struct s2n_connection *s2n_connection_new(s2n_mode mode)
{
struct s2n_blob blob;
struct s2n_connection *conn;
GUARD_PTR(s2n_alloc(&blob, sizeof(struct s2n_connection)));
GUARD_PTR(s2n_blob_zero(&blob));
if (mode == S2N_CLIENT) {
/* At present s2n is not suitable for use in client mode, as it
* does not perform any certificate validation. However it is useful
* to use S2N in client mode for testing purposes. An environment
* variable is required to be set for the client mode to work.
*/
if (getenv("S2N_ENABLE_CLIENT_MODE") == NULL) {
s2n_free(&blob);
S2N_ERROR_PTR(S2N_ERR_CLIENT_MODE_DISABLED);
}
}
/* Cast 'through' void to acknowledge that we are changing alignment,
* which is ok, as blob.data is always aligned.
*/
conn = (struct s2n_connection *)(void *)blob.data;
conn->mode = mode;
conn->blinding = S2N_BUILT_IN_BLINDING;
conn->config = &s2n_default_config;
/* Allocate the fixed-size stuffers */
blob.data = conn->alert_in_data;
blob.size = S2N_ALERT_LENGTH;
GUARD_PTR(s2n_stuffer_init(&conn->alert_in, &blob));
blob.data = conn->reader_alert_out_data;
blob.size = S2N_ALERT_LENGTH;
GUARD_PTR(s2n_stuffer_init(&conn->reader_alert_out, &blob));
blob.data = conn->writer_alert_out_data;
blob.size = S2N_ALERT_LENGTH;
GUARD_PTR(s2n_stuffer_init(&conn->writer_alert_out, &blob));
GUARD_PTR(s2n_stuffer_alloc(&conn->out, S2N_DEFAULT_RECORD_LENGTH));
/* Initialize the growable stuffers. Zero length at first, but the resize
* in _wipe will fix that
*/
blob.data = conn->header_in_data;
blob.size = S2N_TLS_RECORD_HEADER_LENGTH;
GUARD_PTR(s2n_stuffer_init(&conn->header_in, &blob));
GUARD_PTR(s2n_stuffer_growable_alloc(&conn->in, 0));
GUARD_PTR(s2n_stuffer_growable_alloc(&conn->handshake.io, 0));
GUARD_PTR(s2n_connection_wipe(conn));
GUARD_PTR(s2n_timer_start(conn->config, &conn->write_timer));
return conn;
}
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 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_kem_find_supported_kem(struct s2n_blob *client_kem_ids, const struct s2n_kem *server_kem_pref_list,
const int num_server_supported_kems, const struct s2n_kem **matching_kem)
{
struct s2n_stuffer client_kems_in = {{0}};
GUARD(s2n_stuffer_init(&client_kems_in, client_kem_ids));
GUARD(s2n_stuffer_write(&client_kems_in, client_kem_ids));
for (int i = 0; i < num_server_supported_kems; i++) {
const struct s2n_kem candidate_server_kem_name = server_kem_pref_list[i];
for (int j = 0; j < client_kem_ids->size / 2; j++) {
kem_extension_size candidate_client_kem_id;
GUARD(s2n_stuffer_read_uint16(&client_kems_in, &candidate_client_kem_id));
if (candidate_server_kem_name.kem_extension_id == candidate_client_kem_id) {
*matching_kem = &server_kem_pref_list[i];
return 0;
}
}
GUARD(s2n_stuffer_reread(&client_kems_in));
}
/* Nothing found */
S2N_ERROR(S2N_ERR_KEM_UNSUPPORTED_PARAMS);
return 0;
}
static int s2n_composite_cipher_aes_sha_initial_hmac(struct s2n_session_key *key, uint8_t *sequence_number, uint8_t content_type,
uint16_t protocol_version, uint16_t payload_and_eiv_len, int *extra)
{
uint8_t ctrl_buf[S2N_TLS12_AAD_LEN];
struct s2n_blob ctrl_blob = { .data = ctrl_buf, .size = S2N_TLS12_AAD_LEN };
struct s2n_stuffer ctrl_stuffer;
GUARD(s2n_stuffer_init(&ctrl_stuffer, &ctrl_blob));
GUARD(s2n_stuffer_write_bytes(&ctrl_stuffer, sequence_number, S2N_TLS_SEQUENCE_NUM_LEN));
GUARD(s2n_stuffer_write_uint8(&ctrl_stuffer, content_type));
GUARD(s2n_stuffer_write_uint8(&ctrl_stuffer, protocol_version / 10));
GUARD(s2n_stuffer_write_uint8(&ctrl_stuffer, protocol_version % 10));
GUARD(s2n_stuffer_write_uint16(&ctrl_stuffer, payload_and_eiv_len));
/* This will unnecessarily mangle the input buffer, which is fine since it's temporary
* Return value will be length of digest, padding, and padding length byte.
* See https://github.com/openssl/openssl/blob/master/crypto/evp/e_aes_cbc_hmac_sha1.c#L814
* and https://github.com/openssl/openssl/blob/4f0c475719defd7c051964ef9964cc6e5b3a63bf/ssl/record/ssl3_record.c#L743
*/
int ctrl_ret = EVP_CIPHER_CTX_ctrl(key->evp_cipher_ctx, EVP_CTRL_AEAD_TLS1_AAD, S2N_TLS12_AAD_LEN, ctrl_buf);
if (ctrl_ret < 0) {
S2N_ERROR(S2N_ERR_INITIAL_HMAC);
}
*extra = ctrl_ret;
return 0;
}
int s2n_stuffer_alloc(struct s2n_stuffer *stuffer, const uint32_t size)
{
GUARD(s2n_alloc(&stuffer->blob, size));
GUARD(s2n_stuffer_init(stuffer, &stuffer->blob));
stuffer->alloced = 1;
return 0;
}
static int s2n_stuffer_pem_read_contents(struct s2n_stuffer *pem, struct s2n_stuffer *asn1)
{
uint8_t base64_buf[64] = { 0 };
struct s2n_blob base64__blob = { .data = base64_buf, .size = sizeof(base64_buf) };
struct s2n_stuffer base64_stuffer = {{0}};
GUARD(s2n_stuffer_init(&base64_stuffer, &base64__blob));
while (1) {
char c;
/* Peek to see if the next char is a dash, meaning end of pem_contents */
GUARD(s2n_stuffer_peek_char(pem, &c));
if (c == '-') {
break;
} else {
/* Else, move read pointer forward by 1 byte since we will be consuming it. */
GUARD(s2n_stuffer_skip_read(pem, 1));
}
/* Skip non-base64 characters */
if (!s2n_is_base64_char(c)) {
continue;
}
/* Flush base64_stuffer to asn1 stuffer if we're out of space, and reset base64_stuffer read/write pointers */
if (s2n_stuffer_space_remaining(&base64_stuffer) == 0) {
GUARD(s2n_stuffer_read_base64(&base64_stuffer, asn1));
GUARD(s2n_stuffer_rewrite(&base64_stuffer));
}
/* Copy next char to base64_stuffer */
GUARD(s2n_stuffer_write_bytes(&base64_stuffer, (uint8_t *) &c, 1));
};
/* Flush any remaining bytes to asn1 */
GUARD(s2n_stuffer_read_base64(&base64_stuffer, asn1));
return 0;
}
static int s2n_stuffer_data_from_pem(struct s2n_stuffer *pem, struct s2n_stuffer *asn1, const char *keyword)
{
GUARD(s2n_stuffer_pem_read_begin(pem, keyword));
GUARD(s2n_stuffer_pem_read_contents(pem, asn1));
GUARD(s2n_stuffer_pem_read_end(pem, keyword));
return 0;
}
/* Due to the need to support some older assemblers,
* we cannot use either the compiler intrinsics or
* the RDRAND assembly mnemonic. For this reason,
* we're using the opcode directly (0F C7/6). This
* stores the result in eax.
*
* volatile is important to prevent the compiler from
* re-ordering or optimizing the use of RDRAND.
*/
int s2n_get_rdrand_data(struct s2n_blob *out)
{
#if defined(__x86_64__)||defined(__i386__)
int space_remaining = 0;
struct s2n_stuffer stuffer;
union {
uint64_t u64;
uint8_t u8[8];
} output;
GUARD(s2n_stuffer_init(&stuffer, out));
while((space_remaining = s2n_stuffer_space_remaining(&stuffer))) {
int success = 0;
for (int tries = 0; tries < 10; tries++) {
__asm__ __volatile__(
".byte 0x48;\n"
".byte 0x0f;\n"
".byte 0xc7;\n"
".byte 0xf0;\n"
"adcl $0x00, %%ebx;\n"
:"=b"(success), "=a"(output.u64)
:"b"(0)
:"cc"
);
if (success) {
break;
}
}
if (!success) {
return -1;
}
int data_to_fill = MIN(sizeof(output), space_remaining);
GUARD(s2n_stuffer_write_bytes(&stuffer, output.u8, data_to_fill));
}
return 0;
#else
return -1;
#endif
}
int s2n_server_hello_send(struct s2n_connection *conn)
{
uint32_t gmt_unix_time = time(NULL);
struct s2n_stuffer *out = &conn->handshake.io;
struct s2n_stuffer server_random;
struct s2n_blob b, r;
uint8_t session_id_len = 0;
uint8_t protocol_version[S2N_TLS_PROTOCOL_VERSION_LEN];
b.data = conn->pending.server_random;
b.size = S2N_TLS_RANDOM_DATA_LEN;
/* Create the server random data */
GUARD(s2n_stuffer_init(&server_random, &b));
GUARD(s2n_stuffer_write_uint32(&server_random, gmt_unix_time));
r.data = s2n_stuffer_raw_write(&server_random, S2N_TLS_RANDOM_DATA_LEN - 4);
r.size = S2N_TLS_RANDOM_DATA_LEN - 4;
notnull_check(r.data);
GUARD(s2n_get_public_random_data(&r));
conn->actual_protocol_version = MIN(conn->client_protocol_version, conn->server_protocol_version);
protocol_version[0] = conn->actual_protocol_version / 10;
protocol_version[1] = conn->actual_protocol_version % 10;
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_write_bytes(out, protocol_version, S2N_TLS_PROTOCOL_VERSION_LEN));
GUARD(s2n_stuffer_write_bytes(out, conn->pending.server_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_stuffer_write_uint8(out, session_id_len));
GUARD(s2n_stuffer_write_bytes(out, conn->pending.cipher_suite->value, S2N_TLS_CIPHER_SUITE_LEN));
GUARD(s2n_stuffer_write_uint8(out, S2N_TLS_COMPRESSION_METHOD_NULL));
GUARD(s2n_server_extensions_send(conn, out));
conn->actual_protocol_version_established = 1;
return 0;
}
int s2n_client_hello_send(struct s2n_connection *conn)
{
uint32_t gmt_unix_time = time(NULL);
struct s2n_stuffer *out = &conn->handshake.io;
struct s2n_stuffer client_random;
struct s2n_blob b, r;
uint8_t session_id_len = 0;
uint8_t client_protocol_version[S2N_TLS_PROTOCOL_VERSION_LEN];
b.data = conn->secure.client_random;
b.size = S2N_TLS_RANDOM_DATA_LEN;
/* Create the client random data */
GUARD(s2n_stuffer_init(&client_random, &b));
GUARD(s2n_stuffer_write_uint32(&client_random, gmt_unix_time));
r.data = s2n_stuffer_raw_write(&client_random, S2N_TLS_RANDOM_DATA_LEN - 4);
r.size = S2N_TLS_RANDOM_DATA_LEN - 4;
notnull_check(r.data);
GUARD(s2n_get_public_random_data(&r));
client_protocol_version[0] = conn->client_protocol_version / 10;
client_protocol_version[1] = conn->client_protocol_version % 10;
conn->client_hello_version = conn->client_protocol_version;
GUARD(s2n_stuffer_write_bytes(out, client_protocol_version, S2N_TLS_PROTOCOL_VERSION_LEN));
GUARD(s2n_stuffer_copy(&client_random, out, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_stuffer_write_uint8(out, session_id_len));
GUARD(s2n_stuffer_write_uint16(out, conn->config->cipher_preferences->count * S2N_TLS_CIPHER_SUITE_LEN));
GUARD(s2n_stuffer_write_bytes(out, conn->config->cipher_preferences->wire_format, conn->config->cipher_preferences->count * S2N_TLS_CIPHER_SUITE_LEN));
/* Zero compression methods */
GUARD(s2n_stuffer_write_uint8(out, 1));
GUARD(s2n_stuffer_write_uint8(out, 0));
/* Write the extensions */
GUARD(s2n_client_extensions_send(conn, out));
return 0;
}
int main(int argc, char **argv)
{
uint8_t digest_pad[64];
uint8_t output_pad[96];
uint8_t hello[] = "Hello world!\n";
struct s2n_stuffer output;
struct s2n_hash_state hash, copy;
struct s2n_blob out = {.data = output_pad,.size = sizeof(output_pad) };
BEGIN_TEST();
/* Initialise our output stuffers */
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
uint8_t md5_digest_size;
GUARD(s2n_hash_digest_size(S2N_HASH_MD5, &md5_digest_size));
EXPECT_EQUAL(md5_digest_size, 16);
EXPECT_SUCCESS(s2n_hash_init(&hash, S2N_HASH_MD5));
EXPECT_SUCCESS(s2n_hash_update(&hash, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hash_copy(©, &hash));
EXPECT_SUCCESS(s2n_hash_digest(&hash, digest_pad, MD5_DIGEST_LENGTH));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from command line md5sum */
EXPECT_EQUAL(memcmp(output_pad, "59ca0efa9f5633cb0371bbc0355478d8", 16 * 2), 0);
/* Check the copy */
EXPECT_SUCCESS(s2n_hash_digest(©, digest_pad, MD5_DIGEST_LENGTH));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from command line md5sum */
EXPECT_EQUAL(memcmp(output_pad, "59ca0efa9f5633cb0371bbc0355478d8", 16 * 2), 0);
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
uint8_t sha1_digest_size;
GUARD(s2n_hash_digest_size(S2N_HASH_SHA1, &sha1_digest_size));
EXPECT_EQUAL(sha1_digest_size, 20);
EXPECT_SUCCESS(s2n_hash_init(&hash, S2N_HASH_SHA1));
EXPECT_SUCCESS(s2n_hash_update(&hash, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hash_digest(&hash, digest_pad, SHA_DIGEST_LENGTH));
for (int i = 0; i < 20; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from command line sha1sum */
EXPECT_EQUAL(memcmp(output_pad, "47a013e660d408619d894b20806b1d5086aab03b", 20 * 2), 0);
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
uint8_t sha256_digest_size;
GUARD(s2n_hash_digest_size(S2N_HASH_SHA256, &sha256_digest_size));
EXPECT_EQUAL(sha256_digest_size, 32);
EXPECT_SUCCESS(s2n_hash_init(&hash, S2N_HASH_SHA256));
EXPECT_SUCCESS(s2n_hash_update(&hash, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hash_digest(&hash, digest_pad, SHA256_DIGEST_LENGTH));
for (int i = 0; i < 32; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from command line sha256sum */
EXPECT_EQUAL(memcmp(output_pad, "0ba904eae8773b70c75333db4de2f3ac45a8ad4ddba1b242f0b3cfc199391dd8", 32 * 2), 0);
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
uint8_t sha384_digest_size;
GUARD(s2n_hash_digest_size(S2N_HASH_SHA384, &sha384_digest_size));
EXPECT_EQUAL(sha384_digest_size, 48);
EXPECT_SUCCESS(s2n_hash_init(&hash, S2N_HASH_SHA384));
EXPECT_SUCCESS(s2n_hash_update(&hash, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hash_digest(&hash, digest_pad, SHA384_DIGEST_LENGTH));
for (int i = 0; i < 48; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from command line sha512sum */
EXPECT_EQUAL(memcmp(output_pad, "f7f8f1b9d5a9a61742eeda26c20990282ac08dabda14e70376fcb4c8b46198a9959ea9d7d194b38520eed5397ffe6d8e", 48 * 2), 0);
END_TEST();
}
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;
}
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)
{
uint8_t digest_pad[256];
uint8_t check_pad[256];
uint8_t output_pad[256];
struct s2n_stuffer output;
uint8_t sekrit[] = "sekrit";
uint8_t longsekrit[] = "This is a really really really long key on purpose to make sure that it's longer than the block size";
uint8_t hello[] = "Hello world!";
struct s2n_hmac_state hmac, copy;
struct s2n_hmac_state cmac;
struct s2n_blob out = {.data = output_pad,.size = sizeof(output_pad) };
BEGIN_TEST();
/* Initialise our output stuffers */
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_MD5), 16);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_MD5, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_copy(©, &hmac));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "3ad68c53dc1a3cf35f6469877fae4585", 16 * 2), 0);
/* Check the copy */
EXPECT_SUCCESS(s2n_hmac_digest(©, digest_pad, 16));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "3ad68c53dc1a3cf35f6469877fae4585", 16 * 2), 0);
/* Test that a reset works */
EXPECT_SUCCESS(s2n_hmac_reset(&hmac));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "3ad68c53dc1a3cf35f6469877fae4585", 16 * 2), 0);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_MD5, longsekrit, strlen((char *)longsekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "2ce569d61f4ee6ad9ceebe02a112ace7", 16 * 2), 0);
/* Test that a reset works */
EXPECT_SUCCESS(s2n_hmac_reset(&hmac));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "2ce569d61f4ee6ad9ceebe02a112ace7", 16 * 2), 0);
/* Verify that _verify works */
EXPECT_SUCCESS(s2n_hmac_init(&cmac, S2N_HMAC_MD5, longsekrit, strlen((char *)longsekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&cmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&cmac, check_pad, 16));
EXPECT_SUCCESS(s2n_hmac_digest_verify(digest_pad, 16, check_pad, 16));
/* Try SHA1 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SHA1), 20);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SHA1, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 20));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 20; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "6d301861b599938eca94f6de917362886d97882f", 20 * 2), 0);
/* Try SHA256 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SHA256), 32);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SHA256, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 32));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 32; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "adc20b12d236e6d1824d690622e33ead4f67ba5a2be9606fe762b2dd859a78a9", 32 * 2), 0);
/* Try SHA384 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SHA384), 48);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SHA384, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 48));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 48; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "8552563cadd583b79dcc7225bb79bc6483c63f259187162e1c9d4283eb6299ef1bc3ca81c0c40fc7b22f7a1f3b93adb4", 48 * 2), 0);
/* Try SHA512 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SHA512), 64);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SHA512, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 64));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 64; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from python */
EXPECT_EQUAL(memcmp(output_pad, "0a834a1ed265042e2897405edb4fdd9818950cd5bea10b828f2fed45a1cb6dbd2107e4b04eb20f211998cd4e8c7e11ebdcb0103ac63882481e1bb8083d07f4be", 64 * 2), 0);
/* Try SSLv3 MD5 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SSLv3_MD5), 16);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SSLv3_MD5, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from Go */
EXPECT_EQUAL(memcmp(output_pad, "d4f0d06b9765de23e6c3e33a24c5ded0", 16 * 2), 0);
/* Test that a reset works */
EXPECT_SUCCESS(s2n_hmac_reset(&hmac));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 16));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 16; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
EXPECT_EQUAL(memcmp(output_pad, "d4f0d06b9765de23e6c3e33a24c5ded0", 16 * 2), 0);
/* Try SSLv3 SHA1 */
EXPECT_EQUAL(s2n_hmac_digest_size(S2N_HMAC_SSLv3_SHA1), 20);
EXPECT_SUCCESS(s2n_hmac_init(&hmac, S2N_HMAC_SSLv3_SHA1, sekrit, strlen((char *)sekrit)));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 20));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 20; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
/* Reference value from Go */
EXPECT_EQUAL(memcmp(output_pad, "b0c66179f6eb5a46b4b7c4fca84b3ea5161b7326", 20 * 2), 0);
/* Test that a reset works */
EXPECT_SUCCESS(s2n_hmac_reset(&hmac));
EXPECT_SUCCESS(s2n_hmac_update(&hmac, hello, strlen((char *)hello)));
EXPECT_SUCCESS(s2n_hmac_digest(&hmac, digest_pad, 20));
EXPECT_SUCCESS(s2n_stuffer_init(&output, &out));
for (int i = 0; i < 20; i++) {
EXPECT_SUCCESS(s2n_stuffer_write_uint8_hex(&output, digest_pad[i]));
}
EXPECT_EQUAL(memcmp(output_pad, "b0c66179f6eb5a46b4b7c4fca84b3ea5161b7326", 20 * 2), 0);
END_TEST();
}
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;
}
int s2n_record_write(struct s2n_connection *conn, uint8_t content_type, struct s2n_blob *in)
{
struct s2n_blob out, iv, aad;
uint8_t padding = 0;
uint16_t block_size = 0;
uint8_t aad_gen[S2N_TLS_MAX_AAD_LEN] = { 0 };
uint8_t aad_iv[S2N_TLS_MAX_IV_LEN] = { 0 };
uint8_t *sequence_number = conn->server->server_sequence_number;
struct s2n_hmac_state *mac = &conn->server->server_record_mac;
struct s2n_session_key *session_key = &conn->server->server_key;
const struct s2n_cipher_suite *cipher_suite = conn->server->cipher_suite;
uint8_t *implicit_iv = conn->server->server_implicit_iv;
if (conn->mode == S2N_CLIENT) {
sequence_number = conn->client->client_sequence_number;
mac = &conn->client->client_record_mac;
session_key = &conn->client->client_key;
cipher_suite = conn->client->cipher_suite;
implicit_iv = conn->client->client_implicit_iv;
}
S2N_ERROR_IF(s2n_stuffer_data_available(&conn->out), S2N_ERR_BAD_MESSAGE);
uint8_t mac_digest_size;
GUARD(s2n_hmac_digest_size(mac->alg, &mac_digest_size));
/* Before we do anything, we need to figure out what the length of the
* fragment is going to be.
*/
uint16_t data_bytes_to_take = MIN(in->size, s2n_record_max_write_payload_size(conn));
uint16_t extra = overhead(conn);
/* If we have padding to worry about, figure that out too */
if (cipher_suite->record_alg->cipher->type == S2N_CBC) {
block_size = cipher_suite->record_alg->cipher->io.cbc.block_size;
if (((data_bytes_to_take + extra) % block_size)) {
padding = block_size - ((data_bytes_to_take + extra) % block_size);
}
} else if (cipher_suite->record_alg->cipher->type == S2N_COMPOSITE) {
block_size = cipher_suite->record_alg->cipher->io.comp.block_size;
}
/* Start the MAC with the sequence number */
GUARD(s2n_hmac_update(mac, sequence_number, S2N_TLS_SEQUENCE_NUM_LEN));
/* Now that we know the length, start writing the record */
GUARD(s2n_stuffer_write_uint8(&conn->out, content_type));
GUARD(s2n_record_write_protocol_version(conn));
/* First write a header that has the payload length, this is for the MAC */
GUARD(s2n_stuffer_write_uint16(&conn->out, data_bytes_to_take));
if (conn->actual_protocol_version > S2N_SSLv3) {
GUARD(s2n_hmac_update(mac, conn->out.blob.data, S2N_TLS_RECORD_HEADER_LENGTH));
} else {
/* SSLv3 doesn't include the protocol version in the MAC */
GUARD(s2n_hmac_update(mac, conn->out.blob.data, 1));
GUARD(s2n_hmac_update(mac, conn->out.blob.data + 3, 2));
}
/* Compute non-payload parts of the MAC(seq num, type, proto vers, fragment length) for composite ciphers.
* Composite "encrypt" will MAC the payload data and fill in padding.
*/
if (cipher_suite->record_alg->cipher->type == S2N_COMPOSITE) {
/* Only fragment length is needed for MAC, but the EVP ctrl function needs fragment length + eiv len. */
uint16_t payload_and_eiv_len = data_bytes_to_take;
if (conn->actual_protocol_version > S2N_TLS10) {
payload_and_eiv_len += block_size;
}
/* Outputs number of extra bytes required for MAC and padding */
int pad_and_mac_len;
GUARD(cipher_suite->record_alg->cipher->io.comp.initial_hmac(session_key, sequence_number, content_type, conn->actual_protocol_version,
payload_and_eiv_len, &pad_and_mac_len));
extra += pad_and_mac_len;
}
/* Rewrite the length to be the actual fragment length */
uint16_t actual_fragment_length = data_bytes_to_take + padding + extra;
GUARD(s2n_stuffer_wipe_n(&conn->out, 2));
GUARD(s2n_stuffer_write_uint16(&conn->out, actual_fragment_length));
/* If we're AEAD, write the sequence number as an IV, and generate the AAD */
if (cipher_suite->record_alg->cipher->type == S2N_AEAD) {
struct s2n_stuffer iv_stuffer = {{0}};
iv.data = aad_iv;
iv.size = sizeof(aad_iv);
GUARD(s2n_stuffer_init(&iv_stuffer, &iv));
if (cipher_suite->record_alg->flags & S2N_TLS12_AES_GCM_AEAD_NONCE) {
/* Partially explicit nonce. See RFC 5288 Section 3 */
GUARD(s2n_stuffer_write_bytes(&conn->out, sequence_number, S2N_TLS_SEQUENCE_NUM_LEN));
GUARD(s2n_stuffer_write_bytes(&iv_stuffer, implicit_iv, cipher_suite->record_alg->cipher->io.aead.fixed_iv_size));
GUARD(s2n_stuffer_write_bytes(&iv_stuffer, sequence_number, S2N_TLS_SEQUENCE_NUM_LEN));
} else if (cipher_suite->record_alg->flags & S2N_TLS12_CHACHA_POLY_AEAD_NONCE) {
/* Fully implicit nonce. See RFC7905 Section 2 */
uint8_t four_zeroes[4] = { 0 };
GUARD(s2n_stuffer_write_bytes(&iv_stuffer, four_zeroes, 4));
GUARD(s2n_stuffer_write_bytes(&iv_stuffer, sequence_number, S2N_TLS_SEQUENCE_NUM_LEN));
for(int i = 0; i < cipher_suite->record_alg->cipher->io.aead.fixed_iv_size; i++) {
aad_iv[i] = aad_iv[i] ^ implicit_iv[i];
}
} else {
S2N_ERROR(S2N_ERR_INVALID_NONCE_TYPE);
}
/* Set the IV size to the amount of data written */
iv.size = s2n_stuffer_data_available(&iv_stuffer);
aad.data = aad_gen;
aad.size = sizeof(aad_gen);
struct s2n_stuffer ad_stuffer = {{0}};
GUARD(s2n_stuffer_init(&ad_stuffer, &aad));
GUARD(s2n_aead_aad_init(conn, sequence_number, content_type, data_bytes_to_take, &ad_stuffer));
} else if (cipher_suite->record_alg->cipher->type == S2N_CBC || cipher_suite->record_alg->cipher->type == S2N_COMPOSITE) {
iv.size = block_size;
iv.data = implicit_iv;
/* For TLS1.1/1.2; write the IV with random data */
if (conn->actual_protocol_version > S2N_TLS10) {
GUARD(s2n_get_public_random_data(&iv));
GUARD(s2n_stuffer_write(&conn->out, &iv));
}
}
/* We are done with this sequence number, so we can increment it */
struct s2n_blob seq = {.data = sequence_number,.size = S2N_TLS_SEQUENCE_NUM_LEN };
GUARD(s2n_increment_sequence_number(&seq));
/* Write the plaintext data */
out.data = in->data;
out.size = data_bytes_to_take;
GUARD(s2n_stuffer_write(&conn->out, &out));
GUARD(s2n_hmac_update(mac, out.data, out.size));
/* Write the digest */
uint8_t *digest = s2n_stuffer_raw_write(&conn->out, mac_digest_size);
notnull_check(digest);
GUARD(s2n_hmac_digest(mac, digest, mac_digest_size));
GUARD(s2n_hmac_reset(mac));
if (cipher_suite->record_alg->cipher->type == S2N_CBC) {
/* Include padding bytes, each with the value 'p', and
* include an extra padding length byte, also with the value 'p'.
*/
for (int i = 0; i <= padding; i++) {
GUARD(s2n_stuffer_write_uint8(&conn->out, padding));
}
}
/* Rewind to rewrite/encrypt the packet */
GUARD(s2n_stuffer_rewrite(&conn->out));
/* Skip the header */
GUARD(s2n_stuffer_skip_write(&conn->out, S2N_TLS_RECORD_HEADER_LENGTH));
uint16_t encrypted_length = data_bytes_to_take + mac_digest_size;
switch (cipher_suite->record_alg->cipher->type) {
case S2N_AEAD:
GUARD(s2n_stuffer_skip_write(&conn->out, cipher_suite->record_alg->cipher->io.aead.record_iv_size));
encrypted_length += cipher_suite->record_alg->cipher->io.aead.tag_size;
break;
case S2N_CBC:
if (conn->actual_protocol_version > S2N_TLS10) {
/* Leave the IV alone and unencrypted */
GUARD(s2n_stuffer_skip_write(&conn->out, iv.size));
}
/* Encrypt the padding and the padding length byte too */
encrypted_length += padding + 1;
break;
case S2N_COMPOSITE:
/* Composite CBC expects a pointer starting at explicit IV: [Explicit IV | fragment | MAC | padding | padding len ]
* extra will account for the explicit IV len(if applicable), MAC digest len, padding len + padding byte.
*/
encrypted_length += extra;
break;
default:
break;
}
/* Do the encryption */
struct s2n_blob en = {0};
en.size = encrypted_length;
en.data = s2n_stuffer_raw_write(&conn->out, en.size);
notnull_check(en.data);
switch (cipher_suite->record_alg->cipher->type) {
case S2N_STREAM:
GUARD(cipher_suite->record_alg->cipher->io.stream.encrypt(session_key, &en, &en));
break;
case S2N_CBC:
GUARD(cipher_suite->record_alg->cipher->io.cbc.encrypt(session_key, &iv, &en, &en));
/* Copy the last encrypted block to be the next IV */
if (conn->actual_protocol_version < S2N_TLS11) {
gte_check(en.size, block_size);
memcpy_check(implicit_iv, en.data + en.size - block_size, block_size);
}
break;
case S2N_AEAD:
GUARD(cipher_suite->record_alg->cipher->io.aead.encrypt(session_key, &iv, &aad, &en, &en));
break;
case S2N_COMPOSITE:
/* This will: compute mac, append padding, append padding length, and encrypt */
GUARD(cipher_suite->record_alg->cipher->io.comp.encrypt(session_key, &iv, &en, &en));
/* Copy the last encrypted block to be the next IV */
gte_check(en.size, block_size);
memcpy_check(implicit_iv, en.data + en.size - block_size, block_size);
break;
default:
S2N_ERROR(S2N_ERR_CIPHER_TYPE);
break;
}
conn->wire_bytes_out += actual_fragment_length + S2N_TLS_RECORD_HEADER_LENGTH;
return data_bytes_to_take;
}
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;
}
