blob: 3d0d8dc4d730898f9e393b03bc9b36dd228f9481 [file] [log] [blame]
// Copyright (c) 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/third_party/quiche/src/quic/core/tls_server_handshaker.h"
#include <memory>
#include <string>
#include "absl/base/macros.h"
#include "absl/strings/string_view.h"
#include "third_party/boringssl/src/include/openssl/pool.h"
#include "third_party/boringssl/src/include/openssl/ssl.h"
#include "net/third_party/quiche/src/quic/core/crypto/quic_crypto_server_config.h"
#include "net/third_party/quiche/src/quic/core/crypto/transport_parameters.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_flag_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_flags.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_hostname_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
#include "net/third_party/quiche/src/common/platform/api/quiche_text_utils.h"
namespace quic {
TlsServerHandshaker::SignatureCallback::SignatureCallback(
TlsServerHandshaker* handshaker)
: handshaker_(handshaker) {}
void TlsServerHandshaker::SignatureCallback::Run(
bool ok,
std::string signature,
std::unique_ptr<ProofSource::Details> details) {
if (handshaker_ == nullptr) {
return;
}
if (ok) {
handshaker_->cert_verify_sig_ = std::move(signature);
handshaker_->proof_source_details_ = std::move(details);
}
int last_expected_ssl_error = handshaker_->expected_ssl_error();
handshaker_->set_expected_ssl_error(SSL_ERROR_WANT_READ);
handshaker_->signature_callback_ = nullptr;
if (last_expected_ssl_error == SSL_ERROR_WANT_PRIVATE_KEY_OPERATION) {
handshaker_->AdvanceHandshakeFromCallback();
}
}
void TlsServerHandshaker::SignatureCallback::Cancel() {
handshaker_ = nullptr;
}
TlsServerHandshaker::DecryptCallback::DecryptCallback(
TlsServerHandshaker* handshaker)
: handshaker_(handshaker) {}
void TlsServerHandshaker::DecryptCallback::Run(std::vector<uint8_t> plaintext) {
if (handshaker_ == nullptr) {
// The callback was cancelled before we could run.
return;
}
handshaker_->decrypted_session_ticket_ = std::move(plaintext);
// DecryptCallback::Run could be called synchronously. When that happens, we
// are currently in the middle of a call to AdvanceHandshake.
// (AdvanceHandshake called SSL_do_handshake, which through some layers called
// SessionTicketOpen, which called TicketCrypter::Decrypt, which synchronously
// called this function.) In that case, the handshake will continue to be
// processed when this function returns.
//
// When this callback is called asynchronously (i.e. the ticket decryption is
// pending), TlsServerHandshaker is not actively processing handshake
// messages. We need to have it resume processing handshake messages by
// calling AdvanceHandshake.
if (handshaker_->expected_ssl_error() == SSL_ERROR_PENDING_TICKET) {
handshaker_->AdvanceHandshakeFromCallback();
}
// The TicketDecrypter took ownership of this callback when Decrypt was
// called. Once the callback returns, it will be deleted. Remove the
// (non-owning) pointer to the callback from the handshaker so the handshaker
// doesn't have an invalid pointer hanging around.
handshaker_->ticket_decryption_callback_ = nullptr;
}
void TlsServerHandshaker::DecryptCallback::Cancel() {
DCHECK(handshaker_);
handshaker_ = nullptr;
}
TlsServerHandshaker::TlsServerHandshaker(
QuicSession* session,
const QuicCryptoServerConfig& crypto_config)
: TlsHandshaker(this, session),
QuicCryptoServerStreamBase(session),
proof_source_(crypto_config.proof_source()),
pre_shared_key_(crypto_config.pre_shared_key()),
crypto_negotiated_params_(new QuicCryptoNegotiatedParameters),
tls_connection_(crypto_config.ssl_ctx(), this) {
DCHECK_EQ(PROTOCOL_TLS1_3,
session->connection()->version().handshake_protocol);
// Configure the SSL to be a server.
SSL_set_accept_state(ssl());
if (GetQuicFlag(FLAGS_quic_disable_server_tls_resumption)) {
SSL_set_options(ssl(), SSL_OP_NO_TICKET);
}
}
TlsServerHandshaker::~TlsServerHandshaker() {
CancelOutstandingCallbacks();
}
void TlsServerHandshaker::CancelOutstandingCallbacks() {
if (signature_callback_) {
signature_callback_->Cancel();
signature_callback_ = nullptr;
}
if (ticket_decryption_callback_) {
ticket_decryption_callback_->Cancel();
ticket_decryption_callback_ = nullptr;
}
}
bool TlsServerHandshaker::GetBase64SHA256ClientChannelID(
std::string* /*output*/) const {
// Channel ID is not supported when TLS is used in QUIC.
return false;
}
void TlsServerHandshaker::SendServerConfigUpdate(
const CachedNetworkParameters* /*cached_network_params*/) {
// SCUP messages aren't supported when using the TLS handshake.
}
bool TlsServerHandshaker::IsZeroRtt() const {
return SSL_early_data_accepted(ssl());
}
bool TlsServerHandshaker::IsResumption() const {
return SSL_session_reused(ssl());
}
bool TlsServerHandshaker::ResumptionAttempted() const {
return ticket_received_;
}
int TlsServerHandshaker::NumServerConfigUpdateMessagesSent() const {
// SCUP messages aren't supported when using the TLS handshake.
return 0;
}
const CachedNetworkParameters*
TlsServerHandshaker::PreviousCachedNetworkParams() const {
return nullptr;
}
void TlsServerHandshaker::SetPreviousCachedNetworkParams(
CachedNetworkParameters /*cached_network_params*/) {}
void TlsServerHandshaker::OnPacketDecrypted(EncryptionLevel level) {
if (level == ENCRYPTION_HANDSHAKE && state_ < HANDSHAKE_PROCESSED) {
state_ = HANDSHAKE_PROCESSED;
handshaker_delegate()->DiscardOldEncryptionKey(ENCRYPTION_INITIAL);
handshaker_delegate()->DiscardOldDecryptionKey(ENCRYPTION_INITIAL);
}
}
void TlsServerHandshaker::OnHandshakeDoneReceived() {
DCHECK(false);
}
bool TlsServerHandshaker::ShouldSendExpectCTHeader() const {
return false;
}
const ProofSource::Details* TlsServerHandshaker::ProofSourceDetails() const {
return proof_source_details_.get();
}
void TlsServerHandshaker::OnConnectionClosed(QuicErrorCode error,
ConnectionCloseSource source) {
TlsHandshaker::OnConnectionClosed(error, source);
}
ssl_early_data_reason_t TlsServerHandshaker::EarlyDataReason() const {
return TlsHandshaker::EarlyDataReason();
}
bool TlsServerHandshaker::encryption_established() const {
return encryption_established_;
}
bool TlsServerHandshaker::one_rtt_keys_available() const {
return state_ == HANDSHAKE_CONFIRMED;
}
const QuicCryptoNegotiatedParameters&
TlsServerHandshaker::crypto_negotiated_params() const {
return *crypto_negotiated_params_;
}
CryptoMessageParser* TlsServerHandshaker::crypto_message_parser() {
return TlsHandshaker::crypto_message_parser();
}
HandshakeState TlsServerHandshaker::GetHandshakeState() const {
return state_;
}
void TlsServerHandshaker::SetServerApplicationStateForResumption(
std::unique_ptr<ApplicationState> state) {
application_state_ = std::move(state);
}
size_t TlsServerHandshaker::BufferSizeLimitForLevel(
EncryptionLevel level) const {
return TlsHandshaker::BufferSizeLimitForLevel(level);
}
bool TlsServerHandshaker::KeyUpdateSupportedLocally() const {
return true;
}
std::unique_ptr<QuicDecrypter>
TlsServerHandshaker::AdvanceKeysAndCreateCurrentOneRttDecrypter() {
return TlsHandshaker::AdvanceKeysAndCreateCurrentOneRttDecrypter();
}
std::unique_ptr<QuicEncrypter>
TlsServerHandshaker::CreateCurrentOneRttEncrypter() {
return TlsHandshaker::CreateCurrentOneRttEncrypter();
}
void TlsServerHandshaker::OverrideQuicConfigDefaults(QuicConfig* /*config*/) {}
void TlsServerHandshaker::AdvanceHandshakeFromCallback() {
AdvanceHandshake();
if (GetQuicReloadableFlag(
quic_process_undecryptable_packets_after_async_decrypt_callback) &&
!is_connection_closed()) {
QUIC_RELOADABLE_FLAG_COUNT(
quic_process_undecryptable_packets_after_async_decrypt_callback);
handshaker_delegate()->OnHandshakeCallbackDone();
}
}
bool TlsServerHandshaker::ProcessTransportParameters(
const SSL_CLIENT_HELLO* client_hello,
std::string* error_details) {
TransportParameters client_params;
const uint8_t* client_params_bytes;
size_t params_bytes_len;
if (use_early_select_cert_) {
// When using early select cert callback, SSL_get_peer_quic_transport_params
// can not be used to retrieve the client's transport parameters, but we can
// use SSL_early_callback_ctx_extension_get to do that.
if (!SSL_early_callback_ctx_extension_get(
client_hello, TLSEXT_TYPE_quic_transport_parameters,
&client_params_bytes, &params_bytes_len)) {
params_bytes_len = 0;
}
} else {
DCHECK_EQ(client_hello, nullptr);
SSL_get_peer_quic_transport_params(ssl(), &client_params_bytes,
&params_bytes_len);
}
if (params_bytes_len == 0) {
*error_details = "Client's transport parameters are missing";
return false;
}
std::string parse_error_details;
if (!ParseTransportParameters(session()->connection()->version(),
Perspective::IS_CLIENT, client_params_bytes,
params_bytes_len, &client_params,
&parse_error_details)) {
DCHECK(!parse_error_details.empty());
*error_details =
"Unable to parse client's transport parameters: " + parse_error_details;
return false;
}
// Notify QuicConnectionDebugVisitor.
session()->connection()->OnTransportParametersReceived(client_params);
// Chrome clients before 86.0.4233.0 did not send the
// key_update_not_yet_supported transport parameter, but they did send a
// Google-internal transport parameter with identifier 0x4751. We treat
// reception of 0x4751 as having received key_update_not_yet_supported to
// ensure we do not use key updates with those older clients.
// TODO(dschinazi) remove this workaround once all of our QUIC+TLS Finch
// experiments have a min_version greater than 86.0.4233.0.
if (client_params.custom_parameters.find(
static_cast<TransportParameters::TransportParameterId>(0x4751)) !=
client_params.custom_parameters.end()) {
client_params.key_update_not_yet_supported = true;
}
// When interoperating with non-Google implementations that do not send
// the version extension, set it to what we expect.
if (client_params.version == 0) {
client_params.version =
CreateQuicVersionLabel(session()->connection()->version());
}
if (CryptoUtils::ValidateClientHelloVersion(
client_params.version, session()->connection()->version(),
session()->supported_versions(), error_details) != QUIC_NO_ERROR ||
handshaker_delegate()->ProcessTransportParameters(
client_params, /* is_resumption = */ false, error_details) !=
QUIC_NO_ERROR) {
return false;
}
ProcessAdditionalTransportParameters(client_params);
if (!session()->user_agent_id().has_value() &&
client_params.user_agent_id.has_value()) {
session()->SetUserAgentId(client_params.user_agent_id.value());
}
return true;
}
bool TlsServerHandshaker::SetTransportParameters() {
TransportParameters server_params;
server_params.perspective = Perspective::IS_SERVER;
server_params.supported_versions =
CreateQuicVersionLabelVector(session()->supported_versions());
server_params.version =
CreateQuicVersionLabel(session()->connection()->version());
if (!handshaker_delegate()->FillTransportParameters(&server_params)) {
return false;
}
// Notify QuicConnectionDebugVisitor.
session()->connection()->OnTransportParametersSent(server_params);
std::vector<uint8_t> server_params_bytes;
if (!SerializeTransportParameters(session()->connection()->version(),
server_params, &server_params_bytes) ||
SSL_set_quic_transport_params(ssl(), server_params_bytes.data(),
server_params_bytes.size()) != 1) {
return false;
}
if (application_state_) {
std::vector<uint8_t> early_data_context;
if (!SerializeTransportParametersForTicket(
server_params, *application_state_, &early_data_context)) {
QUIC_BUG << "Failed to serialize Transport Parameters for ticket.";
return false;
}
SSL_set_quic_early_data_context(ssl(), early_data_context.data(),
early_data_context.size());
application_state_.reset(nullptr);
}
return true;
}
void TlsServerHandshaker::SetWriteSecret(
EncryptionLevel level,
const SSL_CIPHER* cipher,
const std::vector<uint8_t>& write_secret) {
if (is_connection_closed()) {
return;
}
if (level == ENCRYPTION_FORWARD_SECURE) {
encryption_established_ = true;
// Fill crypto_negotiated_params_:
const SSL_CIPHER* cipher = SSL_get_current_cipher(ssl());
if (cipher) {
crypto_negotiated_params_->cipher_suite = SSL_CIPHER_get_value(cipher);
}
crypto_negotiated_params_->key_exchange_group = SSL_get_curve_id(ssl());
}
TlsHandshaker::SetWriteSecret(level, cipher, write_secret);
}
void TlsServerHandshaker::FinishHandshake() {
if (SSL_in_early_data(ssl())) {
// If the server accepts early data, SSL_do_handshake returns success twice:
// once after processing the ClientHello and sending the server's first
// flight, and then again after the handshake is complete. This results in
// FinishHandshake getting called twice. On the first call to
// FinishHandshake, we don't have any confirmation that the client is live,
// so all end of handshake processing is deferred until the handshake is
// actually complete.
QUIC_RESTART_FLAG_COUNT(quic_enable_zero_rtt_for_tls_v2);
return;
}
if (!valid_alpn_received_) {
QUIC_DLOG(ERROR)
<< "Server: handshake finished without receiving a known ALPN";
// TODO(b/130164908) this should send no_application_protocol
// instead of QUIC_HANDSHAKE_FAILED.
CloseConnection(QUIC_HANDSHAKE_FAILED,
"Server did not receive a known ALPN");
return;
}
ssl_early_data_reason_t reason_code = EarlyDataReason();
QUIC_DLOG(INFO) << "Server: handshake finished. Early data reason "
<< reason_code << " ("
<< CryptoUtils::EarlyDataReasonToString(reason_code) << ")";
state_ = HANDSHAKE_CONFIRMED;
handshaker_delegate()->OnTlsHandshakeComplete();
handshaker_delegate()->DiscardOldEncryptionKey(ENCRYPTION_HANDSHAKE);
handshaker_delegate()->DiscardOldDecryptionKey(ENCRYPTION_HANDSHAKE);
handshaker_delegate()->DiscardOldDecryptionKey(ENCRYPTION_ZERO_RTT);
}
QuicAsyncStatus TlsServerHandshaker::VerifyCertChain(
const std::vector<std::string>& /*certs*/,
std::string* /*error_details*/,
std::unique_ptr<ProofVerifyDetails>* /*details*/,
uint8_t* /*out_alert*/,
std::unique_ptr<ProofVerifierCallback> /*callback*/) {
QUIC_BUG << "Client certificates are not yet supported on the server";
return QUIC_FAILURE;
}
void TlsServerHandshaker::OnProofVerifyDetailsAvailable(
const ProofVerifyDetails& /*verify_details*/) {}
ssl_private_key_result_t TlsServerHandshaker::PrivateKeySign(
uint8_t* out,
size_t* out_len,
size_t max_out,
uint16_t sig_alg,
absl::string_view in) {
signature_callback_ = new SignatureCallback(this);
proof_source_->ComputeTlsSignature(
session()->connection()->self_address(),
session()->connection()->peer_address(), hostname_, sig_alg, in,
std::unique_ptr<SignatureCallback>(signature_callback_));
if (signature_callback_) {
set_expected_ssl_error(SSL_ERROR_WANT_PRIVATE_KEY_OPERATION);
return ssl_private_key_retry;
}
return PrivateKeyComplete(out, out_len, max_out);
}
ssl_private_key_result_t TlsServerHandshaker::PrivateKeyComplete(
uint8_t* out,
size_t* out_len,
size_t max_out) {
if (expected_ssl_error() == SSL_ERROR_WANT_PRIVATE_KEY_OPERATION) {
return ssl_private_key_retry;
}
if (cert_verify_sig_.size() > max_out || cert_verify_sig_.empty()) {
return ssl_private_key_failure;
}
*out_len = cert_verify_sig_.size();
memcpy(out, cert_verify_sig_.data(), *out_len);
cert_verify_sig_.clear();
cert_verify_sig_.shrink_to_fit();
return ssl_private_key_success;
}
size_t TlsServerHandshaker::SessionTicketMaxOverhead() {
DCHECK(proof_source_->GetTicketCrypter());
return proof_source_->GetTicketCrypter()->MaxOverhead();
}
int TlsServerHandshaker::SessionTicketSeal(uint8_t* out,
size_t* out_len,
size_t max_out_len,
absl::string_view in) {
DCHECK(proof_source_->GetTicketCrypter());
std::vector<uint8_t> ticket = proof_source_->GetTicketCrypter()->Encrypt(in);
if (max_out_len < ticket.size()) {
QUIC_BUG
<< "TicketCrypter returned " << ticket.size()
<< " bytes of ciphertext, which is larger than its max overhead of "
<< max_out_len;
return 0; // failure
}
*out_len = ticket.size();
memcpy(out, ticket.data(), ticket.size());
return 1; // success
}
ssl_ticket_aead_result_t TlsServerHandshaker::SessionTicketOpen(
uint8_t* out,
size_t* out_len,
size_t max_out_len,
absl::string_view in) {
DCHECK(proof_source_->GetTicketCrypter());
if (!ticket_decryption_callback_) {
ticket_received_ = true;
ticket_decryption_callback_ = new DecryptCallback(this);
proof_source_->GetTicketCrypter()->Decrypt(
in, std::unique_ptr<DecryptCallback>(ticket_decryption_callback_));
// Decrypt can run the callback synchronously. In that case, the callback
// will clear the ticket_decryption_callback_ pointer, and instead of
// returning ssl_ticket_aead_retry, we should continue processing to return
// the decrypted ticket.
//
// If the callback is not run asynchronously, return ssl_ticket_aead_retry
// and when the callback is complete this function will be run again to
// return the result.
if (ticket_decryption_callback_) {
set_expected_ssl_error(SSL_ERROR_PENDING_TICKET);
return ssl_ticket_aead_retry;
}
}
ticket_decryption_callback_ = nullptr;
set_expected_ssl_error(SSL_ERROR_WANT_READ);
if (decrypted_session_ticket_.empty()) {
QUIC_DLOG(ERROR) << "Session ticket decryption failed; ignoring ticket";
// Ticket decryption failed. Ignore the ticket.
return ssl_ticket_aead_ignore_ticket;
}
if (max_out_len < decrypted_session_ticket_.size()) {
return ssl_ticket_aead_error;
}
memcpy(out, decrypted_session_ticket_.data(),
decrypted_session_ticket_.size());
*out_len = decrypted_session_ticket_.size();
return ssl_ticket_aead_success;
}
ssl_select_cert_result_t TlsServerHandshaker::EarlySelectCertCallback(
const SSL_CLIENT_HELLO* client_hello) {
if (!use_early_select_cert_) {
return ssl_select_cert_success;
}
QUIC_RELOADABLE_FLAG_COUNT(quic_tls_use_early_select_cert);
if (!pre_shared_key_.empty()) {
// TODO(b/154162689) add PSK support to QUIC+TLS.
QUIC_BUG << "QUIC server pre-shared keys not yet supported with TLS";
return ssl_select_cert_error;
}
// This callback is called very early by Boring SSL, most of the SSL_get_foo
// function do not work at this point, but SSL_get_servername does.
const char* hostname = SSL_get_servername(ssl(), TLSEXT_NAMETYPE_host_name);
if (hostname) {
hostname_ = hostname;
crypto_negotiated_params_->sni =
QuicHostnameUtils::NormalizeHostname(hostname_);
if (!ValidateHostname(hostname_)) {
return ssl_select_cert_error;
}
} else {
QUIC_LOG(INFO) << "No hostname indicated in SNI";
}
QuicReferenceCountedPointer<ProofSource::Chain> chain =
proof_source_->GetCertChain(session()->connection()->self_address(),
session()->connection()->peer_address(),
hostname_);
if (!chain || chain->certs.empty()) {
QUIC_LOG(ERROR) << "No certs provided for host '" << hostname_ << "'";
return ssl_select_cert_error;
}
CryptoBuffers cert_buffers = chain->ToCryptoBuffers();
tls_connection_.SetCertChain(cert_buffers.value);
std::string error_details;
if (!ProcessTransportParameters(client_hello, &error_details)) {
CloseConnection(QUIC_HANDSHAKE_FAILED, error_details);
return ssl_select_cert_error;
}
OverrideQuicConfigDefaults(session()->config());
session()->OnConfigNegotiated();
if (!SetTransportParameters()) {
QUIC_LOG(ERROR) << "Failed to set transport parameters";
return ssl_select_cert_error;
}
QUIC_DLOG(INFO) << "Set " << chain->certs.size() << " certs for server "
<< "with hostname " << hostname_;
return ssl_select_cert_success;
}
bool TlsServerHandshaker::ValidateHostname(const std::string& hostname) const {
if (!QuicHostnameUtils::IsValidSNI(hostname)) {
// TODO(b/151676147): Include this error string in the CONNECTION_CLOSE
// frame.
QUIC_LOG(ERROR) << "Invalid SNI provided: \"" << hostname << "\"";
return false;
}
return true;
}
int TlsServerHandshaker::SelectCertificate(int* out_alert) {
if (use_early_select_cert_) {
return SSL_TLSEXT_ERR_OK;
}
const char* hostname = SSL_get_servername(ssl(), TLSEXT_NAMETYPE_host_name);
if (hostname) {
hostname_ = hostname;
crypto_negotiated_params_->sni =
QuicHostnameUtils::NormalizeHostname(hostname_);
if (!ValidateHostname(hostname_)) {
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
} else {
QUIC_LOG(INFO) << "No hostname indicated in SNI";
}
QuicReferenceCountedPointer<ProofSource::Chain> chain =
proof_source_->GetCertChain(session()->connection()->self_address(),
session()->connection()->peer_address(),
hostname_);
if (!chain || chain->certs.empty()) {
QUIC_LOG(ERROR) << "No certs provided for host '" << hostname_ << "'";
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
if (!pre_shared_key_.empty()) {
// TODO(b/154162689) add PSK support to QUIC+TLS.
QUIC_BUG << "QUIC server pre-shared keys not yet supported with TLS";
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
CryptoBuffers cert_buffers = chain->ToCryptoBuffers();
tls_connection_.SetCertChain(cert_buffers.value);
std::string error_details;
if (!ProcessTransportParameters(nullptr, &error_details)) {
CloseConnection(QUIC_HANDSHAKE_FAILED, error_details);
*out_alert = SSL_AD_INTERNAL_ERROR;
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
OverrideQuicConfigDefaults(session()->config());
session()->OnConfigNegotiated();
if (!SetTransportParameters()) {
QUIC_LOG(ERROR) << "Failed to set transport parameters";
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
QUIC_DLOG(INFO) << "Set " << chain->certs.size() << " certs for server "
<< "with hostname " << hostname_;
return SSL_TLSEXT_ERR_OK;
}
int TlsServerHandshaker::SelectAlpn(const uint8_t** out,
uint8_t* out_len,
const uint8_t* in,
unsigned in_len) {
// |in| contains a sequence of 1-byte-length-prefixed values.
*out_len = 0;
*out = nullptr;
if (in_len == 0) {
QUIC_DLOG(ERROR) << "No ALPN provided by client";
return SSL_TLSEXT_ERR_NOACK;
}
CBS all_alpns;
CBS_init(&all_alpns, in, in_len);
std::vector<absl::string_view> alpns;
while (CBS_len(&all_alpns) > 0) {
CBS alpn;
if (!CBS_get_u8_length_prefixed(&all_alpns, &alpn)) {
QUIC_DLOG(ERROR) << "Failed to parse ALPN length";
return SSL_TLSEXT_ERR_NOACK;
}
const size_t alpn_length = CBS_len(&alpn);
if (alpn_length == 0) {
QUIC_DLOG(ERROR) << "Received invalid zero-length ALPN";
return SSL_TLSEXT_ERR_NOACK;
}
alpns.emplace_back(reinterpret_cast<const char*>(CBS_data(&alpn)),
alpn_length);
}
auto selected_alpn = session()->SelectAlpn(alpns);
if (selected_alpn == alpns.end()) {
QUIC_DLOG(ERROR) << "No known ALPN provided by client";
return SSL_TLSEXT_ERR_NOACK;
}
session()->OnAlpnSelected(*selected_alpn);
valid_alpn_received_ = true;
*out_len = selected_alpn->size();
*out = reinterpret_cast<const uint8_t*>(selected_alpn->data());
return SSL_TLSEXT_ERR_OK;
}
} // namespace quic