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/*
* Copyright 2016 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/p2p/quic/quictransportchannel.h"
#include <utility>
#include "net/quic/crypto/proof_source.h"
#include "net/quic/crypto/proof_verifier.h"
#include "net/quic/crypto/quic_crypto_client_config.h"
#include "net/quic/crypto/quic_crypto_server_config.h"
#include "net/quic/quic_connection.h"
#include "net/quic/quic_crypto_client_stream.h"
#include "net/quic/quic_crypto_server_stream.h"
#include "net/quic/quic_packet_writer.h"
#include "net/quic/quic_protocol.h"
#include "webrtc/base/checks.h"
#include "webrtc/base/helpers.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/socket.h"
#include "webrtc/base/thread.h"
#include "webrtc/p2p/base/common.h"
namespace {
// QUIC public header constants for net::QuicConnection. These are arbitrary
// given that |channel_| only receives packets specific to this channel,
// in which case we already know the QUIC packets have the correct destination.
const net::QuicConnectionId kConnectionId = 0;
const net::IPAddress kConnectionIpAddress(0, 0, 0, 0);
const net::IPEndPoint kConnectionIpEndpoint(kConnectionIpAddress, 0);
// Arbitrary server port number for net::QuicCryptoClientConfig.
const int kQuicServerPort = 0;
// QUIC connection timeout. This is large so that |channel_| can
// be responsible for connection timeout.
const int kIdleConnectionStateLifetime = 1000; // seconds
// Length of HKDF input keying material, equal to its number of bytes.
// https://tools.ietf.org/html/rfc5869#section-2.2.
// TODO(mikescarlett): Verify that input keying material length is correct.
const size_t kInputKeyingMaterialLength = 32;
// We don't pull the RTP constants from rtputils.h, to avoid a layer violation.
const size_t kMinRtpPacketLen = 12;
bool IsRtpPacket(const char* data, size_t len) {
const uint8_t* u = reinterpret_cast<const uint8_t*>(data);
return (len >= kMinRtpPacketLen && (u[0] & 0xC0) == 0x80);
}
// Function for detecting QUIC packets based off
// https://tools.ietf.org/html/draft-tsvwg-quic-protocol-02#section-6.
const size_t kMinQuicPacketLen = 2;
bool IsQuicPacket(const char* data, size_t len) {
const uint8_t* u = reinterpret_cast<const uint8_t*>(data);
return (len >= kMinQuicPacketLen && (u[0] & 0x80) == 0);
}
// Used by QuicCryptoServerConfig to provide dummy proof credentials.
// TODO(mikescarlett): Remove when secure P2P QUIC handshake is possible.
class DummyProofSource : public net::ProofSource {
public:
DummyProofSource() {}
~DummyProofSource() override {}
// ProofSource override.
bool GetProof(const net::IPAddress& server_ip,
const std::string& hostname,
const std::string& server_config,
net::QuicVersion quic_version,
base::StringPiece chlo_hash,
bool ecdsa_ok,
scoped_refptr<net::ProofSource::Chain>* out_chain,
std::string* out_signature,
std::string* out_leaf_cert_sct) override {
LOG(LS_INFO) << "GetProof() providing dummy credentials for insecure QUIC";
std::vector<std::string> certs;
certs.push_back("Dummy cert");
*out_chain = new ProofSource::Chain(certs);
*out_signature = "Dummy signature";
*out_leaf_cert_sct = "Dummy timestamp";
return true;
}
};
// Used by QuicCryptoClientConfig to ignore the peer's credentials
// and establish an insecure QUIC connection.
// TODO(mikescarlett): Remove when secure P2P QUIC handshake is possible.
class InsecureProofVerifier : public net::ProofVerifier {
public:
InsecureProofVerifier() {}
~InsecureProofVerifier() override {}
// ProofVerifier override.
net::QuicAsyncStatus VerifyProof(
const std::string& hostname,
const uint16_t port,
const std::string& server_config,
net::QuicVersion quic_version,
base::StringPiece chlo_hash,
const std::vector<std::string>& certs,
const std::string& cert_sct,
const std::string& signature,
const net::ProofVerifyContext* context,
std::string* error_details,
std::unique_ptr<net::ProofVerifyDetails>* verify_details,
net::ProofVerifierCallback* callback) override {
LOG(LS_INFO) << "VerifyProof() ignoring credentials and returning success";
return net::QUIC_SUCCESS;
}
};
} // namespace
namespace cricket {
QuicTransportChannel::QuicTransportChannel(TransportChannelImpl* channel)
: TransportChannelImpl(channel->transport_name(), channel->component()),
network_thread_(rtc::Thread::Current()),
channel_(channel),
helper_(network_thread_) {
channel_->SignalWritableState.connect(this,
&QuicTransportChannel::OnWritableState);
channel_->SignalReadPacket.connect(this, &QuicTransportChannel::OnReadPacket);
channel_->SignalSentPacket.connect(this, &QuicTransportChannel::OnSentPacket);
channel_->SignalReadyToSend.connect(this,
&QuicTransportChannel::OnReadyToSend);
channel_->SignalGatheringState.connect(
this, &QuicTransportChannel::OnGatheringState);
channel_->SignalCandidateGathered.connect(
this, &QuicTransportChannel::OnCandidateGathered);
channel_->SignalRoleConflict.connect(this,
&QuicTransportChannel::OnRoleConflict);
channel_->SignalRouteChange.connect(this,
&QuicTransportChannel::OnRouteChange);
channel_->SignalSelectedCandidatePairChanged.connect(
this, &QuicTransportChannel::OnSelectedCandidatePairChanged);
channel_->SignalStateChanged.connect(
this, &QuicTransportChannel::OnChannelStateChanged);
channel_->SignalReceivingState.connect(
this, &QuicTransportChannel::OnReceivingState);
// Set the QUIC connection timeout.
config_.SetIdleConnectionStateLifetime(
net::QuicTime::Delta::FromSeconds(kIdleConnectionStateLifetime),
net::QuicTime::Delta::FromSeconds(kIdleConnectionStateLifetime));
// Set the bytes reserved for the QUIC connection ID to zero.
config_.SetBytesForConnectionIdToSend(0);
}
QuicTransportChannel::~QuicTransportChannel() {}
bool QuicTransportChannel::SetLocalCertificate(
const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) {
if (!certificate) {
LOG_J(LS_ERROR, this)
<< "No local certificate was supplied. Not doing QUIC.";
return false;
}
if (!local_certificate_) {
local_certificate_ = certificate;
return true;
}
if (certificate == local_certificate_) {
// This may happen during renegotiation.
LOG_J(LS_INFO, this) << "Ignoring identical certificate";
return true;
}
LOG_J(LS_ERROR, this)
<< "Local certificate of the QUIC connection already set. "
"Can't change the local certificate once it's active.";
return false;
}
rtc::scoped_refptr<rtc::RTCCertificate>
QuicTransportChannel::GetLocalCertificate() const {
return local_certificate_;
}
bool QuicTransportChannel::SetSslRole(rtc::SSLRole role) {
if (ssl_role_ && *ssl_role_ == role) {
LOG_J(LS_WARNING, this) << "Ignoring SSL Role identical to current role.";
return true;
}
if (quic_state_ != QUIC_TRANSPORT_CONNECTED) {
ssl_role_ = rtc::Optional<rtc::SSLRole>(role);
return true;
}
LOG_J(LS_ERROR, this)
<< "SSL Role can't be reversed after the session is setup.";
return false;
}
bool QuicTransportChannel::GetSslRole(rtc::SSLRole* role) const {
if (!ssl_role_) {
return false;
}
*role = *ssl_role_;
return true;
}
bool QuicTransportChannel::SetRemoteFingerprint(const std::string& digest_alg,
const uint8_t* digest,
size_t digest_len) {
if (digest_alg.empty()) {
RTC_DCHECK(!digest_len);
LOG_J(LS_ERROR, this) << "Remote peer doesn't support digest algorithm.";
return false;
}
std::string remote_fingerprint_value(reinterpret_cast<const char*>(digest),
digest_len);
// Once we have the local certificate, the same remote fingerprint can be set
// multiple times. This may happen during renegotiation.
if (remote_fingerprint_ &&
remote_fingerprint_->value == remote_fingerprint_value &&
remote_fingerprint_->algorithm == digest_alg) {
LOG_J(LS_INFO, this)
<< "Ignoring identical remote fingerprint and algorithm";
return true;
}
remote_fingerprint_ = rtc::Optional<RemoteFingerprint>(RemoteFingerprint());
remote_fingerprint_->value = remote_fingerprint_value;
remote_fingerprint_->algorithm = digest_alg;
return true;
}
bool QuicTransportChannel::ExportKeyingMaterial(const std::string& label,
const uint8_t* context,
size_t context_len,
bool use_context,
uint8_t* result,
size_t result_len) {
std::string quic_context(reinterpret_cast<const char*>(context), context_len);
std::string quic_result;
if (!quic_->ExportKeyingMaterial(label, quic_context, result_len,
&quic_result)) {
return false;
}
quic_result.copy(reinterpret_cast<char*>(result), result_len);
return true;
}
bool QuicTransportChannel::GetSrtpCryptoSuite(int* cipher) {
*cipher = rtc::SRTP_AES128_CM_SHA1_80;
return true;
}
// Called from upper layers to send a media packet.
int QuicTransportChannel::SendPacket(const char* data,
size_t size,
const rtc::PacketOptions& options,
int flags) {
if ((flags & PF_SRTP_BYPASS) && IsRtpPacket(data, size)) {
return channel_->SendPacket(data, size, options);
}
LOG(LS_ERROR) << "Failed to send an invalid SRTP bypass packet using QUIC.";
return -1;
}
// The state transition logic here is as follows:
// - Before the QUIC handshake is complete, the QUIC channel is unwritable.
// - When |channel_| goes writable we start the QUIC handshake.
// - Once the QUIC handshake completes, the state is that of the
// |channel_| again.
void QuicTransportChannel::OnWritableState(TransportChannel* channel) {
RTC_DCHECK(rtc::Thread::Current() == network_thread_);
RTC_DCHECK(channel == channel_.get());
LOG_J(LS_VERBOSE, this)
<< "QuicTransportChannel: channel writable state changed to "
<< channel_->writable();
switch (quic_state_) {
case QUIC_TRANSPORT_NEW:
// Start the QUIC handshake when |channel_| is writable.
// This will fail if the SSL role or remote fingerprint are not set.
// Otherwise failure could result from network or QUIC errors.
MaybeStartQuic();
break;
case QUIC_TRANSPORT_CONNECTED:
// Note: SignalWritableState fired by set_writable.
set_writable(channel_->writable());
if (HasDataToWrite()) {
OnCanWrite();
}
break;
case QUIC_TRANSPORT_CONNECTING:
// This channel is not writable until the QUIC handshake finishes. It
// might have been write blocked.
if (HasDataToWrite()) {
OnCanWrite();
}
break;
case QUIC_TRANSPORT_CLOSED:
// TODO(mikescarlett): Allow the QUIC connection to be reset if it drops
// due to a non-failure.
break;
}
}
void QuicTransportChannel::OnReceivingState(TransportChannel* channel) {
RTC_DCHECK(rtc::Thread::Current() == network_thread_);
RTC_DCHECK(channel == channel_.get());
LOG_J(LS_VERBOSE, this)
<< "QuicTransportChannel: channel receiving state changed to "
<< channel_->receiving();
if (quic_state_ == QUIC_TRANSPORT_CONNECTED) {
// Note: SignalReceivingState fired by set_receiving.
set_receiving(channel_->receiving());
}
}
void QuicTransportChannel::OnReadPacket(TransportChannel* channel,
const char* data,
size_t size,
const rtc::PacketTime& packet_time,
int flags) {
RTC_DCHECK(rtc::Thread::Current() == network_thread_);
RTC_DCHECK(channel == channel_.get());
RTC_DCHECK(flags == 0);
switch (quic_state_) {
case QUIC_TRANSPORT_NEW:
// This would occur if other peer is ready to start QUIC but this peer
// hasn't started QUIC.
LOG_J(LS_INFO, this) << "Dropping packet received before QUIC started.";
break;
case QUIC_TRANSPORT_CONNECTING:
case QUIC_TRANSPORT_CONNECTED:
// We should only get QUIC or SRTP packets; STUN's already been demuxed.
// Is this potentially a QUIC packet?
if (IsQuicPacket(data, size)) {
if (!HandleQuicPacket(data, size)) {
LOG_J(LS_ERROR, this) << "Failed to handle QUIC packet.";
return;
}
} else {
// If this is an RTP packet, signal upwards as a bypass packet.
if (!IsRtpPacket(data, size)) {
LOG_J(LS_ERROR, this)
<< "Received unexpected non-QUIC, non-RTP packet.";
return;
}
SignalReadPacket(this, data, size, packet_time, PF_SRTP_BYPASS);
}
break;
case QUIC_TRANSPORT_CLOSED:
// This shouldn't be happening. Drop the packet.
break;
}
}
void QuicTransportChannel::OnSentPacket(TransportChannel* channel,
const rtc::SentPacket& sent_packet) {
RTC_DCHECK(rtc::Thread::Current() == network_thread_);
SignalSentPacket(this, sent_packet);
}
void QuicTransportChannel::OnReadyToSend(TransportChannel* channel) {
if (writable()) {
SignalReadyToSend(this);
}
}
void QuicTransportChannel::OnGatheringState(TransportChannelImpl* channel) {
RTC_DCHECK(channel == channel_.get());
SignalGatheringState(this);
}
void QuicTransportChannel::OnCandidateGathered(TransportChannelImpl* channel,
const Candidate& c) {
RTC_DCHECK(channel == channel_.get());
SignalCandidateGathered(this, c);
}
void QuicTransportChannel::OnRoleConflict(TransportChannelImpl* channel) {
RTC_DCHECK(channel == channel_.get());
SignalRoleConflict(this);
}
void QuicTransportChannel::OnRouteChange(TransportChannel* channel,
const Candidate& candidate) {
RTC_DCHECK(channel == channel_.get());
SignalRouteChange(this, candidate);
}
void QuicTransportChannel::OnSelectedCandidatePairChanged(
TransportChannel* channel,
CandidatePairInterface* selected_candidate_pair,
int last_sent_packet_id,
bool ready_to_send) {
RTC_DCHECK(channel == channel_.get());
SignalSelectedCandidatePairChanged(this, selected_candidate_pair,
last_sent_packet_id, ready_to_send);
}
void QuicTransportChannel::OnChannelStateChanged(
TransportChannelImpl* channel) {
RTC_DCHECK(channel == channel_.get());
SignalStateChanged(this);
}
bool QuicTransportChannel::MaybeStartQuic() {
if (!channel_->writable()) {
LOG_J(LS_ERROR, this) << "Couldn't start QUIC handshake.";
return false;
}
if (!CreateQuicSession() || !StartQuicHandshake()) {
LOG_J(LS_WARNING, this)
<< "Underlying channel is writable but cannot start "
"the QUIC handshake.";
return false;
}
// Verify connection is not closed due to QUIC bug or network failure.
// A closed connection should not happen since |channel_| is writable.
if (!quic_->connection()->connected()) {
LOG_J(LS_ERROR, this)
<< "QUIC connection should not be closed if underlying "
"channel is writable.";
return false;
}
// Indicate that |quic_| is ready to receive QUIC packets.
set_quic_state(QUIC_TRANSPORT_CONNECTING);
return true;
}
bool QuicTransportChannel::CreateQuicSession() {
if (!ssl_role_ || !remote_fingerprint_) {
return false;
}
net::Perspective perspective = (*ssl_role_ == rtc::SSL_CLIENT)
? net::Perspective::IS_CLIENT
: net::Perspective::IS_SERVER;
bool owns_writer = false;
std::unique_ptr<net::QuicConnection> connection(new net::QuicConnection(
kConnectionId, kConnectionIpEndpoint, &helper_, this, owns_writer,
perspective, net::QuicSupportedVersions()));
quic_.reset(new QuicSession(std::move(connection), config_));
quic_->SignalHandshakeComplete.connect(
this, &QuicTransportChannel::OnHandshakeComplete);
quic_->SignalConnectionClosed.connect(
this, &QuicTransportChannel::OnConnectionClosed);
quic_->SignalIncomingStream.connect(this,
&QuicTransportChannel::OnIncomingStream);
return true;
}
bool QuicTransportChannel::StartQuicHandshake() {
if (*ssl_role_ == rtc::SSL_CLIENT) {
// Unique identifier for remote peer.
net::QuicServerId server_id(remote_fingerprint_->value, kQuicServerPort);
// Perform authentication of remote peer; owned by QuicCryptoClientConfig.
// TODO(mikescarlett): Actually verify proof.
net::ProofVerifier* proof_verifier = new InsecureProofVerifier();
quic_crypto_client_config_.reset(
new net::QuicCryptoClientConfig(proof_verifier));
net::QuicCryptoClientStream* crypto_stream =
new net::QuicCryptoClientStream(server_id, quic_.get(),
new net::ProofVerifyContext(),
quic_crypto_client_config_.get(), this);
quic_->StartClientHandshake(crypto_stream);
LOG_J(LS_INFO, this) << "QuicTransportChannel: Started client handshake.";
} else {
RTC_DCHECK_EQ(*ssl_role_, rtc::SSL_SERVER);
// Provide credentials to remote peer; owned by QuicCryptoServerConfig.
// TODO(mikescarlett): Actually provide credentials.
net::ProofSource* proof_source = new DummyProofSource();
// Input keying material to HKDF, per http://tools.ietf.org/html/rfc5869.
// This is pseudorandom so that HKDF-Extract outputs a pseudorandom key,
// since QuicCryptoServerConfig does not use a salt value.
std::string source_address_token_secret;
if (!rtc::CreateRandomString(kInputKeyingMaterialLength,
&source_address_token_secret)) {
LOG_J(LS_ERROR, this)
<< "Error generating input keying material for HKDF.";
return false;
}
quic_crypto_server_config_.reset(new net::QuicCryptoServerConfig(
source_address_token_secret, helper_.GetRandomGenerator(),
proof_source));
// Provide server with serialized config string to prove ownership.
net::QuicCryptoServerConfig::ConfigOptions options;
quic_crypto_server_config_->AddDefaultConfig(helper_.GetRandomGenerator(),
helper_.GetClock(), options);
quic_compressed_certs_cache_.reset(new net::QuicCompressedCertsCache(
net::QuicCompressedCertsCache::kQuicCompressedCertsCacheSize));
// TODO(mikescarlett): Add support for stateless rejects.
bool use_stateless_rejects_if_peer_supported = false;
net::QuicCryptoServerStream* crypto_stream =
new net::QuicCryptoServerStream(quic_crypto_server_config_.get(),
quic_compressed_certs_cache_.get(),
use_stateless_rejects_if_peer_supported,
quic_.get());
quic_->StartServerHandshake(crypto_stream);
LOG_J(LS_INFO, this) << "QuicTransportChannel: Started server handshake.";
}
return true;
}
bool QuicTransportChannel::HandleQuicPacket(const char* data, size_t size) {
RTC_DCHECK(rtc::Thread::Current() == network_thread_);
return quic_->OnReadPacket(data, size);
}
net::WriteResult QuicTransportChannel::WritePacket(
const char* buffer,
size_t buf_len,
const net::IPAddress& self_address,
const net::IPEndPoint& peer_address,
net::PerPacketOptions* options) {
// QUIC should never call this if IsWriteBlocked, but just in case...
if (IsWriteBlocked()) {
return net::WriteResult(net::WRITE_STATUS_BLOCKED, EWOULDBLOCK);
}
// TODO(mikescarlett): Figure out how to tell QUIC "I dropped your packet, but
// don't block" without the QUIC connection tearing itself down.
int sent = channel_->SendPacket(buffer, buf_len, rtc::PacketOptions());
int bytes_written = sent > 0 ? sent : 0;
return net::WriteResult(net::WRITE_STATUS_OK, bytes_written);
}
// TODO(mikescarlett): Implement check for whether |channel_| is currently
// write blocked so that |quic_| does not try to write packet. This is
// necessary because |channel_| can be writable yet write blocked and
// channel_->GetError() is not flushed when there is no error.
bool QuicTransportChannel::IsWriteBlocked() const {
return !channel_->writable();
}
void QuicTransportChannel::OnHandshakeComplete() {
set_quic_state(QUIC_TRANSPORT_CONNECTED);
set_writable(true);
// OnReceivingState might have been called before the QUIC channel was
// connected, in which case the QUIC channel is now receiving.
if (channel_->receiving()) {
set_receiving(true);
}
}
void QuicTransportChannel::OnConnectionClosed(net::QuicErrorCode error,
bool from_peer) {
LOG_J(LS_INFO, this) << "Connection closed by "
<< (from_peer ? "other" : "this") << " peer "
<< "with QUIC error " << error;
// TODO(mikescarlett): Allow the QUIC session to be reset when the connection
// does not close due to failure.
set_quic_state(QUIC_TRANSPORT_CLOSED);
set_writable(false);
SignalClosed();
}
void QuicTransportChannel::OnProofValid(
const net::QuicCryptoClientConfig::CachedState& cached) {
LOG_J(LS_INFO, this) << "Cached proof marked valid";
}
void QuicTransportChannel::OnProofVerifyDetailsAvailable(
const net::ProofVerifyDetails& verify_details) {
LOG_J(LS_INFO, this) << "Proof verify details available from"
<< " QuicCryptoClientStream";
}
bool QuicTransportChannel::HasDataToWrite() const {
return quic_ && quic_->HasDataToWrite();
}
void QuicTransportChannel::OnCanWrite() {
RTC_DCHECK(quic_ != nullptr);
quic_->connection()->OnCanWrite();
}
void QuicTransportChannel::set_quic_state(QuicTransportState state) {
LOG_J(LS_VERBOSE, this) << "set_quic_state from:" << quic_state_ << " to "
<< state;
quic_state_ = state;
}
ReliableQuicStream* QuicTransportChannel::CreateQuicStream() {
if (quic_) {
net::SpdyPriority priority = 0; // Priority of the QUIC stream
return quic_->CreateOutgoingDynamicStream(priority);
}
return nullptr;
}
void QuicTransportChannel::OnIncomingStream(ReliableQuicStream* stream) {
SignalIncomingStream(stream);
}
} // namespace cricket