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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 "s2n_test.h"
#include "testlib/s2n_testlib.h"
#include "tls/s2n_prf.h"
#include "utils/s2n_random.h"
static S2N_RESULT s2n_test_validate_key_material(struct s2n_key_material *key_material,
struct s2n_blob *test_data_blob, uint8_t mac_size, uint8_t key_size, uint8_t iv_size)
{
/* confirm that the data is copied to key_material */
RESULT_ENSURE_EQ(test_data_blob->size, sizeof(key_material->key_block));
RESULT_ENSURE_EQ(memcmp(test_data_blob->data, key_material->key_block, test_data_blob->size), 0);
struct s2n_stuffer test_data_stuffer = { 0 };
RESULT_GUARD_POSIX(s2n_stuffer_init_written(&test_data_stuffer, test_data_blob));
/* test that its possible to access data from s2n_key_material */
/* client MAC */
uint8_t *test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, mac_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->client_mac.data, mac_size), 0);
/* server MAC */
test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, mac_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->server_mac.data, mac_size), 0);
/* client KEY */
test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, key_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->client_key.data, key_size), 0);
/* server KEY */
test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, key_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->server_key.data, key_size), 0);
/* client IV */
test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, iv_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->client_iv.data, iv_size), 0);
/* server IV */
test_ptr = s2n_stuffer_raw_read(&test_data_stuffer, iv_size);
RESULT_ENSURE_REF(test_ptr);
RESULT_ENSURE_EQ(memcmp(test_ptr, key_material->server_iv.data, iv_size), 0);
return S2N_RESULT_OK;
}
int main(int argc, char **argv)
{
BEGIN_TEST();
/* prepare test data */
uint8_t test_data[S2N_MAX_KEY_BLOCK_LEN] = { 0 };
struct s2n_blob test_data_blob = { 0 };
EXPECT_SUCCESS(s2n_blob_init(&test_data_blob, test_data, sizeof(test_data)));
EXPECT_OK(s2n_get_public_random_data(&test_data_blob));
/* fuzz s2n_key_material_init with different mac, key, iv sizes */
{
for (uint8_t mac_size = 0; mac_size < SHA512_DIGEST_LENGTH; mac_size++) {
for (uint8_t key_size = 0; key_size < S2N_TLS_AES_256_GCM_KEY_LEN; key_size++) {
for (uint8_t iv_size = 0; iv_size < S2N_TLS_MAX_IV_LEN; iv_size++) {
if ((mac_size * 2 + key_size * 2 + iv_size * 2 > S2N_MAX_KEY_BLOCK_LEN)) {
continue;
}
DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
/* test varying size of mac, key and iv */
conn->actual_protocol_version = S2N_TLS10;
struct s2n_cipher temp_cipher = {
.type = S2N_COMPOSITE,
.key_material_size = key_size,
.io.comp = {
/* interpreted as iv size for composite ciphers.. which makes
* it easy for testing */
.block_size = iv_size,
.mac_key_size = mac_size,
},
};
struct s2n_record_algorithm temp_record_alg = {
.cipher = &temp_cipher,
};
struct s2n_cipher_suite temp_cipher_suite = {
.record_alg = &temp_record_alg,
};
conn->secure->cipher_suite = &temp_cipher_suite;
/* init s2n_key_material */
struct s2n_key_material key_material = { 0 };
EXPECT_OK(s2n_key_material_init(&key_material, conn));
/* assert that sizes match */
EXPECT_EQUAL(key_material.client_mac.size, mac_size);
EXPECT_EQUAL(key_material.client_key.size, key_size);
EXPECT_EQUAL(key_material.client_iv.size, iv_size);
EXPECT_EQUAL(key_material.server_mac.size, mac_size);
EXPECT_EQUAL(key_material.server_key.size, key_size);
EXPECT_EQUAL(key_material.server_iv.size, iv_size);
/* copy data into key_material and validate accessing key_material is sound */
EXPECT_EQUAL(sizeof(key_material.key_block), sizeof(test_data));
POSIX_CHECKED_MEMCPY(key_material.key_block, test_data, sizeof(key_material.key_block));
EXPECT_OK(s2n_test_validate_key_material(&key_material, &test_data_blob, mac_size, key_size, iv_size));
}
}
}
}
/* confirm that s2n_key_material can correctly handle all cipher suites */
{
for (size_t i = 0; i < cipher_preferences_test_all.count; i++) {
DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
struct s2n_cipher_suite *cipher_suite = cipher_preferences_test_all.suites[i];
if (!cipher_suite->available) {
continue;
}
conn->secure->cipher_suite = cipher_suite;
/* init s2n_key_material */
struct s2n_key_material key_material = { 0 };
EXPECT_OK(s2n_key_material_init(&key_material, conn));
/* copy data into key_material and validate accessing key_material is sound */
EXPECT_EQUAL(sizeof(key_material.key_block), sizeof(test_data));
POSIX_CHECKED_MEMCPY(key_material.key_block, test_data, sizeof(key_material.key_block));
/* test that its possible to access mac, key and iv correctly from s2n_key_material */
EXPECT_OK(s2n_test_validate_key_material(
&key_material,
&test_data_blob,
key_material.client_mac.size,
key_material.client_key.size,
key_material.client_iv.size));
}
}
/* AEAD cipher
* IV size should be the same regardless of protocol version
*/
{
DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
conn->secure->cipher_suite = &s2n_tls13_aes_128_gcm_sha256;
EXPECT_EQUAL(conn->secure->cipher_suite->record_alg->cipher->type, S2N_AEAD);
struct s2n_key_material key_material = { 0 };
uint32_t mac = 0;
uint32_t key = S2N_TLS_AES_128_GCM_KEY_LEN;
uint32_t iv = S2N_TLS13_FIXED_IV_LEN;
/* initialize s2n_key_material */
conn->actual_protocol_version = S2N_TLS10;
EXPECT_OK(s2n_key_material_init(&key_material, conn));
EXPECT_EQUAL(key_material.client_mac.size, mac);
EXPECT_EQUAL(key_material.client_key.size, key);
EXPECT_EQUAL(key_material.client_iv.size, iv);
EXPECT_EQUAL(key_material.server_mac.size, mac);
EXPECT_EQUAL(key_material.server_key.size, key);
EXPECT_EQUAL(key_material.server_iv.size, iv);
/* re-initialize s2n_key_material */
conn->actual_protocol_version = S2N_TLS11;
EXPECT_OK(s2n_key_material_init(&key_material, conn));
/* assert same IV size regardless of protocol version */
EXPECT_EQUAL(key_material.client_mac.size, mac);
EXPECT_EQUAL(key_material.client_key.size, key);
EXPECT_EQUAL(key_material.client_iv.size, iv);
EXPECT_EQUAL(key_material.server_mac.size, mac);
EXPECT_EQUAL(key_material.server_key.size, key);
EXPECT_EQUAL(key_material.server_iv.size, iv);
}
/* NON AEAD cipher
* IV size depends on protocol version
*/
{
DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
s2n_connection_ptr_free);
conn->secure->cipher_suite = &s2n_rsa_with_aes_128_cbc_sha256;
const struct s2n_cipher *cipher = conn->secure->cipher_suite->record_alg->cipher;
/* assert that the cipher chosen is non AEAD */
EXPECT_TRUE(cipher->type == S2N_COMPOSITE || cipher->type == S2N_CBC);
struct s2n_key_material key_material = { 0 };
uint32_t mac = SHA256_DIGEST_LENGTH;
uint32_t key = S2N_TLS_AES_128_GCM_KEY_LEN;
uint32_t iv = 16;
/* initialize s2n_key_material */
conn->actual_protocol_version = S2N_TLS10;
EXPECT_OK(s2n_key_material_init(&key_material, conn));
/* assert IV of non 0 if protocol version <= S2N_TLS10 */
EXPECT_EQUAL(key_material.client_mac.size, mac);
EXPECT_EQUAL(key_material.client_key.size, key);
EXPECT_EQUAL(key_material.client_iv.size, iv);
EXPECT_EQUAL(key_material.server_mac.size, mac);
EXPECT_EQUAL(key_material.server_key.size, key);
EXPECT_EQUAL(key_material.server_iv.size, iv);
/* re-initialize s2n_key_material */
conn->actual_protocol_version = S2N_TLS11;
EXPECT_OK(s2n_key_material_init(&key_material, conn));
/* assert IV of size == 0 if protocol version > S2N_TLS10 */
iv = 0;
EXPECT_EQUAL(key_material.client_mac.size, mac);
EXPECT_EQUAL(key_material.client_key.size, key);
EXPECT_EQUAL(key_material.client_iv.size, iv);
EXPECT_EQUAL(key_material.server_mac.size, mac);
EXPECT_EQUAL(key_material.server_key.size, key);
EXPECT_EQUAL(key_material.server_iv.size, iv);
}
END_TEST();
}
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