Google Git
Sign in
boringssl / boringssl / e38cf79cdf47606f6768fb85dc066d7ebce304ac / . / ssl / tls13_client.cc
blob: bff7fb91800d4f03e310c7f7058050d424dbf996 [file] [log] [blame]
/* Copyright (c) 2016, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/ssl.h>
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <utility>
#include <openssl/bytestring.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/sha.h>
#include <openssl/stack.h>
#include "../crypto/internal.h"
#include "internal.h"
BSSL_NAMESPACE_BEGIN
enum client_hs_state_t {
state_read_hello_retry_request = 0,
state_send_second_client_hello,
state_read_server_hello,
state_read_encrypted_extensions,
state_read_certificate_request,
state_read_server_certificate,
state_read_server_certificate_verify,
state_server_certificate_reverify,
state_read_server_finished,
state_send_end_of_early_data,
state_send_client_encrypted_extensions,
state_send_client_certificate,
state_send_client_certificate_verify,
state_complete_second_flight,
state_done,
};
static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
// end_of_early_data closes the early data stream for |hs| and switches the
// encryption level to |level|. It returns true on success and false on error.
static bool close_early_data(SSL_HANDSHAKE *hs, ssl_encryption_level_t level) {
SSL *const ssl = hs->ssl;
assert(hs->in_early_data);
// Note |can_early_write| may already be false if |SSL_write| exceeded the
// early data write limit.
hs->can_early_write = false;
// 0-RTT write states on the client differ between TLS 1.3, DTLS 1.3, and
// QUIC. TLS 1.3 has one write encryption level at a time. 0-RTT write keys
// overwrite the null cipher and defer handshake write keys. While a
// HelloRetryRequest can cause us to rewind back to the null cipher, sequence
// numbers have no effect, so we can install a "new" null cipher.
//
// In QUIC and DTLS 1.3, 0-RTT write state cannot override or defer the normal
// write state. The two ClientHello sequence numbers must align, and handshake
// write keys must be installed early to ACK the EncryptedExtensions.
//
// We do not currently implement DTLS 1.3 and, in QUIC, the caller handles
// 0-RTT data, so we can skip installing 0-RTT keys and act as if there is one
// write level. If we implement DTLS 1.3, we'll need to model this better.
if (ssl->quic_method == nullptr) {
if (level == ssl_encryption_initial) {
bssl::UniquePtr<SSLAEADContext> null_ctx =
SSLAEADContext::CreateNullCipher(SSL_is_dtls(ssl));
if (!null_ctx ||
!ssl->method->set_write_state(ssl, ssl_encryption_initial,
std::move(null_ctx),
/*secret_for_quic=*/{})) {
return false;
}
ssl->s3->aead_write_ctx->SetVersionIfNullCipher(ssl->version);
} else {
assert(level == ssl_encryption_handshake);
if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal,
hs->new_session.get(),
hs->client_handshake_secret())) {
return false;
}
}
}
assert(ssl->s3->write_level == level);
return true;
}
static enum ssl_hs_wait_t do_read_hello_retry_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
assert(ssl->s3->have_version);
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
// Queue up a ChangeCipherSpec for whenever we next send something. This
// will be before the second ClientHello. If we offered early data, this was
// already done.
if (!hs->early_data_offered &&
!ssl->method->add_change_cipher_spec(ssl)) {
return ssl_hs_error;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS body = msg.body, extensions, server_random, session_id;
uint16_t server_version, cipher_suite;
uint8_t compression_method;
if (!CBS_get_u16(&body, &server_version) ||
!CBS_get_bytes(&body, &server_random, SSL3_RANDOM_SIZE) ||
!CBS_get_u8_length_prefixed(&body, &session_id) ||
!CBS_mem_equal(&session_id, hs->session_id, hs->session_id_len) ||
!CBS_get_u16(&body, &cipher_suite) ||
!CBS_get_u8(&body, &compression_method) ||
compression_method != 0 ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
CBS_len(&extensions) == 0 ||
CBS_len(&body) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!CBS_mem_equal(&server_random, kHelloRetryRequest, SSL3_RANDOM_SIZE)) {
hs->tls13_state = state_read_server_hello;
return ssl_hs_ok;
}
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
// Check if the cipher is a TLS 1.3 cipher.
if (cipher == NULL ||
SSL_CIPHER_get_min_version(cipher) > ssl_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl_protocol_version(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
hs->new_cipher = cipher;
bool have_cookie, have_key_share, have_supported_versions;
CBS cookie, key_share, supported_versions;
SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_key_share, &have_key_share, &key_share},
{TLSEXT_TYPE_cookie, &have_cookie, &cookie},
{TLSEXT_TYPE_supported_versions, &have_supported_versions,
&supported_versions},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
/*ignore_unknown=*/false)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (!have_cookie && !have_key_share) {
OPENSSL_PUT_ERROR(SSL, SSL_R_EMPTY_HELLO_RETRY_REQUEST);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (have_cookie) {
CBS cookie_value;
if (!CBS_get_u16_length_prefixed(&cookie, &cookie_value) ||
CBS_len(&cookie_value) == 0 ||
CBS_len(&cookie) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!hs->cookie.CopyFrom(cookie_value)) {
return ssl_hs_error;
}
}
if (have_key_share) {
uint16_t group_id;
if (!CBS_get_u16(&key_share, &group_id) || CBS_len(&key_share) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
// The group must be supported.
if (!tls1_check_group_id(hs, group_id)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
return ssl_hs_error;
}
// Check that the HelloRetryRequest does not request a key share that was
// provided in the initial ClientHello.
if (hs->key_shares[0]->GroupID() == group_id ||
(hs->key_shares[1] && hs->key_shares[1]->GroupID() == group_id)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
return ssl_hs_error;
}
if (!ssl_setup_key_shares(hs, group_id)) {
return ssl_hs_error;
}
}
// We do not know whether ECH was chosen until ServerHello and must
// concurrently update both transcripts.
//
// TODO(https://crbug.com/boringssl/275): A later draft will likely add an ECH
// signal to HRR and change this.
if (!hs->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher) ||
!hs->transcript.UpdateForHelloRetryRequest() ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
if (hs->selected_ech_config) {
if (!hs->inner_transcript.InitHash(ssl_protocol_version(ssl),
hs->new_cipher) ||
!hs->inner_transcript.UpdateForHelloRetryRequest() ||
!hs->inner_transcript.Update(msg.raw)) {
return ssl_hs_error;
}
}
// HelloRetryRequest should be the end of the flight.
if (ssl->method->has_unprocessed_handshake_data(ssl)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESS_HANDSHAKE_DATA);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
ssl->s3->used_hello_retry_request = true;
hs->tls13_state = state_send_second_client_hello;
// 0-RTT is rejected if we receive a HelloRetryRequest.
if (hs->in_early_data) {
ssl->s3->early_data_reason = ssl_early_data_hello_retry_request;
if (!close_early_data(hs, ssl_encryption_initial)) {
return ssl_hs_error;
}
return ssl_hs_early_data_rejected;
}
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_second_client_hello(SSL_HANDSHAKE *hs) {
// Any 0-RTT keys must have been discarded.
assert(hs->ssl->s3->write_level == ssl_encryption_initial);
// Build the second ClientHelloInner, if applicable. The second ClientHello
// uses an empty string for |enc|.
if (hs->selected_ech_config && !ssl_encrypt_client_hello(hs, {})) {
return ssl_hs_error;
}
if (!ssl_add_client_hello(hs)) {
return ssl_hs_error;
}
ssl_done_writing_client_hello(hs);
hs->tls13_state = state_read_server_hello;
return ssl_hs_flush;
}
static enum ssl_hs_wait_t do_read_server_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS body = msg.body, server_random, session_id, extensions;
uint16_t server_version;
uint16_t cipher_suite;
uint8_t compression_method;
if (!CBS_get_u16(&body, &server_version) ||
!CBS_get_bytes(&body, &server_random, SSL3_RANDOM_SIZE) ||
!CBS_get_u8_length_prefixed(&body, &session_id) ||
!CBS_mem_equal(&session_id, hs->session_id, hs->session_id_len) ||
!CBS_get_u16(&body, &cipher_suite) ||
!CBS_get_u8(&body, &compression_method) ||
compression_method != 0 ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
CBS_len(&body) != 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (server_version != TLS1_2_VERSION) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
return ssl_hs_error;
}
// Forbid a second HelloRetryRequest.
if (CBS_mem_equal(&server_random, kHelloRetryRequest, SSL3_RANDOM_SIZE)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
return ssl_hs_error;
}
OPENSSL_memcpy(ssl->s3->server_random, CBS_data(&server_random),
SSL3_RANDOM_SIZE);
// Check if the cipher is a TLS 1.3 cipher.
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
if (cipher == nullptr ||
SSL_CIPHER_get_min_version(cipher) > ssl_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl_protocol_version(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
// Check that the cipher matches the one in the HelloRetryRequest.
if (ssl->s3->used_hello_retry_request && hs->new_cipher != cipher) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
// Parse out the extensions.
bool have_key_share = false, have_pre_shared_key = false,
have_supported_versions = false;
CBS key_share, pre_shared_key, supported_versions;
SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_key_share, &have_key_share, &key_share},
{TLSEXT_TYPE_pre_shared_key, &have_pre_shared_key, &pre_shared_key},
{TLSEXT_TYPE_supported_versions, &have_supported_versions,
&supported_versions},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
/*ignore_unknown=*/false)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
// Recheck supported_versions, in case this is the second ServerHello.
uint16_t version;
if (!have_supported_versions ||
!CBS_get_u16(&supported_versions, &version) ||
version != ssl->version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SECOND_SERVERHELLO_VERSION_MISMATCH);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
alert = SSL_AD_DECODE_ERROR;
if (have_pre_shared_key) {
if (ssl->session == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
if (!ssl_ext_pre_shared_key_parse_serverhello(hs, &alert,
&pre_shared_key)) {
ssl_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);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (ssl->session->cipher->algorithm_prf != cipher->algorithm_prf) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_PRF_HASH_MISMATCH);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl_session_is_context_valid(hs, ssl->session.get())) {
// This is actually a client application bug.
OPENSSL_PUT_ERROR(SSL,
SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
ssl->s3->session_reused = true;
hs->can_release_private_key = true;
// Only authentication information carries over in TLS 1.3.
hs->new_session =
SSL_SESSION_dup(ssl->session.get(), SSL_SESSION_DUP_AUTH_ONLY);
if (!hs->new_session) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
ssl_set_session(ssl, NULL);
// Resumption incorporates fresh key material, so refresh the timeout.
ssl_session_renew_timeout(ssl, hs->new_session.get(),
ssl->session_ctx->session_psk_dhe_timeout);
} else if (!ssl_get_new_session(hs)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->new_session->cipher = cipher;
hs->new_cipher = cipher;
size_t hash_len =
EVP_MD_size(ssl_get_handshake_digest(ssl_protocol_version(ssl), cipher));
// Set up the key schedule and incorporate the PSK into the running secret.
if (!tls13_init_key_schedule(
hs, ssl->s3->session_reused
? MakeConstSpan(hs->new_session->secret,
hs->new_session->secret_length)
: MakeConstSpan(kZeroes, hash_len))) {
return ssl_hs_error;
}
if (!have_key_share) {
// We do not support psk_ke and thus always require a key share.
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_KEY_SHARE);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
return ssl_hs_error;
}
// Resolve ECDHE and incorporate it into the secret.
Array<uint8_t> dhe_secret;
alert = SSL_AD_DECODE_ERROR;
if (!ssl_ext_key_share_parse_serverhello(hs, &dhe_secret, &alert,
&key_share)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (!tls13_advance_key_schedule(hs, dhe_secret)) {
return ssl_hs_error;
}
// Determine whether the server accepted ECH.
//
// TODO(https://crbug.com/boringssl/275): This is a bit late in the process of
// parsing ServerHello. |ssl->session| is only valid for ClientHelloInner, so
// the decisions made based on PSK need to be double-checked. draft-11 will
// fix this, at which point this logic can be moved before any processing.
if (hs->selected_ech_config) {
uint8_t ech_confirmation[ECH_CONFIRMATION_SIGNAL_LEN];
if (!hs->inner_transcript.InitHash(ssl_protocol_version(ssl),
hs->new_cipher) ||
!ssl_ech_accept_confirmation(hs, ech_confirmation, hs->inner_transcript,
msg.raw)) {
return ssl_hs_error;
}
if (CRYPTO_memcmp(ech_confirmation,
ssl->s3->server_random + sizeof(ssl->s3->server_random) -
sizeof(ech_confirmation),
sizeof(ech_confirmation)) == 0) {
ssl->s3->ech_status = ssl_ech_accepted;
hs->transcript = std::move(hs->inner_transcript);
hs->extensions.sent = hs->inner_extensions_sent;
// Report the inner random value through |SSL_get_client_random|.
OPENSSL_memcpy(ssl->s3->client_random, hs->inner_client_random,
SSL3_RANDOM_SIZE);
} else {
// Resuming against the ClientHelloOuter was an unsolicited extension.
if (have_pre_shared_key) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
ssl->s3->ech_status = ssl_ech_rejected;
}
}
if (!ssl_hash_message(hs, msg) ||
!tls13_derive_handshake_secrets(hs)) {
return ssl_hs_error;
}
// If currently sending early data over TCP, we defer installing client
// traffic keys to when the early data stream is closed. See
// |close_early_data|. Note if the server has already rejected 0-RTT via
// HelloRetryRequest, |in_early_data| is already false.
if (!hs->in_early_data || ssl->quic_method != nullptr) {
if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal,
hs->new_session.get(),
hs->client_handshake_secret())) {
return ssl_hs_error;
}
}
if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_open,
hs->new_session.get(),
hs->server_handshake_secret())) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_encrypted_extensions;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_encrypted_extensions(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_ENCRYPTED_EXTENSIONS)) {
return ssl_hs_error;
}
CBS body = msg.body;
if (!ssl_parse_serverhello_tlsext(hs, &body)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
if (CBS_len(&body) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (ssl->s3->early_data_accepted) {
// The extension parser checks the server resumed the session.
assert(ssl->s3->session_reused);
// If offering ECH, the server may not accept early data with
// ClientHelloOuter. We do not offer sessions with ClientHelloOuter, so this
// this should be implied by checking |session_reused|.
assert(ssl->s3->ech_status != ssl_ech_rejected);
if (hs->early_session->cipher != hs->new_session->cipher) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_MISMATCH_ON_EARLY_DATA);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (MakeConstSpan(hs->early_session->early_alpn) !=
ssl->s3->alpn_selected) {
OPENSSL_PUT_ERROR(SSL, SSL_R_ALPN_MISMATCH_ON_EARLY_DATA);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
// Channel ID is incompatible with 0-RTT. The ALPS extension should be
// negotiated implicitly.
if (hs->channel_id_negotiated ||
hs->new_session->has_application_settings) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION_ON_EARLY_DATA);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
hs->new_session->has_application_settings =
hs->early_session->has_application_settings;
if (!hs->new_session->local_application_settings.CopyFrom(
hs->early_session->local_application_settings) ||
!hs->new_session->peer_application_settings.CopyFrom(
hs->early_session->peer_application_settings)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
}
// Store the negotiated ALPN in the session.
if (!hs->new_session->early_alpn.CopyFrom(ssl->s3->alpn_selected)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_certificate_request;
if (hs->in_early_data && !ssl->s3->early_data_accepted) {
if (!close_early_data(hs, ssl_encryption_handshake)) {
return ssl_hs_error;
}
return ssl_hs_early_data_rejected;
}
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_certificate_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// CertificateRequest may only be sent in non-resumption handshakes.
if (ssl->s3->session_reused) {
if (ssl->ctx->reverify_on_resume && !ssl->s3->early_data_accepted) {
hs->tls13_state = state_server_certificate_reverify;
return ssl_hs_ok;
}
hs->tls13_state = state_read_server_finished;
return ssl_hs_ok;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
// CertificateRequest is optional.
if (msg.type != SSL3_MT_CERTIFICATE_REQUEST) {
hs->tls13_state = state_read_server_certificate;
return ssl_hs_ok;
}
bool have_sigalgs = false, have_ca = false;
CBS sigalgs, ca;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_signature_algorithms, &have_sigalgs, &sigalgs},
{TLSEXT_TYPE_certificate_authorities, &have_ca, &ca},
};
CBS body = msg.body, context, extensions, supported_signature_algorithms;
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!CBS_get_u8_length_prefixed(&body, &context) ||
// The request context is always empty during the handshake.
CBS_len(&context) != 0 ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
CBS_len(&body) != 0 ||
!ssl_parse_extensions(&extensions, &alert, ext_types,
/*ignore_unknown=*/true) ||
(have_ca && CBS_len(&ca) == 0) ||
!have_sigalgs ||
!CBS_get_u16_length_prefixed(&sigalgs,
&supported_signature_algorithms) ||
!tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (have_ca) {
hs->ca_names = ssl_parse_client_CA_list(ssl, &alert, &ca);
if (!hs->ca_names) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
} else {
hs->ca_names.reset(sk_CRYPTO_BUFFER_new_null());
if (!hs->ca_names) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
}
hs->cert_request = true;
ssl->ctx->x509_method->hs_flush_cached_ca_names(hs);
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_server_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_certificate(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (msg.type != SSL3_MT_COMPRESSED_CERTIFICATE &&
!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE)) {
return ssl_hs_error;
}
if (!tls13_process_certificate(hs, msg, false /* certificate required */) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_server_certificate_verify;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_certificate_verify(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
switch (ssl_verify_peer_cert(hs)) {
case ssl_verify_ok:
break;
case ssl_verify_invalid:
return ssl_hs_error;
case ssl_verify_retry:
hs->tls13_state = state_read_server_certificate_verify;
return ssl_hs_certificate_verify;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_VERIFY) ||
!tls13_process_certificate_verify(hs, msg) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_server_finished;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_server_certificate_reverify(SSL_HANDSHAKE *hs) {
switch (ssl_reverify_peer_cert(hs, /*send_alert=*/true)) {
case ssl_verify_ok:
break;
case ssl_verify_invalid:
return ssl_hs_error;
case ssl_verify_retry:
hs->tls13_state = state_server_certificate_reverify;
return ssl_hs_certificate_verify;
}
hs->tls13_state = state_read_server_finished;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_finished(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_FINISHED) ||
!tls13_process_finished(hs, msg, false /* don't use saved value */) ||
!ssl_hash_message(hs, msg) ||
// Update the secret to the master secret and derive traffic keys.
!tls13_advance_key_schedule(
hs, MakeConstSpan(kZeroes, hs->transcript.DigestLen())) ||
!tls13_derive_application_secrets(hs)) {
return ssl_hs_error;
}
// Finished should be the end of the flight.
if (ssl->method->has_unprocessed_handshake_data(ssl)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESS_HANDSHAKE_DATA);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_send_end_of_early_data;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_end_of_early_data(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->s3->early_data_accepted) {
// QUIC omits the EndOfEarlyData message. See RFC 9001, section 8.3.
if (ssl->quic_method == nullptr) {
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_END_OF_EARLY_DATA) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
return ssl_hs_error;
}
}
if (!close_early_data(hs, ssl_encryption_handshake)) {
return ssl_hs_error;
}
}
hs->tls13_state = state_send_client_encrypted_extensions;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_encrypted_extensions(
SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// For now, only one extension uses client EncryptedExtensions. This function
// may be generalized if others use it in the future.
if (hs->new_session->has_application_settings &&
!ssl->s3->early_data_accepted) {
ScopedCBB cbb;
CBB body, extensions, extension;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_ENCRYPTED_EXTENSIONS) ||
!CBB_add_u16_length_prefixed(&body, &extensions) ||
!CBB_add_u16(&extensions, TLSEXT_TYPE_application_settings) ||
!CBB_add_u16_length_prefixed(&extensions, &extension) ||
!CBB_add_bytes(&extension,
hs->new_session->local_application_settings.data(),
hs->new_session->local_application_settings.size()) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
return ssl_hs_error;
}
}
hs->tls13_state = state_send_client_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_certificate(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// The peer didn't request a certificate.
if (!hs->cert_request) {
hs->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
}
if (ssl->s3->ech_status == ssl_ech_rejected) {
// Do not send client certificates on ECH reject. We have not authenticated
// the server for the name that can learn the certificate.
SSL_certs_clear(ssl);
} else if (hs->config->cert->cert_cb != nullptr) {
// Call cert_cb to update the certificate.
int rv = hs->config->cert->cert_cb(ssl, hs->config->cert->cert_cb_arg);
if (rv == 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
return ssl_hs_error;
}
if (rv < 0) {
hs->tls13_state = state_send_client_certificate;
return ssl_hs_x509_lookup;
}
}
if (!ssl_on_certificate_selected(hs) ||
!tls13_add_certificate(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_send_client_certificate_verify;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_certificate_verify(SSL_HANDSHAKE *hs) {
// Don't send CertificateVerify if there is no certificate.
if (!ssl_has_certificate(hs)) {
hs->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
}
switch (tls13_add_certificate_verify(hs)) {
case ssl_private_key_success:
hs->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
case ssl_private_key_retry:
hs->tls13_state = state_send_client_certificate_verify;
return ssl_hs_private_key_operation;
case ssl_private_key_failure:
return ssl_hs_error;
}
assert(0);
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_complete_second_flight(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
hs->can_release_private_key = true;
// Send a Channel ID assertion if necessary.
if (hs->channel_id_negotiated) {
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CHANNEL_ID) ||
!tls1_write_channel_id(hs, &body) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
return ssl_hs_error;
}
}
// Send a Finished message.
if (!tls13_add_finished(hs)) {
return ssl_hs_error;
}
// Derive the final keys and enable them.
if (!tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_seal,
hs->new_session.get(),
hs->client_traffic_secret_0()) ||
!tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_open,
hs->new_session.get(),
hs->server_traffic_secret_0()) ||
!tls13_derive_resumption_secret(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_done;
return ssl_hs_flush;
}
enum ssl_hs_wait_t tls13_client_handshake(SSL_HANDSHAKE *hs) {
while (hs->tls13_state != state_done) {
enum ssl_hs_wait_t ret = ssl_hs_error;
enum client_hs_state_t state =
static_cast<enum client_hs_state_t>(hs->tls13_state);
switch (state) {
case state_read_hello_retry_request:
ret = do_read_hello_retry_request(hs);
break;
case state_send_second_client_hello:
ret = do_send_second_client_hello(hs);
break;
case state_read_server_hello:
ret = do_read_server_hello(hs);
break;
case state_read_encrypted_extensions:
ret = do_read_encrypted_extensions(hs);
break;
case state_read_certificate_request:
ret = do_read_certificate_request(hs);
break;
case state_read_server_certificate:
ret = do_read_server_certificate(hs);
break;
case state_read_server_certificate_verify:
ret = do_read_server_certificate_verify(hs);
break;
case state_server_certificate_reverify:
ret = do_server_certificate_reverify(hs);
break;
case state_read_server_finished:
ret = do_read_server_finished(hs);
break;
case state_send_end_of_early_data:
ret = do_send_end_of_early_data(hs);
break;
case state_send_client_certificate:
ret = do_send_client_certificate(hs);
break;
case state_send_client_encrypted_extensions:
ret = do_send_client_encrypted_extensions(hs);
break;
case state_send_client_certificate_verify:
ret = do_send_client_certificate_verify(hs);
break;
case state_complete_second_flight:
ret = do_complete_second_flight(hs);
break;
case state_done:
ret = ssl_hs_ok;
break;
}
if (hs->tls13_state != state) {
ssl_do_info_callback(hs->ssl, SSL_CB_CONNECT_LOOP, 1);
}
if (ret != ssl_hs_ok) {
return ret;
}
}
return ssl_hs_ok;
}
const char *tls13_client_handshake_state(SSL_HANDSHAKE *hs) {
enum client_hs_state_t state =
static_cast<enum client_hs_state_t>(hs->tls13_state);
switch (state) {
case state_read_hello_retry_request:
return "TLS 1.3 client read_hello_retry_request";
case state_send_second_client_hello:
return "TLS 1.3 client send_second_client_hello";
case state_read_server_hello:
return "TLS 1.3 client read_server_hello";
case state_read_encrypted_extensions:
return "TLS 1.3 client read_encrypted_extensions";
case state_read_certificate_request:
return "TLS 1.3 client read_certificate_request";
case state_read_server_certificate:
return "TLS 1.3 client read_server_certificate";
case state_read_server_certificate_verify:
return "TLS 1.3 client read_server_certificate_verify";
case state_server_certificate_reverify:
return "TLS 1.3 client server_certificate_reverify";
case state_read_server_finished:
return "TLS 1.3 client read_server_finished";
case state_send_end_of_early_data:
return "TLS 1.3 client send_end_of_early_data";
case state_send_client_encrypted_extensions:
return "TLS 1.3 client send_client_encrypted_extensions";
case state_send_client_certificate:
return "TLS 1.3 client send_client_certificate";
case state_send_client_certificate_verify:
return "TLS 1.3 client send_client_certificate_verify";
case state_complete_second_flight:
return "TLS 1.3 client complete_second_flight";
case state_done:
return "TLS 1.3 client done";
}
return "TLS 1.3 client unknown";
}
bool tls13_process_new_session_ticket(SSL *ssl, const SSLMessage &msg) {
if (ssl->s3->write_shutdown != ssl_shutdown_none) {
// Ignore tickets on shutdown. Callers tend to indiscriminately call
// |SSL_shutdown| before destroying an |SSL|, at which point calling the new
// session callback may be confusing.
return true;
}
CBS body = msg.body;
UniquePtr<SSL_SESSION> session = tls13_create_session_with_ticket(ssl, &body);
if (!session) {
return false;
}
if ((ssl->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) &&
ssl->session_ctx->new_session_cb != NULL &&
ssl->session_ctx->new_session_cb(ssl, session.get())) {
// |new_session_cb|'s return value signals that it took ownership.
session.release();
}
return true;
}
UniquePtr<SSL_SESSION> tls13_create_session_with_ticket(SSL *ssl, CBS *body) {
UniquePtr<SSL_SESSION> session = SSL_SESSION_dup(
ssl->s3->established_session.get(), SSL_SESSION_INCLUDE_NONAUTH);
if (!session) {
return nullptr;
}
ssl_session_rebase_time(ssl, session.get());
uint32_t server_timeout;
CBS ticket_nonce, ticket, extensions;
if (!CBS_get_u32(body, &server_timeout) ||
!CBS_get_u32(body, &session->ticket_age_add) ||
!CBS_get_u8_length_prefixed(body, &ticket_nonce) ||
!CBS_get_u16_length_prefixed(body, &ticket) ||
!session->ticket.CopyFrom(ticket) ||
!CBS_get_u16_length_prefixed(body, &extensions) ||
CBS_len(body) != 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return nullptr;
}
// Cap the renewable lifetime by the server advertised value. This avoids
// wasting bandwidth on 0-RTT when we know the server will reject it.
if (session->timeout > server_timeout) {
session->timeout = server_timeout;
}
if (!tls13_derive_session_psk(session.get(), ticket_nonce)) {
return nullptr;
}
// Parse out the extensions.
bool have_early_data = false;
CBS early_data;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_early_data, &have_early_data, &early_data},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
/*ignore_unknown=*/true)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return nullptr;
}
if (have_early_data) {
if (!CBS_get_u32(&early_data, &session->ticket_max_early_data) ||
CBS_len(&early_data) != 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return nullptr;
}
// QUIC does not use the max_early_data_size parameter and always sets it to
// a fixed value. See RFC 9001, section 4.6.1.
if (ssl->quic_method != nullptr &&
session->ticket_max_early_data != 0xffffffff) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return nullptr;
}
}
// Historically, OpenSSL filled in fake session IDs for ticket-based sessions.
// Envoy's tests depend on this, although perhaps they shouldn't.
SHA256(CBS_data(&ticket), CBS_len(&ticket), session->session_id);
session->session_id_length = SHA256_DIGEST_LENGTH;
session->ticket_age_add_valid = true;
session->not_resumable = false;
return session;
}
BSSL_NAMESPACE_END