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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.
*/
/* Target Functions: s2n_certificate_extensions_parse
s2n_recv_server_sct_list s2n_server_certificate_status_recv
s2n_x509_validator_validate_cert_stapled_ocsp_response */
#include <stdint.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include "api/s2n.h"
#include "stuffer/s2n_stuffer.h"
#include "tls/extensions/s2n_extension_list.h"
#include "tls/s2n_config.h"
#include "tls/s2n_connection.h"
#include "tls/s2n_tls.h"
#include "utils/s2n_safety.h"
#include "s2n_test.h"
#include "testlib/s2n_testlib.h"
#include "tls/s2n_tls13.h"
struct host_verify_data {
const char *name;
uint8_t found_name;
uint8_t callback_invoked;
};
static uint8_t verify_host_accept_everything(const char *host_name, size_t host_name_len, void *data)
{
struct host_verify_data *verify_data = (struct host_verify_data *) data;
verify_data->callback_invoked = 1;
return 1;
}
/* This test is for TLS versions 1.3 and up only */
static const uint8_t TLS_VERSIONS[] = {S2N_TLS13};
int s2n_fuzz_init(int *argc, char **argv[])
{
/* Initialize the trust store */
POSIX_GUARD_RESULT(s2n_config_testing_defaults_init_tls13_certs());
POSIX_GUARD(s2n_enable_tls13_in_test());
return S2N_SUCCESS;
}
int s2n_fuzz_test(const uint8_t *buf, size_t len)
{
/* We need at least one byte of input to set parameters */
S2N_FUZZ_ENSURE_MIN_LEN(len, 1);
/* Setup */
struct s2n_stuffer fuzz_stuffer = {0};
POSIX_GUARD(s2n_stuffer_alloc(&fuzz_stuffer, len));
POSIX_GUARD(s2n_stuffer_write_bytes(&fuzz_stuffer, buf, len));
struct s2n_connection *client_conn = s2n_connection_new(S2N_CLIENT);
POSIX_ENSURE_REF(client_conn);
/* Pull a byte off the libfuzzer input and use it to set parameters */
uint8_t randval = 0;
POSIX_GUARD(s2n_stuffer_read_uint8(&fuzz_stuffer, &randval));
client_conn->x509_validator.skip_cert_validation = (randval >> 7) % 2;
/* Set connection to TLS 1.2 to temporary work around cert validation setup */
client_conn->actual_protocol_version = S2N_TLS12;
/* Set cert chain and trust store for verification of OCSP response */
if ((randval >> 6) % 2 && OPENSSL_VERSION_NUMBER >= 0x10101000L) {
struct host_verify_data verify_data = { .callback_invoked = 0, .found_name = 0, .name = NULL };
POSIX_GUARD(s2n_connection_set_verify_host_callback(client_conn, verify_host_accept_everything, &verify_data));
char cert_chain[S2N_MAX_TEST_PEM_SIZE];
POSIX_GUARD(s2n_read_test_pem(S2N_OCSP_CA_CERT, cert_chain, S2N_MAX_TEST_PEM_SIZE));
POSIX_GUARD(s2n_x509_trust_store_add_pem(client_conn->x509_validator.trust_store, cert_chain));
DEFER_CLEANUP(struct s2n_stuffer cert_chain_stuffer = { 0 }, s2n_stuffer_free);
EXPECT_OK(s2n_test_cert_chain_data_from_pem(client_conn, S2N_OCSP_SERVER_CERT, &cert_chain_stuffer));
uint32_t chain_len = s2n_stuffer_data_available(&cert_chain_stuffer);
uint8_t *chain_data = s2n_stuffer_raw_read(&cert_chain_stuffer, chain_len);
EXPECT_NOT_NULL(chain_data);
struct s2n_pkey public_key_out;
POSIX_GUARD(s2n_pkey_zero_init(&public_key_out));
s2n_pkey_type pkey_type;
POSIX_GUARD_RESULT(s2n_x509_validator_validate_cert_chain(&client_conn->x509_validator, client_conn, chain_data, chain_len, &pkey_type, &public_key_out));
POSIX_GUARD(s2n_pkey_free(&public_key_out));
}
client_conn->actual_protocol_version = TLS_VERSIONS[(randval & 0x07) % s2n_array_len(TLS_VERSIONS)];
client_conn->client_protocol_version = TLS_VERSIONS[((randval >> 3) & 0x07) % s2n_array_len(TLS_VERSIONS)];
/* Run Test
* Do not use GUARD macro here since the connection memory hasn't been freed.
*/
s2n_extension_list_recv(S2N_EXTENSION_LIST_CERTIFICATE, client_conn, &fuzz_stuffer);
/* Cleanup */
POSIX_GUARD(s2n_connection_free(client_conn));
POSIX_GUARD(s2n_stuffer_free(&fuzz_stuffer));
return S2N_SUCCESS;
}
S2N_FUZZ_TARGET(s2n_fuzz_init, s2n_fuzz_test, NULL)
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