int s2n_dhe_server_key_recv_read_data(struct s2n_connection *conn, struct s2n_blob *data_to_verify, union s2n_kex_raw_server_data *raw_server_data)
{
struct s2n_stuffer *in = &conn->handshake.io;
struct s2n_dhe_raw_server_points *dhe_data = &raw_server_data->dhe_data;
uint16_t p_length;
uint16_t g_length;
uint16_t Ys_length;
/* Keep a copy to the start of the whole structure for the signature check */
data_to_verify->data = s2n_stuffer_raw_read(in, 0);
notnull_check(data_to_verify->data);
/* Read each of the three elements in */
GUARD(s2n_stuffer_read_uint16(in, &p_length));
dhe_data->p.size = p_length;
dhe_data->p.data = s2n_stuffer_raw_read(in, p_length);
notnull_check(dhe_data->p.data);
GUARD(s2n_stuffer_read_uint16(in, &g_length));
dhe_data->g.size = g_length;
dhe_data->g.data = s2n_stuffer_raw_read(in, g_length);
notnull_check(dhe_data->g.data);
GUARD(s2n_stuffer_read_uint16(in, &Ys_length));
dhe_data->Ys.size = Ys_length;
dhe_data->Ys.data = s2n_stuffer_raw_read(in, Ys_length);
notnull_check(dhe_data->Ys.data);
/* Now we know the total size of the structure */
data_to_verify->size = 2 + p_length + 2 + g_length + 2 + Ys_length;
return 0;
}
int s2n_kem_server_key_recv_read_data(struct s2n_connection *conn, struct s2n_blob *data_to_verify, union s2n_kex_raw_server_data *raw_server_data)
{
struct s2n_kem_raw_server_params *kem_data = &raw_server_data->kem_data;
struct s2n_stuffer *in = &conn->handshake.io;
const struct s2n_kem *kem = conn->secure.s2n_kem_keys.negotiated_kem;
kem_public_key_size key_length;
/* Keep a copy to the start of the whole structure for the signature check */
data_to_verify->data = s2n_stuffer_raw_read(in, 0);
notnull_check(data_to_verify->data);
/* the server sends the KEM ID again and this must match what was agreed upon during server hello */
kem_extension_size kem_id;
GUARD(s2n_stuffer_read_uint8(in, &kem_id));
eq_check(kem_id, kem->kem_extension_id);
GUARD(s2n_stuffer_read_uint16(in, &key_length));
S2N_ERROR_IF(key_length > s2n_stuffer_data_available(in), S2N_ERR_BAD_MESSAGE);
S2N_ERROR_IF(key_length != conn->secure.s2n_kem_keys.negotiated_kem->public_key_length, S2N_ERR_BAD_MESSAGE);
kem_data->raw_public_key.data = s2n_stuffer_raw_read(in, key_length);
notnull_check(kem_data->raw_public_key.data);
kem_data->raw_public_key.size = key_length;
data_to_verify->size = sizeof(kem_extension_size) + sizeof(kem_public_key_size) + key_length;
return 0;
}
int s2n_dh_compute_shared_secret_as_server(struct s2n_dh_params *server_dh_params, struct s2n_stuffer *Yc_in, struct s2n_blob *shared_key)
{
uint16_t Yc_length;
struct s2n_blob Yc;
int shared_key_size;
BIGNUM *pub_key;
GUARD(s2n_check_all_dh_params(server_dh_params));
GUARD(s2n_stuffer_read_uint16(Yc_in, &Yc_length));
Yc.size = Yc_length;
Yc.data = s2n_stuffer_raw_read(Yc_in, Yc.size);
notnull_check(Yc.data);
pub_key = BN_bin2bn((const unsigned char *)Yc.data, Yc.size, NULL);
notnull_check(pub_key);
GUARD(s2n_alloc(shared_key, DH_size(server_dh_params->dh)));
shared_key_size = DH_compute_key(shared_key->data, pub_key, server_dh_params->dh);
if (shared_key_size <= 0) {
BN_free(pub_key);
S2N_ERROR(S2N_ERR_DH_SHARED_SECRET);
}
shared_key->size = shared_key_size;
BN_free(pub_key);
return 0;
}
int s2n_server_extensions_recv(struct s2n_connection *conn, struct s2n_blob *extensions)
{
struct s2n_stuffer in;
GUARD(s2n_stuffer_init(&in, extensions));
GUARD(s2n_stuffer_write(&in, extensions));
while (s2n_stuffer_data_available(&in)) {
struct s2n_blob ext;
uint16_t extension_type, extension_size;
struct s2n_stuffer extension;
GUARD(s2n_stuffer_read_uint16(&in, &extension_type));
GUARD(s2n_stuffer_read_uint16(&in, &extension_size));
ext.size = extension_size;
ext.data = s2n_stuffer_raw_read(&in, ext.size);
notnull_check(ext.data);
GUARD(s2n_stuffer_init(&extension, &ext));
GUARD(s2n_stuffer_write(&extension, &ext));
switch (extension_type) {
case TLS_EXTENSION_ALPN:
GUARD(s2n_recv_server_alpn(conn, &extension));
break;
case TLS_EXTENSION_STATUS_REQUEST:
GUARD(s2n_recv_server_status_request(conn, &extension));
break;
}
}
return 0;
}
int main(int argc, char **argv)
{
struct s2n_stuffer dhparams_in, dhparams_out;
struct s2n_dh_params dh_params;
struct s2n_blob b;
BEGIN_TEST();
EXPECT_EQUAL(s2n_get_private_random_bytes_used(), 0);
/* Parse the DH params */
b.data = dhparams;
b.size = sizeof(dhparams);
EXPECT_SUCCESS(s2n_stuffer_alloc(&dhparams_in, sizeof(dhparams)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&dhparams_out, sizeof(dhparams)));
EXPECT_SUCCESS(s2n_stuffer_write(&dhparams_in, &b));
EXPECT_SUCCESS(s2n_stuffer_dhparams_from_pem(&dhparams_in, &dhparams_out));
b.size = s2n_stuffer_data_available(&dhparams_out);
b.data = s2n_stuffer_raw_read(&dhparams_out, b.size);
EXPECT_SUCCESS(s2n_pkcs3_to_dh_params(&dh_params, &b));
EXPECT_SUCCESS(s2n_dh_generate_ephemeral_key(&dh_params));
/* Verify that our DRBG is called and that over-riding works */
EXPECT_NOT_EQUAL(s2n_get_private_random_bytes_used(), 0);
EXPECT_SUCCESS(s2n_dh_params_free(&dh_params));
EXPECT_SUCCESS(s2n_stuffer_free(&dhparams_out));
EXPECT_SUCCESS(s2n_stuffer_free(&dhparams_in));
END_TEST();
}
/* See http://www-archive.mozilla.org/projects/security/pki/nss/ssl/draft02.html 2.5 */
int s2n_sslv2_client_hello_recv(struct s2n_connection *conn)
{
struct s2n_stuffer *in = &conn->handshake.io;
uint16_t session_id_length;
uint16_t cipher_suites_length;
uint16_t challenge_length;
uint8_t *cipher_suites;
if (conn->client_protocol_version < conn->config->cipher_preferences->minimum_protocol_version || conn->client_protocol_version > conn->server_protocol_version) {
GUARD(s2n_queue_reader_unsupported_protocol_version_alert(conn));
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
conn->actual_protocol_version = MIN(conn->client_protocol_version, conn->server_protocol_version);
conn->client_hello_version = S2N_SSLv2;
/* We start 5 bytes into the record */
GUARD(s2n_stuffer_read_uint16(in, &cipher_suites_length));
if (cipher_suites_length % S2N_SSLv2_CIPHER_SUITE_LEN) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
GUARD(s2n_stuffer_read_uint16(in, &session_id_length));
GUARD(s2n_stuffer_read_uint16(in, &challenge_length));
if (challenge_length > S2N_TLS_RANDOM_DATA_LEN) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
cipher_suites = s2n_stuffer_raw_read(in, cipher_suites_length);
notnull_check(cipher_suites);
GUARD(s2n_set_cipher_as_sslv2_server(conn, cipher_suites, cipher_suites_length / S2N_SSLv2_CIPHER_SUITE_LEN));
if (session_id_length > s2n_stuffer_data_available(in)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
if (session_id_length > 0 && session_id_length <= S2N_TLS_SESSION_ID_MAX_LEN) {
GUARD(s2n_stuffer_read_bytes(in, conn->session_id, session_id_length));
conn->session_id_len = (uint8_t) session_id_length;
} else {
GUARD(s2n_stuffer_skip_read(in, session_id_length));
}
struct s2n_blob b;
b.data = conn->secure.client_random;
b.size = S2N_TLS_RANDOM_DATA_LEN;
b.data += S2N_TLS_RANDOM_DATA_LEN - challenge_length;
b.size -= S2N_TLS_RANDOM_DATA_LEN - challenge_length;
GUARD(s2n_stuffer_read(in, &b));
conn->server->chosen_cert_chain = conn->config->cert_and_key_pairs;
GUARD(s2n_conn_set_handshake_type(conn));
return 0;
}
int s2n_client_extensions_recv(struct s2n_connection *conn, struct s2n_blob *extensions)
{
struct s2n_stuffer in;
GUARD(s2n_stuffer_init(&in, extensions));
GUARD(s2n_stuffer_write(&in, extensions));
while (s2n_stuffer_data_available(&in)) {
struct s2n_blob ext;
uint16_t extension_type, extension_size;
struct s2n_stuffer extension;
GUARD(s2n_stuffer_read_uint16(&in, &extension_type));
GUARD(s2n_stuffer_read_uint16(&in, &extension_size));
ext.size = extension_size;
lte_check(extension_size, s2n_stuffer_data_available(&in));
ext.data = s2n_stuffer_raw_read(&in, ext.size);
notnull_check(ext.data);
GUARD(s2n_stuffer_init(&extension, &ext));
GUARD(s2n_stuffer_write(&extension, &ext));
switch (extension_type) {
case TLS_EXTENSION_SERVER_NAME:
GUARD(s2n_recv_client_server_name(conn, &extension));
break;
case TLS_EXTENSION_SIGNATURE_ALGORITHMS:
GUARD(s2n_recv_client_signature_algorithms(conn, &extension, &conn->secure.conn_hash_alg, &conn->secure.conn_sig_alg));
break;
case TLS_EXTENSION_ALPN:
GUARD(s2n_recv_client_alpn(conn, &extension));
break;
case TLS_EXTENSION_STATUS_REQUEST:
GUARD(s2n_recv_client_status_request(conn, &extension));
break;
case TLS_EXTENSION_ELLIPTIC_CURVES:
GUARD(s2n_recv_client_elliptic_curves(conn, &extension));
break;
case TLS_EXTENSION_EC_POINT_FORMATS:
GUARD(s2n_recv_client_ec_point_formats(conn, &extension));
break;
case TLS_EXTENSION_RENEGOTIATION_INFO:
GUARD(s2n_recv_client_renegotiation_info(conn, &extension));
break;
case TLS_EXTENSION_SCT_LIST:
GUARD(s2n_recv_client_sct_list(conn, &extension));
break;
case TLS_EXTENSION_MAX_FRAG_LEN:
GUARD(s2n_recv_client_max_frag_len(conn, &extension));
break;
}
}
return 0;
}
int s2n_client_finished_recv(struct s2n_connection *conn)
{
uint8_t *our_version;
our_version = conn->handshake.client_finished;
uint8_t *their_version = s2n_stuffer_raw_read(&conn->handshake.io, S2N_TLS_FINISHED_LEN);
notnull_check(their_version);
if (!s2n_constant_time_equals(our_version, their_version, S2N_TLS_FINISHED_LEN)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
conn->handshake.next_state = SERVER_CHANGE_CIPHER_SPEC;
return 0;
}
int s2n_server_status_recv(struct s2n_connection *conn)
{
uint8_t type;
struct s2n_blob status = { .data = NULL, .size = 0 };
GUARD(s2n_stuffer_read_uint8(&conn->handshake.io, &type));
GUARD(s2n_stuffer_read_uint24(&conn->handshake.io, &status.size));
status.data = s2n_stuffer_raw_read(&conn->handshake.io, status.size);
notnull_check(status.data);
if (type == S2N_STATUS_REQUEST_OCSP) {
GUARD(s2n_alloc(&conn->status_response, status.size));
memcpy_check(conn->status_response.data, status.data, status.size);
conn->status_response.size = status.size;
}
return 0;
}
int s2n_choose_preferred_signature_hash_pair(struct s2n_stuffer *in, int pairs_available,
s2n_hash_algorithm *hash_alg_out, s2n_signature_algorithm *signature_alg_out)
{
uint8_t *their_hash_sig_pairs = s2n_stuffer_raw_read(in, pairs_available * 2);
notnull_check(their_hash_sig_pairs);
for(int our_hash_idx = 0; our_hash_idx < sizeof(s2n_preferred_hashes); our_hash_idx++) {
for(int their_sig_hash_idx = 0; their_sig_hash_idx < pairs_available; their_sig_hash_idx++){
uint8_t their_hash_alg = their_hash_sig_pairs[2 * their_sig_hash_idx];
uint8_t their_sig_alg = their_hash_sig_pairs[2 * their_sig_hash_idx + 1];
if(their_sig_alg == TLS_SIGNATURE_ALGORITHM_RSA && their_hash_alg == s2n_preferred_hashes[our_hash_idx]) {
*hash_alg_out = s2n_hash_tls_to_alg[their_hash_alg];
*signature_alg_out = their_sig_alg;
return 0;
}
}
}
S2N_ERROR(S2N_ERR_HASH_INVALID_ALGORITHM);
}
int s2n_recv_server_alpn(struct s2n_connection *conn, struct s2n_stuffer *extension)
{
uint16_t size_of_all;
GUARD(s2n_stuffer_read_uint16(extension, &size_of_all));
if (size_of_all > s2n_stuffer_data_available(extension) || size_of_all < 3) {
/* ignore invalid extension size */
return 0;
}
uint8_t protocol_len;
GUARD(s2n_stuffer_read_uint8(extension, &protocol_len));
uint8_t *protocol = s2n_stuffer_raw_read(extension, protocol_len);
notnull_check(protocol);
/* copy the first protocol name */
memcpy_check(conn->application_protocol, protocol, protocol_len);
conn->application_protocol[protocol_len] = '\0';
return 0;
}
int s2n_server_cert_recv(struct s2n_connection *conn)
{
uint32_t size_of_all_certificates;
GUARD(s2n_stuffer_read_uint24(&conn->handshake.io, &size_of_all_certificates));
S2N_ERROR_IF(size_of_all_certificates > s2n_stuffer_data_available(&conn->handshake.io) || size_of_all_certificates < 3, S2N_ERR_BAD_MESSAGE);
s2n_cert_public_key public_key;
GUARD(s2n_pkey_zero_init(&public_key));
s2n_cert_type cert_type;
struct s2n_blob cert_chain = {0};
cert_chain.data = s2n_stuffer_raw_read(&conn->handshake.io, size_of_all_certificates);
cert_chain.size = size_of_all_certificates;
S2N_ERROR_IF(s2n_x509_validator_validate_cert_chain(&conn->x509_validator, conn, cert_chain.data,
cert_chain.size, &cert_type, &public_key) != S2N_CERT_OK, S2N_ERR_CERT_UNTRUSTED);
s2n_authentication_method expected_auth_method = conn->secure.cipher_suite->auth_method;
switch (cert_type) {
case S2N_CERT_TYPE_RSA_SIGN:
if (expected_auth_method == S2N_AUTHENTICATION_RSA) {
break;
}
case S2N_CERT_TYPE_ECDSA_SIGN:
if (expected_auth_method == S2N_AUTHENTICATION_ECDSA) {
break;
}
default:
S2N_ERROR(S2N_ERR_CERT_TYPE_UNSUPPORTED);
}
conn->secure.client_cert_type = cert_type;
s2n_pkey_setup_for_type(&public_key, cert_type);
conn->secure.server_public_key = public_key;
return 0;
}
int s2n_server_status_recv(struct s2n_connection *conn)
{
uint8_t type;
struct s2n_blob status = { .data = NULL, .size = 0 };
GUARD(s2n_stuffer_read_uint8(&conn->handshake.io, &type));
GUARD(s2n_stuffer_read_uint24(&conn->handshake.io, &status.size));
status.data = s2n_stuffer_raw_read(&conn->handshake.io, status.size);
notnull_check(status.data);
if (type == S2N_STATUS_REQUEST_OCSP) {
GUARD(s2n_alloc(&conn->status_response, status.size));
memcpy_check(conn->status_response.data, status.data, status.size);
conn->status_response.size = status.size;
}
conn->handshake.next_state = SERVER_HELLO_DONE;
if (conn->pending.cipher_suite->key_exchange_alg->flags & S2N_KEY_EXCHANGE_EPH) {
conn->handshake.next_state = SERVER_KEY;
}
return 0;
}
static int s2n_recv_client_server_name(struct s2n_connection *conn, struct s2n_stuffer *extension)
{
uint16_t size_of_all;
uint8_t server_name_type;
uint16_t server_name_len;
uint8_t *server_name;
GUARD(s2n_stuffer_read_uint16(extension, &size_of_all));
if (size_of_all > s2n_stuffer_data_available(extension) || size_of_all < 3) {
/* the size of all server names is incorrect, ignore the extension */
return 0;
}
GUARD(s2n_stuffer_read_uint8(extension, &server_name_type));
if (server_name_type != 0) {
/* unknown server name type, ignore the extension */
return 0;
}
GUARD(s2n_stuffer_read_uint16(extension, &server_name_len));
if (server_name_len + 3 > size_of_all) {
/* the server name length is incorrect, ignore the extension */
return 0;
}
if (server_name_len > sizeof(conn->server_name) - 1) {
/* the server name is too long, ignore the extension */
return 0;
}
notnull_check(server_name = s2n_stuffer_raw_read(extension, server_name_len));
/* copy the first server name */
memcpy_check(conn->server_name, server_name, server_name_len);
return 0;
}
s2n_cert_validation_code s2n_x509_validator_validate_cert_chain(struct s2n_x509_validator *validator, struct s2n_connection *conn,
uint8_t *cert_chain_in, uint32_t cert_chain_len,
s2n_cert_type *cert_type, struct s2n_pkey *public_key_out) {
if (!validator->skip_cert_validation && !s2n_x509_trust_store_has_certs(validator->trust_store)) {
return S2N_CERT_ERR_UNTRUSTED;
}
DEFER_CLEANUP(X509_STORE_CTX *ctx = NULL, X509_STORE_CTX_free_pointer);
struct s2n_blob cert_chain_blob = {.data = cert_chain_in, .size = cert_chain_len};
DEFER_CLEANUP(struct s2n_stuffer cert_chain_in_stuffer = {{0}}, s2n_stuffer_free);
if (s2n_stuffer_init(&cert_chain_in_stuffer, &cert_chain_blob) < 0) {
return S2N_CERT_ERR_INVALID;
}
if (s2n_stuffer_write(&cert_chain_in_stuffer, &cert_chain_blob) < 0) {
return S2N_CERT_ERR_INVALID;
}
uint32_t certificate_count = 0;
X509 *server_cert = NULL;
DEFER_CLEANUP(struct s2n_pkey public_key = {{{0}}}, s2n_pkey_free);
s2n_pkey_zero_init(&public_key);
while (s2n_stuffer_data_available(&cert_chain_in_stuffer) && certificate_count < validator->max_chain_depth) {
uint32_t certificate_size = 0;
if (s2n_stuffer_read_uint24(&cert_chain_in_stuffer, &certificate_size) < 0) {
return S2N_CERT_ERR_INVALID;
}
if (certificate_size == 0 || certificate_size > s2n_stuffer_data_available(&cert_chain_in_stuffer)) {
return S2N_CERT_ERR_INVALID;
}
struct s2n_blob asn1cert = {0};
asn1cert.data = s2n_stuffer_raw_read(&cert_chain_in_stuffer, certificate_size);
asn1cert.size = certificate_size;
if (asn1cert.data == NULL) {
return S2N_CERT_ERR_INVALID;
}
const uint8_t *data = asn1cert.data;
if (!validator->skip_cert_validation) {
/* the cert is der encoded, just convert it. */
server_cert = d2i_X509(NULL, &data, asn1cert.size);
if (!server_cert) {
return S2N_CERT_ERR_INVALID;
}
/* add the cert to the chain. */
if (!sk_X509_push(validator->cert_chain, server_cert)) {
X509_free(server_cert);
return S2N_CERT_ERR_INVALID;
}
}
/* Pull the public key from the first certificate */
if (certificate_count == 0) {
if (s2n_asn1der_to_public_key_and_type(&public_key, cert_type, &asn1cert) < 0) {
return S2N_CERT_ERR_INVALID;
}
}
certificate_count++;
}
/* if this occurred we exceeded validator->max_chain_depth */
if (!validator->skip_cert_validation && s2n_stuffer_data_available(&cert_chain_in_stuffer)) {
return S2N_CERT_ERR_MAX_CHAIN_DEPTH_EXCEEDED;
}
if (certificate_count < 1) {
return S2N_CERT_ERR_INVALID;
}
if (!validator->skip_cert_validation) {
X509 *leaf = sk_X509_value(validator->cert_chain, 0);
if (!leaf) {
return S2N_CERT_ERR_INVALID;
}
if (conn->verify_host_fn && !s2n_verify_host_information(validator, conn, leaf)) {
return S2N_CERT_ERR_UNTRUSTED;
}
/* now that we have a chain, get the store and check against it. */
ctx = X509_STORE_CTX_new();
int op_code = X509_STORE_CTX_init(ctx, validator->trust_store->trust_store, leaf,
validator->cert_chain);
if (op_code <= 0) {
return S2N_CERT_ERR_INVALID;
}
X509_VERIFY_PARAM *param = X509_STORE_CTX_get0_param(ctx);
X509_VERIFY_PARAM_set_depth(param, validator->max_chain_depth);
uint64_t current_sys_time = 0;
conn->config->wall_clock(conn->config->sys_clock_ctx, ¤t_sys_time);
/* this wants seconds not nanoseconds */
time_t current_time = (time_t)(current_sys_time / 1000000000);
X509_STORE_CTX_set_time(ctx, 0, current_time);
op_code = X509_verify_cert(ctx);
if (op_code <= 0) {
return S2N_CERT_ERR_UNTRUSTED;
}
}
*public_key_out = public_key;
/* Reset the old struct, so we don't clean up public_key_out */
s2n_pkey_zero_init(&public_key);
return S2N_CERT_OK;
}
int main(int argc, char **argv) {
BEGIN_TEST();
EXPECT_SUCCESS(setenv("S2N_ENABLE_CLIENT_MODE", "1", 0));
/* Part 1 setup a client and server connection with everything they need for a key exchange */
struct s2n_connection *client_conn, *server_conn;
EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
EXPECT_NOT_NULL(server_conn = s2n_connection_new(S2N_SERVER));
struct s2n_config *server_config, *client_config;
client_config = s2n_fetch_unsafe_client_testing_config();
GUARD(s2n_connection_set_config(client_conn, client_config));
/* Part 1.1 setup server's keypair and the give the client the certificate */
char *cert_chain;
char *private_key;
char *client_chain;
EXPECT_NOT_NULL(cert_chain = malloc(S2N_MAX_TEST_PEM_SIZE));
EXPECT_NOT_NULL(private_key = malloc(S2N_MAX_TEST_PEM_SIZE));
EXPECT_NOT_NULL(client_chain = malloc(S2N_MAX_TEST_PEM_SIZE));
EXPECT_NOT_NULL(server_config = s2n_config_new());
EXPECT_SUCCESS(s2n_read_test_pem(S2N_RSA_2048_PKCS1_CERT_CHAIN, cert_chain, S2N_MAX_TEST_PEM_SIZE));
EXPECT_SUCCESS(s2n_read_test_pem(S2N_RSA_2048_PKCS1_KEY, private_key, S2N_MAX_TEST_PEM_SIZE));
EXPECT_SUCCESS(s2n_read_test_pem(S2N_RSA_2048_PKCS1_LEAF_CERT, client_chain, S2N_MAX_TEST_PEM_SIZE));
struct s2n_cert_chain_and_key *chain_and_key;
EXPECT_NOT_NULL(chain_and_key = s2n_cert_chain_and_key_new());
EXPECT_SUCCESS(s2n_cert_chain_and_key_load_pem(chain_and_key, cert_chain, private_key));
EXPECT_SUCCESS(s2n_config_add_cert_chain_and_key_to_store(server_config, chain_and_key));
EXPECT_SUCCESS(s2n_connection_set_config(server_conn, server_config));
GUARD(s2n_set_signature_hash_pair_from_preference_list(server_conn, &server_conn->handshake_params.client_sig_hash_algs, &server_conn->secure.conn_hash_alg, &server_conn->secure.conn_sig_alg));
DEFER_CLEANUP(struct s2n_stuffer certificate_in = {{0}}, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_alloc(&certificate_in, S2N_MAX_TEST_PEM_SIZE));
DEFER_CLEANUP(struct s2n_stuffer certificate_out = {{0}}, s2n_stuffer_free);
EXPECT_SUCCESS(s2n_stuffer_alloc(&certificate_out, S2N_MAX_TEST_PEM_SIZE));
struct s2n_blob temp_blob;
temp_blob.data = (uint8_t *) client_chain;
temp_blob.size = strlen(client_chain) + 1;
EXPECT_SUCCESS(s2n_stuffer_write(&certificate_in, &temp_blob));
EXPECT_SUCCESS(s2n_stuffer_certificate_from_pem(&certificate_in, &certificate_out));
temp_blob.size = s2n_stuffer_data_available(&certificate_out);
temp_blob.data = s2n_stuffer_raw_read(&certificate_out, temp_blob.size);
s2n_cert_type cert_type;
EXPECT_SUCCESS(s2n_asn1der_to_public_key_and_type(&client_conn->secure.server_public_key, &cert_type, &temp_blob));
server_conn->handshake_params.our_chain_and_key = chain_and_key;
EXPECT_SUCCESS(setup_connection(server_conn));
EXPECT_SUCCESS(setup_connection(client_conn));
#if S2N_LIBCRYPTO_SUPPORTS_CUSTOM_RAND
/* Read the seed from the RSP_FILE and create the DRBG for the test. Since the seed is the same (and prediction
* resistance is off) all calls to generate random data will return the same sequence. Thus the server always
* generates the same ECDHE point and KEM public key, the client does the same. */
FILE *kat_file = fopen(RSP_FILE_NAME, "r");
EXPECT_NOT_NULL(kat_file);
EXPECT_SUCCESS(s2n_alloc(&kat_entropy_blob, 48));
EXPECT_SUCCESS(ReadHex(kat_file, kat_entropy_blob.data, 48, "seed = "));
struct s2n_drbg drbg = {.entropy_generator = &s2n_entropy_generator};
s2n_stack_blob(personalization_string, 32, 32);
EXPECT_SUCCESS(s2n_drbg_instantiate(&drbg, &personalization_string, S2N_DANGEROUS_AES_256_CTR_NO_DF_NO_PR));
EXPECT_SUCCESS(s2n_set_private_drbg_for_test(drbg));
#endif
/* Part 2 server sends key first */
EXPECT_SUCCESS(s2n_server_key_send(server_conn));
/* Part 2.1 verify the results as best we can */
EXPECT_EQUAL(server_conn->handshake.io.write_cursor, SERVER_KEY_MESSAGE_LENGTH);
struct s2n_blob server_key_message = {.size = SERVER_KEY_MESSAGE_LENGTH, .data = s2n_stuffer_raw_read(&server_conn->handshake.io, SERVER_KEY_MESSAGE_LENGTH)};
#if S2N_LIBCRYPTO_SUPPORTS_CUSTOM_RAND
/* Part 2.1.1 if we're running in known answer mode check the server's key exchange message matches the expected value */
uint8_t expected_server_key_message[SERVER_KEY_MESSAGE_LENGTH];
EXPECT_SUCCESS(ReadHex(kat_file, expected_server_key_message, SERVER_KEY_MESSAGE_LENGTH, "expected_server_key_exchange = "));
EXPECT_BYTEARRAY_EQUAL(expected_server_key_message, server_key_message.data, SERVER_KEY_MESSAGE_LENGTH);
#endif
/* Part 2.2 copy server's message to the client's stuffer */
s2n_stuffer_write(&client_conn->handshake.io, &server_key_message);
/* Part 3 client recvs the server's key and sends the client key exchange message */
EXPECT_SUCCESS(s2n_server_key_recv(client_conn));
EXPECT_SUCCESS(s2n_client_key_send(client_conn));
/* Part 3.1 verify the results as best we can */
EXPECT_EQUAL(client_conn->handshake.io.write_cursor - client_conn->handshake.io.read_cursor, CLIENT_KEY_MESSAGE_LENGTH);
struct s2n_blob client_key_message = {.size = CLIENT_KEY_MESSAGE_LENGTH, .data = s2n_stuffer_raw_read(&client_conn->handshake.io, CLIENT_KEY_MESSAGE_LENGTH)};
#if S2N_LIBCRYPTO_SUPPORTS_CUSTOM_RAND
/* Part 3.1.1 if we're running in known answer mode check the client's key exchange message matches the expected value */
uint8_t expected_client_key_message[CLIENT_KEY_MESSAGE_LENGTH];
EXPECT_SUCCESS(ReadHex(kat_file, expected_client_key_message, CLIENT_KEY_MESSAGE_LENGTH, "expected_client_key_exchange = "));
EXPECT_BYTEARRAY_EQUAL(expected_client_key_message, client_key_message.data, CLIENT_KEY_MESSAGE_LENGTH);
#endif
/* Part 3.2 copy the client's message back to the server's stuffer */
s2n_stuffer_write(&server_conn->handshake.io, &client_key_message);
/* Part 4 server receives the client's message */
EXPECT_SUCCESS(s2n_client_key_recv(server_conn));
/* Part 4.1 verify results as best we can, the client and server should at least have the same master secret */
EXPECT_BYTEARRAY_EQUAL(server_conn->secure.master_secret, client_conn->secure.master_secret, S2N_TLS_SECRET_LEN);
#if S2N_LIBCRYPTO_SUPPORTS_CUSTOM_RAND
/* Part 4.1.1 if we're running in known answer mode check that both the client and server got the expected master secret
* from the RSP_FILE */
uint8_t expected_master_secret[S2N_TLS_SECRET_LEN];
EXPECT_SUCCESS(ReadHex(kat_file, expected_master_secret, S2N_TLS_SECRET_LEN, "expected_master_secret = "));
EXPECT_BYTEARRAY_EQUAL(expected_master_secret, client_conn->secure.master_secret, S2N_TLS_SECRET_LEN);
EXPECT_BYTEARRAY_EQUAL(expected_master_secret, server_conn->secure.master_secret, S2N_TLS_SECRET_LEN);
#endif
EXPECT_SUCCESS(s2n_cert_chain_and_key_free(chain_and_key));
EXPECT_SUCCESS(s2n_connection_free(client_conn));
EXPECT_SUCCESS(s2n_connection_free(server_conn));
EXPECT_SUCCESS(s2n_config_free(server_config));
free(cert_chain);
free(client_chain);
free(private_key);
#if S2N_LIBCRYPTO_SUPPORTS_CUSTOM_RAND
/* Extra cleanup needed for the known answer test */
fclose(kat_file);
#endif
END_TEST();
}
int s2n_server_hello_recv(struct s2n_connection *conn)
{
struct s2n_stuffer *in = &conn->handshake.io;
uint8_t compression_method;
uint8_t session_id[S2N_TLS_SESSION_ID_LEN];
uint8_t session_id_len;
uint16_t extensions_size;
uint8_t protocol_version[S2N_TLS_PROTOCOL_VERSION_LEN];
GUARD(s2n_stuffer_read_bytes(in, protocol_version, S2N_TLS_PROTOCOL_VERSION_LEN));
conn->server_protocol_version = (protocol_version[0] * 10) + protocol_version[1];
if (conn->server_protocol_version > conn->actual_protocol_version) {
GUARD(s2n_queue_reader_unsupported_protocol_version_alert(conn));
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
conn->actual_protocol_version = conn->server_protocol_version;
conn->actual_protocol_version_established = 1;
/* Verify that the protocol version is sane */
if (conn->actual_protocol_version < S2N_SSLv3 || conn->actual_protocol_version > S2N_TLS12) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
conn->pending.signature_digest_alg = S2N_HASH_MD5_SHA1;
if (conn->actual_protocol_version == S2N_TLS12) {
conn->pending.signature_digest_alg = S2N_HASH_SHA1;
}
GUARD(s2n_stuffer_read_bytes(in, conn->pending.server_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_stuffer_read_uint8(in, &session_id_len));
if (session_id_len > S2N_TLS_SESSION_ID_LEN) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
GUARD(s2n_stuffer_read_bytes(in, session_id, session_id_len));
uint8_t *cipher_suite_wire = s2n_stuffer_raw_read(in, S2N_TLS_CIPHER_SUITE_LEN);
notnull_check(cipher_suite_wire);
GUARD(s2n_set_cipher_as_client(conn, cipher_suite_wire));
GUARD(s2n_stuffer_read_uint8(in, &compression_method));
if (compression_method != S2N_TLS_COMPRESSION_METHOD_NULL) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
if (s2n_stuffer_data_available(in) < 2) {
GUARD(s2n_conn_set_handshake_type(conn));
/* No extensions */
return 0;
}
GUARD(s2n_stuffer_read_uint16(in, &extensions_size));
if (extensions_size > s2n_stuffer_data_available(in)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
struct s2n_blob extensions;
extensions.size = extensions_size;
extensions.data = s2n_stuffer_raw_read(in, extensions.size);
GUARD(s2n_server_extensions_recv(conn, &extensions));
GUARD(s2n_conn_set_handshake_type(conn));
return 0;
}
static int s2n_ecdhe_server_key_recv(struct s2n_connection *conn)
{
struct s2n_hash_state signature_hash;
struct s2n_stuffer *in = &conn->handshake.io;
struct s2n_blob ecdhparams;
struct s2n_blob signature;
uint16_t signature_length;
/* Read server ECDH params and calculate their hash */
GUARD(s2n_ecc_read_ecc_params(&conn->secure.server_ecc_params, in, &ecdhparams));
GUARD(s2n_hash_init(&signature_hash, conn->secure.signature_digest_alg));
if (conn->actual_protocol_version == S2N_TLS12) {
uint8_t hash_algorithm;
uint8_t signature_algorithm;
GUARD(s2n_stuffer_read_uint8(in, &hash_algorithm));
GUARD(s2n_stuffer_read_uint8(in, &signature_algorithm));
if (signature_algorithm != TLS_SIGNATURE_ALGORITHM_RSA) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
switch(hash_algorithm) {
case TLS_HASH_ALGORITHM_MD5:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_MD5));
break;
case TLS_HASH_ALGORITHM_SHA1:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA1));
break;
case TLS_HASH_ALGORITHM_SHA224:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA224));
break;
case TLS_HASH_ALGORITHM_SHA256:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA256));
break;
case TLS_HASH_ALGORITHM_SHA384:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA384));
break;
case TLS_HASH_ALGORITHM_SHA512:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA512));
break;
default:
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
}
GUARD(s2n_hash_update(&signature_hash, conn->secure.client_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, conn->secure.server_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, ecdhparams.data, ecdhparams.size));
/* Verify the signature */
GUARD(s2n_stuffer_read_uint16(in, &signature_length));
signature.size = signature_length;
signature.data = s2n_stuffer_raw_read(in, signature.size);
notnull_check(signature.data);
gt_check(signature_length, 0);
if (s2n_rsa_verify(&conn->secure.server_rsa_public_key, &signature_hash, &signature) < 0) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
/* We don't need the key any more, so free it */
GUARD(s2n_rsa_public_key_free(&conn->secure.server_rsa_public_key));
return 0;
}
static int s2n_dhe_server_key_recv(struct s2n_connection *conn)
{
struct s2n_hash_state signature_hash;
struct s2n_stuffer *in = &conn->handshake.io;
struct s2n_blob p, g, Ys, serverDHparams, signature;
uint16_t p_length;
uint16_t g_length;
uint16_t Ys_length;
uint16_t signature_length;
/* Keep a copy to the start of the whole structure for the signature check */
serverDHparams.data = s2n_stuffer_raw_read(in, 0);
notnull_check(serverDHparams.data);
/* Read each of the three elements in */
GUARD(s2n_stuffer_read_uint16(in, &p_length));
p.size = p_length;
p.data = s2n_stuffer_raw_read(in, p.size);
notnull_check(p.data);
GUARD(s2n_stuffer_read_uint16(in, &g_length));
g.size = g_length;
g.data = s2n_stuffer_raw_read(in, g.size);
notnull_check(g.data);
GUARD(s2n_stuffer_read_uint16(in, &Ys_length));
Ys.size = Ys_length;
Ys.data = s2n_stuffer_raw_read(in, Ys.size);
notnull_check(Ys.data);
/* Now we know the total size of the structure */
serverDHparams.size = 2 + p_length + 2 + g_length + 2 + Ys_length;
GUARD(s2n_hash_init(&signature_hash, conn->secure.signature_digest_alg));
if (conn->actual_protocol_version == S2N_TLS12) {
uint8_t hash_algorithm;
uint8_t signature_algorithm;
GUARD(s2n_stuffer_read_uint8(in, &hash_algorithm));
GUARD(s2n_stuffer_read_uint8(in, &signature_algorithm));
if (signature_algorithm != TLS_SIGNATURE_ALGORITHM_RSA) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
switch(hash_algorithm) {
case TLS_HASH_ALGORITHM_MD5:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_MD5));
break;
case TLS_HASH_ALGORITHM_SHA1:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA1));
break;
case TLS_HASH_ALGORITHM_SHA224:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA224));
break;
case TLS_HASH_ALGORITHM_SHA256:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA256));
break;
case TLS_HASH_ALGORITHM_SHA384:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA384));
break;
case TLS_HASH_ALGORITHM_SHA512:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA512));
break;
default:
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
}
GUARD(s2n_hash_update(&signature_hash, conn->secure.client_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, conn->secure.server_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, serverDHparams.data, serverDHparams.size));
GUARD(s2n_stuffer_read_uint16(in, &signature_length));
signature.size = signature_length;
signature.data = s2n_stuffer_raw_read(in, signature.size);
notnull_check(signature.data);
gt_check(signature_length, 0);
if (s2n_rsa_verify(&conn->secure.server_rsa_public_key, &signature_hash, &signature) < 0) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
/* We don't need the key any more, so free it */
GUARD(s2n_rsa_public_key_free(&conn->secure.server_rsa_public_key));
/* Copy the DH details */
GUARD(s2n_dh_p_g_Ys_to_dh_params(&conn->secure.server_dh_params, &p, &g, &Ys));
return 0;
}
int main(int argc, char **argv)
{
struct s2n_stuffer certificate_in, certificate_out;
struct s2n_stuffer dhparams_in, dhparams_out;
struct s2n_stuffer rsa_key_in, rsa_key_out;
struct s2n_blob b;
BEGIN_TEST();
EXPECT_SUCCESS(s2n_stuffer_alloc(&certificate_in, sizeof(certificate)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&certificate_out, sizeof(certificate)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&dhparams_in, sizeof(dhparams)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&dhparams_out, sizeof(dhparams)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&rsa_key_in, sizeof(private_key)));
EXPECT_SUCCESS(s2n_stuffer_alloc(&rsa_key_out, sizeof(private_key)));
b.data = certificate;
b.size = sizeof(certificate);
EXPECT_SUCCESS(s2n_stuffer_write(&certificate_in, &b));
b.data = private_key;
b.size = sizeof(private_key);
EXPECT_SUCCESS(s2n_stuffer_write(&rsa_key_in, &b));
b.data = dhparams;
b.size = sizeof(dhparams);
EXPECT_SUCCESS(s2n_stuffer_write(&dhparams_in, &b));
EXPECT_SUCCESS(s2n_stuffer_certificate_from_pem(&certificate_in, &certificate_out));
EXPECT_SUCCESS(s2n_stuffer_rsa_private_key_from_pem(&rsa_key_in, &rsa_key_out));
EXPECT_SUCCESS(s2n_stuffer_dhparams_from_pem(&dhparams_in, &dhparams_out));
struct s2n_rsa_private_key priv_key;
struct s2n_rsa_public_key pub_key;
b.size = s2n_stuffer_data_available(&certificate_out);
b.data = s2n_stuffer_raw_read(&certificate_out, b.size);
EXPECT_SUCCESS(s2n_asn1der_to_rsa_public_key(&pub_key, &b));
b.size = s2n_stuffer_data_available(&rsa_key_out);
b.data = s2n_stuffer_raw_read(&rsa_key_out, b.size);
EXPECT_SUCCESS(s2n_asn1der_to_rsa_private_key(&priv_key, &b));
EXPECT_SUCCESS(s2n_rsa_keys_match(&pub_key, &priv_key));
struct s2n_connection *conn;
EXPECT_NOT_NULL(conn = s2n_connection_new(S2N_SERVER));
EXPECT_SUCCESS(s2n_config_add_cert_chain_and_key(conn->config, (char *)chain, (char *)private_key));
struct s2n_dh_params dh_params;
b.size = s2n_stuffer_data_available(&dhparams_out);
b.data = s2n_stuffer_raw_read(&dhparams_out, b.size);
EXPECT_SUCCESS(s2n_pkcs3_to_dh_params(&dh_params, &b));
EXPECT_SUCCESS(s2n_config_add_dhparams(conn->config, (char *)dhparams));
/* Try signing and verification with RSA */
uint8_t inputpad[] = "Hello world!";
struct s2n_blob signature;
struct s2n_hash_state tls10_one, tls10_two, tls12_one, tls12_two;
EXPECT_SUCCESS(s2n_hash_init(&tls10_one, S2N_HASH_MD5_SHA1));
EXPECT_SUCCESS(s2n_hash_init(&tls10_two, S2N_HASH_MD5_SHA1));
EXPECT_SUCCESS(s2n_hash_init(&tls12_one, S2N_HASH_SHA1));
EXPECT_SUCCESS(s2n_hash_init(&tls12_two, S2N_HASH_SHA1));
EXPECT_SUCCESS(s2n_alloc(&signature, s2n_rsa_public_encrypted_size(&pub_key)));
EXPECT_SUCCESS(s2n_hash_update(&tls10_one, inputpad, sizeof(inputpad)));
EXPECT_SUCCESS(s2n_hash_update(&tls10_two, inputpad, sizeof(inputpad)));
EXPECT_SUCCESS(s2n_rsa_sign(&priv_key, &tls10_one, &signature));
EXPECT_SUCCESS(s2n_rsa_verify(&pub_key, &tls10_two, &signature));
EXPECT_SUCCESS(s2n_hash_update(&tls12_one, inputpad, sizeof(inputpad)));
EXPECT_SUCCESS(s2n_hash_update(&tls12_two, inputpad, sizeof(inputpad)));
EXPECT_SUCCESS(s2n_rsa_sign(&priv_key, &tls12_one, &signature));
EXPECT_SUCCESS(s2n_rsa_verify(&pub_key, &tls12_two, &signature));
EXPECT_SUCCESS(s2n_dh_params_free(&dh_params));
EXPECT_SUCCESS(s2n_rsa_private_key_free(&priv_key));
EXPECT_SUCCESS(s2n_rsa_public_key_free(&pub_key));
EXPECT_SUCCESS(s2n_config_free_dhparams(conn->config));
EXPECT_SUCCESS(s2n_config_free_cert_chain_and_key(conn->config));
EXPECT_SUCCESS(s2n_connection_free(conn));
EXPECT_SUCCESS(s2n_free(&signature));
EXPECT_SUCCESS(s2n_stuffer_free(&certificate_in));
EXPECT_SUCCESS(s2n_stuffer_free(&certificate_out));
EXPECT_SUCCESS(s2n_stuffer_free(&dhparams_in));
EXPECT_SUCCESS(s2n_stuffer_free(&dhparams_out));
EXPECT_SUCCESS(s2n_stuffer_free(&rsa_key_in));
EXPECT_SUCCESS(s2n_stuffer_free(&rsa_key_out));
END_TEST();
}
int s2n_config_free_cert_chain_and_key(struct s2n_config *config)
{
struct s2n_blob b = {
.data = (uint8_t *) config->cert_and_key_pairs,
.size = sizeof(struct s2n_cert_chain_and_key)
};
/* If there were cert and key pairs set, walk the chain and free the certs */
if (config->cert_and_key_pairs) {
struct s2n_cert_chain *node = config->cert_and_key_pairs->head;
while (node) {
struct s2n_blob n = {
.data = (uint8_t *)node,
.size = sizeof(struct s2n_cert_chain)
};
/* Free the cert */
GUARD(s2n_free(&node->cert));
/* Advance to next */
node = node->next;
/* Free the node */
GUARD(s2n_free(&n));
}
GUARD(s2n_rsa_private_key_free(&config->cert_and_key_pairs->private_key));
GUARD(s2n_free(&config->cert_and_key_pairs->ocsp_status));
}
GUARD(s2n_free(&b));
return 0;
}
int s2n_config_free_dhparams(struct s2n_config *config)
{
struct s2n_blob b = {
.data = (uint8_t *) config->dhparams,
.size = sizeof(struct s2n_dh_params)
};
if (config->dhparams) {
GUARD(s2n_dh_params_free(config->dhparams));
}
GUARD(s2n_free(&b));
return 0;
}
int s2n_config_free(struct s2n_config *config)
{
struct s2n_blob b = {.data = (uint8_t *) config,.size = sizeof(struct s2n_config) };
GUARD(s2n_config_free_cert_chain_and_key(config));
GUARD(s2n_config_free_dhparams(config));
GUARD(s2n_free(&config->application_protocols));
GUARD(s2n_free(&b));
return 0;
}
int s2n_config_set_cipher_preferences(struct s2n_config *config, const char *version)
{
for (int i = 0; selection[i].version != NULL; i++) {
if (!strcasecmp(version, selection[i].version)) {
config->cipher_preferences = selection[i].preferences;
return 0;
}
}
s2n_errno = S2N_ERR_INVALID_CIPHER_PREFERENCES;
return -1;
}
int s2n_config_set_protocol_preferences(struct s2n_config *config, const char * const *protocols, int protocol_count)
{
struct s2n_stuffer protocol_stuffer;
GUARD(s2n_free(&config->application_protocols));
if (protocols == NULL || protocol_count == 0) {
/* NULL value indicates no prference, so nothing to do */
return 0;
}
GUARD(s2n_stuffer_growable_alloc(&protocol_stuffer, 256));
for (int i = 0; i < protocol_count; i++) {
size_t length = strlen(protocols[i]);
uint8_t protocol[255];
if (length > 255 || (s2n_stuffer_data_available(&protocol_stuffer) + length + 1) > 65535) {
return S2N_ERR_APPLICATION_PROTOCOL_TOO_LONG;
}
memcpy_check(protocol, protocols[i], length);
GUARD(s2n_stuffer_write_uint8(&protocol_stuffer, length));
GUARD(s2n_stuffer_write_bytes(&protocol_stuffer, protocol, length));
}
uint32_t size = s2n_stuffer_data_available(&protocol_stuffer);
/* config->application_protocols blob now owns this data */
config->application_protocols.size = size;
config->application_protocols.data = s2n_stuffer_raw_read(&protocol_stuffer, size);
notnull_check(config->application_protocols.data);
return 0;
}
int s2n_config_set_status_request_type(struct s2n_config *config, s2n_status_request_type type)
{
config->status_request_type = type;
return 0;
}
int s2n_config_add_cert_chain_and_key_with_status(struct s2n_config *config,
char *cert_chain_pem, char *private_key_pem, const uint8_t *status, uint32_t length)
{
struct s2n_stuffer chain_in_stuffer, cert_out_stuffer, key_in_stuffer, key_out_stuffer;
struct s2n_blob key_blob;
struct s2n_blob mem;
/* Allocate the memory for the chain and key struct */
GUARD(s2n_alloc(&mem, sizeof(struct s2n_cert_chain_and_key)));
config->cert_and_key_pairs = (struct s2n_cert_chain_and_key *)(void *)mem.data;
config->cert_and_key_pairs->ocsp_status.data = NULL;
config->cert_and_key_pairs->ocsp_status.size = 0;
/* Put the private key pem in a stuffer */
GUARD(s2n_stuffer_alloc_ro_from_string(&key_in_stuffer, private_key_pem));
GUARD(s2n_stuffer_growable_alloc(&key_out_stuffer, strlen(private_key_pem)));
/* Convert pem to asn1 and asn1 to the private key */
GUARD(s2n_stuffer_rsa_private_key_from_pem(&key_in_stuffer, &key_out_stuffer));
GUARD(s2n_stuffer_free(&key_in_stuffer));
key_blob.size = s2n_stuffer_data_available(&key_out_stuffer);
key_blob.data = s2n_stuffer_raw_read(&key_out_stuffer, key_blob.size);
notnull_check(key_blob.data);
GUARD(s2n_asn1der_to_rsa_private_key(&config->cert_and_key_pairs->private_key, &key_blob));
GUARD(s2n_stuffer_free(&key_out_stuffer));
/* Turn the chain into a stuffer */
GUARD(s2n_stuffer_alloc_ro_from_string(&chain_in_stuffer, cert_chain_pem));
GUARD(s2n_stuffer_growable_alloc(&cert_out_stuffer, 2048));
struct s2n_cert_chain **insert = &config->cert_and_key_pairs->head;
uint32_t chain_size = 0;
do {
struct s2n_cert_chain *new_node;
if (s2n_stuffer_certificate_from_pem(&chain_in_stuffer, &cert_out_stuffer) < 0) {
if (chain_size == 0) {
S2N_ERROR(S2N_ERR_NO_CERTIFICATE_IN_PEM);
}
break;
}
GUARD(s2n_alloc(&mem, sizeof(struct s2n_cert_chain)));
new_node = (struct s2n_cert_chain *)(void *)mem.data;
GUARD(s2n_alloc(&new_node->cert, s2n_stuffer_data_available(&cert_out_stuffer)));
GUARD(s2n_stuffer_read(&cert_out_stuffer, &new_node->cert));
/* Additional 3 bytes for the length field in the protocol */
chain_size += new_node->cert.size + 3;
new_node->next = NULL;
*insert = new_node;
insert = &new_node->next;
} while (s2n_stuffer_data_available(&chain_in_stuffer));
GUARD(s2n_stuffer_free(&chain_in_stuffer));
GUARD(s2n_stuffer_free(&cert_out_stuffer));
config->cert_and_key_pairs->chain_size = chain_size;
if (status && length > 0) {
GUARD(s2n_alloc(&config->cert_and_key_pairs->ocsp_status, length));
memcpy_check(config->cert_and_key_pairs->ocsp_status.data, status, length);
}
return 0;
}
int s2n_config_add_cert_chain_and_key(struct s2n_config *config, char *cert_chain_pem, char *private_key_pem)
{
GUARD(s2n_config_add_cert_chain_and_key_with_status(config, cert_chain_pem, private_key_pem, NULL, 0));
return 0;
}
int s2n_config_add_dhparams(struct s2n_config *config, char *dhparams_pem)
{
struct s2n_stuffer dhparams_in_stuffer, dhparams_out_stuffer;
struct s2n_blob dhparams_blob;
struct s2n_blob mem;
/* Allocate the memory for the chain and key struct */
GUARD(s2n_alloc(&mem, sizeof(struct s2n_dh_params)));
config->dhparams = (struct s2n_dh_params *)(void *)mem.data;
GUARD(s2n_stuffer_alloc_ro_from_string(&dhparams_in_stuffer, dhparams_pem));
GUARD(s2n_stuffer_growable_alloc(&dhparams_out_stuffer, strlen(dhparams_pem)));
/* Convert pem to asn1 and asn1 to the private key */
GUARD(s2n_stuffer_dhparams_from_pem(&dhparams_in_stuffer, &dhparams_out_stuffer));
GUARD(s2n_stuffer_free(&dhparams_in_stuffer));
dhparams_blob.size = s2n_stuffer_data_available(&dhparams_out_stuffer);
dhparams_blob.data = s2n_stuffer_raw_read(&dhparams_out_stuffer, dhparams_blob.size);
notnull_check(dhparams_blob.data);
GUARD(s2n_pkcs3_to_dh_params(config->dhparams, &dhparams_blob));
GUARD(s2n_free(&dhparams_blob));
return 0;
}
int s2n_config_set_nanoseconds_since_epoch_callback(struct s2n_config *config, int (*nanoseconds_since_epoch)(void *, uint64_t *), void * data)
{
notnull_check(nanoseconds_since_epoch);
config->nanoseconds_since_epoch = nanoseconds_since_epoch;
config->data_for_nanoseconds_since_epoch = data;
return 0;
}
static int s2n_recv_client_alpn(struct s2n_connection *conn, struct s2n_stuffer *extension)
{
uint16_t size_of_all;
struct s2n_stuffer client_protos;
struct s2n_stuffer server_protos;
if (!conn->config->application_protocols.size) {
/* No protocols configured, nothing to do */
return 0;
}
GUARD(s2n_stuffer_read_uint16(extension, &size_of_all));
if (size_of_all > s2n_stuffer_data_available(extension) || size_of_all < 3) {
/* Malformed length, ignore the extension */
return 0;
}
struct s2n_blob application_protocols = {
.data = s2n_stuffer_raw_read(extension, size_of_all),
.size = size_of_all
};
notnull_check(application_protocols.data);
/* Find a matching protocol */
GUARD(s2n_stuffer_init(&client_protos, &application_protocols));
GUARD(s2n_stuffer_write(&client_protos, &application_protocols));
GUARD(s2n_stuffer_init(&server_protos, &conn->config->application_protocols));
GUARD(s2n_stuffer_write(&server_protos, &conn->config->application_protocols));
while (s2n_stuffer_data_available(&server_protos)) {
uint8_t length;
uint8_t protocol[255];
GUARD(s2n_stuffer_read_uint8(&server_protos, &length));
GUARD(s2n_stuffer_read_bytes(&server_protos, protocol, length));
while (s2n_stuffer_data_available(&client_protos)) {
uint8_t client_length;
GUARD(s2n_stuffer_read_uint8(&client_protos, &client_length));
if (client_length > s2n_stuffer_data_available(&client_protos)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
if (client_length != length) {
GUARD(s2n_stuffer_skip_read(&client_protos, client_length));
} else {
uint8_t client_protocol[255];
GUARD(s2n_stuffer_read_bytes(&client_protos, client_protocol, client_length));
if (memcmp(client_protocol, protocol, client_length) == 0) {
memcpy_check(conn->application_protocol, client_protocol, client_length);
conn->application_protocol[client_length] = '\0';
return 0;
}
}
}
GUARD(s2n_stuffer_reread(&client_protos));
}
S2N_ERROR(S2N_ERR_NO_APPLICATION_PROTOCOL);
}
static int s2n_recv_client_status_request(struct s2n_connection *conn, struct s2n_stuffer *extension)
{
if (s2n_stuffer_data_available(extension) < 5) {
/* Malformed length, ignore the extension */
return 0;
}
uint8_t type;
GUARD(s2n_stuffer_read_uint8(extension, &type));
if (type != (uint8_t) S2N_STATUS_REQUEST_OCSP) {
/* We only support OCSP (type 1), ignore the extension */
return 0;
}
conn->status_type = (s2n_status_request_type) type;
return 0;
}
static int s2n_recv_client_elliptic_curves(struct s2n_connection *conn, struct s2n_stuffer *extension)
{
uint16_t size_of_all;
struct s2n_blob proposed_curves;
GUARD(s2n_stuffer_read_uint16(extension, &size_of_all));
if (size_of_all > s2n_stuffer_data_available(extension) || size_of_all % 2) {
/* Malformed length, ignore the extension */
return 0;
}
proposed_curves.size = size_of_all;
proposed_curves.data = s2n_stuffer_raw_read(extension, proposed_curves.size);
notnull_check(proposed_curves.data);
if (s2n_ecc_find_supported_curve(&proposed_curves, &conn->secure.server_ecc_params.negotiated_curve) != 0) {
/* Can't agree on a curve, ECC is not allowed. Return success to proceed with the handshake. */
conn->secure.server_ecc_params.negotiated_curve = NULL;
}
return 0;
}
static int s2n_prf(struct s2n_connection *conn, struct s2n_blob *secret, struct s2n_blob *label, struct s2n_blob *seed_a,
struct s2n_blob *seed_b, struct s2n_blob *seed_c, struct s2n_blob *out)
{
/* seed_a is always required, seed_b is optional, if seed_c is provided seed_b must also be provided */
S2N_ERROR_IF(seed_a == NULL, S2N_ERR_PRF_INVALID_SEED);
S2N_ERROR_IF(seed_b == NULL && seed_c != NULL, S2N_ERR_PRF_INVALID_SEED);
if (conn->actual_protocol_version == S2N_SSLv3) {
return s2n_sslv3_prf(&conn->prf_space, secret, seed_a, seed_b, seed_c, out);
}
/* We zero the out blob because p_hash works by XOR'ing with the existing
* buffer. This is a little convoluted but means we can avoid dynamic memory
* allocation. When we call p_hash once (in the TLS1.2 case) it will produce
* the right values. When we call it twice in the regular case, the two
* outputs will be XORd just ass the TLS 1.0 and 1.1 RFCs require.
*/
GUARD(s2n_blob_zero(out));
/* Ensure that p_hash_hmac_impl is set, as it may have been reset for prf_space on s2n_connection_wipe.
* When in FIPS mode, the EVP API's must be used for the p_hash HMAC.
*/
conn->prf_space.tls.p_hash_hmac_impl = s2n_is_in_fips_mode() ? &s2n_evp_hmac : &s2n_hmac;
if (conn->actual_protocol_version == S2N_TLS12) {
return s2n_p_hash(&conn->prf_space, conn->secure.cipher_suite->tls12_prf_alg, secret, label, seed_a, seed_b,
seed_c, out);
}
struct s2n_blob half_secret = {.data = secret->data,.size = (secret->size + 1) / 2 };
GUARD(s2n_p_hash(&conn->prf_space, S2N_HMAC_MD5, &half_secret, label, seed_a, seed_b, seed_c, out));
half_secret.data += secret->size - half_secret.size;
GUARD(s2n_p_hash(&conn->prf_space, S2N_HMAC_SHA1, &half_secret, label, seed_a, seed_b, seed_c, out));
return 0;
}
int s2n_tls_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret)
{
struct s2n_blob client_random = {.size = sizeof(conn->secure.client_random), .data = conn->secure.client_random};
struct s2n_blob server_random = {.size = sizeof(conn->secure.server_random), .data = conn->secure.server_random};
struct s2n_blob master_secret = {.size = sizeof(conn->secure.master_secret), .data = conn->secure.master_secret};
uint8_t master_secret_label[] = "master secret";
struct s2n_blob label = {.size = sizeof(master_secret_label) - 1, .data = master_secret_label};
return s2n_prf(conn, premaster_secret, &label, &client_random, &server_random, NULL, &master_secret);
}
int s2n_hybrid_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret)
{
struct s2n_blob client_random = {.size = sizeof(conn->secure.client_random), .data = conn->secure.client_random};
struct s2n_blob server_random = {.size = sizeof(conn->secure.server_random), .data = conn->secure.server_random};
struct s2n_blob master_secret = {.size = sizeof(conn->secure.master_secret), .data = conn->secure.master_secret};
uint8_t master_secret_label[] = "hybrid master secret";
struct s2n_blob label = {.size = sizeof(master_secret_label) - 1, .data = master_secret_label};
return s2n_prf(conn, premaster_secret, &label, &client_random, &server_random, &conn->secure.client_key_exchange_message, &master_secret);
}
static int s2n_sslv3_finished(struct s2n_connection *conn, uint8_t prefix[4], struct s2n_hash_state *md5, struct s2n_hash_state *sha1, uint8_t * out)
{
uint8_t xorpad1[48] =
{ 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
};
uint8_t xorpad2[48] =
{ 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
};
uint8_t *md5_digest = out;
uint8_t *sha_digest = out + MD5_DIGEST_LENGTH;
lte_check(MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, sizeof(conn->handshake.client_finished));
GUARD(s2n_hash_update(md5, prefix, 4));
GUARD(s2n_hash_update(md5, conn->secure.master_secret, sizeof(conn->secure.master_secret)));
GUARD(s2n_hash_update(md5, xorpad1, 48));
GUARD(s2n_hash_digest(md5, md5_digest, MD5_DIGEST_LENGTH));
GUARD(s2n_hash_reset(md5));
GUARD(s2n_hash_update(md5, conn->secure.master_secret, sizeof(conn->secure.master_secret)));
GUARD(s2n_hash_update(md5, xorpad2, 48));
GUARD(s2n_hash_update(md5, md5_digest, MD5_DIGEST_LENGTH));
GUARD(s2n_hash_digest(md5, md5_digest, MD5_DIGEST_LENGTH));
GUARD(s2n_hash_reset(md5));
GUARD(s2n_hash_update(sha1, prefix, 4));
GUARD(s2n_hash_update(sha1, conn->secure.master_secret, sizeof(conn->secure.master_secret)));
GUARD(s2n_hash_update(sha1, xorpad1, 40));
GUARD(s2n_hash_digest(sha1, sha_digest, SHA_DIGEST_LENGTH));
GUARD(s2n_hash_reset(sha1));
GUARD(s2n_hash_update(sha1, conn->secure.master_secret, sizeof(conn->secure.master_secret)));
GUARD(s2n_hash_update(sha1, xorpad2, 40));
GUARD(s2n_hash_update(sha1, sha_digest, SHA_DIGEST_LENGTH));
GUARD(s2n_hash_digest(sha1, sha_digest, SHA_DIGEST_LENGTH));
GUARD(s2n_hash_reset(sha1));
return 0;
}
static int s2n_sslv3_client_finished(struct s2n_connection *conn)
{
uint8_t prefix[4] = { 0x43, 0x4c, 0x4e, 0x54 };
lte_check(MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, sizeof(conn->handshake.client_finished));
GUARD(s2n_hash_copy(&conn->handshake.prf_md5_hash_copy, &conn->handshake.md5));
GUARD(s2n_hash_copy(&conn->handshake.prf_sha1_hash_copy, &conn->handshake.sha1));
return s2n_sslv3_finished(conn, prefix, &conn->handshake.prf_md5_hash_copy, &conn->handshake.prf_sha1_hash_copy, conn->handshake.client_finished);
}
static int s2n_sslv3_server_finished(struct s2n_connection *conn)
{
uint8_t prefix[4] = { 0x53, 0x52, 0x56, 0x52 };
lte_check(MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, sizeof(conn->handshake.server_finished));
GUARD(s2n_hash_copy(&conn->handshake.prf_md5_hash_copy, &conn->handshake.md5));
GUARD(s2n_hash_copy(&conn->handshake.prf_sha1_hash_copy, &conn->handshake.sha1));
return s2n_sslv3_finished(conn, prefix, &conn->handshake.prf_md5_hash_copy, &conn->handshake.prf_sha1_hash_copy, conn->handshake.server_finished);
}
int s2n_prf_client_finished(struct s2n_connection *conn)
{
struct s2n_blob master_secret, md5, sha;
uint8_t md5_digest[MD5_DIGEST_LENGTH];
uint8_t sha_digest[SHA384_DIGEST_LENGTH];
uint8_t client_finished_label[] = "client finished";
struct s2n_blob client_finished = {0};
struct s2n_blob label = {0};
if (conn->actual_protocol_version == S2N_SSLv3) {
return s2n_sslv3_client_finished(conn);
}
client_finished.data = conn->handshake.client_finished;
client_finished.size = S2N_TLS_FINISHED_LEN;
label.data = client_finished_label;
label.size = sizeof(client_finished_label) - 1;
master_secret.data = conn->secure.master_secret;
master_secret.size = sizeof(conn->secure.master_secret);
if (conn->actual_protocol_version == S2N_TLS12) {
switch (conn->secure.cipher_suite->tls12_prf_alg) {
case S2N_HMAC_SHA256:
GUARD(s2n_hash_copy(&conn->handshake.prf_tls12_hash_copy, &conn->handshake.sha256));
GUARD(s2n_hash_digest(&conn->handshake.prf_tls12_hash_copy, sha_digest, SHA256_DIGEST_LENGTH));
sha.size = SHA256_DIGEST_LENGTH;
break;
case S2N_HMAC_SHA384:
GUARD(s2n_hash_copy(&conn->handshake.prf_tls12_hash_copy, &conn->handshake.sha384));
GUARD(s2n_hash_digest(&conn->handshake.prf_tls12_hash_copy, sha_digest, SHA384_DIGEST_LENGTH));
sha.size = SHA384_DIGEST_LENGTH;
break;
default:
S2N_ERROR(S2N_ERR_PRF_INVALID_ALGORITHM);
}
sha.data = sha_digest;
return s2n_prf(conn, &master_secret, &label, &sha, NULL, NULL, &client_finished);
}
GUARD(s2n_hash_copy(&conn->handshake.prf_md5_hash_copy, &conn->handshake.md5));
GUARD(s2n_hash_copy(&conn->handshake.prf_sha1_hash_copy, &conn->handshake.sha1));
GUARD(s2n_hash_digest(&conn->handshake.prf_md5_hash_copy, md5_digest, MD5_DIGEST_LENGTH));
GUARD(s2n_hash_digest(&conn->handshake.prf_sha1_hash_copy, sha_digest, SHA_DIGEST_LENGTH));
md5.data = md5_digest;
md5.size = MD5_DIGEST_LENGTH;
sha.data = sha_digest;
sha.size = SHA_DIGEST_LENGTH;
return s2n_prf(conn, &master_secret, &label, &md5, &sha, NULL, &client_finished);
}
int s2n_prf_server_finished(struct s2n_connection *conn)
{
struct s2n_blob master_secret, md5, sha;
uint8_t md5_digest[MD5_DIGEST_LENGTH];
uint8_t sha_digest[SHA384_DIGEST_LENGTH];
uint8_t server_finished_label[] = "server finished";
struct s2n_blob server_finished = {0};
struct s2n_blob label = {0};
if (conn->actual_protocol_version == S2N_SSLv3) {
return s2n_sslv3_server_finished(conn);
}
server_finished.data = conn->handshake.server_finished;
server_finished.size = S2N_TLS_FINISHED_LEN;
label.data = server_finished_label;
label.size = sizeof(server_finished_label) - 1;
master_secret.data = conn->secure.master_secret;
master_secret.size = sizeof(conn->secure.master_secret);
if (conn->actual_protocol_version == S2N_TLS12) {
switch (conn->secure.cipher_suite->tls12_prf_alg) {
case S2N_HMAC_SHA256:
GUARD(s2n_hash_copy(&conn->handshake.prf_tls12_hash_copy, &conn->handshake.sha256));
GUARD(s2n_hash_digest(&conn->handshake.prf_tls12_hash_copy, sha_digest, SHA256_DIGEST_LENGTH));
sha.size = SHA256_DIGEST_LENGTH;
break;
case S2N_HMAC_SHA384:
GUARD(s2n_hash_copy(&conn->handshake.prf_tls12_hash_copy, &conn->handshake.sha384));
GUARD(s2n_hash_digest(&conn->handshake.prf_tls12_hash_copy, sha_digest, SHA384_DIGEST_LENGTH));
sha.size = SHA384_DIGEST_LENGTH;
break;
default:
S2N_ERROR(S2N_ERR_PRF_INVALID_ALGORITHM);
}
sha.data = sha_digest;
return s2n_prf(conn, &master_secret, &label, &sha, NULL, NULL, &server_finished);
}
GUARD(s2n_hash_copy(&conn->handshake.prf_md5_hash_copy, &conn->handshake.md5));
GUARD(s2n_hash_copy(&conn->handshake.prf_sha1_hash_copy, &conn->handshake.sha1));
GUARD(s2n_hash_digest(&conn->handshake.prf_md5_hash_copy, md5_digest, MD5_DIGEST_LENGTH));
GUARD(s2n_hash_digest(&conn->handshake.prf_sha1_hash_copy, sha_digest, SHA_DIGEST_LENGTH));
md5.data = md5_digest;
md5.size = MD5_DIGEST_LENGTH;
sha.data = sha_digest;
sha.size = SHA_DIGEST_LENGTH;
return s2n_prf(conn, &master_secret, &label, &md5, &sha, NULL, &server_finished);
}
static int s2n_prf_make_client_key(struct s2n_connection *conn, struct s2n_stuffer *key_material)
{
struct s2n_blob client_key = {0};
client_key.size = conn->secure.cipher_suite->record_alg->cipher->key_material_size;
client_key.data = s2n_stuffer_raw_read(key_material, client_key.size);
notnull_check(client_key.data);
if (conn->mode == S2N_CLIENT) {
GUARD(conn->secure.cipher_suite->record_alg->cipher->set_encryption_key(&conn->secure.client_key, &client_key));
} else {
GUARD(conn->secure.cipher_suite->record_alg->cipher->set_decryption_key(&conn->secure.client_key, &client_key));
}
return 0;
}
static int s2n_prf_make_server_key(struct s2n_connection *conn, struct s2n_stuffer *key_material)
{
struct s2n_blob server_key = {0};
server_key.size = conn->secure.cipher_suite->record_alg->cipher->key_material_size;
server_key.data = s2n_stuffer_raw_read(key_material, server_key.size);
notnull_check(server_key.data);
if (conn->mode == S2N_SERVER) {
GUARD(conn->secure.cipher_suite->record_alg->cipher->set_encryption_key(&conn->secure.server_key, &server_key));
} else {
GUARD(conn->secure.cipher_suite->record_alg->cipher->set_decryption_key(&conn->secure.server_key, &server_key));
}
return 0;
}
int s2n_prf_key_expansion(struct s2n_connection *conn)
{
struct s2n_blob client_random = {.data = conn->secure.client_random,.size = sizeof(conn->secure.client_random) };
struct s2n_blob server_random = {.data = conn->secure.server_random,.size = sizeof(conn->secure.server_random) };
struct s2n_blob master_secret = {.data = conn->secure.master_secret,.size = sizeof(conn->secure.master_secret) };
struct s2n_blob label, out;
uint8_t key_expansion_label[] = "key expansion";
uint8_t key_block[S2N_MAX_KEY_BLOCK_LEN];
label.data = key_expansion_label;
label.size = sizeof(key_expansion_label) - 1;
out.data = key_block;
out.size = sizeof(key_block);
struct s2n_stuffer key_material = {{0}};
GUARD(s2n_prf(conn, &master_secret, &label, &server_random, &client_random, NULL, &out));
GUARD(s2n_stuffer_init(&key_material, &out));
GUARD(s2n_stuffer_write(&key_material, &out));
GUARD(conn->secure.cipher_suite->record_alg->cipher->init(&conn->secure.client_key));
GUARD(conn->secure.cipher_suite->record_alg->cipher->init(&conn->secure.server_key));
/* Check that we have a valid MAC and key size */
uint8_t mac_size;
if (conn->secure.cipher_suite->record_alg->cipher->type == S2N_COMPOSITE) {
mac_size = conn->secure.cipher_suite->record_alg->cipher->io.comp.mac_key_size;
} else {
GUARD(s2n_hmac_digest_size(conn->secure.cipher_suite->record_alg->hmac_alg, &mac_size));
}
/* Seed the client MAC */
uint8_t *client_mac_write_key = s2n_stuffer_raw_read(&key_material, mac_size);
notnull_check(client_mac_write_key);
GUARD(s2n_hmac_reset(&conn->secure.client_record_mac));
GUARD(s2n_hmac_init(&conn->secure.client_record_mac, conn->secure.cipher_suite->record_alg->hmac_alg, client_mac_write_key, mac_size));
/* Seed the server MAC */
uint8_t *server_mac_write_key = s2n_stuffer_raw_read(&key_material, mac_size);
notnull_check(server_mac_write_key);
GUARD(s2n_hmac_reset(&conn->secure.server_record_mac));
GUARD(s2n_hmac_init(&conn->secure.server_record_mac, conn->secure.cipher_suite->record_alg->hmac_alg, server_mac_write_key, mac_size));
/* Make the client key */
GUARD(s2n_prf_make_client_key(conn, &key_material));
/* Make the server key */
GUARD(s2n_prf_make_server_key(conn, &key_material));
/* Composite CBC does MAC inside the cipher, pass it the MAC key.
* Must happen after setting encryption/decryption keys.
*/
if (conn->secure.cipher_suite->record_alg->cipher->type == S2N_COMPOSITE) {
GUARD(conn->secure.cipher_suite->record_alg->cipher->io.comp.set_mac_write_key(&conn->secure.server_key, server_mac_write_key, mac_size));
GUARD(conn->secure.cipher_suite->record_alg->cipher->io.comp.set_mac_write_key(&conn->secure.client_key, client_mac_write_key, mac_size));
}
/* TLS >= 1.1 has no implicit IVs for non AEAD ciphers */
if (conn->actual_protocol_version > S2N_TLS10 && conn->secure.cipher_suite->record_alg->cipher->type != S2N_AEAD) {
return 0;
}
uint32_t implicit_iv_size = 0;
switch (conn->secure.cipher_suite->record_alg->cipher->type) {
case S2N_AEAD:
implicit_iv_size = conn->secure.cipher_suite->record_alg->cipher->io.aead.fixed_iv_size;
break;
case S2N_CBC:
implicit_iv_size = conn->secure.cipher_suite->record_alg->cipher->io.cbc.block_size;
break;
case S2N_COMPOSITE:
implicit_iv_size = conn->secure.cipher_suite->record_alg->cipher->io.comp.block_size;
break;
/* No-op for stream ciphers */
default:
break;
}
struct s2n_blob client_implicit_iv = {.data = conn->secure.client_implicit_iv,.size = implicit_iv_size };
struct s2n_blob server_implicit_iv = {.data = conn->secure.server_implicit_iv,.size = implicit_iv_size };
GUARD(s2n_stuffer_read(&key_material, &client_implicit_iv));
GUARD(s2n_stuffer_read(&key_material, &server_implicit_iv));
return 0;
}
int s2n_client_hello_recv(struct s2n_connection *conn)
{
struct s2n_stuffer *in = &conn->handshake.io;
uint8_t compression_methods;
uint16_t extensions_size;
uint16_t cipher_suites_length;
uint8_t *cipher_suites;
uint8_t client_protocol_version[S2N_TLS_PROTOCOL_VERSION_LEN];
GUARD(s2n_stuffer_read_bytes(in, client_protocol_version, S2N_TLS_PROTOCOL_VERSION_LEN));
GUARD(s2n_stuffer_read_bytes(in, conn->secure.client_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_stuffer_read_uint8(in, &conn->session_id_len));
conn->client_protocol_version = (client_protocol_version[0] * 10) + client_protocol_version[1];
if (conn->client_protocol_version < conn->config->cipher_preferences->minimum_protocol_version || conn->client_protocol_version > conn->server_protocol_version) {
GUARD(s2n_queue_reader_unsupported_protocol_version_alert(conn));
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
conn->client_hello_version = conn->client_protocol_version;
conn->actual_protocol_version = MIN(conn->client_protocol_version, conn->server_protocol_version);
if (conn->session_id_len > S2N_TLS_SESSION_ID_MAX_LEN || conn->session_id_len > s2n_stuffer_data_available(in)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
GUARD(s2n_stuffer_read_bytes(in, conn->session_id, conn->session_id_len));
GUARD(s2n_stuffer_read_uint16(in, &cipher_suites_length));
if (cipher_suites_length % S2N_TLS_CIPHER_SUITE_LEN) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
cipher_suites = s2n_stuffer_raw_read(in, cipher_suites_length);
notnull_check(cipher_suites);
/* Don't choose the cipher yet, read the extensions first */
GUARD(s2n_stuffer_read_uint8(in, &compression_methods));
GUARD(s2n_stuffer_skip_read(in, compression_methods));
/* This is going to be our default if the client has no preference. */
conn->secure.server_ecc_params.negotiated_curve = &s2n_ecc_supported_curves[0];
if (s2n_stuffer_data_available(in) >= 2) {
/* Read extensions if they are present */
GUARD(s2n_stuffer_read_uint16(in, &extensions_size));
if (extensions_size > s2n_stuffer_data_available(in)) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
struct s2n_blob extensions;
extensions.size = extensions_size;
extensions.data = s2n_stuffer_raw_read(in, extensions.size);
notnull_check(extensions.data);
GUARD(s2n_client_extensions_recv(conn, &extensions));
}
/* Now choose the ciphers and the cert chain. */
GUARD(s2n_set_cipher_as_tls_server(conn, cipher_suites, cipher_suites_length / 2));
conn->server->chosen_cert_chain = conn->config->cert_and_key_pairs;
/* Set the handshake type */
GUARD(s2n_conn_set_handshake_type(conn));
return 0;
}
int s2n_prf_key_expansion(struct s2n_connection *conn)
{
struct s2n_blob client_random = {.data = conn->secure.client_random,.size = sizeof(conn->secure.client_random) };
struct s2n_blob server_random = {.data = conn->secure.server_random,.size = sizeof(conn->secure.server_random) };
struct s2n_blob master_secret = {.data = conn->secure.master_secret,.size = sizeof(conn->secure.master_secret) };
struct s2n_blob label, out;
uint8_t key_expansion_label[] = "key expansion";
uint8_t key_block[S2N_MAX_KEY_BLOCK_LEN];
label.data = key_expansion_label;
label.size = sizeof(key_expansion_label) - 1;
out.data = key_block;
out.size = sizeof(key_block);
struct s2n_stuffer key_material;
GUARD(s2n_prf(conn, &master_secret, &label, &server_random, &client_random, &out));
GUARD(s2n_stuffer_init(&key_material, &out));
GUARD(s2n_stuffer_write(&key_material, &out));
GUARD(conn->secure.cipher_suite->cipher->init(&conn->secure.client_key));
GUARD(conn->secure.cipher_suite->cipher->init(&conn->secure.server_key));
/* What's our hmac algorithm? */
s2n_hmac_algorithm hmac_alg = conn->secure.cipher_suite->hmac_alg;
if (conn->actual_protocol_version == S2N_SSLv3) {
if (hmac_alg == S2N_HMAC_SHA1) {
hmac_alg = S2N_HMAC_SSLv3_SHA1;
} else if (hmac_alg == S2N_HMAC_MD5) {
hmac_alg = S2N_HMAC_SSLv3_MD5;
} else {
S2N_ERROR(S2N_ERR_HMAC_INVALID_ALGORITHM);
}
}
/* Check that we have a valid MAC and key size */
int mac_size;
GUARD((mac_size = s2n_hmac_digest_size(hmac_alg)));
/* Seed the client MAC */
uint8_t *client_write_mac_key = s2n_stuffer_raw_read(&key_material, mac_size);
notnull_check(client_write_mac_key);
GUARD(s2n_hmac_init(&conn->secure.client_record_mac, hmac_alg, client_write_mac_key, mac_size));
/* Seed the server MAC */
uint8_t *server_write_mac_key = s2n_stuffer_raw_read(&key_material, mac_size);
notnull_check(server_write_mac_key);
GUARD(s2n_hmac_init(&conn->secure.server_record_mac, hmac_alg, server_write_mac_key, mac_size));
/* Make the client key */
struct s2n_blob client_key;
client_key.size = conn->secure.cipher_suite->cipher->key_material_size;
client_key.data = s2n_stuffer_raw_read(&key_material, client_key.size);
notnull_check(client_key.data);
if (conn->mode == S2N_CLIENT) {
GUARD(conn->secure.cipher_suite->cipher->get_encryption_key(&conn->secure.client_key, &client_key));
} else {
GUARD(conn->secure.cipher_suite->cipher->get_decryption_key(&conn->secure.client_key, &client_key));
}
/* Make the server key */
struct s2n_blob server_key;
server_key.size = conn->secure.cipher_suite->cipher->key_material_size;
server_key.data = s2n_stuffer_raw_read(&key_material, server_key.size);
notnull_check(server_key.data);
if (conn->mode == S2N_SERVER) {
GUARD(conn->secure.cipher_suite->cipher->get_encryption_key(&conn->secure.server_key, &server_key));
} else {
GUARD(conn->secure.cipher_suite->cipher->get_decryption_key(&conn->secure.server_key, &server_key));
}
/* TLS >= 1.1 has no implicit IVs for non AEAD ciphers */
if (conn->actual_protocol_version > S2N_TLS10 &&
conn->secure.cipher_suite->cipher->type != S2N_AEAD) {
return 0;
}
uint32_t implicit_iv_size = 0;
switch(conn->secure.cipher_suite->cipher->type) {
case S2N_AEAD:
implicit_iv_size = conn->secure.cipher_suite->cipher->io.aead.fixed_iv_size;
break;
case S2N_CBC:
implicit_iv_size = conn->secure.cipher_suite->cipher->io.cbc.block_size;
break;
/* No-op for stream ciphers */
default:
break;
}
struct s2n_blob client_implicit_iv = { .data = conn->secure.client_implicit_iv, .size = implicit_iv_size };
struct s2n_blob server_implicit_iv = { .data = conn->secure.server_implicit_iv, .size = implicit_iv_size };
GUARD(s2n_stuffer_read(&key_material, &client_implicit_iv));
GUARD(s2n_stuffer_read(&key_material, &server_implicit_iv));
return 0;
}