_group_params.kem_group = NULL;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.send(conn, &stuffer), S2N_ERR_ECDHE_UNSUPPORTED_CURVE);
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.recv with supported curves */
{
const struct s2n_ecc_preferences *ecc_pref = NULL;
int i = 0;
do {
struct s2n_connection *server_send_conn;
struct s2n_connection *client_recv_conn;
EXPECT_NOT_NULL(server_send_conn = s2n_connection_new(S2N_SERVER));
EXPECT_NOT_NULL(client_recv_conn = s2n_connection_new(S2N_CLIENT));
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(server_send_conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
struct s2n_stuffer *extension_stuffer = &server_send_conn->handshake.io;
server_send_conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[i];
server_send_conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[i];
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&server_send_conn->kex_params.client_ecc_evp_params));
EXPECT_SUCCESS(s2n_server_key_share_extension.send(server_send_conn, extension_stuffer));
client_recv_conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[i];
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_recv_conn->kex_params.client_ecc_evp_params));
/* Parse key share */
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_recv_conn, extension_stuffer));
EXPECT_EQUAL(s2n_stuffer_data_available(extension_stuffer), 0);
EXPECT_EQUAL(server_send_conn->kex_params.server_ecc_evp_params.negotiated_curve->iana_id, client_recv_conn->kex_params.server_ecc_evp_params.negotiated_curve->iana_id);
EXPECT_EQUAL(server_send_conn->kex_params.server_ecc_evp_params.negotiated_curve, ecc_pref->ecc_curves[i]);
EXPECT_SUCCESS(s2n_connection_free(server_send_conn));
EXPECT_SUCCESS(s2n_connection_free(client_recv_conn));
i += 1;
} while (i < ecc_pref->count);
};
/* Test s2n_server_key_share_extension.recv with various sample payloads */
{
/* valid extension payloads */
if (s2n_is_evp_apis_supported()) {
/* Payload values were generated by connecting to openssl */
const char *key_share_payloads[] = {
/* x25519 */
"001d00206b24ffd795c496899cd14b7742a5ffbdc453c23085a7f82f0ed1e0296adb9e0e",
/* p256 */
"001700410474cfd75c0ab7b57247761a277e1c92b5810dacb251bb758f43e9d15aaf292c4a2be43e886425ba55653ebb7a4f32fe368bacce3df00c618645cf1eb646f22552",
/* p384 */
"00180061040a27264201368540483e97d324a3093e11a5862b0a1be0cf5d8510bc47ec285f5304e9ec3ba01a0c375c3b6fa4bd0ad44aae041bb776aebc7ee92462ad481fe86f8b6e3858d5c41d0f83b0404f711832a4119aec3da2eac86266f424b50aa212"
};
for (int i = 0; i < 3; i++) {
struct s2n_stuffer extension_stuffer = { 0 };
struct s2n_connection *client_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(client_conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
const char *payload = key_share_payloads[i];
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&extension_stuffer, payload));
client_conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[i];
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_conn->kex_params.client_ecc_evp_params));
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &extension_stuffer));
EXPECT_EQUAL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve, ecc_pref->ecc_curves[i]);
EXPECT_EQUAL(s2n_stuffer_data_available(&extension_stuffer), 0);
EXPECT_SUCCESS(s2n_stuffer_free(&extension_stuffer));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
}
/* Test that s2n_server_key_share_extension.recv is a no-op
* if tls1.3 not enabled */
{
struct s2n_stuffer extension_stuffer = { 0 };
struct s2n_connection *client_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
EXPECT_SUCCESS(s2n_connection_allow_response_extension(client_conn, s2n_server_key_share_extension.iana_value));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(client_conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
const char *payload = key_share_payloads[0];
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&extension_stuffer, payload));
client_conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_conn->kex_params.client_ecc_evp_params));
client_conn->actual_protocol_version = S2N_TLS12;
EXPECT_SUCCESS(s2n_extension_recv(&s2n_server_key_share_extension, client_conn, &extension_stuffer));
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_NOT_EQUAL(s2n_stuffer_data_available(&extension_stuffer), 0);
client_conn->actual_protocol_version = S2N_TLS13;
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &extension_stuffer));
EXPECT_EQUAL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve, ecc_pref->ecc_curves[0]);
EXPECT_EQUAL(s2n_stuffer_data_available(&extension_stuffer), 0);
EXPECT_SUCCESS(s2n_stuffer_free(&extension_stuffer));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
};
}
/* Test error handling parsing broken/trancated p256 key share */
{
struct s2n_stuffer extension_stuffer = { 0 };
struct s2n_connection *client_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
const char *p256 = "001700410474cfd75c0ab7b57247761a277e1c92b5810dacb251bb758f43e9d15aaf292c4a2be43e886425ba55653ebb7a4f32fe368bacce3df00c618645cf1eb6";
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&extension_stuffer, p256));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &extension_stuffer), S2N_ERR_BAD_KEY_SHARE);
EXPECT_SUCCESS(s2n_stuffer_free(&extension_stuffer));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
};
/* Test failure for receiving p256 key share for client configured p384 key share */
{
struct s2n_stuffer extension_stuffer = { 0 };
struct s2n_connection *client_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(client_conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
const char *p256 = "001700410474cfd75c0ab7b57247761a277e1c92b5810dacb251bb758f43e9d15aaf292c4a2be43e886425ba55653ebb7a4f32fe368bacce3df00c618645cf1eb646f22552";
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&extension_stuffer, p256));
/* If s2n_is_evp_apis_supported is not supported, the ecc_prefs->ecc_curves contains only p-256, p-384 curves. */
int p_384_index = s2n_is_evp_apis_supported() ? 2 : 1;
client_conn->kex_params.client_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[p_384_index];
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_conn->kex_params.client_ecc_evp_params));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &extension_stuffer), S2N_ERR_BAD_KEY_SHARE);
EXPECT_SUCCESS(s2n_stuffer_free(&extension_stuffer));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
};
};
/* Test Shared Key Generation */
{
struct s2n_connection *client_conn, *server_conn;
struct s2n_stuffer key_share_extension = { 0 };
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
EXPECT_NOT_NULL(server_conn = s2n_connection_new(S2N_SERVER));
server_conn->actual_protocol_version = S2N_TLS13;
EXPECT_OK(s2n_set_all_mutually_supported_groups(server_conn));
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&key_share_extension, 0));
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(server_conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
EXPECT_SUCCESS(s2n_client_key_share_extension.send(client_conn, &key_share_extension));
EXPECT_SUCCESS(s2n_client_key_share_extension.recv(server_conn, &key_share_extension));
/* should read all data */
EXPECT_EQUAL(s2n_stuffer_data_available(&key_share_extension), 0);
/* Server configures the "negotiated_curve" */
server_conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
EXPECT_SUCCESS(s2n_server_key_share_extension.send(server_conn, &key_share_extension));
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &key_share_extension));
EXPECT_EQUAL(s2n_stuffer_data_available(&key_share_extension), 0);
EXPECT_EQUAL(server_conn->kex_params.server_ecc_evp_params.negotiated_curve, client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
/* Ensure both client and server public key matches */
s2n_public_ecc_keys_are_equal(&server_conn->kex_params.server_ecc_evp_params, &client_conn->kex_params.server_ecc_evp_params);
s2n_public_ecc_keys_are_equal(&server_conn->kex_params.client_ecc_evp_params, &client_conn->kex_params.client_ecc_evp_params);
/* Server generates shared key based on Server's Key and Client's public key */
struct s2n_blob server_shared_secret = { 0 };
EXPECT_SUCCESS(s2n_ecc_evp_compute_shared_secret_from_params(
&server_conn->kex_params.server_ecc_evp_params,
&server_conn->kex_params.client_ecc_evp_params,
&server_shared_secret));
/* Clients generates shared key based on Client's Key and Server's public key */
struct s2n_blob client_shared_secret = { 0 };
EXPECT_SUCCESS(s2n_ecc_evp_compute_shared_secret_from_params(
&client_conn->kex_params.client_ecc_evp_params,
&client_conn->kex_params.server_ecc_evp_params,
&client_shared_secret));
/* Test that server shared secret matches client shared secret */
if (ecc_pref->ecc_curves[0] == &s2n_ecc_curve_secp256r1 || ecc_pref->ecc_curves[0] == &s2n_ecc_curve_secp384r1) {
/* Share sizes are described here: https://tools.ietf.org/html/rfc8446#section-4.2.8.2
* and include the extra "legacy_form" byte */
EXPECT_EQUAL(server_shared_secret.size, (ecc_pref->ecc_curves[0]->share_size - 1) * 0.5);
} else {
EXPECT_EQUAL(server_shared_secret.size, ecc_pref->ecc_curves[0]->share_size);
}
S2N_BLOB_EXPECT_EQUAL(server_shared_secret, client_shared_secret);
EXPECT_SUCCESS(s2n_free(&client_shared_secret));
EXPECT_SUCCESS(s2n_free(&server_shared_secret));
/* Clean up */
EXPECT_SUCCESS(s2n_stuffer_free(&key_share_extension));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
EXPECT_SUCCESS(s2n_connection_free(server_conn));
};
/* Test s2n_server_key_share_extension.send with supported curve not in s2n_ecc_preferences list selected */
if (s2n_is_evp_apis_supported()) {
struct s2n_connection *conn;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
EXPECT_NOT_NULL(conn->config);
/* x25519 is supported by s2n, but NOT included in the 20140601 ecc_preferences list */
const struct s2n_ecc_named_curve *test_curve = &s2n_ecc_curve_x25519;
EXPECT_SUCCESS(s2n_config_set_cipher_preferences(conn->config, "20140601"));
conn->kex_params.server_ecc_evp_params.negotiated_curve = test_curve;
conn->kex_params.client_ecc_evp_params.negotiated_curve = test_curve;
EXPECT_FAILURE(s2n_server_key_share_extension.send(conn, &conn->handshake.io));
EXPECT_SUCCESS(s2n_connection_free(conn));
}
/* Test s2n_server_key_share_extension.recv with supported curve not in s2n_ecc_preferences list selected */
if (s2n_is_evp_apis_supported()) {
struct s2n_connection *conn;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_CLIENT));
struct s2n_stuffer *extension_stuffer = &conn->handshake.io;
/* x25519 is supported by s2n, but NOT included in the 20140601 ecc_preferences list */
const struct s2n_ecc_named_curve *test_curve = &s2n_ecc_curve_x25519;
EXPECT_SUCCESS(s2n_config_set_cipher_preferences(conn->config, "20140601"));
/* Write the iana id of x25519 as the group */
EXPECT_SUCCESS(s2n_stuffer_write_uint16(extension_stuffer, test_curve->iana_id));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(conn, extension_stuffer),
S2N_ERR_ECDHE_UNSUPPORTED_CURVE);
EXPECT_SUCCESS(s2n_connection_free(conn));
}
/* Test the s2n_server_key_share_extension.recv with HelloRetryRequest */
{
EXPECT_SUCCESS(s2n_enable_tls13_in_test());
/* For a HelloRetryRequest, we won't have a key share. We just have the server selected group/negotiated curve.
* Test that s2n_server_key_share_extension.recv obtains the server negotiate curve successfully. */
{
struct s2n_connection *client_conn;
struct s2n_connection *server_conn;
EXPECT_NOT_NULL(server_conn = s2n_connection_new(S2N_SERVER));
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
struct s2n_stuffer *key_share_extension = &server_conn->handshake.io;
EXPECT_SUCCESS(s2n_connection_set_all_protocol_versions(server_conn, S2N_TLS13));
EXPECT_OK(s2n_conn_choose_state_machine(server_conn, S2N_TLS13));
client_conn->security_policy_override = &security_policy_test_tls13_retry;
server_conn->kex_params.server_ecc_evp_params.negotiated_curve = s2n_all_supported_curves_list[0];
EXPECT_SUCCESS(s2n_set_connection_hello_retry_flags(server_conn));
EXPECT_MEMCPY_SUCCESS(server_conn->handshake_params.server_random, hello_retry_req_random, S2N_TLS_RANDOM_DATA_LEN);
EXPECT_SUCCESS(s2n_server_key_share_extension.send(server_conn, key_share_extension));
const struct s2n_ecc_preferences *ecc_preferences = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(server_conn, &ecc_preferences));
EXPECT_NOT_NULL(ecc_preferences);
/* Verify that no key shares are sent */
struct s2n_ecc_evp_params *ecc_evp_params = &server_conn->kex_params.client_ecc_evp_params;
EXPECT_NULL(ecc_evp_params->negotiated_curve);
EXPECT_NULL(ecc_evp_params->evp_pkey);
/* Setup the client to have received a HelloRetryRequest */
EXPECT_MEMCPY_SUCCESS(client_conn->handshake_params.server_random, hello_retry_req_random, S2N_TLS_RANDOM_DATA_LEN);
EXPECT_SUCCESS(s2n_connection_set_all_protocol_versions(client_conn, S2N_TLS13));
EXPECT_SUCCESS(s2n_set_connection_hello_retry_flags(client_conn));
EXPECT_SUCCESS(s2n_set_hello_retry_required(client_conn));
/* Parse the key share */
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, key_share_extension));
EXPECT_EQUAL(s2n_stuffer_data_available(key_share_extension), 0);
EXPECT_EQUAL(server_conn->kex_params.server_ecc_evp_params.negotiated_curve, client_conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_NULL(client_conn->kex_params.server_ecc_evp_params.evp_pkey);
EXPECT_SUCCESS(s2n_stuffer_free(key_share_extension));
EXPECT_SUCCESS(s2n_connection_free(server_conn));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
};
EXPECT_SUCCESS(s2n_disable_tls13_in_test());
};
{
/* KEM groups with Test Vectors defined in /tests/unit/kats/tls13_server_hybrid_key_share_recv.kat */
const struct s2n_kem_group *test_kem_groups[] = {
&s2n_secp256r1_kyber_512_r3,
&s2n_x25519_kyber_512_r3,
};
const struct s2n_kem_preferences test_kem_prefs = {
.kem_count = 0,
.kems = NULL,
.tls13_kem_group_count = s2n_array_len(test_kem_groups),
.tls13_kem_groups = test_kem_groups,
.tls13_pq_hybrid_draft_revision = 0
};
const struct s2n_security_policy test_security_policy = {
.minimum_protocol_version = S2N_SSLv3,
.cipher_preferences = &cipher_preferences_test_all_tls13,
.kem_preferences = &test_kem_prefs,
.signature_preferences = &s2n_signature_preferences_20200207,
.ecc_preferences = &s2n_ecc_preferences_20200310,
};
const struct s2n_kem_preferences test_all_supported_kem_prefs = {
.kem_count = 0,
.kems = NULL,
.tls13_kem_group_count = kem_preferences_all.tls13_kem_group_count,
.tls13_kem_groups = kem_preferences_all.tls13_kem_groups,
.tls13_pq_hybrid_draft_revision = 0
};
const struct s2n_security_policy test_all_supported_kems_security_policy = {
.minimum_protocol_version = S2N_SSLv3,
.cipher_preferences = &cipher_preferences_test_all_tls13,
.kem_preferences = &test_all_supported_kem_prefs,
.signature_preferences = &s2n_signature_preferences_20200207,
.ecc_preferences = &s2n_ecc_preferences_20200310,
};
/* Tests for s2n_server_key_share_extension.recv with hybrid PQ key shares */
{
EXPECT_SUCCESS(s2n_enable_tls13_in_test());
/* If PQ is disabled, the client will not have sent PQ IDs/keyshares in the ClientHello;
* if the server responded with a PQ keyshare, we should error. */
if (!s2n_pq_is_enabled()) {
struct s2n_connection *client_conn = NULL;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
client_conn->security_policy_override = &test_security_policy;
uint8_t iana_buffer[2];
struct s2n_blob iana_blob = { 0 };
struct s2n_stuffer iana_stuffer = { 0 };
EXPECT_SUCCESS(s2n_blob_init(&iana_blob, iana_buffer, 2));
EXPECT_SUCCESS(s2n_stuffer_init(&iana_stuffer, &iana_blob));
EXPECT_SUCCESS(s2n_stuffer_write_uint16(&iana_stuffer, test_security_policy.kem_preferences->tls13_kem_groups[0]->iana_id));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &iana_stuffer), S2N_ERR_NO_SUPPORTED_LIBCRYPTO_API);
EXPECT_SUCCESS(s2n_connection_free(client_conn));
}
/* Test s2n_server_key_share_extension.recv with KAT pq key shares */
if (s2n_pq_is_enabled()) {
{
for (size_t i = 0; i < s2n_array_len(test_kem_groups); i++) {
const struct s2n_kem_group *kem_group = test_kem_groups[i];
if (!s2n_kem_group_is_available(kem_group)) {
continue;
}
struct s2n_connection *client_conn = NULL;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
client_conn->security_policy_override = &test_security_policy;
/* Read the test vectors from the KAT file (the PQ key shares are too long to hardcode inline).
* pq_private_key is intentionally missing DERFER_CLEANUP; it will get freed during s2n_connection_free. */
struct s2n_blob *pq_private_key = &client_conn->kex_params.client_kem_group_params.kem_params.private_key;
DEFER_CLEANUP(struct s2n_stuffer pq_shared_secret = { 0 }, s2n_stuffer_free);
DEFER_CLEANUP(struct s2n_stuffer key_share_payload = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_read_server_key_share_hybrid_test_vectors(kem_group, pq_private_key,
&pq_shared_secret, &key_share_payload));
/* Assert correct initial state */
EXPECT_NULL(client_conn->kex_params.server_kem_group_params.kem_group);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_group);
const struct s2n_kem_preferences *kem_prefs = NULL;
EXPECT_SUCCESS(s2n_connection_get_kem_preferences(client_conn, &kem_prefs));
EXPECT_NOT_NULL(kem_prefs);
EXPECT_EQUAL(kem_group, kem_prefs->tls13_kem_groups[i]);
/* This set up would have been done when the client sent its key share(s) */
client_conn->kex_params.client_kem_group_params.kem_group = kem_group;
client_conn->kex_params.client_kem_group_params.ecc_params.negotiated_curve = kem_group->curve;
client_conn->kex_params.client_kem_group_params.kem_params.kem = kem_group->kem;
client_conn->kex_params.client_kem_group_params.kem_params.len_prefixed = true;
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_conn->kex_params.client_kem_group_params.ecc_params));
/* Call the function and assert correctness */
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &key_share_payload));
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.kem_group);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.kem_group, kem_group);
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.ecc_params.negotiated_curve);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.ecc_params.negotiated_curve, kem_group->curve);
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.kem_params.kem);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.kem_params.kem, kem_group->kem);
EXPECT_EQUAL(client_conn->kex_params.client_kem_group_params.kem_group, kem_group);
EXPECT_EQUAL(client_conn->kex_params.client_kem_group_params.ecc_params.negotiated_curve, kem_group->curve);
EXPECT_EQUAL(client_conn->kex_params.client_kem_group_params.kem_params.kem, kem_group->kem);
EXPECT_NOT_NULL(client_conn->kex_params.client_kem_group_params.kem_params.shared_secret.data);
EXPECT_EQUAL(client_conn->kex_params.client_kem_group_params.kem_params.shared_secret.size,
kem_group->kem->shared_secret_key_length);
EXPECT_BYTEARRAY_EQUAL(client_conn->kex_params.client_kem_group_params.kem_params.shared_secret.data,
pq_shared_secret.blob.data, kem_group->kem->shared_secret_key_length);
EXPECT_EQUAL(s2n_stuffer_data_available(&key_share_payload), 0);
EXPECT_SUCCESS(s2n_connection_free(client_conn));
}
};
/* Test s2n_server_key_share_extension.recv with HRR for PQ */
{
struct s2n_connection *client_conn = NULL;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
client_conn->security_policy_override = &test_security_policy;
client_conn->actual_protocol_version = S2N_TLS13;
EXPECT_OK(s2n_conn_choose_state_machine(client_conn, S2N_TLS13));
client_conn->handshake.handshake_type = HELLO_RETRY_REQUEST;
client_conn->handshake.message_number = HELLO_RETRY_MSG_NO;
client_conn->actual_protocol_version_established = 1;
/* In the HRR, the server indicated p256+Kyber as it's choice in the key share extension */
const struct s2n_kem_group *kem_group = &s2n_secp256r1_kyber_512_r3;
DEFER_CLEANUP(struct s2n_stuffer key_share_payload = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&key_share_payload, "2F3A"));
/* Client should successfully parse the indicated group */
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &key_share_payload));
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.kem_group);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.kem_group, kem_group);
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.ecc_params.negotiated_curve);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.ecc_params.negotiated_curve, kem_group->curve);
EXPECT_NOT_NULL(client_conn->kex_params.server_kem_group_params.kem_params.kem);
EXPECT_EQUAL(client_conn->kex_params.server_kem_group_params.kem_params.kem, kem_group->kem);
/* s2n_server_key_share_extension.recv should have exited early after parsing the indicated group,
* so everything else should be NULL */
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_group);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.ecc_params.negotiated_curve);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.ecc_params.evp_pkey);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_params.kem);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_params.private_key.data);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_params.public_key.data);
EXPECT_NULL(client_conn->kex_params.client_kem_group_params.kem_params.shared_secret.data);
EXPECT_NULL(client_conn->kex_params.server_kem_group_params.ecc_params.evp_pkey);
EXPECT_NULL(client_conn->kex_params.server_kem_group_params.kem_params.shared_secret.data);
EXPECT_SUCCESS(s2n_connection_free(client_conn));
};
/* Various failure cases */
{
for (size_t i = 0; i < s2n_array_len(test_kem_groups); i++) {
const struct s2n_kem_group *kem_group = test_kem_groups[i];
if (!s2n_kem_group_is_available(kem_group)) {
continue;
}
struct s2n_connection *client_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
client_conn->security_policy_override = &test_security_policy;
/* Server sends a named group identifier that isn't in the client's KEM preferences */
const char *bad_group = "2F2C"; /* IANA ID for secp256r1_threebears-babybear-r2 (not imported into s2n) */
DEFER_CLEANUP(struct s2n_stuffer bad_group_stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&bad_group_stuffer, bad_group));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &bad_group_stuffer),
S2N_ERR_ECDHE_UNSUPPORTED_CURVE);
/* Server sends a key share that is in the client's KEM preferences, but client didn't send a key share */
const char *wrong_share = "2F1F"; /* Full extension truncated - not necessary */
DEFER_CLEANUP(struct s2n_stuffer wrong_share_stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_alloc_ro_from_hex_string(&wrong_share_stuffer, wrong_share));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &wrong_share_stuffer),
S2N_ERR_ECDHE_UNSUPPORTED_CURVE);
/* To test the remaining failure cases, we need to read in the test vector from the KAT file, then
* manipulate it as necessary. (We do this now, instead of earlier, because we needed
* client_kem_group_params[i].kem_params.private_key to be empty to test the previous case.) */
struct s2n_blob *pq_private_key = &client_conn->kex_params.client_kem_group_params.kem_params.private_key;
DEFER_CLEANUP(struct s2n_stuffer pq_shared_secret = { 0 }, s2n_stuffer_free);
DEFER_CLEANUP(struct s2n_stuffer key_share_payload = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_read_server_key_share_hybrid_test_vectors(kem_group, pq_private_key,
&pq_shared_secret, &key_share_payload));
/* Server sends the wrong (total) size: data[2] and data[3] are the bytes containing the total size
* of the key share; bitflip data[2] to invalidate the sent size */
key_share_payload.blob.data[2] = ~key_share_payload.blob.data[2];
client_conn->kex_params.client_kem_group_params.kem_group = kem_group;
client_conn->kex_params.client_kem_group_params.ecc_params.negotiated_curve = kem_group->curve;
client_conn->kex_params.client_kem_group_params.kem_params.kem = kem_group->kem;
client_conn->kex_params.client_kem_group_params.kem_params.len_prefixed = true;
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_conn->kex_params.client_kem_group_params.ecc_params));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &key_share_payload),
S2N_ERR_BAD_KEY_SHARE);
/* Revert key_share_payload back to correct state */
key_share_payload.blob.data[2] = ~key_share_payload.blob.data[2];
EXPECT_SUCCESS(s2n_stuffer_reread(&key_share_payload));
/* Server sends the correct (total) size, but the extension doesn't contain all the data */
uint8_t truncated_extension[10];
EXPECT_MEMCPY_SUCCESS(truncated_extension, key_share_payload.blob.data, 10);
struct s2n_blob trunc_ext_blob = { 0 };
EXPECT_SUCCESS(s2n_blob_init(&trunc_ext_blob, truncated_extension, 10));
struct s2n_stuffer trunc_ext_stuffer = { 0 };
EXPECT_SUCCESS(s2n_stuffer_init(&trunc_ext_stuffer, &trunc_ext_blob));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &trunc_ext_stuffer),
S2N_ERR_BAD_KEY_SHARE);
/* Server sends the wrong ECC key share size: data[4] and data[5] are the two bytes containing
* the size of the ECC key share; bitflip data[4] to invalidate the size */
key_share_payload.blob.data[4] = ~key_share_payload.blob.data[4];
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &key_share_payload),
S2N_ERR_BAD_KEY_SHARE);
/* Revert key_share_payload back to correct state */
key_share_payload.blob.data[4] = ~key_share_payload.blob.data[4];
EXPECT_SUCCESS(s2n_stuffer_reread(&key_share_payload));
/* Server sends the wrong PQ share size size: index of the first byte of the size of the PQ key share
* depends of how large the ECC key share is */
size_t pq_share_size_index =
S2N_SIZE_OF_NAMED_GROUP
+ S2N_SIZE_OF_KEY_SHARE_SIZE /* Not a typo; PQ shares have an overall (combined) size */
+ S2N_SIZE_OF_KEY_SHARE_SIZE /* and a size for each contribution of the hybrid share. */
+ kem_group->curve->share_size;
key_share_payload.blob.data[pq_share_size_index] = ~key_share_payload.blob.data[pq_share_size_index];
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.recv(client_conn, &key_share_payload),
S2N_ERR_BAD_KEY_SHARE);
/* Revert key_share_payload back to correct state */
key_share_payload.blob.data[pq_share_size_index] = ~key_share_payload.blob.data[pq_share_size_index];
EXPECT_SUCCESS(s2n_stuffer_reread(&key_share_payload));
/* Server sends a bad PQ key share (ciphertext): in order to guarantee certain crypto properties,
* the PQ KEM decapsulation functions are written so that the decaps will succeed without error
* in this case, but the returned PQ shared secret will be incorrect. In practice, this means
* that the key_share.recv function will succeed, but the overall handshake will fail later when
* client+server attempt to use the (different) shared secrets they each derived. */
size_t pq_key_share_first_byte_index = pq_share_size_index + 2;
key_share_payload.blob.data[pq_key_share_first_byte_index] = ~key_share_payload.blob.data[pq_key_share_first_byte_index];
EXPECT_SUCCESS(s2n_server_key_share_extension.recv(client_conn, &key_share_payload));
EXPECT_BYTEARRAY_NOT_EQUAL(client_conn->kex_params.client_kem_group_params.kem_params.shared_secret.data,
pq_shared_secret.blob.data, kem_group->kem->shared_secret_key_length);
EXPECT_SUCCESS(s2n_connection_free(client_conn));
}
};
}
EXPECT_SUCCESS(s2n_disable_tls13_in_test());
};
/* Test s2n_server_key_share_send_check_pq_hybrid */
{
struct s2n_connection *conn = NULL;
EXPECT_FAILURE(s2n_server_key_share_send_check_pq_hybrid(conn));
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
if (!s2n_pq_is_enabled()) {
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_NO_SUPPORTED_LIBCRYPTO_API);
}
if (s2n_pq_is_enabled()) {
conn->security_policy_override = &test_all_supported_kems_security_policy;
EXPECT_FAILURE(s2n_server_key_share_send_check_pq_hybrid(conn));
conn->kex_params.server_kem_group_params.kem_params.kem = &s2n_kyber_512_r3;
EXPECT_FAILURE(s2n_server_key_share_send_check_pq_hybrid(conn));
conn->kex_params.server_kem_group_params.ecc_params.negotiated_curve = &s2n_ecc_curve_secp256r1;
conn->kex_params.server_kem_group_params.kem_group = &s2n_secp256r1_kyber_512_r3;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
conn->kex_params.server_kem_group_params.kem_group = &s2n_secp256r1_kyber_512_r3;
conn->kex_params.server_kem_group_params.kem_params.kem = &s2n_kyber_512_r3;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
conn->kex_params.client_kem_group_params.kem_group = &s2n_secp256r1_kyber_512_r3;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
conn->kex_params.client_kem_group_params.ecc_params.negotiated_curve = s2n_secp256r1_kyber_512_r3.curve;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&conn->kex_params.client_kem_group_params.ecc_params));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
conn->kex_params.client_kem_group_params.kem_params.kem = s2n_secp256r1_kyber_512_r3.kem;
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_send_check_pq_hybrid(conn), S2N_ERR_BAD_KEY_SHARE);
EXPECT_SUCCESS(s2n_alloc(&conn->kex_params.client_kem_group_params.kem_params.public_key,
s2n_secp256r1_kyber_512_r3.kem->public_key_length));
EXPECT_OK(s2n_kem_generate_keypair(&conn->kex_params.client_kem_group_params.kem_params));
EXPECT_SUCCESS(s2n_server_key_share_send_check_pq_hybrid(conn));
}
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.send sends key share success (PQ) */
if (s2n_pq_is_enabled()) {
for (int len_prefixed = 0; len_prefixed < 2; len_prefixed++) {
for (size_t i = 0; i < S2N_KEM_GROUPS_COUNT; i++) {
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
conn->security_policy_override = &test_all_supported_kems_security_policy;
const struct s2n_kem_preferences *kem_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_kem_preferences(conn, &kem_pref));
EXPECT_NOT_NULL(kem_pref);
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 4096));
/* Set up the server so that it's chosen the correct KEM group and received
* a correspond keyshare from client */
conn->kex_params.server_ecc_evp_params.negotiated_curve = NULL;
struct s2n_kem_group_params *server_params = &conn->kex_params.server_kem_group_params;
const struct s2n_kem_group *kem_group = kem_pref->tls13_kem_groups[i];
if (!s2n_kem_group_is_available(kem_group)) {
EXPECT_SUCCESS(s2n_connection_free(conn));
continue;
}
server_params->kem_group = kem_group;
server_params->kem_params.kem = kem_group->kem;
server_params->ecc_params.negotiated_curve = kem_group->curve;
struct s2n_kem_group_params *client_params = &conn->kex_params.client_kem_group_params;
client_params->kem_group = kem_group;
client_params->kem_params.kem = kem_group->kem;
client_params->kem_params.len_prefixed = (bool) len_prefixed; /* This would normally be auto-detected when receiving the Client's KeyShare*/
client_params->ecc_params.negotiated_curve = kem_group->curve;
EXPECT_SUCCESS(s2n_ecc_evp_generate_ephemeral_key(&client_params->ecc_params));
EXPECT_SUCCESS(s2n_alloc(&client_params->kem_params.public_key, kem_group->kem->public_key_length));
EXPECT_OK(s2n_kem_generate_keypair(&client_params->kem_params));
EXPECT_SUCCESS(s2n_server_key_share_extension.send(conn, &stuffer));
uint16_t expected_hybrid_share_size = kem_group->curve->share_size + kem_group->kem->ciphertext_length;
if (client_params->kem_params.len_prefixed) {
expected_hybrid_share_size += (2 * S2N_SIZE_OF_KEY_SHARE_SIZE);
}
/* IANA ID (2 bytes) + total share size (2 bytes) + Hybrid Share */
EXPECT_EQUAL(s2n_stuffer_data_available(&stuffer), ((2 * sizeof(uint16_t)) + expected_hybrid_share_size));
/* Assert we sent a hybrid key share */
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, kem_group->iana_id, uint16);
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, expected_hybrid_share_size, uint16);
if (len_prefixed) {
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, kem_group->curve->share_size, uint16);
}
EXPECT_SUCCESS(s2n_stuffer_skip_read(&stuffer, kem_group->curve->share_size));
if (len_prefixed) {
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, kem_group->kem->ciphertext_length, uint16);
}
S2N_STUFFER_LENGTH_WRITTEN_EXPECT_EQUAL(&stuffer, kem_group->kem->ciphertext_length);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_EQUAL(server_params->kem_group, kem_group);
EXPECT_EQUAL(server_params->kem_params.kem, kem_group->kem);
EXPECT_EQUAL(server_params->ecc_params.negotiated_curve, kem_group->curve);
EXPECT_EQUAL(client_params->kem_params.shared_secret.size, kem_group->kem->shared_secret_key_length);
EXPECT_NOT_NULL(client_params->kem_params.shared_secret.data);
EXPECT_SUCCESS(s2n_connection_free(conn));
}
}
}
/* Test s2n_server_key_share_extension.send sends IANA ID for HRR (PQ) */
{
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
conn->security_policy_override = &test_all_supported_kems_security_policy;
conn->actual_protocol_version = S2N_TLS13;
EXPECT_OK(s2n_conn_choose_state_machine(conn, S2N_TLS13));
conn->handshake.handshake_type = HELLO_RETRY_REQUEST;
conn->handshake.message_number = HELLO_RETRY_MSG_NO;
const struct s2n_kem_preferences *kem_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_kem_preferences(conn, &kem_pref));
EXPECT_NOT_NULL(kem_pref);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.negotiated_curve);
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 1024));
for (size_t i = 0; i < kem_pref->tls13_kem_group_count; i++) {
struct s2n_kem_group_params *server_params = &conn->kex_params.server_kem_group_params;
const struct s2n_kem_group *kem_group = kem_pref->tls13_kem_groups[i];
if (!s2n_kem_group_is_available(kem_group)) {
continue;
}
server_params->kem_group = kem_group;
server_params->kem_params.kem = kem_group->kem;
server_params->ecc_params.negotiated_curve = kem_group->curve;
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.evp_pkey);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_SUCCESS(s2n_server_key_share_extension.send(conn, &stuffer));
S2N_STUFFER_READ_EXPECT_EQUAL(&stuffer, kem_group->iana_id, uint16);
EXPECT_EQUAL(0, s2n_stuffer_data_available(&stuffer));
EXPECT_EQUAL(server_params->kem_group, kem_group);
EXPECT_EQUAL(server_params->kem_params.kem, kem_group->kem);
EXPECT_EQUAL(server_params->ecc_params.negotiated_curve, kem_group->curve);
EXPECT_NULL(server_params->kem_params.shared_secret.data);
EXPECT_EQUAL(0, server_params->kem_params.shared_secret.size);
EXPECT_NULL(server_params->ecc_params.evp_pkey);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.negotiated_curve);
EXPECT_NULL(conn->kex_params.server_ecc_evp_params.evp_pkey);
}
EXPECT_SUCCESS(s2n_connection_free(conn));
};
/* Test s2n_server_key_share_extension.send fails when both server_kem_group and server_curve are non-NULL */
{
struct s2n_connection *conn = NULL;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
conn->security_policy_override = &test_all_supported_kems_security_policy;
const struct s2n_kem_preferences *kem_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_kem_preferences(conn, &kem_pref));
EXPECT_NOT_NULL(kem_pref);
const struct s2n_ecc_preferences *ecc_pref = NULL;
EXPECT_SUCCESS(s2n_connection_get_ecc_preferences(conn, &ecc_pref));
EXPECT_NOT_NULL(ecc_pref);
conn->kex_params.server_ecc_evp_params.negotiated_curve = ecc_pref->ecc_curves[0];
conn->kex_params.server_kem_group_params.kem_group = kem_pref->tls13_kem_groups[0];
DEFER_CLEANUP(struct s2n_stuffer stuffer = { 0 }, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 0));
EXPECT_FAILURE_WITH_ERRNO(s2n_server_key_share_extension.send(conn, &stuffer), S2N_ERR_ECDHE_UNSUPPORTED_CURVE);
EXPECT_SUCCESS(s2n_connection_free(conn));
};
};
END_TEST();
return 0;
}
static int s2n_read_server_key_share_hybrid_test_vectors(const struct s2n_kem_group *kem_group, struct s2n_blob *pq_private_key,
struct s2n_stuffer *pq_shared_secret, struct s2n_stuffer *key_share_payload)
{
FILE *kat_file = fopen("kats/tls13_server_hybrid_key_share_recv.kat", "r");
POSIX_ENSURE_REF(kat_file);
/* 50 should be plenty big enough to hold the entire marker string */
char marker[50] = "kem_group = ";
strcat(marker, kem_group->name);
POSIX_GUARD(FindMarker(kat_file, marker));
POSIX_GUARD(s2n_alloc(pq_private_key, kem_group->kem->private_key_length));
POSIX_GUARD(ReadHex(kat_file, pq_private_key->data, kem_group->kem->private_key_length, "pq_private_key = "));
pq_private_key->size = kem_group->kem->private_key_length;
POSIX_GUARD(s2n_stuffer_alloc(pq_shared_secret, kem_group->kem->shared_secret_key_length));
uint8_t *pq_shared_secret_ptr = s2n_stuffer_raw_write(pq_shared_secret, kem_group->kem->shared_secret_key_length);
POSIX_ENSURE_REF(pq_shared_secret_ptr);
POSIX_GUARD(ReadHex(kat_file, pq_shared_secret_ptr, kem_group->kem->shared_secret_key_length, "pq_shared_secret = "));
size_t key_share_payload_size =
S2N_SIZE_OF_NAMED_GROUP
+ S2N_SIZE_OF_KEY_SHARE_SIZE /* Not a typo; PQ shares have an overall (combined) size */
+ S2N_SIZE_OF_KEY_SHARE_SIZE /* and a size for each contribution of the hybrid share. */
+ kem_group->curve->share_size
+ S2N_SIZE_OF_KEY_SHARE_SIZE
+ kem_group->kem->ciphertext_length;
POSIX_GUARD(s2n_stuffer_alloc(key_share_payload, key_share_payload_size));
uint8_t *key_share_payload_ptr = s2n_stuffer_raw_write(key_share_payload, key_share_payload_size);
POSIX_ENSURE_REF(key_share_payload_ptr);
POSIX_GUARD(ReadHex(kat_file, key_share_payload_ptr, key_share_payload_size, "server_key_share_payload = "));
fclose(kat_file);
return S2N_SUCCESS;
}
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