static enum ssl_hs_wait_t do_select_parameters(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!ssl->s3->session_reused) {
/* Call |cert_cb| to update server certificates if required. */
if (ssl->cert->cert_cb != NULL) {
int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg);
if (rv == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
if (rv < 0) {
hs->state = state_select_parameters;
return ssl_hs_x509_lookup;
}
}
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!ssl->s3->session_reused) {
const SSL_CIPHER *cipher =
ssl3_choose_cipher(ssl, &client_hello, ssl_get_cipher_preferences(ssl));
if (cipher == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
ssl->s3->new_session->cipher = cipher;
ssl->s3->tmp.new_cipher = cipher;
} else {
uint16_t resumption_cipher;
if (!ssl_cipher_get_ecdhe_psk_cipher(ssl->s3->new_session->cipher,
&resumption_cipher)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
ssl->s3->tmp.new_cipher = SSL_get_cipher_by_value(resumption_cipher);
}
ssl->method->received_flight(ssl);
/* The PRF hash is now known. Set up the key schedule and hash the
* ClientHello. */
size_t resumption_ctx_len =
EVP_MD_size(ssl_get_handshake_digest(ssl_get_algorithm_prf(ssl)));
if (ssl->s3->session_reused) {
uint8_t resumption_ctx[EVP_MAX_MD_SIZE];
if (!tls13_resumption_context(ssl, resumption_ctx, resumption_ctx_len,
ssl->s3->new_session) ||
!tls13_init_key_schedule(ssl, resumption_ctx, resumption_ctx_len)) {
return ssl_hs_error;
}
} else {
if (!tls13_init_key_schedule(ssl, kZeroes, resumption_ctx_len)) {
return ssl_hs_error;
}
}
/* Resolve PSK and incorporate it into the secret. */
if (!resolve_psk_secret(ssl)) {
return ssl_hs_error;
}
/* Resolve ECDHE and incorporate it into the secret. */
int need_retry;
if (!resolve_ecdhe_secret(ssl, &need_retry, &client_hello)) {
if (need_retry) {
hs->state = state_send_hello_retry_request;
return ssl_hs_ok;
}
return ssl_hs_error;
}
hs->state = state_send_server_hello;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_process_server_hello(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!tls13_check_message_type(ssl, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS cbs, server_random, extensions;
uint16_t server_wire_version;
uint16_t cipher_suite;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!CBS_get_u16(&cbs, &server_wire_version) ||
!CBS_get_bytes(&cbs, &server_random, SSL3_RANDOM_SIZE) ||
!CBS_get_u16(&cbs, &cipher_suite) ||
!CBS_get_u16_length_prefixed(&cbs, &extensions) ||
CBS_len(&cbs) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (server_wire_version != ssl->version) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
return ssl_hs_error;
}
/* Parse out the extensions. */
int have_key_share = 0, have_pre_shared_key = 0;
CBS key_share, pre_shared_key;
while (CBS_len(&extensions) != 0) {
uint16_t type;
CBS extension;
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
switch (type) {
case TLSEXT_TYPE_key_share:
if (have_key_share) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_EXTENSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
key_share = extension;
have_key_share = 1;
break;
case TLSEXT_TYPE_pre_shared_key:
if (have_pre_shared_key) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_EXTENSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
pre_shared_key = extension;
have_pre_shared_key = 1;
break;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
}
assert(ssl->s3->have_version);
memcpy(ssl->s3->server_random, CBS_data(&server_random), SSL3_RANDOM_SIZE);
uint8_t alert = SSL_AD_DECODE_ERROR;
if (have_pre_shared_key) {
if (ssl->session == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
if (!ssl_ext_pre_shared_key_parse_serverhello(ssl, &alert,
&pre_shared_key)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (ssl->session->ssl_version != ssl->version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_VERSION_NOT_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl_session_is_context_valid(ssl, ssl->session)) {
/* This is actually a client application bug. */
OPENSSL_PUT_ERROR(SSL,
SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
ssl->s3->session_reused = 1;
/* Only authentication information carries over in TLS 1.3. */
ssl->s3->new_session =
SSL_SESSION_dup(ssl->session, SSL_SESSION_DUP_AUTH_ONLY);
if (ssl->s3->new_session == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
SSL_set_session(ssl, NULL);
} else {
if (!ssl_get_new_session(ssl, 0)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
}
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
if (cipher == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl->s3->session_reused) {
/* Check if the cipher is disabled. */
if ((cipher->algorithm_mkey & ssl->cert->mask_k) ||
(cipher->algorithm_auth & ssl->cert->mask_a) ||
SSL_CIPHER_get_min_version(cipher) > ssl3_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl3_protocol_version(ssl) ||
!sk_SSL_CIPHER_find(ssl_get_ciphers_by_id(ssl), NULL, cipher)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
} else {
uint16_t resumption_cipher;
if (!ssl_cipher_get_ecdhe_psk_cipher(ssl->s3->new_session->cipher,
&resumption_cipher) ||
resumption_cipher != ssl_cipher_get_value(cipher)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
}
ssl->s3->new_session->cipher = cipher;
ssl->s3->tmp.new_cipher = cipher;
/* The PRF hash is now known. Set up the key schedule. */
static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
size_t resumption_ctx_len =
EVP_MD_size(ssl_get_handshake_digest(ssl_get_algorithm_prf(ssl)));
if (ssl->s3->session_reused) {
uint8_t resumption_ctx[EVP_MAX_MD_SIZE];
if (!tls13_resumption_context(ssl, resumption_ctx, resumption_ctx_len,
ssl->s3->new_session) ||
!tls13_init_key_schedule(ssl, resumption_ctx, resumption_ctx_len)) {
return ssl_hs_error;
}
} else if (!tls13_init_key_schedule(ssl, kZeroes, resumption_ctx_len)) {
return ssl_hs_error;
}
/* Resolve PSK and incorporate it into the secret. */
if (cipher->algorithm_auth == SSL_aPSK) {
if (!ssl->s3->session_reused) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
uint8_t resumption_psk[EVP_MAX_MD_SIZE];
if (!tls13_resumption_psk(ssl, resumption_psk, hs->hash_len,
ssl->s3->new_session) ||
!tls13_advance_key_schedule(ssl, resumption_psk, hs->hash_len)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
} else if (!tls13_advance_key_schedule(ssl, kZeroes, hs->hash_len)) {
return ssl_hs_error;
}
/* Resolve ECDHE and incorporate it into the secret. */
if (cipher->algorithm_mkey == SSL_kECDHE) {
if (!have_key_share) {
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_KEY_SHARE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
return ssl_hs_error;
}
uint8_t *dhe_secret;
size_t dhe_secret_len;
if (!ssl_ext_key_share_parse_serverhello(ssl, &dhe_secret, &dhe_secret_len,
&alert, &key_share)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
int ok = tls13_advance_key_schedule(ssl, dhe_secret, dhe_secret_len);
OPENSSL_free(dhe_secret);
if (!ok) {
return ssl_hs_error;
}
} else {
if (have_key_share) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
if (!tls13_advance_key_schedule(ssl, kZeroes, hs->hash_len)) {
return ssl_hs_error;
}
}
/* If there was no HelloRetryRequest, the version negotiation logic has
* already hashed the message. */
if (ssl->s3->hs->retry_group != 0 &&
!ssl->method->hash_current_message(ssl)) {
return ssl_hs_error;
}
if (!tls13_set_handshake_traffic(ssl)) {
return ssl_hs_error;
}
hs->state = state_process_encrypted_extensions;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_client_hello(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!tls13_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) {
return ssl_hs_error;
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
assert(ssl->s3->have_version);
/* Load the client random. */
if (client_hello.random_len != SSL3_RANDOM_SIZE) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
memcpy(ssl->s3->client_random, client_hello.random, client_hello.random_len);
uint8_t alert = SSL_AD_DECODE_ERROR;
SSL_SESSION *session = NULL;
CBS pre_shared_key;
if (ssl_early_callback_get_extension(&client_hello, &pre_shared_key,
TLSEXT_TYPE_pre_shared_key) &&
!ssl_ext_pre_shared_key_parse_clienthello(ssl, &session, &alert,
&pre_shared_key)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return 0;
}
uint16_t resumption_cipher;
if (session != NULL &&
/* We currently only support ECDHE-PSK resumption. */
((session->ticket_flags & SSL_TICKET_ALLOW_DHE_RESUMPTION) == 0 ||
/* Only resume if the session's version matches. */
session->ssl_version != ssl->version ||
!ssl_cipher_get_ecdhe_psk_cipher(session->cipher, &resumption_cipher) ||
!ssl_client_cipher_list_contains_cipher(&client_hello,
resumption_cipher))) {
SSL_SESSION_free(session);
session = NULL;
}
if (session == NULL) {
if (!ssl_get_new_session(ssl, 1 /* server */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
} else {
/* Only authentication information carries over in TLS 1.3. */
ssl->s3->new_session = SSL_SESSION_dup(session, SSL_SESSION_DUP_AUTH_ONLY);
if (ssl->s3->new_session == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
ssl->s3->session_reused = 1;
SSL_SESSION_free(session);
}
if (ssl->ctx->dos_protection_cb != NULL &&
ssl->ctx->dos_protection_cb(&client_hello) == 0) {
/* Connection rejected for DOS reasons. */
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
/* TLS 1.3 requires the peer only advertise the null compression. */
if (client_hello.compression_methods_len != 1 ||
client_hello.compression_methods[0] != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMPRESSION_LIST);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* TLS extensions. */
if (!ssl_parse_clienthello_tlsext(ssl, &client_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
hs->state = state_select_parameters;
return ssl_hs_ok;
}
