From ab0ddd4313a2bccc3138166bf17fe7ee4a8293f9 Mon Sep 17 00:00:00 2001
From: Darien Raymond <admin@v2ray.com>
Date: Mon, 14 Jan 2019 20:52:10 +0100
Subject: [PATCH] sync quic package. fixes #1503

---
 .../lucas-clemente/quic-go/interface.go       |  14 +-
 .../ackhandler/received_packet_handler.go     |   2 +-
 .../quic-go/internal/ackhandler/send_mode.go  |  12 +-
 .../ackhandler/sent_packet_handler.go         | 118 ++++------------
 .../quic-go/internal/handshake/aead.go        |  60 +++-----
 .../internal/handshake/crypto_setup.go        |  38 ++---
 .../internal/handshake/initial_aead.go        |  36 ++---
 .../internal/handshake/tls_extension.go       |   2 +-
 .../quic-go/internal/protocol/params.go       |   4 +
 .../quic-go/internal/protocol/version.go      |   2 +-
 .../quic-go/internal/wire/extended_header.go  |   1 -
 .../quic-go/packet_handler_map.go             |  18 +--
 .../lucas-clemente/quic-go/packet_unpacker.go |  42 ++----
 .../lucas-clemente/quic-go/server.go          |  79 ++++++++++-
 .../lucas-clemente/quic-go/session.go         | 133 ++++++++++--------
 .../lucas-clemente/quic-go/streams_map.go     |  12 ++
 .../quic-go/streams_map_outgoing_bidi.go      |  14 +-
 .../quic-go/streams_map_outgoing_generic.go   |  14 +-
 .../quic-go/streams_map_outgoing_uni.go       |  14 +-
 .../marten-seemann/qtls/cipher_suites.go      |   5 +
 20 files changed, 304 insertions(+), 316 deletions(-)

diff --git a/vendor/github.com/lucas-clemente/quic-go/interface.go b/vendor/github.com/lucas-clemente/quic-go/interface.go
index 6342fbb0c..689647553 100644
--- a/vendor/github.com/lucas-clemente/quic-go/interface.go
+++ b/vendor/github.com/lucas-clemente/quic-go/interface.go
@@ -124,20 +124,22 @@ type Session interface {
 	// AcceptUniStream returns the next unidirectional stream opened by the peer, blocking until one is available.
 	AcceptUniStream() (ReceiveStream, error)
 	// OpenStream opens a new bidirectional QUIC stream.
-	// It returns a special error when the peer's concurrent stream limit is reached.
 	// There is no signaling to the peer about new streams:
 	// The peer can only accept the stream after data has been sent on the stream.
-	// TODO(#1152): Enable testing for the special error
+	// If the error is non-nil, it satisfies the net.Error interface.
+	// When reaching the peer's stream limit, err.Temporary() will be true.
 	OpenStream() (Stream, error)
 	// OpenStreamSync opens a new bidirectional QUIC stream.
-	// It blocks until the peer's concurrent stream limit allows a new stream to be opened.
+	// It blocks until a new stream can be opened.
+	// If the error is non-nil, it satisfies the net.Error interface.
 	OpenStreamSync() (Stream, error)
 	// OpenUniStream opens a new outgoing unidirectional QUIC stream.
-	// It returns a special error when the peer's concurrent stream limit is reached.
-	// TODO(#1152): Enable testing for the special error
+	// If the error is non-nil, it satisfies the net.Error interface.
+	// When reaching the peer's stream limit, Temporary() will be true.
 	OpenUniStream() (SendStream, error)
 	// OpenUniStreamSync opens a new outgoing unidirectional QUIC stream.
-	// It blocks until the peer's concurrent stream limit allows a new stream to be opened.
+	// It blocks until a new stream can be opened.
+	// If the error is non-nil, it satisfies the net.Error interface.
 	OpenUniStreamSync() (SendStream, error)
 	// LocalAddr returns the local address.
 	LocalAddr() net.Addr
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/received_packet_handler.go b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/received_packet_handler.go
index 8af213245..93931b4eb 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/received_packet_handler.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/received_packet_handler.go
@@ -74,7 +74,7 @@ func (h *receivedPacketHandler) ReceivedPacket(packetNumber protocol.PacketNumbe
 	}
 
 	isMissing := h.isMissing(packetNumber)
-	if packetNumber > h.largestObserved {
+	if packetNumber >= h.largestObserved {
 		h.largestObserved = packetNumber
 		h.largestObservedReceivedTime = rcvTime
 	}
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/send_mode.go b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/send_mode.go
index 76c833c4b..8cdaa7e6b 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/send_mode.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/send_mode.go
@@ -12,10 +12,8 @@ const (
 	SendAck
 	// SendRetransmission means that retransmissions should be sent
 	SendRetransmission
-	// SendRTO means that an RTO probe packet should be sent
-	SendRTO
-	// SendTLP means that a TLP probe packet should be sent
-	SendTLP
+	// SendPTO means that a probe packet should be sent
+	SendPTO
 	// SendAny means that any packet should be sent
 	SendAny
 )
@@ -28,10 +26,8 @@ func (s SendMode) String() string {
 		return "ack"
 	case SendRetransmission:
 		return "retransmission"
-	case SendRTO:
-		return "rto"
-	case SendTLP:
-		return "tlp"
+	case SendPTO:
+		return "pto"
 	case SendAny:
 		return "any"
 	default:
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/sent_packet_handler.go b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/sent_packet_handler.go
index 776f87a89..0c67b0da4 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/sent_packet_handler.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/sent_packet_handler.go
@@ -17,16 +17,8 @@ const (
 	// Maximum reordering in time space before time based loss detection considers a packet lost.
 	// In fraction of an RTT.
 	timeReorderingFraction = 1.0 / 8
-	// defaultRTOTimeout is the RTO time on new connections
-	defaultRTOTimeout = 500 * time.Millisecond
-	// Minimum time in the future a tail loss probe alarm may be set for.
-	minTPLTimeout = 10 * time.Millisecond
-	// Maximum number of tail loss probes before an RTO fires.
-	maxTLPs = 2
-	// Minimum time in the future an RTO alarm may be set for.
-	minRTOTimeout = 200 * time.Millisecond
-	// maxRTOTimeout is the maximum RTO time
-	maxRTOTimeout = 60 * time.Second
+	// Timer granularity. The timer will not be set to a value smaller than granularity.
+	granularity = time.Millisecond
 )
 
 type sentPacketHandler struct {
@@ -44,7 +36,6 @@ type sentPacketHandler struct {
 	// example: we send an ACK for packets 90-100 with packet number 20
 	// once we receive an ACK from the peer for packet 20, the lowestPacketNotConfirmedAcked is 101
 	lowestPacketNotConfirmedAcked protocol.PacketNumber
-	largestSentBeforeRTO          protocol.PacketNumber
 
 	packetHistory *sentPacketHistory
 
@@ -56,17 +47,13 @@ type sentPacketHandler struct {
 	rttStats   *congestion.RTTStats
 
 	handshakeComplete bool
+
 	// The number of times the crypto packets have been retransmitted without receiving an ack.
 	cryptoCount uint32
-
-	// The number of times a TLP has been sent without receiving an ack.
-	tlpCount uint32
-	allowTLP bool
-
-	// The number of times an RTO has been sent without receiving an ack.
-	rtoCount uint32
-	// The number of RTO probe packets that should be sent.
-	numRTOs int
+	// The number of times a PTO has been sent without receiving an ack.
+	ptoCount uint32
+	// The number of PTO probe packets that should be sent.
+	numProbesToSend int
 
 	// The time at which the next packet will be considered lost based on early transmit or exceeding the reordering window in time.
 	lossTime time.Time
@@ -173,10 +160,9 @@ func (h *sentPacketHandler) sentPacketImpl(packet *Packet) bool /* isRetransmitt
 		packet.includedInBytesInFlight = true
 		h.bytesInFlight += packet.Length
 		packet.canBeRetransmitted = true
-		if h.numRTOs > 0 {
-			h.numRTOs--
+		if h.numProbesToSend > 0 {
+			h.numProbesToSend--
 		}
-		h.allowTLP = false
 	}
 	h.congestion.OnPacketSent(packet.SendTime, h.bytesInFlight, packet.PacketNumber, packet.Length, isRetransmittable)
 
@@ -210,6 +196,9 @@ func (h *sentPacketHandler) ReceivedAck(ackFrame *wire.AckFrame, withPacketNumbe
 	if err != nil {
 		return err
 	}
+	if len(ackedPackets) == 0 {
+		return nil
+	}
 
 	priorInFlight := h.bytesInFlight
 	for _, p := range ackedPackets {
@@ -235,6 +224,10 @@ func (h *sentPacketHandler) ReceivedAck(ackFrame *wire.AckFrame, withPacketNumbe
 	if err := h.detectLostPackets(rcvTime, priorInFlight); err != nil {
 		return err
 	}
+
+	h.ptoCount = 0
+	h.cryptoCount = 0
+
 	h.updateLossDetectionAlarm()
 	return nil
 }
@@ -310,15 +303,8 @@ func (h *sentPacketHandler) updateLossDetectionAlarm() {
 	} else if !h.lossTime.IsZero() {
 		// Early retransmit timer or time loss detection.
 		h.alarm = h.lossTime
-	} else {
-		// RTO or TLP alarm
-		alarmDuration := h.computeRTOTimeout()
-		if h.tlpCount < maxTLPs {
-			tlpAlarm := h.computeTLPTimeout()
-			// if the RTO duration is shorter than the TLP duration, use the RTO duration
-			alarmDuration = utils.MinDuration(alarmDuration, tlpAlarm)
-		}
-		h.alarm = h.lastSentRetransmittablePacketTime.Add(alarmDuration)
+	} else { // PTO alarm
+		h.alarm = h.lastSentRetransmittablePacketTime.Add(h.computePTOTimeout())
 	}
 }
 
@@ -346,6 +332,7 @@ func (h *sentPacketHandler) detectLostPackets(now time.Time, priorInFlight proto
 		}
 		return true, nil
 	})
+
 	if h.logger.Debug() && len(lostPackets) > 0 {
 		pns := make([]protocol.PacketNumber, len(lostPackets))
 		for i, p := range lostPackets {
@@ -399,21 +386,12 @@ func (h *sentPacketHandler) onVerifiedAlarm() error {
 		}
 		// Early retransmit or time loss detection
 		err = h.detectLostPackets(time.Now(), h.bytesInFlight)
-	} else if h.tlpCount < maxTLPs { // TLP
+	} else { // PTO
 		if h.logger.Debug() {
-			h.logger.Debugf("Loss detection alarm fired in TLP mode. TLP count: %d", h.tlpCount)
+			h.logger.Debugf("Loss detection alarm fired in PTO mode. PTO count: %d", h.ptoCount)
 		}
-		h.allowTLP = true
-		h.tlpCount++
-	} else { // RTO
-		if h.logger.Debug() {
-			h.logger.Debugf("Loss detection alarm fired in RTO mode. RTO count: %d", h.rtoCount)
-		}
-		if h.rtoCount == 0 {
-			h.largestSentBeforeRTO = h.lastSentPacketNumber
-		}
-		h.rtoCount++
-		h.numRTOs += 2
+		h.ptoCount++
+		h.numProbesToSend += 2
 	}
 	return err
 }
@@ -454,15 +432,9 @@ func (h *sentPacketHandler) onPacketAcked(p *Packet, rcvTime time.Time) error {
 	if p.includedInBytesInFlight {
 		h.bytesInFlight -= p.Length
 	}
-	if h.rtoCount > 0 {
-		h.verifyRTO(p.PacketNumber)
-	}
 	if err := h.stopRetransmissionsFor(p); err != nil {
 		return err
 	}
-	h.rtoCount = 0
-	h.tlpCount = 0
-	h.cryptoCount = 0
 	return h.packetHistory.Remove(p.PacketNumber)
 }
 
@@ -480,18 +452,6 @@ func (h *sentPacketHandler) stopRetransmissionsFor(p *Packet) error {
 	return nil
 }
 
-func (h *sentPacketHandler) verifyRTO(pn protocol.PacketNumber) {
-	if pn <= h.largestSentBeforeRTO {
-		h.logger.Debugf("Spurious RTO detected. Received an ACK for %#x (largest sent before RTO: %#x)", pn, h.largestSentBeforeRTO)
-		// Replace SRTT with latest_rtt and increase the variance to prevent
-		// a spurious RTO from happening again.
-		h.rttStats.ExpireSmoothedMetrics()
-		return
-	}
-	h.logger.Debugf("RTO verified. Received an ACK for %#x (largest sent before RTO: %#x", pn, h.largestSentBeforeRTO)
-	h.congestion.OnRetransmissionTimeout(true)
-}
-
 func (h *sentPacketHandler) DequeuePacketForRetransmission() *Packet {
 	if len(h.retransmissionQueue) == 0 {
 		return nil
@@ -539,11 +499,8 @@ func (h *sentPacketHandler) SendMode() SendMode {
 		}
 		return SendNone
 	}
-	if h.allowTLP {
-		return SendTLP
-	}
-	if h.numRTOs > 0 {
-		return SendRTO
+	if h.numProbesToSend > 0 {
+		return SendPTO
 	}
 	// Only send ACKs if we're congestion limited.
 	if cwnd := h.congestion.GetCongestionWindow(); h.bytesInFlight > cwnd {
@@ -570,9 +527,9 @@ func (h *sentPacketHandler) TimeUntilSend() time.Time {
 }
 
 func (h *sentPacketHandler) ShouldSendNumPackets() int {
-	if h.numRTOs > 0 {
+	if h.numProbesToSend > 0 {
 		// RTO probes should not be paced, but must be sent immediately.
-		return h.numRTOs
+		return h.numProbesToSend
 	}
 	delay := h.congestion.TimeUntilSend(h.bytesInFlight)
 	if delay == 0 || delay > protocol.MinPacingDelay {
@@ -610,27 +567,14 @@ func (h *sentPacketHandler) queuePacketForRetransmission(p *Packet) error {
 }
 
 func (h *sentPacketHandler) computeCryptoTimeout() time.Duration {
-	duration := utils.MaxDuration(2*h.rttStats.SmoothedOrInitialRTT(), minTPLTimeout)
+	duration := utils.MaxDuration(2*h.rttStats.SmoothedOrInitialRTT(), granularity)
 	// exponential backoff
 	// There's an implicit limit to this set by the crypto timeout.
 	return duration << h.cryptoCount
 }
 
-func (h *sentPacketHandler) computeTLPTimeout() time.Duration {
+func (h *sentPacketHandler) computePTOTimeout() time.Duration {
 	// TODO(#1236): include the max_ack_delay
-	return utils.MaxDuration(h.rttStats.SmoothedOrInitialRTT()*3/2, minTPLTimeout)
-}
-
-func (h *sentPacketHandler) computeRTOTimeout() time.Duration {
-	var rto time.Duration
-	rtt := h.rttStats.SmoothedRTT()
-	if rtt == 0 {
-		rto = defaultRTOTimeout
-	} else {
-		rto = rtt + 4*h.rttStats.MeanDeviation()
-	}
-	rto = utils.MaxDuration(rto, minRTOTimeout)
-	// Exponential backoff
-	rto <<= h.rtoCount
-	return utils.MinDuration(rto, maxRTOTimeout)
+	duration := utils.MaxDuration(h.rttStats.SmoothedOrInitialRTT()+4*h.rttStats.MeanDeviation(), granularity)
+	return duration << h.ptoCount
 }
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/aead.go b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/aead.go
index 26d481df2..07ce74f74 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/aead.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/aead.go
@@ -8,13 +8,12 @@ import (
 )
 
 type sealer struct {
-	iv          []byte
 	aead        cipher.AEAD
-	pnEncrypter cipher.Block
+	hpEncrypter cipher.Block
 
 	// use a single slice to avoid allocations
 	nonceBuf []byte
-	pnMask   []byte
+	hpMask   []byte
 
 	// short headers protect 5 bits in the first byte, long headers only 4
 	is1RTT bool
@@ -22,41 +21,35 @@ type sealer struct {
 
 var _ Sealer = &sealer{}
 
-func newSealer(aead cipher.AEAD, iv []byte, pnEncrypter cipher.Block, is1RTT bool) Sealer {
+func newSealer(aead cipher.AEAD, hpEncrypter cipher.Block, is1RTT bool) Sealer {
 	return &sealer{
-		iv:          iv,
 		aead:        aead,
 		nonceBuf:    make([]byte, aead.NonceSize()),
 		is1RTT:      is1RTT,
-		pnEncrypter: pnEncrypter,
-		pnMask:      make([]byte, pnEncrypter.BlockSize()),
+		hpEncrypter: hpEncrypter,
+		hpMask:      make([]byte, hpEncrypter.BlockSize()),
 	}
 }
 
 func (s *sealer) Seal(dst, src []byte, pn protocol.PacketNumber, ad []byte) []byte {
 	binary.BigEndian.PutUint64(s.nonceBuf[len(s.nonceBuf)-8:], uint64(pn))
-	for i := 0; i < len(s.nonceBuf); i++ {
-		s.nonceBuf[i] ^= s.iv[i]
-	}
-	sealed := s.aead.Seal(dst, s.nonceBuf, src, ad)
-	for i := 0; i < len(s.nonceBuf); i++ {
-		s.nonceBuf[i] = 0
-	}
-	return sealed
+	// The AEAD we're using here will be the qtls.aeadAESGCM13.
+	// It uses the nonce provided here and XOR it with the IV.
+	return s.aead.Seal(dst, s.nonceBuf, src, ad)
 }
 
 func (s *sealer) EncryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
-	if len(sample) != s.pnEncrypter.BlockSize() {
+	if len(sample) != s.hpEncrypter.BlockSize() {
 		panic("invalid sample size")
 	}
-	s.pnEncrypter.Encrypt(s.pnMask, sample)
+	s.hpEncrypter.Encrypt(s.hpMask, sample)
 	if s.is1RTT {
-		*firstByte ^= s.pnMask[0] & 0x1f
+		*firstByte ^= s.hpMask[0] & 0x1f
 	} else {
-		*firstByte ^= s.pnMask[0] & 0xf
+		*firstByte ^= s.hpMask[0] & 0xf
 	}
 	for i := range pnBytes {
-		pnBytes[i] ^= s.pnMask[i+1]
+		pnBytes[i] ^= s.hpMask[i+1]
 	}
 }
 
@@ -65,13 +58,12 @@ func (s *sealer) Overhead() int {
 }
 
 type opener struct {
-	iv          []byte
 	aead        cipher.AEAD
 	pnDecrypter cipher.Block
 
 	// use a single slice to avoid allocations
 	nonceBuf []byte
-	pnMask   []byte
+	hpMask   []byte
 
 	// short headers protect 5 bits in the first byte, long headers only 4
 	is1RTT bool
@@ -79,40 +71,34 @@ type opener struct {
 
 var _ Opener = &opener{}
 
-func newOpener(aead cipher.AEAD, iv []byte, pnDecrypter cipher.Block, is1RTT bool) Opener {
+func newOpener(aead cipher.AEAD, pnDecrypter cipher.Block, is1RTT bool) Opener {
 	return &opener{
-		iv:          iv,
 		aead:        aead,
 		nonceBuf:    make([]byte, aead.NonceSize()),
 		is1RTT:      is1RTT,
 		pnDecrypter: pnDecrypter,
-		pnMask:      make([]byte, pnDecrypter.BlockSize()),
+		hpMask:      make([]byte, pnDecrypter.BlockSize()),
 	}
 }
 
 func (o *opener) Open(dst, src []byte, pn protocol.PacketNumber, ad []byte) ([]byte, error) {
 	binary.BigEndian.PutUint64(o.nonceBuf[len(o.nonceBuf)-8:], uint64(pn))
-	for i := 0; i < len(o.nonceBuf); i++ {
-		o.nonceBuf[i] ^= o.iv[i]
-	}
-	opened, err := o.aead.Open(dst, o.nonceBuf, src, ad)
-	for i := 0; i < len(o.nonceBuf); i++ {
-		o.nonceBuf[i] = 0
-	}
-	return opened, err
+	// The AEAD we're using here will be the qtls.aeadAESGCM13.
+	// It uses the nonce provided here and XOR it with the IV.
+	return o.aead.Open(dst, o.nonceBuf, src, ad)
 }
 
 func (o *opener) DecryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
 	if len(sample) != o.pnDecrypter.BlockSize() {
 		panic("invalid sample size")
 	}
-	o.pnDecrypter.Encrypt(o.pnMask, sample)
+	o.pnDecrypter.Encrypt(o.hpMask, sample)
 	if o.is1RTT {
-		*firstByte ^= o.pnMask[0] & 0x1f
+		*firstByte ^= o.hpMask[0] & 0x1f
 	} else {
-		*firstByte ^= o.pnMask[0] & 0xf
+		*firstByte ^= o.hpMask[0] & 0xf
 	}
 	for i := range pnBytes {
-		pnBytes[i] ^= o.pnMask[i+1]
+		pnBytes[i] ^= o.hpMask[i+1]
 	}
 }
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/crypto_setup.go b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/crypto_setup.go
index e5afaab63..42a0c4e95 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/crypto_setup.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/crypto_setup.go
@@ -181,7 +181,7 @@ func newCryptoSetup(
 	logger utils.Logger,
 	perspective protocol.Perspective,
 ) (CryptoSetup, <-chan struct{} /* ClientHello written */, error) {
-	initialSealer, initialOpener, err := newInitialAEAD(connID, perspective)
+	initialSealer, initialOpener, err := NewInitialAEAD(connID, perspective)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -410,28 +410,22 @@ func (h *cryptoSetup) ReadHandshakeMessage() ([]byte, error) {
 }
 
 func (h *cryptoSetup) SetReadKey(suite *qtls.CipherSuite, trafficSecret []byte) {
-	key := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "key", suite.KeyLen())
-	iv := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "iv", suite.IVLen())
-	pnKey := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "pn", suite.KeyLen())
-	pnDecrypter, err := aes.NewCipher(pnKey)
+	key := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic key", suite.KeyLen())
+	iv := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic iv", suite.IVLen())
+	hpKey := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic hp", suite.KeyLen())
+	hpDecrypter, err := aes.NewCipher(hpKey)
 	if err != nil {
 		panic(fmt.Sprintf("error creating new AES cipher: %s", err))
 	}
-	opener := newOpener(
-		suite.AEAD(key, iv),
-		iv,
-		pnDecrypter,
-		h.readEncLevel == protocol.Encryption1RTT,
-	)
 
 	switch h.readEncLevel {
 	case protocol.EncryptionInitial:
 		h.readEncLevel = protocol.EncryptionHandshake
-		h.handshakeOpener = opener
+		h.handshakeOpener = newOpener(suite.AEAD(key, iv), hpDecrypter, false)
 		h.logger.Debugf("Installed Handshake Read keys")
 	case protocol.EncryptionHandshake:
 		h.readEncLevel = protocol.Encryption1RTT
-		h.opener = opener
+		h.opener = newOpener(suite.AEAD(key, iv), hpDecrypter, true)
 		h.logger.Debugf("Installed 1-RTT Read keys")
 	default:
 		panic("unexpected read encryption level")
@@ -440,28 +434,22 @@ func (h *cryptoSetup) SetReadKey(suite *qtls.CipherSuite, trafficSecret []byte)
 }
 
 func (h *cryptoSetup) SetWriteKey(suite *qtls.CipherSuite, trafficSecret []byte) {
-	key := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "key", suite.KeyLen())
-	iv := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "iv", suite.IVLen())
-	pnKey := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "pn", suite.KeyLen())
-	pnEncrypter, err := aes.NewCipher(pnKey)
+	key := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic key", suite.KeyLen())
+	iv := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic iv", suite.IVLen())
+	hpKey := qtls.HkdfExpandLabel(suite.Hash(), trafficSecret, []byte{}, "quic hp", suite.KeyLen())
+	hpEncrypter, err := aes.NewCipher(hpKey)
 	if err != nil {
 		panic(fmt.Sprintf("error creating new AES cipher: %s", err))
 	}
-	sealer := newSealer(
-		suite.AEAD(key, iv),
-		iv,
-		pnEncrypter,
-		h.writeEncLevel == protocol.Encryption1RTT,
-	)
 
 	switch h.writeEncLevel {
 	case protocol.EncryptionInitial:
 		h.writeEncLevel = protocol.EncryptionHandshake
-		h.handshakeSealer = sealer
+		h.handshakeSealer = newSealer(suite.AEAD(key, iv), hpEncrypter, false)
 		h.logger.Debugf("Installed Handshake Write keys")
 	case protocol.EncryptionHandshake:
 		h.writeEncLevel = protocol.Encryption1RTT
-		h.sealer = sealer
+		h.sealer = newSealer(suite.AEAD(key, iv), hpEncrypter, true)
 		h.logger.Debugf("Installed 1-RTT Write keys")
 	default:
 		panic("unexpected write encryption level")
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/initial_aead.go b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/initial_aead.go
index 1a6efb086..90334a1b0 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/initial_aead.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/initial_aead.go
@@ -3,7 +3,6 @@ package handshake
 import (
 	"crypto"
 	"crypto/aes"
-	"crypto/cipher"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/marten-seemann/qtls"
@@ -11,7 +10,8 @@ import (
 
 var quicVersion1Salt = []byte{0xef, 0x4f, 0xb0, 0xab, 0xb4, 0x74, 0x70, 0xc4, 0x1b, 0xef, 0xcf, 0x80, 0x31, 0x33, 0x4f, 0xae, 0x48, 0x5e, 0x09, 0xa0}
 
-func newInitialAEAD(connID protocol.ConnectionID, pers protocol.Perspective) (Sealer, Opener, error) {
+// NewInitialAEAD creates a new AEAD for Initial encryption / decryption.
+func NewInitialAEAD(connID protocol.ConnectionID, pers protocol.Perspective) (Sealer, Opener, error) {
 	clientSecret, serverSecret := computeSecrets(connID)
 	var mySecret, otherSecret []byte
 	if pers == protocol.PerspectiveClient {
@@ -21,34 +21,20 @@ func newInitialAEAD(connID protocol.ConnectionID, pers protocol.Perspective) (Se
 		mySecret = serverSecret
 		otherSecret = clientSecret
 	}
-	myKey, myPNKey, myIV := computeInitialKeyAndIV(mySecret)
-	otherKey, otherPNKey, otherIV := computeInitialKeyAndIV(otherSecret)
+	myKey, myHPKey, myIV := computeInitialKeyAndIV(mySecret)
+	otherKey, otherHPKey, otherIV := computeInitialKeyAndIV(otherSecret)
 
-	encrypterCipher, err := aes.NewCipher(myKey)
+	encrypter := qtls.AEADAESGCM13(myKey, myIV)
+	hpEncrypter, err := aes.NewCipher(myHPKey)
 	if err != nil {
 		return nil, nil, err
 	}
-	encrypter, err := cipher.NewGCM(encrypterCipher)
+	decrypter := qtls.AEADAESGCM13(otherKey, otherIV)
+	hpDecrypter, err := aes.NewCipher(otherHPKey)
 	if err != nil {
 		return nil, nil, err
 	}
-	pnEncrypter, err := aes.NewCipher(myPNKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	decrypterCipher, err := aes.NewCipher(otherKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	decrypter, err := cipher.NewGCM(decrypterCipher)
-	if err != nil {
-		return nil, nil, err
-	}
-	pnDecrypter, err := aes.NewCipher(otherPNKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	return newSealer(encrypter, myIV, pnEncrypter, false), newOpener(decrypter, otherIV, pnDecrypter, false), nil
+	return newSealer(encrypter, hpEncrypter, false), newOpener(decrypter, hpDecrypter, false), nil
 }
 
 func computeSecrets(connID protocol.ConnectionID) (clientSecret, serverSecret []byte) {
@@ -58,9 +44,9 @@ func computeSecrets(connID protocol.ConnectionID) (clientSecret, serverSecret []
 	return
 }
 
-func computeInitialKeyAndIV(secret []byte) (key, pnKey, iv []byte) {
+func computeInitialKeyAndIV(secret []byte) (key, hpKey, iv []byte) {
 	key = qtls.HkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic key", 16)
-	pnKey = qtls.HkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic hp", 16)
+	hpKey = qtls.HkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic hp", 16)
 	iv = qtls.HkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic iv", 12)
 	return
 }
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/tls_extension.go b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/tls_extension.go
index 9cfb665a3..96b890bf2 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/handshake/tls_extension.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/handshake/tls_extension.go
@@ -10,7 +10,7 @@ import (
 	"github.com/lucas-clemente/quic-go/internal/utils"
 )
 
-const quicTLSExtensionType = 0xff5
+const quicTLSExtensionType = 0xffa5
 
 type clientHelloTransportParameters struct {
 	InitialVersion protocol.VersionNumber
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/protocol/params.go b/vendor/github.com/lucas-clemente/quic-go/internal/protocol/params.go
index 7f4661e81..e6f9493fa 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/protocol/params.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/protocol/params.go
@@ -53,6 +53,10 @@ const SkipPacketAveragePeriodLength PacketNumber = 500
 // MaxTrackedSkippedPackets is the maximum number of skipped packet numbers the SentPacketHandler keep track of for Optimistic ACK attack mitigation
 const MaxTrackedSkippedPackets = 10
 
+// MaxAcceptQueueSize is the maximum number of sessions that the server queues for accepting.
+// If the queue is full, new connection attempts will be rejected.
+const MaxAcceptQueueSize = 32
+
 // CookieExpiryTime is the valid time of a cookie
 const CookieExpiryTime = 24 * time.Hour
 
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/protocol/version.go b/vendor/github.com/lucas-clemente/quic-go/internal/protocol/version.go
index 9c5d3830a..3406cfa46 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/protocol/version.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/protocol/version.go
@@ -18,7 +18,7 @@ const (
 
 // The version numbers, making grepping easier
 const (
-	VersionTLS      VersionNumber = 101
+	VersionTLS      VersionNumber = 0x51474fff
 	VersionWhatever VersionNumber = 1 // for when the version doesn't matter
 	VersionUnknown  VersionNumber = math.MaxUint32
 )
diff --git a/vendor/github.com/lucas-clemente/quic-go/internal/wire/extended_header.go b/vendor/github.com/lucas-clemente/quic-go/internal/wire/extended_header.go
index b95c9cc6b..19a0b064e 100644
--- a/vendor/github.com/lucas-clemente/quic-go/internal/wire/extended_header.go
+++ b/vendor/github.com/lucas-clemente/quic-go/internal/wire/extended_header.go
@@ -15,7 +15,6 @@ type ExtendedHeader struct {
 	Header
 
 	typeByte byte
-	Raw      []byte
 
 	PacketNumberLen protocol.PacketNumberLen
 	PacketNumber    protocol.PacketNumber
diff --git a/vendor/github.com/lucas-clemente/quic-go/packet_handler_map.go b/vendor/github.com/lucas-clemente/quic-go/packet_handler_map.go
index ce4c55156..3c0f5bdd3 100644
--- a/vendor/github.com/lucas-clemente/quic-go/packet_handler_map.go
+++ b/vendor/github.com/lucas-clemente/quic-go/packet_handler_map.go
@@ -186,10 +186,6 @@ func (h *packetHandlerMap) parsePacket(
 	var counter int
 	var lastConnID protocol.ConnectionID
 	for len(data) > 0 {
-		if counter > 0 && h.logger.Debug() {
-			h.logger.Debugf("Parsed a coalesced packet. Part %d: %d bytes", counter, len(packets[counter-1].data))
-		}
-
 		hdr, err := wire.ParseHeader(bytes.NewReader(data), h.connIDLen)
 		// drop the packet if we can't parse the header
 		if err != nil {
@@ -221,6 +217,12 @@ func (h *packetHandlerMap) parsePacket(
 			data:       data,
 			buffer:     buffer,
 		})
+
+		// only log if this actually a coalesced packet
+		if h.logger.Debug() && (counter > 1 || len(rest) > 0) {
+			h.logger.Debugf("Parsed a coalesced packet. Part %d: %d bytes. Remaining: %d bytes.", counter, len(packets[counter-1].data), len(rest))
+		}
+
 		data = rest
 	}
 	return packets, nil
@@ -252,11 +254,11 @@ func (h *packetHandlerMap) handleParsedPackets(packets []*receivedPacket) {
 			// TODO(#943): send a stateless reset
 			h.logger.Debugf("received a short header packet with an unexpected connection ID %s", p.hdr.DestConnectionID)
 			break // a short header packet is always the last in a coalesced packet
-
 		}
-		if h.server != nil { // no server set
-			h.server.handlePacket(p)
+		if h.server == nil { // no server set
+			h.logger.Debugf("received a packet with an unexpected connection ID %s", p.hdr.DestConnectionID)
+			continue
 		}
-		h.logger.Debugf("received a packet with an unexpected connection ID %s", p.hdr.DestConnectionID)
+		h.server.handlePacket(p)
 	}
 }
diff --git a/vendor/github.com/lucas-clemente/quic-go/packet_unpacker.go b/vendor/github.com/lucas-clemente/quic-go/packet_unpacker.go
index cda222324..f3b5a2f77 100644
--- a/vendor/github.com/lucas-clemente/quic-go/packet_unpacker.go
+++ b/vendor/github.com/lucas-clemente/quic-go/packet_unpacker.go
@@ -6,7 +6,6 @@ import (
 
 	"github.com/lucas-clemente/quic-go/internal/handshake"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
-	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 )
@@ -15,7 +14,7 @@ type unpackedPacket struct {
 	packetNumber    protocol.PacketNumber // the decoded packet number
 	hdr             *wire.ExtendedHeader
 	encryptionLevel protocol.EncryptionLevel
-	frames          []wire.Frame
+	data            []byte
 }
 
 // The packetUnpacker unpacks QUIC packets.
@@ -56,6 +55,9 @@ func (u *packetUnpacker) Unpack(hdr *wire.Header, data []byte) (*unpackedPacket,
 		return nil, err
 	}
 	hdrLen := int(hdr.ParsedLen())
+	if len(data) < hdrLen+4+16 {
+		return nil, fmt.Errorf("Packet too small. Expected at least 20 bytes after the header, got %d", len(data)-hdrLen)
+	}
 	// The packet number can be up to 4 bytes long, but we won't know the length until we decrypt it.
 	// 1. save a copy of the 4 bytes
 	origPNBytes := make([]byte, 4)
@@ -66,18 +68,16 @@ func (u *packetUnpacker) Unpack(hdr *wire.Header, data []byte) (*unpackedPacket,
 		&data[0],
 		data[hdrLen:hdrLen+4],
 	)
-
 	// 3. parse the header (and learn the actual length of the packet number)
 	extHdr, err := hdr.ParseExtended(r, u.version)
 	if err != nil {
 		return nil, fmt.Errorf("error parsing extended header: %s", err)
 	}
-	extHdr.Raw = data[:hdrLen+int(extHdr.PacketNumberLen)]
+	extHdrLen := hdrLen + int(extHdr.PacketNumberLen)
 	// 4. if the packet number is shorter than 4 bytes, replace the remaining bytes with the copy we saved earlier
 	if extHdr.PacketNumberLen != protocol.PacketNumberLen4 {
-		copy(data[hdrLen+int(extHdr.PacketNumberLen):hdrLen+4], origPNBytes[int(extHdr.PacketNumberLen):])
+		copy(data[extHdrLen:hdrLen+4], origPNBytes[int(extHdr.PacketNumberLen):])
 	}
-	data = data[hdrLen+int(extHdr.PacketNumberLen):]
 
 	pn := protocol.DecodePacketNumber(
 		extHdr.PacketNumberLen,
@@ -85,7 +85,7 @@ func (u *packetUnpacker) Unpack(hdr *wire.Header, data []byte) (*unpackedPacket,
 		extHdr.PacketNumber,
 	)
 
-	decrypted, err := opener.Open(data[:0], data, pn, extHdr.Raw)
+	decrypted, err := opener.Open(data[extHdrLen:extHdrLen], data[extHdrLen:], pn, data[:extHdrLen])
 	if err != nil {
 		return nil, err
 	}
@@ -93,36 +93,10 @@ func (u *packetUnpacker) Unpack(hdr *wire.Header, data []byte) (*unpackedPacket,
 	// Only do this after decrypting, so we are sure the packet is not attacker-controlled
 	u.largestRcvdPacketNumber = utils.MaxPacketNumber(u.largestRcvdPacketNumber, pn)
 
-	fs, err := u.parseFrames(decrypted)
-	if err != nil {
-		return nil, err
-	}
-
 	return &unpackedPacket{
 		hdr:             extHdr,
 		packetNumber:    pn,
 		encryptionLevel: encLevel,
-		frames:          fs,
+		data:            decrypted,
 	}, nil
 }
-
-func (u *packetUnpacker) parseFrames(decrypted []byte) ([]wire.Frame, error) {
-	r := bytes.NewReader(decrypted)
-	if r.Len() == 0 {
-		return nil, qerr.MissingPayload
-	}
-
-	fs := make([]wire.Frame, 0, 2)
-	// Read all frames in the packet
-	for {
-		frame, err := wire.ParseNextFrame(r, u.version)
-		if err != nil {
-			return nil, err
-		}
-		if frame == nil {
-			break
-		}
-		fs = append(fs, frame)
-	}
-	return fs, nil
-}
diff --git a/vendor/github.com/lucas-clemente/quic-go/server.go b/vendor/github.com/lucas-clemente/quic-go/server.go
index 3fb1ca7a3..f1277838f 100644
--- a/vendor/github.com/lucas-clemente/quic-go/server.go
+++ b/vendor/github.com/lucas-clemente/quic-go/server.go
@@ -8,10 +8,12 @@ import (
 	"io"
 	"net"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/handshake"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 )
@@ -88,7 +90,8 @@ type server struct {
 	errorChan   chan struct{}
 	closed      bool
 
-	sessionQueue chan Session
+	sessionQueue    chan Session
+	sessionQueueLen int32 // to be used as an atomic
 
 	sessionRunner sessionRunner
 
@@ -149,7 +152,7 @@ func listen(conn net.PacketConn, tlsConf *tls.Config, config *Config) (*server,
 		tlsConf:        tlsConf,
 		config:         config,
 		sessionHandler: sessionHandler,
-		sessionQueue:   make(chan Session, 5),
+		sessionQueue:   make(chan Session),
 		errorChan:      make(chan struct{}),
 		newSession:     newSession,
 		logger:         utils.DefaultLogger.WithPrefix("server"),
@@ -164,9 +167,20 @@ func listen(conn net.PacketConn, tlsConf *tls.Config, config *Config) (*server,
 
 func (s *server) setup() error {
 	s.sessionRunner = &runner{
-		onHandshakeCompleteImpl: func(sess Session) { s.sessionQueue <- sess },
-		retireConnectionIDImpl:  s.sessionHandler.Retire,
-		removeConnectionIDImpl:  s.sessionHandler.Remove,
+		onHandshakeCompleteImpl: func(sess Session) {
+			go func() {
+				atomic.AddInt32(&s.sessionQueueLen, 1)
+				defer atomic.AddInt32(&s.sessionQueueLen, -1)
+				select {
+				case s.sessionQueue <- sess:
+					// blocks until the session is accepted
+				case <-sess.Context().Done():
+					// don't pass sessions that were already closed to Accept()
+				}
+			}()
+		},
+		retireConnectionIDImpl: s.sessionHandler.Retire,
+		removeConnectionIDImpl: s.sessionHandler.Remove,
 	}
 	cookieGenerator, err := handshake.NewCookieGenerator()
 	if err != nil {
@@ -333,7 +347,7 @@ func (s *server) handleInitial(p *receivedPacket) {
 		s.logger.Errorf("Error occurred handling initial packet: %s", err)
 		return
 	}
-	if sess == nil { // a retry was done
+	if sess == nil { // a retry was done, or the connection attempt was rejected
 		p.buffer.Release()
 		return
 	}
@@ -371,6 +385,11 @@ func (s *server) handleInitialImpl(p *receivedPacket) (quicSession, protocol.Con
 		return nil, nil, s.sendRetry(p.remoteAddr, hdr)
 	}
 
+	if queueLen := atomic.LoadInt32(&s.sessionQueueLen); queueLen >= protocol.MaxAcceptQueueSize {
+		s.logger.Debugf("Rejecting new connection. Server currently busy. Accept queue length: %d (max %d)", queueLen, protocol.MaxAcceptQueueSize)
+		return nil, nil, s.sendServerBusy(p.remoteAddr, hdr)
+	}
+
 	connID, err := protocol.GenerateConnectionID(s.config.ConnectionIDLength)
 	if err != nil {
 		return nil, nil, err
@@ -460,6 +479,54 @@ func (s *server) sendRetry(remoteAddr net.Addr, hdr *wire.Header) error {
 	return nil
 }
 
+func (s *server) sendServerBusy(remoteAddr net.Addr, hdr *wire.Header) error {
+	sealer, _, err := handshake.NewInitialAEAD(hdr.DestConnectionID, protocol.PerspectiveServer)
+	if err != nil {
+		return err
+	}
+	packetBuffer := getPacketBuffer()
+	defer packetBuffer.Release()
+	buf := bytes.NewBuffer(packetBuffer.Slice[:0])
+
+	// TODO(#1567): use the SERVER_BUSY error code
+	ccf := &wire.ConnectionCloseFrame{ErrorCode: qerr.PeerGoingAway}
+
+	replyHdr := &wire.ExtendedHeader{}
+	replyHdr.IsLongHeader = true
+	replyHdr.Type = protocol.PacketTypeInitial
+	replyHdr.Version = hdr.Version
+	replyHdr.SrcConnectionID = hdr.DestConnectionID
+	replyHdr.DestConnectionID = hdr.SrcConnectionID
+	replyHdr.PacketNumberLen = protocol.PacketNumberLen4
+	replyHdr.Length = 4 /* packet number len */ + ccf.Length(hdr.Version) + protocol.ByteCount(sealer.Overhead())
+	if err := replyHdr.Write(buf, hdr.Version); err != nil {
+		return err
+	}
+	payloadOffset := buf.Len()
+
+	if err := ccf.Write(buf, hdr.Version); err != nil {
+		return err
+	}
+
+	raw := buf.Bytes()
+	_ = sealer.Seal(raw[payloadOffset:payloadOffset], raw[payloadOffset:], replyHdr.PacketNumber, raw[:payloadOffset])
+	raw = raw[0 : buf.Len()+sealer.Overhead()]
+
+	pnOffset := payloadOffset - int(replyHdr.PacketNumberLen)
+	sealer.EncryptHeader(
+		raw[pnOffset+4:pnOffset+4+16],
+		&raw[0],
+		raw[pnOffset:payloadOffset],
+	)
+
+	replyHdr.Log(s.logger)
+	wire.LogFrame(s.logger, ccf, true)
+	if _, err := s.conn.WriteTo(raw, remoteAddr); err != nil {
+		s.logger.Debugf("Error rejecting connection: %s", err)
+	}
+	return nil
+}
+
 func (s *server) sendVersionNegotiationPacket(p *receivedPacket) {
 	defer p.buffer.Release()
 	hdr := p.hdr
diff --git a/vendor/github.com/lucas-clemente/quic-go/session.go b/vendor/github.com/lucas-clemente/quic-go/session.go
index 63aa3d9d7..3021e782d 100644
--- a/vendor/github.com/lucas-clemente/quic-go/session.go
+++ b/vendor/github.com/lucas-clemente/quic-go/session.go
@@ -1,12 +1,14 @@
 package quic
 
 import (
+	"bytes"
 	"context"
 	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
 	"net"
+	"reflect"
 	"sync"
 	"time"
 
@@ -495,14 +497,17 @@ func (s *session) handlePacketImpl(p *receivedPacket) bool /* was the packet suc
 	}
 
 	packet, err := s.unpacker.Unpack(p.hdr, p.data)
-	// if the decryption failed, this might be a packet sent by an attacker
 	if err != nil {
 		if err == handshake.ErrOpenerNotYetAvailable {
+			// Sealer for this encryption level not yet available.
+			// Try again later.
 			wasQueued = true
 			s.tryQueueingUndecryptablePacket(p)
 			return false
 		}
-		s.closeLocal(err)
+		// This might be a packet injected by an attacker.
+		// Drop it.
+		s.logger.Debugf("Dropping packet that could not be unpacked. Unpack error: %s", err)
 		return false
 	}
 
@@ -519,6 +524,10 @@ func (s *session) handlePacketImpl(p *receivedPacket) bool /* was the packet suc
 }
 
 func (s *session) handleUnpackedPacket(packet *unpackedPacket, rcvTime time.Time) error {
+	if len(packet.data) == 0 {
+		return qerr.MissingPayload
+	}
+
 	// The server can change the source connection ID with the first Handshake packet.
 	if s.perspective == protocol.PerspectiveClient && !s.receivedFirstPacket && packet.hdr.IsLongHeader && !packet.hdr.SrcConnectionID.Equal(s.destConnID) {
 		s.logger.Debugf("Received first packet. Switching destination connection ID to: %s", packet.hdr.SrcConnectionID)
@@ -539,66 +548,72 @@ func (s *session) handleUnpackedPacket(packet *unpackedPacket, rcvTime time.Time
 		}
 	}
 
-	// If this is a Retry packet, there's no need to send an ACK.
-	// The session will be closed and recreated as soon as the crypto setup processed the HRR.
-	if packet.hdr.Type != protocol.PacketTypeRetry {
-		isRetransmittable := ackhandler.HasRetransmittableFrames(packet.frames)
-		if err := s.receivedPacketHandler.ReceivedPacket(packet.packetNumber, rcvTime, isRetransmittable); err != nil {
-			return err
-		}
-	}
-
-	return s.handleFrames(packet.frames, packet.packetNumber, packet.encryptionLevel)
-}
-
-func (s *session) handleFrames(fs []wire.Frame, pn protocol.PacketNumber, encLevel protocol.EncryptionLevel) error {
-	for _, ff := range fs {
-		var err error
-		wire.LogFrame(s.logger, ff, false)
-		switch frame := ff.(type) {
-		case *wire.CryptoFrame:
-			err = s.handleCryptoFrame(frame, encLevel)
-		case *wire.StreamFrame:
-			err = s.handleStreamFrame(frame, encLevel)
-		case *wire.AckFrame:
-			err = s.handleAckFrame(frame, pn, encLevel)
-		case *wire.ConnectionCloseFrame:
-			s.closeRemote(qerr.Error(frame.ErrorCode, frame.ReasonPhrase))
-		case *wire.ResetStreamFrame:
-			err = s.handleResetStreamFrame(frame)
-		case *wire.MaxDataFrame:
-			s.handleMaxDataFrame(frame)
-		case *wire.MaxStreamDataFrame:
-			err = s.handleMaxStreamDataFrame(frame)
-		case *wire.MaxStreamsFrame:
-			err = s.handleMaxStreamsFrame(frame)
-		case *wire.DataBlockedFrame:
-		case *wire.StreamDataBlockedFrame:
-		case *wire.StreamsBlockedFrame:
-		case *wire.StopSendingFrame:
-			err = s.handleStopSendingFrame(frame)
-		case *wire.PingFrame:
-		case *wire.PathChallengeFrame:
-			s.handlePathChallengeFrame(frame)
-		case *wire.PathResponseFrame:
-			// since we don't send PATH_CHALLENGEs, we don't expect PATH_RESPONSEs
-			err = errors.New("unexpected PATH_RESPONSE frame")
-		case *wire.NewTokenFrame:
-		case *wire.NewConnectionIDFrame:
-		case *wire.RetireConnectionIDFrame:
-			// since we don't send new connection IDs, we don't expect retirements
-			err = errors.New("unexpected RETIRE_CONNECTION_ID frame")
-		default:
-			return errors.New("Session BUG: unexpected frame type")
-		}
-
+	r := bytes.NewReader(packet.data)
+	var isRetransmittable bool
+	for {
+		frame, err := wire.ParseNextFrame(r, s.version)
 		if err != nil {
 			return err
 		}
+		if frame == nil {
+			break
+		}
+		if ackhandler.IsFrameRetransmittable(frame) {
+			isRetransmittable = true
+		}
+		if err := s.handleFrame(frame, packet.packetNumber, packet.encryptionLevel); err != nil {
+			return err
+		}
+	}
+
+	if err := s.receivedPacketHandler.ReceivedPacket(packet.packetNumber, rcvTime, isRetransmittable); err != nil {
+		return err
 	}
 	return nil
 }
 
+func (s *session) handleFrame(f wire.Frame, pn protocol.PacketNumber, encLevel protocol.EncryptionLevel) error {
+	var err error
+	wire.LogFrame(s.logger, f, false)
+	switch frame := f.(type) {
+	case *wire.CryptoFrame:
+		err = s.handleCryptoFrame(frame, encLevel)
+	case *wire.StreamFrame:
+		err = s.handleStreamFrame(frame, encLevel)
+	case *wire.AckFrame:
+		err = s.handleAckFrame(frame, pn, encLevel)
+	case *wire.ConnectionCloseFrame:
+		s.closeRemote(qerr.Error(frame.ErrorCode, frame.ReasonPhrase))
+	case *wire.ResetStreamFrame:
+		err = s.handleResetStreamFrame(frame)
+	case *wire.MaxDataFrame:
+		s.handleMaxDataFrame(frame)
+	case *wire.MaxStreamDataFrame:
+		err = s.handleMaxStreamDataFrame(frame)
+	case *wire.MaxStreamsFrame:
+		err = s.handleMaxStreamsFrame(frame)
+	case *wire.DataBlockedFrame:
+	case *wire.StreamDataBlockedFrame:
+	case *wire.StreamsBlockedFrame:
+	case *wire.StopSendingFrame:
+		err = s.handleStopSendingFrame(frame)
+	case *wire.PingFrame:
+	case *wire.PathChallengeFrame:
+		s.handlePathChallengeFrame(frame)
+	case *wire.PathResponseFrame:
+		// since we don't send PATH_CHALLENGEs, we don't expect PATH_RESPONSEs
+		err = errors.New("unexpected PATH_RESPONSE frame")
+	case *wire.NewTokenFrame:
+	case *wire.NewConnectionIDFrame:
+	case *wire.RetireConnectionIDFrame:
+		// since we don't send new connection IDs, we don't expect retirements
+		err = errors.New("unexpected RETIRE_CONNECTION_ID frame")
+	default:
+		err = fmt.Errorf("unexpected frame type: %s", reflect.ValueOf(&frame).Elem().Type().Name())
+	}
+	return err
+}
+
 // handlePacket is called by the server with a new packet
 func (s *session) handlePacket(p *receivedPacket) {
 	if s.closed.Get() {
@@ -787,11 +802,7 @@ func (s *session) handleCloseError(closeErr closeError) error {
 	if closeErr.remote {
 		return nil
 	}
-
-	if quicErr.ErrorCode == qerr.DecryptionFailure {
-		// TODO(#943): send a stateless reset
-		return nil
-	}
+	// otherwise send a CONNECTION_CLOSE
 	return s.sendConnectionClose(quicErr)
 }
 
@@ -830,7 +841,7 @@ sendLoop:
 			// There will only be a new ACK after receiving new packets.
 			// SendAck is only returned when we're congestion limited, so we don't need to set the pacingt timer.
 			return s.maybeSendAckOnlyPacket()
-		case ackhandler.SendTLP, ackhandler.SendRTO:
+		case ackhandler.SendPTO:
 			if err := s.sendProbePacket(); err != nil {
 				return err
 			}
diff --git a/vendor/github.com/lucas-clemente/quic-go/streams_map.go b/vendor/github.com/lucas-clemente/quic-go/streams_map.go
index 4be37bf43..b71953756 100644
--- a/vendor/github.com/lucas-clemente/quic-go/streams_map.go
+++ b/vendor/github.com/lucas-clemente/quic-go/streams_map.go
@@ -1,7 +1,9 @@
 package quic
 
 import (
+	"errors"
 	"fmt"
+	"net"
 
 	"github.com/lucas-clemente/quic-go/internal/flowcontrol"
 	"github.com/lucas-clemente/quic-go/internal/handshake"
@@ -9,6 +11,16 @@ import (
 	"github.com/lucas-clemente/quic-go/internal/wire"
 )
 
+type streamOpenErr struct{ error }
+
+var _ net.Error = &streamOpenErr{}
+
+func (e streamOpenErr) Temporary() bool { return e.error == errTooManyOpenStreams }
+func (streamOpenErr) Timeout() bool     { return false }
+
+// errTooManyOpenStreams is used internally by the outgoing streams maps.
+var errTooManyOpenStreams = errors.New("too many open streams")
+
 type streamsMap struct {
 	perspective protocol.Perspective
 
diff --git a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_bidi.go b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_bidi.go
index 6405e4381..480d8d774 100644
--- a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_bidi.go
+++ b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_bidi.go
@@ -49,7 +49,11 @@ func (m *outgoingBidiStreamsMap) OpenStream() (streamI, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	return m.openStreamImpl()
+	str, err := m.openStreamImpl()
+	if err != nil {
+		return nil, streamOpenErr{err}
+	}
+	return str, nil
 }
 
 func (m *outgoingBidiStreamsMap) OpenStreamSync() (streamI, error) {
@@ -59,10 +63,10 @@ func (m *outgoingBidiStreamsMap) OpenStreamSync() (streamI, error) {
 	for {
 		str, err := m.openStreamImpl()
 		if err == nil {
-			return str, err
+			return str, nil
 		}
-		if err != nil && err != qerr.TooManyOpenStreams {
-			return nil, err
+		if err != nil && err != errTooManyOpenStreams {
+			return nil, streamOpenErr{err}
 		}
 		m.cond.Wait()
 	}
@@ -87,7 +91,7 @@ func (m *outgoingBidiStreamsMap) openStreamImpl() (streamI, error) {
 			}
 			m.blockedSent = true
 		}
-		return nil, qerr.TooManyOpenStreams
+		return nil, errTooManyOpenStreams
 	}
 	s := m.newStream(m.nextStream)
 	m.streams[m.nextStream] = s
diff --git a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_generic.go b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_generic.go
index 23bd19176..e9cff98b9 100644
--- a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_generic.go
+++ b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_generic.go
@@ -47,7 +47,11 @@ func (m *outgoingItemsMap) OpenStream() (item, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	return m.openStreamImpl()
+	str, err := m.openStreamImpl()
+	if err != nil {
+		return nil, streamOpenErr{err}
+	}
+	return str, nil
 }
 
 func (m *outgoingItemsMap) OpenStreamSync() (item, error) {
@@ -57,10 +61,10 @@ func (m *outgoingItemsMap) OpenStreamSync() (item, error) {
 	for {
 		str, err := m.openStreamImpl()
 		if err == nil {
-			return str, err
+			return str, nil
 		}
-		if err != nil && err != qerr.TooManyOpenStreams {
-			return nil, err
+		if err != nil && err != errTooManyOpenStreams {
+			return nil, streamOpenErr{err}
 		}
 		m.cond.Wait()
 	}
@@ -85,7 +89,7 @@ func (m *outgoingItemsMap) openStreamImpl() (item, error) {
 			}
 			m.blockedSent = true
 		}
-		return nil, qerr.TooManyOpenStreams
+		return nil, errTooManyOpenStreams
 	}
 	s := m.newStream(m.nextStream)
 	m.streams[m.nextStream] = s
diff --git a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_uni.go b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_uni.go
index 838c9aa9d..98456bfd1 100644
--- a/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_uni.go
+++ b/vendor/github.com/lucas-clemente/quic-go/streams_map_outgoing_uni.go
@@ -49,7 +49,11 @@ func (m *outgoingUniStreamsMap) OpenStream() (sendStreamI, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	return m.openStreamImpl()
+	str, err := m.openStreamImpl()
+	if err != nil {
+		return nil, streamOpenErr{err}
+	}
+	return str, nil
 }
 
 func (m *outgoingUniStreamsMap) OpenStreamSync() (sendStreamI, error) {
@@ -59,10 +63,10 @@ func (m *outgoingUniStreamsMap) OpenStreamSync() (sendStreamI, error) {
 	for {
 		str, err := m.openStreamImpl()
 		if err == nil {
-			return str, err
+			return str, nil
 		}
-		if err != nil && err != qerr.TooManyOpenStreams {
-			return nil, err
+		if err != nil && err != errTooManyOpenStreams {
+			return nil, streamOpenErr{err}
 		}
 		m.cond.Wait()
 	}
@@ -87,7 +91,7 @@ func (m *outgoingUniStreamsMap) openStreamImpl() (sendStreamI, error) {
 			}
 			m.blockedSent = true
 		}
-		return nil, qerr.TooManyOpenStreams
+		return nil, errTooManyOpenStreams
 	}
 	s := m.newStream(m.nextStream)
 	m.streams[m.nextStream] = s
diff --git a/vendor/github.com/lucas-clemente/quic-go/vendor/github.com/marten-seemann/qtls/cipher_suites.go b/vendor/github.com/lucas-clemente/quic-go/vendor/github.com/marten-seemann/qtls/cipher_suites.go
index 3bbc0b90d..781c32282 100644
--- a/vendor/github.com/lucas-clemente/quic-go/vendor/github.com/marten-seemann/qtls/cipher_suites.go
+++ b/vendor/github.com/lucas-clemente/quic-go/vendor/github.com/marten-seemann/qtls/cipher_suites.go
@@ -250,6 +250,11 @@ func aeadAESGCM12(key, fixedNonce []byte) cipher.AEAD {
 	return ret
 }
 
+// AEADAESGCM13 creates a new AES-GCM AEAD for TLS 1.3
+func AEADAESGCM13(key, fixedNonce []byte) cipher.AEAD {
+	return aeadAESGCM13(key, fixedNonce)
+}
+
 func aeadAESGCM13(key, fixedNonce []byte) cipher.AEAD {
 	aes, err := aes.NewCipher(key)
 	if err != nil {