From 9c2be3c6f6c9d63bf2d228a740577b0a8542461e Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 13 Apr 2022 12:57:45 +0100
Subject: [PATCH 01/53] initial commit

---
 p2p/transport/webtransport/conn.go           |  75 +++++++++++
 p2p/transport/webtransport/crypto.go         |  87 ++++++++++++
 p2p/transport/webtransport/listener.go       | 133 +++++++++++++++++++
 p2p/transport/webtransport/multiaddr.go      |  22 +++
 p2p/transport/webtransport/stream.go         |  55 ++++++++
 p2p/transport/webtransport/transport.go      | 104 +++++++++++++++
 p2p/transport/webtransport/transport_test.go |  38 ++++++
 7 files changed, 514 insertions(+)
 create mode 100644 p2p/transport/webtransport/conn.go
 create mode 100644 p2p/transport/webtransport/crypto.go
 create mode 100644 p2p/transport/webtransport/listener.go
 create mode 100644 p2p/transport/webtransport/multiaddr.go
 create mode 100644 p2p/transport/webtransport/stream.go
 create mode 100644 p2p/transport/webtransport/transport.go
 create mode 100644 p2p/transport/webtransport/transport_test.go

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
new file mode 100644
index 0000000000..40ba99f1a1
--- /dev/null
+++ b/p2p/transport/webtransport/conn.go
@@ -0,0 +1,75 @@
+package libp2pwebtransport
+
+import (
+	"context"
+	"github.com/libp2p/go-libp2p-core/crypto"
+	"github.com/libp2p/go-libp2p-core/network"
+	"github.com/libp2p/go-libp2p-core/peer"
+	tpt "github.com/libp2p/go-libp2p-core/transport"
+	"github.com/marten-seemann/webtransport-go"
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+type conn struct {
+	transport tpt.Transport
+	wconn     *webtransport.Conn
+}
+
+var _ tpt.CapableConn = &conn{}
+
+func (c *conn) Close() error {
+	return c.wconn.Close()
+}
+
+func (c *conn) IsClosed() bool {
+	panic("implement me")
+}
+
+func (c *conn) OpenStream(ctx context.Context) (network.MuxedStream, error) {
+	str, err := c.wconn.OpenStreamSync(ctx)
+	return &stream{str}, err
+}
+
+func (c *conn) AcceptStream() (network.MuxedStream, error) {
+	str, err := c.wconn.AcceptStream(context.Background())
+	return &stream{str}, err
+}
+
+func (c *conn) LocalPeer() peer.ID {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) LocalPrivateKey() crypto.PrivKey {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) RemotePeer() peer.ID {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) RemotePublicKey() crypto.PubKey {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) LocalMultiaddr() ma.Multiaddr {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) RemoteMultiaddr() ma.Multiaddr {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) Scope() network.ConnScope {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (c *conn) Transport() tpt.Transport {
+	return c.transport
+}
diff --git a/p2p/transport/webtransport/crypto.go b/p2p/transport/webtransport/crypto.go
new file mode 100644
index 0000000000..f658eee3a5
--- /dev/null
+++ b/p2p/transport/webtransport/crypto.go
@@ -0,0 +1,87 @@
+package libp2pwebtransport
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"math/big"
+	"time"
+)
+
+func certificateHash(c *tls.Config) [32]byte {
+	return sha256.Sum256(c.Certificates[0].Certificate[0])
+}
+
+// TODO: don't generate a chain here. A single cert should be sufficient (and save bytes).
+func getTLSConf() (*tls.Config, error) {
+	ca, caPrivateKey, err := generateCA()
+	if err != nil {
+		return nil, err
+	}
+	leafCert, leafPrivateKey, err := generateLeafCert(ca, caPrivateKey)
+	if err != nil {
+		return nil, err
+	}
+	certPool := x509.NewCertPool()
+	certPool.AddCert(ca)
+	return &tls.Config{
+		Certificates: []tls.Certificate{{
+			Certificate: [][]byte{leafCert.Raw},
+			PrivateKey:  leafPrivateKey,
+		}},
+	}, nil
+}
+
+func generateCA() (*x509.Certificate, *ecdsa.PrivateKey, error) {
+	certTempl := &x509.Certificate{
+		SerialNumber:          big.NewInt(2019),
+		Subject:               pkix.Name{},
+		NotBefore:             time.Now().Add(-time.Hour),
+		NotAfter:              time.Now().Add(24 * time.Hour),
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+	}
+	caPrivateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		return nil, nil, err
+	}
+	caBytes, err := x509.CreateCertificate(rand.Reader, certTempl, certTempl, &caPrivateKey.PublicKey, caPrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	ca, err := x509.ParseCertificate(caBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+	return ca, caPrivateKey, nil
+}
+
+func generateLeafCert(ca *x509.Certificate, caPrivateKey *ecdsa.PrivateKey) (*x509.Certificate, *ecdsa.PrivateKey, error) {
+	certTempl := &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		DNSNames:     []string{"localhost"},
+		NotBefore:    time.Now().Add(-time.Hour),
+		NotAfter:     time.Now().Add(24 * time.Hour),
+		ExtKeyUsage:  []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:     x509.KeyUsageDigitalSignature,
+	}
+	privKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		return nil, nil, err
+	}
+	certBytes, err := x509.CreateCertificate(rand.Reader, certTempl, ca, &privKey.PublicKey, caPrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	cert, err := x509.ParseCertificate(certBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+	return cert, privKey, nil
+}
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
new file mode 100644
index 0000000000..e422e23763
--- /dev/null
+++ b/p2p/transport/webtransport/listener.go
@@ -0,0 +1,133 @@
+package libp2pwebtransport
+
+import (
+	"crypto/tls"
+	"errors"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
+	"net"
+	"net/http"
+
+	tpt "github.com/libp2p/go-libp2p-core/transport"
+
+	"github.com/lucas-clemente/quic-go/http3"
+	"github.com/marten-seemann/webtransport-go"
+	ma "github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
+)
+
+var errClosed = errors.New("closed")
+
+type listener struct {
+	server  webtransport.Server
+	tlsConf *tls.Config
+
+	closed       chan struct{} // is closed when Close is called
+	serverClosed chan struct{} // is closed when server.Serve returns
+
+	addr      net.Addr
+	multiaddr ma.Multiaddr
+
+	queue chan *webtransport.Conn
+}
+
+var _ tpt.Listener = &listener{}
+
+func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error) {
+	network, addr, err := manet.DialArgs(laddr)
+	if err != nil {
+		return nil, err
+	}
+	udpAddr, err := net.ResolveUDPAddr(network, addr)
+	if err != nil {
+		return nil, err
+	}
+	udpConn, err := net.ListenUDP(network, udpAddr)
+	if err != nil {
+		return nil, err
+	}
+	localMultiaddr, err := toWebtransportMultiaddr(udpConn.LocalAddr())
+	if err != nil {
+		return nil, err
+	}
+	ln := &listener{
+		queue:        make(chan *webtransport.Conn, 10),
+		serverClosed: make(chan struct{}),
+		addr:         udpConn.LocalAddr(),
+		tlsConf:      tlsConf,
+		multiaddr:    localMultiaddr,
+	}
+	server := webtransport.Server{
+		H3: http3.Server{
+			Server: &http.Server{
+				TLSConfig: tlsConf,
+			},
+		},
+	}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Hello, world!"))
+	})
+	mux.HandleFunc(webtransportHTTPEndpoint, func(w http.ResponseWriter, r *http.Request) {
+		// TODO: check ?type=multistream URL param
+		c, err := server.Upgrade(w, r)
+		if err != nil {
+			w.WriteHeader(500)
+			return
+		}
+		ln.queue <- c
+	})
+	server.H3.Handler = mux
+	go func() {
+		defer close(ln.serverClosed)
+		defer func() { udpConn.Close() }()
+		if err := server.Serve(udpConn); err != nil {
+			// TODO: only output if the server hasn't been closed
+			log.Debugw("serving failed", "addr", udpConn.LocalAddr(), "error", err)
+		}
+	}()
+	ln.server = server
+	return ln, nil
+}
+
+func (l *listener) Accept() (tpt.CapableConn, error) {
+	select {
+	case <-l.closed:
+		return nil, errClosed
+	default:
+	}
+
+	var c *webtransport.Conn
+	select {
+	case c = <-l.queue:
+		// TODO: libp2p handshake
+		// TODO: pass in transport
+		return &conn{wconn: c}, nil
+	case <-l.closed:
+		return nil, errClosed
+	}
+}
+
+func (l *listener) Addr() net.Addr {
+	return l.addr
+}
+
+func (l *listener) Multiaddr() ma.Multiaddr {
+	certHash := certificateHash(l.tlsConf)
+	h, err := multihash.Encode(certHash[:], multihash.SHA2_256)
+	if err != nil {
+		panic(err)
+	}
+	certHashStr, err := multibase.Encode(multibase.Base58BTC, h)
+	if err != nil {
+		panic(err)
+	}
+	return l.multiaddr.Encapsulate(ma.StringCast("/certhash/" + certHashStr))
+}
+
+func (l *listener) Close() error {
+	close(l.closed)
+	err := l.server.Close()
+	<-l.serverClosed
+	return err
+}
diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
new file mode 100644
index 0000000000..a84853c1ee
--- /dev/null
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -0,0 +1,22 @@
+package libp2pwebtransport
+
+import (
+	"net"
+
+	ma "github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
+)
+
+var webtransportMA = ma.StringCast("/quic/webtransport")
+
+func toWebtransportMultiaddr(na net.Addr) (ma.Multiaddr, error) {
+	udpMA, err := manet.FromNetAddr(na)
+	if err != nil {
+		return nil, err
+	}
+	return udpMA.Encapsulate(webtransportMA), nil
+}
+
+func fromWebtransportMultiaddr(addr ma.Multiaddr) (net.Addr, error) {
+	return manet.ToNetAddr(addr.Decapsulate(webtransportMA))
+}
diff --git a/p2p/transport/webtransport/stream.go b/p2p/transport/webtransport/stream.go
new file mode 100644
index 0000000000..cebfcfb2fb
--- /dev/null
+++ b/p2p/transport/webtransport/stream.go
@@ -0,0 +1,55 @@
+package libp2pwebtransport
+
+import (
+	"errors"
+
+	"github.com/marten-seemann/webtransport-go"
+
+	"github.com/libp2p/go-libp2p-core/network"
+)
+
+const (
+	reset webtransport.ErrorCode = 0
+)
+
+type stream struct {
+	webtransport.Stream
+}
+
+var _ network.MuxedStream = &stream{}
+
+func (s *stream) Read(b []byte) (n int, err error) {
+	n, err = s.Stream.Read(b)
+	if err != nil && errors.Is(err, &webtransport.StreamError{}) {
+		err = network.ErrReset
+	}
+	return n, err
+}
+
+func (s *stream) Write(b []byte) (n int, err error) {
+	n, err = s.Stream.Write(b)
+	if err != nil && errors.Is(err, &webtransport.StreamError{}) {
+		err = network.ErrReset
+	}
+	return n, err
+}
+
+func (s *stream) Reset() error {
+	s.Stream.CancelRead(reset)
+	s.Stream.CancelWrite(reset)
+	return nil
+}
+
+func (s *stream) Close() error {
+	s.Stream.CancelRead(reset)
+	return s.Stream.Close()
+}
+
+func (s *stream) CloseRead() error {
+	s.Stream.CancelRead(reset)
+	return nil
+}
+
+func (s *stream) CloseWrite() error {
+	return s.Stream.Close()
+}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
new file mode 100644
index 0000000000..1c91413c1b
--- /dev/null
+++ b/p2p/transport/webtransport/transport.go
@@ -0,0 +1,104 @@
+package libp2pwebtransport
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
+	"sync"
+
+	"github.com/libp2p/go-libp2p-core/peer"
+	tpt "github.com/libp2p/go-libp2p-core/transport"
+
+	logging "github.com/ipfs/go-log/v2"
+	"github.com/marten-seemann/webtransport-go"
+	ma "github.com/multiformats/go-multiaddr"
+	mafmt "github.com/multiformats/go-multiaddr-fmt"
+	manet "github.com/multiformats/go-multiaddr/net"
+)
+
+var log = logging.Logger("webtransport")
+
+const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
+
+type transport struct {
+	tlsConf *tls.Config
+	dialer  webtransport.Dialer
+
+	initOnce sync.Once
+	server   webtransport.Server
+}
+
+var _ tpt.Transport = &transport{}
+
+func New() (tpt.Transport, error) {
+	tlsConf, err := getTLSConf() // TODO: only do this when initializing a listener
+	if err != nil {
+		return nil, err
+	}
+	return &transport{
+		tlsConf: tlsConf,
+		dialer: webtransport.Dialer{
+			TLSClientConf: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
+		},
+	}, nil
+}
+
+func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
+	_, addr, err := manet.DialArgs(raddr)
+	if err != nil {
+		return nil, err
+	}
+	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
+	certHashesStr := make([]string, 0, 2)
+	ma.ForEach(raddr, func(c ma.Component) bool {
+		if c.Protocol().Code == ma.P_CERTHASH {
+			certHashesStr = append(certHashesStr, c.Value())
+		}
+		return true
+	})
+	var certHashes []multihash.DecodedMultihash
+	for _, s := range certHashesStr {
+		_, ch, err := multibase.Decode(s)
+		if err != nil {
+			return nil, fmt.Errorf("failed to multibase-decode certificate hash: %w", err)
+		}
+		dh, err := multihash.Decode(ch)
+		if err != nil {
+			return nil, fmt.Errorf("failed to multihash-decode certificate hash: %w", err)
+		}
+		certHashes = append(certHashes, *dh)
+	}
+	rsp, wconn, err := t.dialer.Dial(ctx, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	defer rsp.Body.Close()
+	if rsp.StatusCode < 200 || rsp.StatusCode > 299 {
+		return nil, fmt.Errorf("invalid response status code: %d", rsp.StatusCode)
+	}
+	// TODO: run handshake on conn
+	return &conn{
+		transport: t,
+		wconn:     wconn,
+	}, nil
+}
+
+var dialMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
+
+func (t *transport) CanDial(addr ma.Multiaddr) bool {
+	return dialMatcher.Matches(addr)
+}
+
+func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
+	return newListener(laddr, t.tlsConf)
+}
+
+func (t *transport) Protocols() []int {
+	return []int{ma.P_WEBTRANSPORT}
+}
+
+func (t *transport) Proxy() bool {
+	return false
+}
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
new file mode 100644
index 0000000000..bf65017dcf
--- /dev/null
+++ b/p2p/transport/webtransport/transport_test.go
@@ -0,0 +1,38 @@
+package libp2pwebtransport_test
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTransport(t *testing.T) {
+	tr, err := libp2pwebtransport.New()
+	require.NoError(t, err)
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+
+	go func() {
+		tr2, err := libp2pwebtransport.New()
+		require.NoError(t, err)
+		conn, err := tr2.Dial(context.Background(), ln.Multiaddr(), "peer")
+		require.NoError(t, err)
+		str, err := conn.OpenStream(context.Background())
+		require.NoError(t, err)
+		_, err = str.Write([]byte("foobar"))
+		require.NoError(t, err)
+		require.NoError(t, str.Close())
+	}()
+
+	conn, err := ln.Accept()
+	require.NoError(t, err)
+	str, err := conn.AcceptStream()
+	require.NoError(t, err)
+	data, err := io.ReadAll(str)
+	require.NoError(t, err)
+	require.Equal(t, "foobar", string(data))
+}

From 528fa96706a43db1a0388642bf40bb9957fa8e14 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 16 Apr 2022 14:52:10 +0100
Subject: [PATCH 02/53] use a context to control listener shutdown

---
 p2p/transport/webtransport/listener.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index e422e23763..9d95acd9e2 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -1,10 +1,10 @@
 package libp2pwebtransport
 
 import (
+	"context"
 	"crypto/tls"
 	"errors"
-	"github.com/multiformats/go-multibase"
-	"github.com/multiformats/go-multihash"
+
 	"net"
 	"net/http"
 
@@ -14,6 +14,8 @@ import (
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 )
 
 var errClosed = errors.New("closed")
@@ -22,7 +24,9 @@ type listener struct {
 	server  webtransport.Server
 	tlsConf *tls.Config
 
-	closed       chan struct{} // is closed when Close is called
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+
 	serverClosed chan struct{} // is closed when server.Serve returns
 
 	addr      net.Addr
@@ -57,6 +61,7 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error)
 		tlsConf:      tlsConf,
 		multiaddr:    localMultiaddr,
 	}
+	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
 	server := webtransport.Server{
 		H3: http3.Server{
 			Server: &http.Server{
@@ -92,7 +97,7 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error)
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
 	select {
-	case <-l.closed:
+	case <-l.ctx.Done():
 		return nil, errClosed
 	default:
 	}
@@ -103,7 +108,7 @@ func (l *listener) Accept() (tpt.CapableConn, error) {
 		// TODO: libp2p handshake
 		// TODO: pass in transport
 		return &conn{wconn: c}, nil
-	case <-l.closed:
+	case <-l.ctx.Done():
 		return nil, errClosed
 	}
 }
@@ -126,7 +131,7 @@ func (l *listener) Multiaddr() ma.Multiaddr {
 }
 
 func (l *listener) Close() error {
-	close(l.closed)
+	l.ctxCancel()
 	err := l.server.Close()
 	<-l.serverClosed
 	return err

From c7ebc6d8343097c5443c5f74da1330e274465416 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 16 Apr 2022 15:15:06 +0100
Subject: [PATCH 03/53] run a Noise handshake on the first stream

To make this actually secure, we still need to verify the certificate
hashes.
---
 p2p/transport/webtransport/conn.go           | 49 ++++++++------
 p2p/transport/webtransport/listener.go       | 67 +++++++++++++++-----
 p2p/transport/webtransport/stream.go         | 16 +++++
 p2p/transport/webtransport/transport.go      | 39 ++++++++++--
 p2p/transport/webtransport/transport_test.go | 16 ++++-
 5 files changed, 143 insertions(+), 44 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index 40ba99f1a1..e45daedd86 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -2,10 +2,13 @@ package libp2pwebtransport
 
 import (
 	"context"
+
 	"github.com/libp2p/go-libp2p-core/crypto"
+	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
+
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 )
@@ -13,6 +16,29 @@ import (
 type conn struct {
 	transport tpt.Transport
 	wconn     *webtransport.Conn
+
+	localPeer, remotePeer peer.ID
+	privKey               ic.PrivKey
+	remotePubKey          ic.PubKey
+}
+
+func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, remotePubKey ic.PubKey) (*conn, error) {
+	localPeer, err := peer.IDFromPrivateKey(privKey)
+	if err != nil {
+		return nil, err
+	}
+	remotePeer, err := peer.IDFromPublicKey(remotePubKey)
+	if err != nil {
+		return nil, err
+	}
+	return &conn{
+		transport:    tr,
+		wconn:        wconn,
+		privKey:      privKey,
+		localPeer:    localPeer,
+		remotePeer:   remotePeer,
+		remotePubKey: remotePubKey,
+	}, nil
 }
 
 var _ tpt.CapableConn = &conn{}
@@ -35,25 +61,10 @@ func (c *conn) AcceptStream() (network.MuxedStream, error) {
 	return &stream{str}, err
 }
 
-func (c *conn) LocalPeer() peer.ID {
-	// TODO implement me
-	panic("implement me")
-}
-
-func (c *conn) LocalPrivateKey() crypto.PrivKey {
-	// TODO implement me
-	panic("implement me")
-}
-
-func (c *conn) RemotePeer() peer.ID {
-	// TODO implement me
-	panic("implement me")
-}
-
-func (c *conn) RemotePublicKey() crypto.PubKey {
-	// TODO implement me
-	panic("implement me")
-}
+func (c *conn) LocalPeer() peer.ID              { return c.localPeer }
+func (c *conn) LocalPrivateKey() crypto.PrivKey { return c.privKey }
+func (c *conn) RemotePeer() peer.ID             { return c.remotePeer }
+func (c *conn) RemotePublicKey() crypto.PubKey  { return c.remotePubKey }
 
 func (c *conn) LocalMultiaddr() ma.Multiaddr {
 	// TODO implement me
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 9d95acd9e2..0dadec2fa8 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -4,12 +4,14 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-
 	"net"
 	"net/http"
+	"time"
 
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
+	noise "github.com/libp2p/go-libp2p-noise"
+
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
@@ -20,7 +22,13 @@ import (
 
 var errClosed = errors.New("closed")
 
+const queueLen = 16
+const handshakeTimeout = 10 * time.Second
+
 type listener struct {
+	transport tpt.Transport
+	noise     *noise.Transport
+
 	server  webtransport.Server
 	tlsConf *tls.Config
 
@@ -37,7 +45,7 @@ type listener struct {
 
 var _ tpt.Listener = &listener{}
 
-func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error) {
+func newListener(laddr ma.Multiaddr, tlsConf *tls.Config, transport tpt.Transport, noise *noise.Transport) (tpt.Listener, error) {
 	network, addr, err := manet.DialArgs(laddr)
 	if err != nil {
 		return nil, err
@@ -55,7 +63,9 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error)
 		return nil, err
 	}
 	ln := &listener{
-		queue:        make(chan *webtransport.Conn, 10),
+		transport:    transport,
+		noise:        noise,
+		queue:        make(chan *webtransport.Conn, queueLen),
 		serverClosed: make(chan struct{}),
 		addr:         udpConn.LocalAddr(),
 		tlsConf:      tlsConf,
@@ -80,6 +90,7 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error)
 			w.WriteHeader(500)
 			return
 		}
+		// TODO: handle queue overflow
 		ln.queue <- c
 	})
 	server.H3.Handler = mux
@@ -96,21 +107,47 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config) (tpt.Listener, error)
 }
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
-	select {
-	case <-l.ctx.Done():
-		return nil, errClosed
-	default:
+	queue := make(chan tpt.CapableConn, queueLen)
+	for {
+		select {
+		case <-l.ctx.Done():
+			return nil, errClosed
+		default:
+		}
+
+		var c *webtransport.Conn
+		select {
+		case c = <-l.queue:
+			go func(c *webtransport.Conn) {
+				ctx, cancel := context.WithTimeout(l.ctx, handshakeTimeout)
+				defer cancel()
+				conn, err := l.handshake(ctx, c)
+				if err != nil {
+					log.Debugw("handshake failed", "error", err)
+					c.Close()
+					return
+				}
+				// TODO: handle queue overflow
+				queue <- conn
+			}(c)
+		case conn := <-queue:
+			return conn, nil
+		case <-l.ctx.Done():
+			return nil, errClosed
+		}
 	}
+}
 
-	var c *webtransport.Conn
-	select {
-	case c = <-l.queue:
-		// TODO: libp2p handshake
-		// TODO: pass in transport
-		return &conn{wconn: c}, nil
-	case <-l.ctx.Done():
-		return nil, errClosed
+func (l *listener) handshake(ctx context.Context, c *webtransport.Conn) (tpt.CapableConn, error) {
+	str, err := c.AcceptStream(ctx)
+	if err != nil {
+		return nil, err
+	}
+	conn, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wconn: c}, "")
+	if err != nil {
+		return nil, err
 	}
+	return newConn(l.transport, c, conn.LocalPrivateKey(), conn.RemotePublicKey())
 }
 
 func (l *listener) Addr() net.Addr {
diff --git a/p2p/transport/webtransport/stream.go b/p2p/transport/webtransport/stream.go
index cebfcfb2fb..fa34242b6c 100644
--- a/p2p/transport/webtransport/stream.go
+++ b/p2p/transport/webtransport/stream.go
@@ -2,6 +2,7 @@ package libp2pwebtransport
 
 import (
 	"errors"
+	"net"
 
 	"github.com/marten-seemann/webtransport-go"
 
@@ -12,6 +13,21 @@ const (
 	reset webtransport.ErrorCode = 0
 )
 
+type webtransportStream struct {
+	webtransport.Stream
+	wconn *webtransport.Conn
+}
+
+var _ net.Conn = &webtransportStream{}
+
+func (s *webtransportStream) LocalAddr() net.Addr {
+	return s.wconn.LocalAddr()
+}
+
+func (s *webtransportStream) RemoteAddr() net.Addr {
+	return s.wconn.RemoteAddr()
+}
+
 type stream struct {
 	webtransport.Stream
 }
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 1c91413c1b..7a0098fe77 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -8,8 +8,10 @@ import (
 	"github.com/multiformats/go-multihash"
 	"sync"
 
+	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/peer"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
+	noise "github.com/libp2p/go-libp2p-noise"
 
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/marten-seemann/webtransport-go"
@@ -22,26 +24,44 @@ var log = logging.Logger("webtransport")
 
 const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
+const maxProtoSize = 8 << 10
+
 type transport struct {
+	privKey ic.PrivKey
+	pid     peer.ID
+
 	tlsConf *tls.Config
 	dialer  webtransport.Dialer
 
 	initOnce sync.Once
 	server   webtransport.Server
+
+	noise *noise.Transport
 }
 
 var _ tpt.Transport = &transport{}
 
-func New() (tpt.Transport, error) {
+func New(key ic.PrivKey) (tpt.Transport, error) {
+	id, err := peer.IDFromPrivateKey(key)
+	if err != nil {
+		return nil, err
+	}
 	tlsConf, err := getTLSConf() // TODO: only do this when initializing a listener
 	if err != nil {
 		return nil, err
 	}
+	noise, err := noise.New(key)
+	if err != nil {
+		return nil, err
+	}
 	return &transport{
+		pid:     id,
+		privKey: key,
 		tlsConf: tlsConf,
 		dialer: webtransport.Dialer{
 			TLSClientConf: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
 		},
+		noise: noise,
 	}, nil
 }
 
@@ -78,11 +98,16 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if rsp.StatusCode < 200 || rsp.StatusCode > 299 {
 		return nil, fmt.Errorf("invalid response status code: %d", rsp.StatusCode)
 	}
-	// TODO: run handshake on conn
-	return &conn{
-		transport: t,
-		wconn:     wconn,
-	}, nil
+	str, err := wconn.OpenStreamSync(ctx)
+	if err != nil {
+		return nil, err
+	}
+	// TODO: use early data and verify the cert hash
+	sconn, err := t.noise.SecureOutbound(ctx, &webtransportStream{Stream: str, wconn: wconn}, p)
+	if err != nil {
+		return nil, err
+	}
+	return newConn(t, wconn, t.privKey, sconn.RemotePublicKey())
 }
 
 var dialMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
@@ -92,7 +117,7 @@ func (t *transport) CanDial(addr ma.Multiaddr) bool {
 }
 
 func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
-	return newListener(laddr, t.tlsConf)
+	return newListener(laddr, t.tlsConf, t, t.noise)
 }
 
 func (t *transport) Protocols() []int {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index bf65017dcf..338d26ab55 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -2,24 +2,34 @@ package libp2pwebtransport_test
 
 import (
 	"context"
+	"crypto/rand"
 	"io"
 	"testing"
 
+	ic "github.com/libp2p/go-libp2p-core/crypto"
+	"github.com/libp2p/go-libp2p-core/peer"
+
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/stretchr/testify/require"
 )
 
 func TestTransport(t *testing.T) {
-	tr, err := libp2pwebtransport.New()
+	serverKey, _, err := ic.GenerateEd25519Key(rand.Reader)
+	require.NoError(t, err)
+	serverID, err := peer.IDFromPrivateKey(serverKey)
+	require.NoError(t, err)
+	tr, err := libp2pwebtransport.New(serverKey)
 	require.NoError(t, err)
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
 
 	go func() {
-		tr2, err := libp2pwebtransport.New()
+		clientKey, _, err := ic.GenerateEd25519Key(rand.Reader)
+		require.NoError(t, err)
+		tr2, err := libp2pwebtransport.New(clientKey)
 		require.NoError(t, err)
-		conn, err := tr2.Dial(context.Background(), ln.Multiaddr(), "peer")
+		conn, err := tr2.Dial(context.Background(), ln.Multiaddr(), serverID)
 		require.NoError(t, err)
 		str, err := conn.OpenStream(context.Background())
 		require.NoError(t, err)

From 1ea33604b99cd4be9848d5b1847e29f826678bf0 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 16 Apr 2022 18:30:03 +0100
Subject: [PATCH 04/53] generate a single certificate, not a chain

---
 p2p/transport/webtransport/crypto.go | 49 +++++++---------------------
 1 file changed, 12 insertions(+), 37 deletions(-)

diff --git a/p2p/transport/webtransport/crypto.go b/p2p/transport/webtransport/crypto.go
index f658eee3a5..5c6dcdb102 100644
--- a/p2p/transport/webtransport/crypto.go
+++ b/p2p/transport/webtransport/crypto.go
@@ -8,6 +8,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
+	"encoding/binary"
 	"math/big"
 	"time"
 )
@@ -16,31 +17,29 @@ func certificateHash(c *tls.Config) [32]byte {
 	return sha256.Sum256(c.Certificates[0].Certificate[0])
 }
 
-// TODO: don't generate a chain here. A single cert should be sufficient (and save bytes).
 func getTLSConf() (*tls.Config, error) {
-	ca, caPrivateKey, err := generateCA()
+	cert, priv, err := generateCert()
 	if err != nil {
 		return nil, err
 	}
-	leafCert, leafPrivateKey, err := generateLeafCert(ca, caPrivateKey)
-	if err != nil {
-		return nil, err
-	}
-	certPool := x509.NewCertPool()
-	certPool.AddCert(ca)
 	return &tls.Config{
 		Certificates: []tls.Certificate{{
-			Certificate: [][]byte{leafCert.Raw},
-			PrivateKey:  leafPrivateKey,
+			Certificate: [][]byte{cert.Raw},
+			PrivateKey:  priv,
 		}},
 	}, nil
 }
 
-func generateCA() (*x509.Certificate, *ecdsa.PrivateKey, error) {
+func generateCert() (*x509.Certificate, *ecdsa.PrivateKey, error) {
+	b := make([]byte, 8)
+	if _, err := rand.Read(b); err != nil {
+		return nil, nil, err
+	}
+	serial := binary.BigEndian.Uint64(b)
 	certTempl := &x509.Certificate{
-		SerialNumber:          big.NewInt(2019),
+		SerialNumber:          big.NewInt(int64(serial)),
 		Subject:               pkix.Name{},
-		NotBefore:             time.Now().Add(-time.Hour),
+		NotBefore:             time.Now(),
 		NotAfter:              time.Now().Add(24 * time.Hour),
 		IsCA:                  true,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
@@ -61,27 +60,3 @@ func generateCA() (*x509.Certificate, *ecdsa.PrivateKey, error) {
 	}
 	return ca, caPrivateKey, nil
 }
-
-func generateLeafCert(ca *x509.Certificate, caPrivateKey *ecdsa.PrivateKey) (*x509.Certificate, *ecdsa.PrivateKey, error) {
-	certTempl := &x509.Certificate{
-		SerialNumber: big.NewInt(1),
-		DNSNames:     []string{"localhost"},
-		NotBefore:    time.Now().Add(-time.Hour),
-		NotAfter:     time.Now().Add(24 * time.Hour),
-		ExtKeyUsage:  []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
-		KeyUsage:     x509.KeyUsageDigitalSignature,
-	}
-	privKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	if err != nil {
-		return nil, nil, err
-	}
-	certBytes, err := x509.CreateCertificate(rand.Reader, certTempl, ca, &privKey.PublicKey, caPrivateKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	cert, err := x509.ParseCertificate(certBytes)
-	if err != nil {
-		return nil, nil, err
-	}
-	return cert, privKey, nil
-}

From a077c8901ffc82989106bfd577ce99dfaef318aa Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 17 Apr 2022 11:45:54 +0100
Subject: [PATCH 05/53] implement a basic certificate manager

---
 p2p/transport/webtransport/cert_manager.go    | 164 ++++++++++++++++++
 .../webtransport/cert_manager_test.go         |  72 ++++++++
 p2p/transport/webtransport/crypto.go          |  11 +-
 p2p/transport/webtransport/transport.go       |   6 +-
 4 files changed, 247 insertions(+), 6 deletions(-)
 create mode 100644 p2p/transport/webtransport/cert_manager.go
 create mode 100644 p2p/transport/webtransport/cert_manager_test.go

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
new file mode 100644
index 0000000000..83fc2878cf
--- /dev/null
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -0,0 +1,164 @@
+package libp2pwebtransport
+
+import (
+	"context"
+	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509"
+	"sync"
+	"time"
+
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
+)
+
+type certConfig struct {
+	start, end time.Time
+	tlsConf    *tls.Config
+}
+
+func newCertConfig(start, end time.Time, conf *tls.Config) (*certConfig, error) {
+	return &certConfig{
+		start:   start,
+		end:     end,
+		tlsConf: conf,
+	}, nil
+}
+
+// Certificate renewal logic:
+// 0. To simplify the math, assume the certificate is valid for 10 days (in real life: 14 days).
+// 1. On startup, we generate the first certificate (1).
+// 2. After 4 days, we generate a second certificate (2).
+//    We don't use that certificate yet, but we advertise the hashes of (1) and (2).
+//    That allows clients to connect to us using addresses that are 4 days old.
+// 3. After another 4 days, we now actually start using (2).
+//    We also generate a third certificate (3), and start advertising the hashes of (2) and (3).
+//    We continue to remember the hash of (1) for validation during the Noise handshake for another 4 days,
+//    as the client might be connecting with a cached address.
+type certManager struct {
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+	refCount  sync.WaitGroup
+
+	certValidity time.Duration // so we can set it in tests
+
+	mx            sync.Mutex
+	lastConfig    *certConfig // initially nil
+	currentConfig *certConfig
+	nextConfig    *certConfig // nil until we have passed half the certValidity of the current config
+	addrComp      ma.Multiaddr
+}
+
+func newCertManager(certValidity time.Duration) (*certManager, error) {
+	m := &certManager{
+		certValidity: certValidity,
+	}
+	m.ctx, m.ctxCancel = context.WithCancel(context.Background())
+	if err := m.init(); err != nil {
+		return nil, err
+	}
+	m.refCount.Add(1)
+	go func() {
+		defer m.refCount.Done()
+		if err := m.background(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+	return m, nil
+}
+
+func (m *certManager) init() error {
+	start := time.Now()
+	end := start.Add(m.certValidity)
+	tlsConf, err := getTLSConf(start, end)
+	if err != nil {
+		return err
+	}
+	cc, err := newCertConfig(start, end, tlsConf)
+	if err != nil {
+		return err
+	}
+	m.currentConfig = cc
+	return m.cacheAddrComponent()
+}
+
+func (m *certManager) background() error {
+	t := time.NewTicker(m.certValidity * 4 / 9) // make sure we're a bit faster than 1/2
+	defer t.Stop()
+
+	for {
+		select {
+		case <-m.ctx.Done():
+			return nil
+		case start := <-t.C:
+			end := start.Add(m.certValidity)
+			tlsConf, err := getTLSConf(start, end)
+			if err != nil {
+				return err
+			}
+			cc, err := newCertConfig(start, end, tlsConf)
+			if err != nil {
+				return err
+			}
+			m.mx.Lock()
+			if m.nextConfig != nil {
+				m.lastConfig = m.currentConfig
+				m.currentConfig = m.nextConfig
+			}
+			m.nextConfig = cc
+			if err := m.cacheAddrComponent(); err != nil {
+				m.mx.Unlock()
+				return err
+			}
+			m.mx.Unlock()
+		}
+	}
+}
+
+func (m *certManager) GetConfig() *tls.Config {
+	m.mx.Lock()
+	defer m.mx.Unlock()
+	return m.currentConfig.tlsConf
+}
+
+func (m *certManager) AddrComponent() ma.Multiaddr {
+	m.mx.Lock()
+	defer m.mx.Unlock()
+	return m.addrComp
+}
+
+func (m *certManager) cacheAddrComponent() error {
+	addr, err := m.addrComponentForCert(m.currentConfig.tlsConf.Certificates[0].Leaf)
+	if err != nil {
+		return err
+	}
+	if m.nextConfig != nil {
+		comp, err := m.addrComponentForCert(m.nextConfig.tlsConf.Certificates[0].Leaf)
+		if err != nil {
+			return err
+		}
+		addr = addr.Encapsulate(comp)
+	}
+	m.addrComp = addr
+	return nil
+}
+
+func (m *certManager) addrComponentForCert(cert *x509.Certificate) (ma.Multiaddr, error) {
+	hash := sha256.Sum256(cert.Raw)
+	mh, err := multihash.Encode(hash[:], multihash.SHA2_256)
+	if err != nil {
+		return nil, err
+	}
+	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
+	if err != nil {
+		return nil, err
+	}
+	return ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
+}
+
+func (m *certManager) Close() error {
+	m.ctxCancel()
+	m.refCount.Wait()
+	return nil
+}
diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
new file mode 100644
index 0000000000..6b0a9d5795
--- /dev/null
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -0,0 +1,72 @@
+package libp2pwebtransport
+
+import (
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
+	"testing"
+	"time"
+
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/require"
+)
+
+func splitMultiaddr(addr ma.Multiaddr) []ma.Component {
+	var components []ma.Component
+	ma.ForEach(addr, func(c ma.Component) bool {
+		components = append(components, c)
+		return true
+	})
+	return components
+}
+
+func certHashFromComponent(t *testing.T, comp ma.Component) []byte {
+	t.Helper()
+	_, data, err := multibase.Decode(comp.Value())
+	require.NoError(t, err)
+	mh, err := multihash.Decode(data)
+	require.NoError(t, err)
+	require.Equal(t, uint64(multihash.SHA2_256), mh.Code)
+	return mh.Digest
+}
+
+func TestInitialCert(t *testing.T) {
+	m, err := newCertManager(certValidity)
+	require.NoError(t, err)
+	defer m.Close()
+
+	conf := m.GetConfig()
+	require.Len(t, conf.Certificates, 1)
+	cert := conf.Certificates[0]
+	require.WithinDuration(t, time.Now(), cert.Leaf.NotBefore, time.Second)
+	require.WithinDuration(t, time.Now().Add(certValidity), cert.Leaf.NotAfter, time.Second)
+	addr := m.AddrComponent()
+	components := splitMultiaddr(addr)
+	require.Len(t, components, 1)
+	require.Equal(t, ma.P_CERTHASH, components[0].Protocol().Code)
+	hash := certificateHash(conf)
+	require.Equal(t, hash[:], certHashFromComponent(t, components[0]))
+}
+
+func TestCertRenewal(t *testing.T) {
+	const certValidity = 300 * time.Millisecond
+	m, err := newCertManager(certValidity)
+	require.NoError(t, err)
+	defer m.Close()
+
+	firstConf := m.GetConfig()
+	require.Len(t, splitMultiaddr(m.AddrComponent()), 1)
+	// wait for a new certificate to be generated
+	require.Eventually(t, func() bool { return len(splitMultiaddr(m.AddrComponent())) > 1 }, certValidity/2, 10*time.Millisecond)
+	// the actual config used should still be the same, we're just advertising the hash of the next config
+	components := splitMultiaddr(m.AddrComponent())
+	require.Len(t, components, 2)
+	for _, c := range components {
+		require.Equal(t, ma.P_CERTHASH, c.Protocol().Code)
+	}
+	require.Equal(t, firstConf, m.GetConfig())
+	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, certValidity/2, 10*time.Millisecond)
+	newConf := m.GetConfig()
+	// check that the new config now matches the second component
+	hash := certificateHash(newConf)
+	require.Equal(t, hash[:], certHashFromComponent(t, components[1]))
+}
diff --git a/p2p/transport/webtransport/crypto.go b/p2p/transport/webtransport/crypto.go
index 5c6dcdb102..f30943c6f6 100644
--- a/p2p/transport/webtransport/crypto.go
+++ b/p2p/transport/webtransport/crypto.go
@@ -17,8 +17,8 @@ func certificateHash(c *tls.Config) [32]byte {
 	return sha256.Sum256(c.Certificates[0].Certificate[0])
 }
 
-func getTLSConf() (*tls.Config, error) {
-	cert, priv, err := generateCert()
+func getTLSConf(start, end time.Time) (*tls.Config, error) {
+	cert, priv, err := generateCert(start, end)
 	if err != nil {
 		return nil, err
 	}
@@ -26,11 +26,12 @@ func getTLSConf() (*tls.Config, error) {
 		Certificates: []tls.Certificate{{
 			Certificate: [][]byte{cert.Raw},
 			PrivateKey:  priv,
+			Leaf:        cert,
 		}},
 	}, nil
 }
 
-func generateCert() (*x509.Certificate, *ecdsa.PrivateKey, error) {
+func generateCert(start, end time.Time) (*x509.Certificate, *ecdsa.PrivateKey, error) {
 	b := make([]byte, 8)
 	if _, err := rand.Read(b); err != nil {
 		return nil, nil, err
@@ -39,8 +40,8 @@ func generateCert() (*x509.Certificate, *ecdsa.PrivateKey, error) {
 	certTempl := &x509.Certificate{
 		SerialNumber:          big.NewInt(int64(serial)),
 		Subject:               pkix.Name{},
-		NotBefore:             time.Now(),
-		NotAfter:              time.Now().Add(24 * time.Hour),
+		NotBefore:             start,
+		NotAfter:              end,
 		IsCA:                  true,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
 		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 7a0098fe77..4a2700b85f 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -7,6 +7,7 @@ import (
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
 	"sync"
+	"time"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/peer"
@@ -26,6 +27,8 @@ const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
 const maxProtoSize = 8 << 10
 
+const certValidity = 14 * 24 * time.Hour
+
 type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
@@ -46,7 +49,8 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 	if err != nil {
 		return nil, err
 	}
-	tlsConf, err := getTLSConf() // TODO: only do this when initializing a listener
+	now := time.Now()
+	tlsConf, err := getTLSConf(now, now.Add(certValidity)) // TODO: only do this when initializing a listener
 	if err != nil {
 		return nil, err
 	}

From 268725c30cf6cd437176b8fe9253d21ea07c78b7 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 18 Apr 2022 23:08:26 +0100
Subject: [PATCH 06/53] check that addr contains at least one certhash in
 CanDial

---
 p2p/transport/webtransport/transport.go      | 17 ++++++-
 p2p/transport/webtransport/transport_test.go | 49 ++++++++++++++++++--
 2 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 4a2700b85f..dba619ebf1 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,8 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"github.com/multiformats/go-multibase"
-	"github.com/multiformats/go-multihash"
 	"sync"
 	"time"
 
@@ -19,6 +17,8 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 	mafmt "github.com/multiformats/go-multiaddr-fmt"
 	manet "github.com/multiformats/go-multiaddr/net"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 )
 
 var log = logging.Logger("webtransport")
@@ -117,6 +117,19 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 var dialMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
 
 func (t *transport) CanDial(addr ma.Multiaddr) bool {
+	var numHashes int
+	ma.ForEach(addr, func(c ma.Component) bool {
+		if c.Protocol().Code == ma.P_CERTHASH {
+			numHashes++
+		}
+		return true
+	})
+	if numHashes == 0 {
+		return false
+	}
+	for i := 0; i < numHashes; i++ {
+		addr, _ = ma.SplitLast(addr)
+	}
 	return dialMatcher.Matches(addr)
 }
 
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 338d26ab55..a03771f9e8 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -3,6 +3,7 @@ package libp2pwebtransport_test
 import (
 	"context"
 	"crypto/rand"
+	"fmt"
 	"io"
 	"testing"
 
@@ -11,22 +12,27 @@ import (
 
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 	ma "github.com/multiformats/go-multiaddr"
+	"github.com/multiformats/go-multibase"
 	"github.com/stretchr/testify/require"
 )
 
-func TestTransport(t *testing.T) {
-	serverKey, _, err := ic.GenerateEd25519Key(rand.Reader)
+func newIdentity(t *testing.T) (peer.ID, ic.PrivKey) {
+	key, _, err := ic.GenerateEd25519Key(rand.Reader)
 	require.NoError(t, err)
-	serverID, err := peer.IDFromPrivateKey(serverKey)
+	id, err := peer.IDFromPrivateKey(key)
 	require.NoError(t, err)
+	return id, key
+}
+
+func TestTransport(t *testing.T) {
+	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey)
 	require.NoError(t, err)
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
 
 	go func() {
-		clientKey, _, err := ic.GenerateEd25519Key(rand.Reader)
-		require.NoError(t, err)
+		_, clientKey := newIdentity(t)
 		tr2, err := libp2pwebtransport.New(clientKey)
 		require.NoError(t, err)
 		conn, err := tr2.Dial(context.Background(), ln.Multiaddr(), serverID)
@@ -46,3 +52,36 @@ func TestTransport(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, "foobar", string(data))
 }
+
+func TestCanDial(t *testing.T) {
+	randomHash := func(t *testing.T) string {
+		b := make([]byte, 16)
+		rand.Read(b)
+		s, err := multibase.Encode(multibase.Base32hex, b)
+		require.NoError(t, err)
+		return s
+	}
+
+	valid := []ma.Multiaddr{
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomHash(t)),
+		ma.StringCast("/ip6/b16b:8255:efc6:9cd5:1a54:ee86:2d7a:c2e6/udp/1234/quic/webtransport/certhash/" + randomHash(t)),
+		ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s/certhash/%s/certhash/%s", randomHash(t), randomHash(t), randomHash(t))),
+	}
+
+	invalid := []ma.Multiaddr{
+		ma.StringCast("/ip4/127.0.0.1/udp/1234"),                   // missing webtransport
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/webtransport"),      // missing quic
+		ma.StringCast("/ip4/127.0.0.1/tcp/1234/webtransport"),      // WebTransport over TCP? Is this a joke?
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport"), // missing certificate hash
+	}
+
+	_, key := newIdentity(t)
+	tr, err := libp2pwebtransport.New(key)
+	require.NoError(t, err)
+	for _, addr := range valid {
+		require.Truef(t, tr.CanDial(addr), "expected to be able to dial %s", addr)
+	}
+	for _, addr := range invalid {
+		require.Falsef(t, tr.CanDial(addr), "expected to not be able to dial %s", addr)
+	}
+}

From 2d295b586d5f71fc4fb07f867ad6fb04338914b0 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 18 Apr 2022 23:16:41 +0100
Subject: [PATCH 07/53] fix copying of http.Server mutex in listener
 constructor

---
 p2p/transport/webtransport/listener.go | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 0dadec2fa8..6ead26e01c 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
+	"github.com/lucas-clemente/quic-go/http3"
 	"net"
 	"net/http"
 	"time"
@@ -12,7 +13,6 @@ import (
 
 	noise "github.com/libp2p/go-libp2p-noise"
 
-	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
@@ -70,22 +70,22 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config, transport tpt.Transpor
 		addr:         udpConn.LocalAddr(),
 		tlsConf:      tlsConf,
 		multiaddr:    localMultiaddr,
-	}
-	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
-	server := webtransport.Server{
-		H3: http3.Server{
-			Server: &http.Server{
-				TLSConfig: tlsConf,
+		server: webtransport.Server{
+			H3: http3.Server{
+				Server: &http.Server{
+					TLSConfig: tlsConf,
+				},
 			},
 		},
 	}
+	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte("Hello, world!"))
 	})
 	mux.HandleFunc(webtransportHTTPEndpoint, func(w http.ResponseWriter, r *http.Request) {
 		// TODO: check ?type=multistream URL param
-		c, err := server.Upgrade(w, r)
+		c, err := ln.server.Upgrade(w, r)
 		if err != nil {
 			w.WriteHeader(500)
 			return
@@ -93,16 +93,15 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config, transport tpt.Transpor
 		// TODO: handle queue overflow
 		ln.queue <- c
 	})
-	server.H3.Handler = mux
+	ln.server.H3.Handler = mux
 	go func() {
 		defer close(ln.serverClosed)
 		defer func() { udpConn.Close() }()
-		if err := server.Serve(udpConn); err != nil {
+		if err := ln.server.Serve(udpConn); err != nil {
 			// TODO: only output if the server hasn't been closed
 			log.Debugw("serving failed", "addr", udpConn.LocalAddr(), "error", err)
 		}
 	}()
-	ln.server = server
 	return ln, nil
 }
 

From 59fc6efc0e38f37479911ba80b871ff44880b78f Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 18 Apr 2022 23:19:22 +0100
Subject: [PATCH 08/53] fix staticcheck

---
 p2p/transport/webtransport/conn.go      | 9 ++++-----
 p2p/transport/webtransport/multiaddr.go | 4 ----
 p2p/transport/webtransport/transport.go | 7 +------
 3 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index e45daedd86..c1b5742a47 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -3,7 +3,6 @@ package libp2pwebtransport
 import (
 	"context"
 
-	"github.com/libp2p/go-libp2p-core/crypto"
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
@@ -61,10 +60,10 @@ func (c *conn) AcceptStream() (network.MuxedStream, error) {
 	return &stream{str}, err
 }
 
-func (c *conn) LocalPeer() peer.ID              { return c.localPeer }
-func (c *conn) LocalPrivateKey() crypto.PrivKey { return c.privKey }
-func (c *conn) RemotePeer() peer.ID             { return c.remotePeer }
-func (c *conn) RemotePublicKey() crypto.PubKey  { return c.remotePubKey }
+func (c *conn) LocalPeer() peer.ID          { return c.localPeer }
+func (c *conn) LocalPrivateKey() ic.PrivKey { return c.privKey }
+func (c *conn) RemotePeer() peer.ID         { return c.remotePeer }
+func (c *conn) RemotePublicKey() ic.PubKey  { return c.remotePubKey }
 
 func (c *conn) LocalMultiaddr() ma.Multiaddr {
 	// TODO implement me
diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index a84853c1ee..3c281e0859 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -16,7 +16,3 @@ func toWebtransportMultiaddr(na net.Addr) (ma.Multiaddr, error) {
 	}
 	return udpMA.Encapsulate(webtransportMA), nil
 }
-
-func fromWebtransportMultiaddr(addr ma.Multiaddr) (net.Addr, error) {
-	return manet.ToNetAddr(addr.Decapsulate(webtransportMA))
-}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index dba619ebf1..0c32f8fee3 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"sync"
 	"time"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
@@ -25,8 +24,6 @@ var log = logging.Logger("webtransport")
 
 const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
-const maxProtoSize = 8 << 10
-
 const certValidity = 14 * 24 * time.Hour
 
 type transport struct {
@@ -36,9 +33,6 @@ type transport struct {
 	tlsConf *tls.Config
 	dialer  webtransport.Dialer
 
-	initOnce sync.Once
-	server   webtransport.Server
-
 	noise *noise.Transport
 }
 
@@ -107,6 +101,7 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		return nil, err
 	}
 	// TODO: use early data and verify the cert hash
+	_ = certHashes
 	sconn, err := t.noise.SecureOutbound(ctx, &webtransportStream{Stream: str, wconn: wconn}, p)
 	if err != nil {
 		return nil, err

From 85384b744468334f256635ecbb99e9b5c33ddec8 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 18 Apr 2022 23:48:17 +0100
Subject: [PATCH 09/53] fix flaky TestCertRenewal test on CI

---
 p2p/transport/webtransport/cert_manager_test.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
index 6b0a9d5795..3d9c881d4e 100644
--- a/p2p/transport/webtransport/cert_manager_test.go
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -3,6 +3,7 @@ package libp2pwebtransport
 import (
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
+	"os"
 	"testing"
 	"time"
 
@@ -48,7 +49,10 @@ func TestInitialCert(t *testing.T) {
 }
 
 func TestCertRenewal(t *testing.T) {
-	const certValidity = 300 * time.Millisecond
+	var certValidity = 300 * time.Millisecond
+	if os.Getenv("CI") != "" {
+		certValidity = 2 * time.Second
+	}
 	m, err := newCertManager(certValidity)
 	require.NoError(t, err)
 	defer m.Close()

From 77cdde610e75bd3a64b608fbc76ec6d81ca824b2 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 19 Apr 2022 00:00:27 +0100
Subject: [PATCH 10/53] check validity of listen addresses

---
 p2p/transport/webtransport/multiaddr.go      |  3 ++
 p2p/transport/webtransport/transport.go      |  8 ++--
 p2p/transport/webtransport/transport_test.go | 49 +++++++++++++++-----
 3 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index 3c281e0859..5560d90f68 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -4,11 +4,14 @@ import (
 	"net"
 
 	ma "github.com/multiformats/go-multiaddr"
+	mafmt "github.com/multiformats/go-multiaddr-fmt"
 	manet "github.com/multiformats/go-multiaddr/net"
 )
 
 var webtransportMA = ma.StringCast("/quic/webtransport")
 
+var webtransportMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
+
 func toWebtransportMultiaddr(na net.Addr) (ma.Multiaddr, error) {
 	udpMA, err := manet.FromNetAddr(na)
 	if err != nil {
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 0c32f8fee3..4e1efb6cac 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -14,7 +14,6 @@ import (
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
-	mafmt "github.com/multiformats/go-multiaddr-fmt"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
@@ -109,8 +108,6 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	return newConn(t, wconn, t.privKey, sconn.RemotePublicKey())
 }
 
-var dialMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
-
 func (t *transport) CanDial(addr ma.Multiaddr) bool {
 	var numHashes int
 	ma.ForEach(addr, func(c ma.Component) bool {
@@ -125,10 +122,13 @@ func (t *transport) CanDial(addr ma.Multiaddr) bool {
 	for i := 0; i < numHashes; i++ {
 		addr, _ = ma.SplitLast(addr)
 	}
-	return dialMatcher.Matches(addr)
+	return webtransportMatcher.Matches(addr)
 }
 
 func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
+	if !webtransportMatcher.Matches(laddr) {
+		return nil, fmt.Errorf("cannot listen on non-WebTransport addr: %s", laddr)
+	}
 	return newListener(laddr, t.tlsConf, t, t.noise)
 }
 
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index a03771f9e8..bddd23689c 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -24,6 +24,14 @@ func newIdentity(t *testing.T) (peer.ID, ic.PrivKey) {
 	return id, key
 }
 
+func randomMultihash(t *testing.T) string {
+	b := make([]byte, 16)
+	rand.Read(b)
+	s, err := multibase.Encode(multibase.Base32hex, b)
+	require.NoError(t, err)
+	return s
+}
+
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey)
@@ -54,18 +62,10 @@ func TestTransport(t *testing.T) {
 }
 
 func TestCanDial(t *testing.T) {
-	randomHash := func(t *testing.T) string {
-		b := make([]byte, 16)
-		rand.Read(b)
-		s, err := multibase.Encode(multibase.Base32hex, b)
-		require.NoError(t, err)
-		return s
-	}
-
 	valid := []ma.Multiaddr{
-		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomHash(t)),
-		ma.StringCast("/ip6/b16b:8255:efc6:9cd5:1a54:ee86:2d7a:c2e6/udp/1234/quic/webtransport/certhash/" + randomHash(t)),
-		ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s/certhash/%s/certhash/%s", randomHash(t), randomHash(t), randomHash(t))),
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),
+		ma.StringCast("/ip6/b16b:8255:efc6:9cd5:1a54:ee86:2d7a:c2e6/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),
+		ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s/certhash/%s/certhash/%s", randomMultihash(t), randomMultihash(t), randomMultihash(t))),
 	}
 
 	invalid := []ma.Multiaddr{
@@ -85,3 +85,30 @@ func TestCanDial(t *testing.T) {
 		require.Falsef(t, tr.CanDial(addr), "expected to not be able to dial %s", addr)
 	}
 }
+
+func TestListenAddrValidity(t *testing.T) {
+	valid := []ma.Multiaddr{
+		ma.StringCast("/ip6/::/udp/0/quic/webtransport/"),
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/"),
+	}
+
+	invalid := []ma.Multiaddr{
+		ma.StringCast("/ip4/127.0.0.1/udp/1234"),              // missing webtransport
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/webtransport"), // missing quic
+		ma.StringCast("/ip4/127.0.0.1/tcp/1234/webtransport"), // WebTransport over TCP? Is this a joke?
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),
+	}
+
+	_, key := newIdentity(t)
+	tr, err := libp2pwebtransport.New(key)
+	require.NoError(t, err)
+	for _, addr := range valid {
+		ln, err := tr.Listen(addr)
+		require.NoErrorf(t, err, "expected to be able to listen on %s", addr)
+		ln.Close()
+	}
+	for _, addr := range invalid {
+		_, err := tr.Listen(addr)
+		require.Errorf(t, err, "expected to not be able to listen on %s", addr)
+	}
+}

From ee0e2d022f7990f29c7fc6700a0ba281c2561cf6 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 19 Apr 2022 00:02:22 +0100
Subject: [PATCH 11/53] initialize a certiticate manager and pass it to the
 listeners

---
 p2p/transport/webtransport/listener.go       | 31 +++++++-------------
 p2p/transport/webtransport/transport.go      | 22 ++++++++------
 p2p/transport/webtransport/transport_test.go | 26 ++++++++++++++++
 3 files changed, 50 insertions(+), 29 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 6ead26e01c..f29256eef5 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"github.com/lucas-clemente/quic-go/http3"
 	"net"
 	"net/http"
 	"time"
@@ -13,11 +12,10 @@ import (
 
 	noise "github.com/libp2p/go-libp2p-noise"
 
+	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
-	"github.com/multiformats/go-multibase"
-	"github.com/multiformats/go-multihash"
 )
 
 var errClosed = errors.New("closed")
@@ -26,11 +24,11 @@ const queueLen = 16
 const handshakeTimeout = 10 * time.Second
 
 type listener struct {
-	transport tpt.Transport
-	noise     *noise.Transport
+	transport   tpt.Transport
+	noise       *noise.Transport
+	certManager *certManager
 
-	server  webtransport.Server
-	tlsConf *tls.Config
+	server webtransport.Server
 
 	ctx       context.Context
 	ctxCancel context.CancelFunc
@@ -45,7 +43,7 @@ type listener struct {
 
 var _ tpt.Listener = &listener{}
 
-func newListener(laddr ma.Multiaddr, tlsConf *tls.Config, transport tpt.Transport, noise *noise.Transport) (tpt.Listener, error) {
+func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager) (tpt.Listener, error) {
 	network, addr, err := manet.DialArgs(laddr)
 	if err != nil {
 		return nil, err
@@ -65,15 +63,17 @@ func newListener(laddr ma.Multiaddr, tlsConf *tls.Config, transport tpt.Transpor
 	ln := &listener{
 		transport:    transport,
 		noise:        noise,
+		certManager:  certManager,
 		queue:        make(chan *webtransport.Conn, queueLen),
 		serverClosed: make(chan struct{}),
 		addr:         udpConn.LocalAddr(),
-		tlsConf:      tlsConf,
 		multiaddr:    localMultiaddr,
 		server: webtransport.Server{
 			H3: http3.Server{
 				Server: &http.Server{
-					TLSConfig: tlsConf,
+					TLSConfig: &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
+						return certManager.GetConfig(), nil
+					}},
 				},
 			},
 		},
@@ -154,16 +154,7 @@ func (l *listener) Addr() net.Addr {
 }
 
 func (l *listener) Multiaddr() ma.Multiaddr {
-	certHash := certificateHash(l.tlsConf)
-	h, err := multihash.Encode(certHash[:], multihash.SHA2_256)
-	if err != nil {
-		panic(err)
-	}
-	certHashStr, err := multibase.Encode(multibase.Base58BTC, h)
-	if err != nil {
-		panic(err)
-	}
-	return l.multiaddr.Encapsulate(ma.StringCast("/certhash/" + certHashStr))
+	return l.multiaddr.Encapsulate(l.certManager.AddrComponent())
 }
 
 func (l *listener) Close() error {
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 4e1efb6cac..ba47a1d64d 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	"sync"
 	"time"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
@@ -29,8 +30,11 @@ type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
 
-	tlsConf *tls.Config
-	dialer  webtransport.Dialer
+	dialer webtransport.Dialer
+
+	listenOnce    sync.Once
+	listenOnceErr error
+	certManager   *certManager
 
 	noise *noise.Transport
 }
@@ -42,11 +46,6 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 	if err != nil {
 		return nil, err
 	}
-	now := time.Now()
-	tlsConf, err := getTLSConf(now, now.Add(certValidity)) // TODO: only do this when initializing a listener
-	if err != nil {
-		return nil, err
-	}
 	noise, err := noise.New(key)
 	if err != nil {
 		return nil, err
@@ -54,7 +53,6 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 	return &transport{
 		pid:     id,
 		privKey: key,
-		tlsConf: tlsConf,
 		dialer: webtransport.Dialer{
 			TLSClientConf: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
 		},
@@ -129,7 +127,13 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 	if !webtransportMatcher.Matches(laddr) {
 		return nil, fmt.Errorf("cannot listen on non-WebTransport addr: %s", laddr)
 	}
-	return newListener(laddr, t.tlsConf, t, t.noise)
+	t.listenOnce.Do(func() {
+		t.certManager, t.listenOnceErr = newCertManager(certValidity)
+	})
+	if t.listenOnceErr != nil {
+		return nil, t.listenOnceErr
+	}
+	return newListener(laddr, t, t.noise, t.certManager)
 }
 
 func (t *transport) Protocols() []int {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index bddd23689c..84a053be77 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -32,6 +32,17 @@ func randomMultihash(t *testing.T) string {
 	return s
 }
 
+func extractCertHashes(t *testing.T, addr ma.Multiaddr) []string {
+	var certHashesStr []string
+	ma.ForEach(addr, func(c ma.Component) bool {
+		if c.Protocol().Code == ma.P_CERTHASH {
+			certHashesStr = append(certHashesStr, c.Value())
+		}
+		return true
+	})
+	return certHashesStr
+}
+
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey)
@@ -112,3 +123,18 @@ func TestListenAddrValidity(t *testing.T) {
 		require.Errorf(t, err, "expected to not be able to listen on %s", addr)
 	}
 }
+
+func TestListenerAddrs(t *testing.T) {
+	_, key := newIdentity(t)
+	tr, err := libp2pwebtransport.New(key)
+	require.NoError(t, err)
+
+	ln1, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	ln2, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	hashes1 := extractCertHashes(t, ln1.Multiaddr())
+	require.Len(t, hashes1, 1)
+	hashes2 := extractCertHashes(t, ln2.Multiaddr())
+	require.Equal(t, hashes1, hashes2)
+}

From ae21c6c8a0a38ef715cb8c23edc1b4fdf692aaf1 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 19 Apr 2022 22:23:22 +0100
Subject: [PATCH 12/53] implement a Close method for the transport

---
 p2p/transport/webtransport/transport.go      | 10 ++++++++++
 p2p/transport/webtransport/transport_test.go |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index ba47a1d64d..294cc6ccfc 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	"io"
 	"sync"
 	"time"
 
@@ -40,6 +41,7 @@ type transport struct {
 }
 
 var _ tpt.Transport = &transport{}
+var _ io.Closer = &transport{}
 
 func New(key ic.PrivKey) (tpt.Transport, error) {
 	id, err := peer.IDFromPrivateKey(key)
@@ -143,3 +145,11 @@ func (t *transport) Protocols() []int {
 func (t *transport) Proxy() bool {
 	return false
 }
+
+func (t *transport) Close() error {
+	t.listenOnce.Do(func() {})
+	if t.certManager != nil {
+		return t.certManager.Close()
+	}
+	return nil
+}
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 84a053be77..d50832144d 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -47,6 +47,7 @@ func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey)
 	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
 
@@ -54,6 +55,8 @@ func TestTransport(t *testing.T) {
 		_, clientKey := newIdentity(t)
 		tr2, err := libp2pwebtransport.New(clientKey)
 		require.NoError(t, err)
+		defer tr2.(io.Closer).Close()
+
 		conn, err := tr2.Dial(context.Background(), ln.Multiaddr(), serverID)
 		require.NoError(t, err)
 		str, err := conn.OpenStream(context.Background())
@@ -89,6 +92,8 @@ func TestCanDial(t *testing.T) {
 	_, key := newIdentity(t)
 	tr, err := libp2pwebtransport.New(key)
 	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+
 	for _, addr := range valid {
 		require.Truef(t, tr.CanDial(addr), "expected to be able to dial %s", addr)
 	}
@@ -113,6 +118,8 @@ func TestListenAddrValidity(t *testing.T) {
 	_, key := newIdentity(t)
 	tr, err := libp2pwebtransport.New(key)
 	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+
 	for _, addr := range valid {
 		ln, err := tr.Listen(addr)
 		require.NoErrorf(t, err, "expected to be able to listen on %s", addr)
@@ -128,6 +135,7 @@ func TestListenerAddrs(t *testing.T) {
 	_, key := newIdentity(t)
 	tr, err := libp2pwebtransport.New(key)
 	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
 
 	ln1, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)

From 323960e226ab16289a4e943849ea812e35da00bc Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 21 May 2022 21:14:53 +0200
Subject: [PATCH 13/53] chore: update webtransport-go

---
 p2p/transport/webtransport/listener.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index f29256eef5..dd32e181fa 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -70,11 +70,9 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 		multiaddr:    localMultiaddr,
 		server: webtransport.Server{
 			H3: http3.Server{
-				Server: &http.Server{
-					TLSConfig: &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
-						return certManager.GetConfig(), nil
-					}},
-				},
+				TLSConfig: &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
+					return certManager.GetConfig(), nil
+				}},
 			},
 		},
 	}
@@ -92,6 +90,8 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 		}
 		// TODO: handle queue overflow
 		ln.queue <- c
+		// We need to block until we're done with this WebTransport session.
+		<-c.Context().Done()
 	})
 	ln.server.H3.Handler = mux
 	go func() {

From 0af48f54863b78b1b45b7af80a76ac8a5a6dbf48 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 22 May 2022 11:42:39 +0200
Subject: [PATCH 14/53] run a Noise handshake on the first stream to verify
 peer identities

---
 p2p/transport/webtransport/cert_manager.go    |  28 +-
 p2p/transport/webtransport/pb/Makefile        |  11 +
 .../webtransport/pb/webtransport.pb.go        | 315 ++++++++++++++++++
 .../webtransport/pb/webtransport.proto        |   5 +
 p2p/transport/webtransport/transport.go       |  57 +++-
 p2p/transport/webtransport/transport_test.go  |  44 ++-
 6 files changed, 441 insertions(+), 19 deletions(-)
 create mode 100644 p2p/transport/webtransport/pb/Makefile
 create mode 100644 p2p/transport/webtransport/pb/webtransport.pb.go
 create mode 100644 p2p/transport/webtransport/pb/webtransport.proto

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index 83fc2878cf..f2a0afd04e 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -1,10 +1,11 @@
 package libp2pwebtransport
 
 import (
+	"bytes"
 	"context"
 	"crypto/sha256"
 	"crypto/tls"
-	"crypto/x509"
+	"fmt"
 	"sync"
 	"time"
 
@@ -16,6 +17,7 @@ import (
 type certConfig struct {
 	start, end time.Time
 	tlsConf    *tls.Config
+	sha256     [32]byte // cached from the tlsConf
 }
 
 func newCertConfig(start, end time.Time, conf *tls.Config) (*certConfig, error) {
@@ -23,6 +25,7 @@ func newCertConfig(start, end time.Time, conf *tls.Config) (*certConfig, error)
 		start:   start,
 		end:     end,
 		tlsConf: conf,
+		sha256:  sha256.Sum256(conf.Certificates[0].Leaf.Raw),
 	}, nil
 }
 
@@ -128,13 +131,27 @@ func (m *certManager) AddrComponent() ma.Multiaddr {
 	return m.addrComp
 }
 
+func (m *certManager) Verify(hashes []multihash.DecodedMultihash) error {
+	for _, h := range hashes {
+		if h.Code != multihash.SHA2_256 {
+			return fmt.Errorf("expected SHA256 hash, got %d", h.Code)
+		}
+		if !bytes.Equal(h.Digest, m.currentConfig.sha256[:]) &&
+			(m.nextConfig == nil || !bytes.Equal(h.Digest, m.nextConfig.sha256[:])) &&
+			(m.lastConfig == nil || !bytes.Equal(h.Digest, m.lastConfig.sha256[:])) {
+			return fmt.Errorf("found unexpected hash: %+x", h.Digest)
+		}
+	}
+	return nil
+}
+
 func (m *certManager) cacheAddrComponent() error {
-	addr, err := m.addrComponentForCert(m.currentConfig.tlsConf.Certificates[0].Leaf)
+	addr, err := m.addrComponentForCert(m.currentConfig.sha256[:])
 	if err != nil {
 		return err
 	}
 	if m.nextConfig != nil {
-		comp, err := m.addrComponentForCert(m.nextConfig.tlsConf.Certificates[0].Leaf)
+		comp, err := m.addrComponentForCert(m.nextConfig.sha256[:])
 		if err != nil {
 			return err
 		}
@@ -144,9 +161,8 @@ func (m *certManager) cacheAddrComponent() error {
 	return nil
 }
 
-func (m *certManager) addrComponentForCert(cert *x509.Certificate) (ma.Multiaddr, error) {
-	hash := sha256.Sum256(cert.Raw)
-	mh, err := multihash.Encode(hash[:], multihash.SHA2_256)
+func (m *certManager) addrComponentForCert(hash []byte) (ma.Multiaddr, error) {
+	mh, err := multihash.Encode(hash, multihash.SHA2_256)
 	if err != nil {
 		return nil, err
 	}
diff --git a/p2p/transport/webtransport/pb/Makefile b/p2p/transport/webtransport/pb/Makefile
new file mode 100644
index 0000000000..8af2dd8177
--- /dev/null
+++ b/p2p/transport/webtransport/pb/Makefile
@@ -0,0 +1,11 @@
+PB = $(wildcard *.proto)
+GO = $(PB:.proto=.pb.go)
+
+all: $(GO)
+
+%.pb.go: %.proto
+		protoc --proto_path=$(PWD)/../..:. --gogofaster_out=. $<
+
+clean:
+		rm -f *.pb.go
+		rm -f *.go
diff --git a/p2p/transport/webtransport/pb/webtransport.pb.go b/p2p/transport/webtransport/pb/webtransport.pb.go
new file mode 100644
index 0000000000..810d0667c9
--- /dev/null
+++ b/p2p/transport/webtransport/pb/webtransport.pb.go
@@ -0,0 +1,315 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: webtransport.proto
+
+package webtransport
+
+import (
+	fmt "fmt"
+	proto "github.com/gogo/protobuf/proto"
+	io "io"
+	math "math"
+	math_bits "math/bits"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion3 // please upgrade the proto package
+
+type WebTransport struct {
+	CertHashes [][]byte `protobuf:"bytes,1,rep,name=cert_hashes,json=certHashes" json:"cert_hashes,omitempty"`
+}
+
+func (m *WebTransport) Reset()         { *m = WebTransport{} }
+func (m *WebTransport) String() string { return proto.CompactTextString(m) }
+func (*WebTransport) ProtoMessage()    {}
+func (*WebTransport) Descriptor() ([]byte, []int) {
+	return fileDescriptor_db878920ab41a4f3, []int{0}
+}
+func (m *WebTransport) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *WebTransport) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_WebTransport.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *WebTransport) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_WebTransport.Merge(m, src)
+}
+func (m *WebTransport) XXX_Size() int {
+	return m.Size()
+}
+func (m *WebTransport) XXX_DiscardUnknown() {
+	xxx_messageInfo_WebTransport.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_WebTransport proto.InternalMessageInfo
+
+func (m *WebTransport) GetCertHashes() [][]byte {
+	if m != nil {
+		return m.CertHashes
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*WebTransport)(nil), "WebTransport")
+}
+
+func init() { proto.RegisterFile("webtransport.proto", fileDescriptor_db878920ab41a4f3) }
+
+var fileDescriptor_db878920ab41a4f3 = []byte{
+	// 109 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0x2a, 0x4f, 0x4d, 0x2a,
+	0x29, 0x4a, 0xcc, 0x2b, 0x2e, 0xc8, 0x2f, 0x2a, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x57, 0xd2,
+	0xe7, 0xe2, 0x09, 0x4f, 0x4d, 0x0a, 0x81, 0x89, 0x0a, 0xc9, 0x73, 0x71, 0x27, 0xa7, 0x16, 0x95,
+	0xc4, 0x67, 0x24, 0x16, 0x67, 0xa4, 0x16, 0x4b, 0x30, 0x2a, 0x30, 0x6b, 0xf0, 0x04, 0x71, 0x81,
+	0x84, 0x3c, 0xc0, 0x22, 0x4e, 0x12, 0x27, 0x1e, 0xc9, 0x31, 0x5e, 0x78, 0x24, 0xc7, 0xf8, 0xe0,
+	0x91, 0x1c, 0xe3, 0x84, 0xc7, 0x72, 0x0c, 0x17, 0x1e, 0xcb, 0x31, 0xdc, 0x78, 0x2c, 0xc7, 0x00,
+	0x08, 0x00, 0x00, 0xff, 0xff, 0x50, 0x77, 0xe5, 0x52, 0x5f, 0x00, 0x00, 0x00,
+}
+
+func (m *WebTransport) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *WebTransport) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *WebTransport) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if len(m.CertHashes) > 0 {
+		for iNdEx := len(m.CertHashes) - 1; iNdEx >= 0; iNdEx-- {
+			i -= len(m.CertHashes[iNdEx])
+			copy(dAtA[i:], m.CertHashes[iNdEx])
+			i = encodeVarintWebtransport(dAtA, i, uint64(len(m.CertHashes[iNdEx])))
+			i--
+			dAtA[i] = 0xa
+		}
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintWebtransport(dAtA []byte, offset int, v uint64) int {
+	offset -= sovWebtransport(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *WebTransport) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	if len(m.CertHashes) > 0 {
+		for _, b := range m.CertHashes {
+			l = len(b)
+			n += 1 + l + sovWebtransport(uint64(l))
+		}
+	}
+	return n
+}
+
+func sovWebtransport(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+func sozWebtransport(x uint64) (n int) {
+	return sovWebtransport(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *WebTransport) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowWebtransport
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: WebTransport: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: WebTransport: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field CertHashes", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWebtransport
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthWebtransport
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthWebtransport
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.CertHashes = append(m.CertHashes, make([]byte, postIndex-iNdEx))
+			copy(m.CertHashes[len(m.CertHashes)-1], dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipWebtransport(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if (skippy < 0) || (iNdEx+skippy) < 0 {
+				return ErrInvalidLengthWebtransport
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipWebtransport(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	depth := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowWebtransport
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowWebtransport
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+		case 1:
+			iNdEx += 8
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowWebtransport
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if length < 0 {
+				return 0, ErrInvalidLengthWebtransport
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupWebtransport
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthWebtransport
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthWebtransport        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowWebtransport          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupWebtransport = fmt.Errorf("proto: unexpected end of group")
+)
diff --git a/p2p/transport/webtransport/pb/webtransport.proto b/p2p/transport/webtransport/pb/webtransport.proto
new file mode 100644
index 0000000000..a9129ce6c6
--- /dev/null
+++ b/p2p/transport/webtransport/pb/webtransport.proto
@@ -0,0 +1,5 @@
+syntax = "proto2";
+
+message WebTransport {
+  repeated bytes cert_hashes = 1;
+}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 294cc6ccfc..8b35d88b5f 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -8,17 +8,21 @@ import (
 	"sync"
 	"time"
 
+	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
+
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/peer"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
+
 	noise "github.com/libp2p/go-libp2p-noise"
 
-	logging "github.com/ipfs/go-log/v2"
-	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
+
+	logging "github.com/ipfs/go-log/v2"
+	"github.com/marten-seemann/webtransport-go"
 )
 
 var log = logging.Logger("webtransport")
@@ -48,18 +52,19 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 	if err != nil {
 		return nil, err
 	}
-	noise, err := noise.New(key)
-	if err != nil {
-		return nil, err
-	}
-	return &transport{
+	t := &transport{
 		pid:     id,
 		privKey: key,
 		dialer: webtransport.Dialer{
 			TLSClientConf: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
 		},
-		noise: noise,
-	}, nil
+	}
+	noise, err := noise.New(key, noise.WithEarlyDataHandler(t.checkEarlyData))
+	if err != nil {
+		return nil, err
+	}
+	t.noise = noise
+	return t, nil
 }
 
 func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
@@ -99,15 +104,43 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if err != nil {
 		return nil, err
 	}
-	// TODO: use early data and verify the cert hash
-	_ = certHashes
-	sconn, err := t.noise.SecureOutbound(ctx, &webtransportStream{Stream: str, wconn: wconn}, p)
+
+	// Now run a Noise handshake (using early data) and verify the cert hash.
+	msg := pb.WebTransport{CertHashes: make([][]byte, 0, len(certHashes))}
+	for _, certHash := range certHashes {
+		h, err := multihash.Encode(certHash.Digest, certHash.Code)
+		if err != nil {
+			return nil, fmt.Errorf("failed to encode certificate hash: %w", err)
+		}
+		msg.CertHashes = append(msg.CertHashes, h)
+	}
+	msgBytes, err := msg.Marshal()
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal WebTransport protobuf: %w", err)
+	}
+	sconn, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wconn: wconn}, p, msgBytes)
 	if err != nil {
 		return nil, err
 	}
 	return newConn(t, wconn, t.privKey, sconn.RemotePublicKey())
 }
 
+func (t *transport) checkEarlyData(b []byte) error {
+	var msg pb.WebTransport
+	if err := msg.Unmarshal(b); err != nil {
+		return fmt.Errorf("failed to unmarshal early data protobuf: %w", err)
+	}
+	hashes := make([]multihash.DecodedMultihash, 0, len(msg.CertHashes))
+	for _, h := range msg.CertHashes {
+		dh, err := multihash.Decode(h)
+		if err != nil {
+			return fmt.Errorf("failed to decode hash: %w", err)
+		}
+		hashes = append(hashes, *dh)
+	}
+	return t.certManager.Verify(hashes)
+}
+
 func (t *transport) CanDial(addr ma.Multiaddr) bool {
 	var numHashes int
 	ma.ForEach(addr, func(c ma.Component) bool {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index d50832144d..a3fcb34b0b 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -3,16 +3,20 @@ package libp2pwebtransport_test
 import (
 	"context"
 	"crypto/rand"
+	"crypto/sha256"
 	"fmt"
 	"io"
 	"testing"
 
+	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
+
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/peer"
 
-	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
+
 	"github.com/stretchr/testify/require"
 )
 
@@ -50,6 +54,7 @@ func TestTransport(t *testing.T) {
 	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
+	defer ln.Close()
 
 	go func() {
 		_, clientKey := newIdentity(t)
@@ -75,6 +80,43 @@ func TestTransport(t *testing.T) {
 	require.Equal(t, "foobar", string(data))
 }
 
+func TestHashVerification(t *testing.T) {
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		_, err := ln.Accept()
+		require.Error(t, err)
+	}()
+
+	// replace the certificate hash in the multiaddr with a fake hash
+	addr, _ := ma.SplitLast(ln.Multiaddr())
+	h := sha256.Sum256([]byte("foobar"))
+	mh, err := multihash.Encode(h[:], multihash.SHA2_256)
+	require.NoError(t, err)
+	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
+	require.NoError(t, err)
+	comp, err := ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
+	require.NoError(t, err)
+	addr = addr.Encapsulate(comp)
+
+	_, clientKey := newIdentity(t)
+	tr2, err := libp2pwebtransport.New(clientKey)
+	require.NoError(t, err)
+	defer tr2.(io.Closer).Close()
+
+	_, err = tr2.Dial(context.Background(), addr, serverID)
+	require.Error(t, err)
+
+	require.NoError(t, ln.Close())
+	<-done
+}
+
 func TestCanDial(t *testing.T) {
 	valid := []ma.Multiaddr{
 		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),

From 52ae9b79b98986259a6efddc780ea7c3649b8c07 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 22 May 2022 12:15:43 +0200
Subject: [PATCH 15/53] simplify the listener.Accept logic

---
 p2p/transport/webtransport/listener.go | 49 +++++++++-----------------
 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index dd32e181fa..993354f965 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -38,7 +38,7 @@ type listener struct {
 	addr      net.Addr
 	multiaddr ma.Multiaddr
 
-	queue chan *webtransport.Conn
+	queue chan tpt.CapableConn
 }
 
 var _ tpt.Listener = &listener{}
@@ -64,7 +64,7 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 		transport:    transport,
 		noise:        noise,
 		certManager:  certManager,
-		queue:        make(chan *webtransport.Conn, queueLen),
+		queue:        make(chan tpt.CapableConn, queueLen),
 		serverClosed: make(chan struct{}),
 		addr:         udpConn.LocalAddr(),
 		multiaddr:    localMultiaddr,
@@ -88,8 +88,16 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 			w.WriteHeader(500)
 			return
 		}
-		// TODO: handle queue overflow
-		ln.queue <- c
+		ctx, cancel := context.WithTimeout(ln.ctx, handshakeTimeout)
+		conn, err := ln.handshake(ctx, c)
+		if err != nil {
+			cancel()
+			log.Debugw("handshake failed", "error", err)
+			c.Close()
+			return
+		}
+		cancel()
+		ln.queue <- conn
 		// We need to block until we're done with this WebTransport session.
 		<-c.Context().Done()
 	})
@@ -106,34 +114,11 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 }
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
-	queue := make(chan tpt.CapableConn, queueLen)
-	for {
-		select {
-		case <-l.ctx.Done():
-			return nil, errClosed
-		default:
-		}
-
-		var c *webtransport.Conn
-		select {
-		case c = <-l.queue:
-			go func(c *webtransport.Conn) {
-				ctx, cancel := context.WithTimeout(l.ctx, handshakeTimeout)
-				defer cancel()
-				conn, err := l.handshake(ctx, c)
-				if err != nil {
-					log.Debugw("handshake failed", "error", err)
-					c.Close()
-					return
-				}
-				// TODO: handle queue overflow
-				queue <- conn
-			}(c)
-		case conn := <-queue:
-			return conn, nil
-		case <-l.ctx.Done():
-			return nil, errClosed
-		}
+	select {
+	case <-l.ctx.Done():
+		return nil, errClosed
+	case c := <-l.queue:
+		return c, nil
 	}
 }
 

From 91e97305e35114575887aee717f80acea0b041d4 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 22 May 2022 16:47:09 +0200
Subject: [PATCH 16/53] don't close the HTTP response body when dialing

---
 p2p/transport/webtransport/transport.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 8b35d88b5f..2596ba4dcd 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -96,7 +96,6 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if err != nil {
 		return nil, err
 	}
-	defer rsp.Body.Close()
 	if rsp.StatusCode < 200 || rsp.StatusCode > 299 {
 		return nil, fmt.Errorf("invalid response status code: %d", rsp.StatusCode)
 	}

From d8209e3532707c1dc823efe6b7537651a63c979c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 22 May 2022 16:47:35 +0200
Subject: [PATCH 17/53] add more tests for failed handshakes

---
 p2p/transport/webtransport/transport_test.go | 29 +++++++++++++-------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index a3fcb34b0b..58b4c0fa0f 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -94,24 +94,33 @@ func TestHashVerification(t *testing.T) {
 		require.Error(t, err)
 	}()
 
-	// replace the certificate hash in the multiaddr with a fake hash
-	addr, _ := ma.SplitLast(ln.Multiaddr())
+	_, clientKey := newIdentity(t)
+	tr2, err := libp2pwebtransport.New(clientKey)
+	require.NoError(t, err)
+	defer tr2.(io.Closer).Close()
+
+	// create a hash component using the SHA256 of foobar
 	h := sha256.Sum256([]byte("foobar"))
 	mh, err := multihash.Encode(h[:], multihash.SHA2_256)
 	require.NoError(t, err)
 	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
 	require.NoError(t, err)
-	comp, err := ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
+	foobarHash, err := ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
 	require.NoError(t, err)
-	addr = addr.Encapsulate(comp)
 
-	_, clientKey := newIdentity(t)
-	tr2, err := libp2pwebtransport.New(clientKey)
-	require.NoError(t, err)
-	defer tr2.(io.Closer).Close()
+	t.Run("fails using only a wrong hash", func(t *testing.T) {
+		// replace the certificate hash in the multiaddr with a fake hash
+		addr, _ := ma.SplitLast(ln.Multiaddr())
+		addr = addr.Encapsulate(foobarHash)
 
-	_, err = tr2.Dial(context.Background(), addr, serverID)
-	require.Error(t, err)
+		_, err := tr2.Dial(context.Background(), addr, serverID)
+		require.Error(t, err)
+	})
+
+	t.Run("fails when adding a wrong hash", func(t *testing.T) {
+		_, err := tr2.Dial(context.Background(), ln.Multiaddr().Encapsulate(foobarHash), serverID)
+		require.Error(t, err)
+	})
 
 	require.NoError(t, ln.Close())
 	<-done

From 47be4122b7c9e8a5bf4c20abde21fec729cbb2fa Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 22 May 2022 18:26:18 +0200
Subject: [PATCH 18/53] return local and remote multiaddrs from conn

---
 p2p/transport/webtransport/conn.go           | 32 +++++++++++---------
 p2p/transport/webtransport/transport_test.go | 11 +++++++
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index c1b5742a47..e2ab9cd50b 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -2,6 +2,7 @@ package libp2pwebtransport
 
 import (
 	"context"
+	"fmt"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/network"
@@ -17,6 +18,7 @@ type conn struct {
 	wconn     *webtransport.Conn
 
 	localPeer, remotePeer peer.ID
+	local, remote         ma.Multiaddr
 	privKey               ic.PrivKey
 	remotePubKey          ic.PubKey
 }
@@ -30,6 +32,14 @@ func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, rem
 	if err != nil {
 		return nil, err
 	}
+	local, err := toWebtransportMultiaddr(wconn.LocalAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting local addr: %w", err)
+	}
+	remote, err := toWebtransportMultiaddr(wconn.RemoteAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
+	}
 	return &conn{
 		transport:    tr,
 		wconn:        wconn,
@@ -37,6 +47,8 @@ func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, rem
 		localPeer:    localPeer,
 		remotePeer:   remotePeer,
 		remotePubKey: remotePubKey,
+		local:        local,
+		remote:       remote,
 	}, nil
 }
 
@@ -60,20 +72,12 @@ func (c *conn) AcceptStream() (network.MuxedStream, error) {
 	return &stream{str}, err
 }
 
-func (c *conn) LocalPeer() peer.ID          { return c.localPeer }
-func (c *conn) LocalPrivateKey() ic.PrivKey { return c.privKey }
-func (c *conn) RemotePeer() peer.ID         { return c.remotePeer }
-func (c *conn) RemotePublicKey() ic.PubKey  { return c.remotePubKey }
-
-func (c *conn) LocalMultiaddr() ma.Multiaddr {
-	// TODO implement me
-	panic("implement me")
-}
-
-func (c *conn) RemoteMultiaddr() ma.Multiaddr {
-	// TODO implement me
-	panic("implement me")
-}
+func (c *conn) LocalPeer() peer.ID            { return c.localPeer }
+func (c *conn) LocalPrivateKey() ic.PrivKey   { return c.privKey }
+func (c *conn) RemotePeer() peer.ID           { return c.remotePeer }
+func (c *conn) RemotePublicKey() ic.PubKey    { return c.remotePubKey }
+func (c *conn) LocalMultiaddr() ma.Multiaddr  { return c.local }
+func (c *conn) RemoteMultiaddr() ma.Multiaddr { return c.remote }
 
 func (c *conn) Scope() network.ConnScope {
 	// TODO implement me
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 58b4c0fa0f..4d640eb5d3 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -6,6 +6,7 @@ import (
 	"crypto/sha256"
 	"fmt"
 	"io"
+	"strings"
 	"testing"
 
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
@@ -14,6 +15,7 @@ import (
 	"github.com/libp2p/go-libp2p-core/peer"
 
 	ma "github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
 
@@ -56,6 +58,7 @@ func TestTransport(t *testing.T) {
 	require.NoError(t, err)
 	defer ln.Close()
 
+	addrChan := make(chan ma.Multiaddr)
 	go func() {
 		_, clientKey := newIdentity(t)
 		tr2, err := libp2pwebtransport.New(clientKey)
@@ -69,6 +72,13 @@ func TestTransport(t *testing.T) {
 		_, err = str.Write([]byte("foobar"))
 		require.NoError(t, err)
 		require.NoError(t, str.Close())
+
+		// check RemoteMultiaddr
+		_, addr, err := manet.DialArgs(ln.Multiaddr())
+		require.NoError(t, err)
+		port := strings.Split(addr, ":")[1]
+		require.Equal(t, ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/%s/quic/webtransport", port)), conn.RemoteMultiaddr())
+		addrChan <- conn.RemoteMultiaddr()
 	}()
 
 	conn, err := ln.Accept()
@@ -78,6 +88,7 @@ func TestTransport(t *testing.T) {
 	data, err := io.ReadAll(str)
 	require.NoError(t, err)
 	require.Equal(t, "foobar", string(data))
+	require.Equal(t, <-addrChan, conn.LocalMultiaddr())
 }
 
 func TestHashVerification(t *testing.T) {

From a0eec0f0e000d5578c04ea05d70d3cfd3d8a6b1a Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 2 Jul 2022 11:09:28 +0200
Subject: [PATCH 19/53] update webtransport-go, rename webtransport.Conn to
 Session

---
 p2p/transport/webtransport/conn.go      | 16 ++++++++--------
 p2p/transport/webtransport/listener.go  |  8 ++++----
 p2p/transport/webtransport/stream.go    |  6 +++---
 p2p/transport/webtransport/transport.go | 12 +++++++-----
 4 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index e2ab9cd50b..90ae154b8c 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -15,7 +15,7 @@ import (
 
 type conn struct {
 	transport tpt.Transport
-	wconn     *webtransport.Conn
+	wsess     *webtransport.Session
 
 	localPeer, remotePeer peer.ID
 	local, remote         ma.Multiaddr
@@ -23,7 +23,7 @@ type conn struct {
 	remotePubKey          ic.PubKey
 }
 
-func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, remotePubKey ic.PubKey) (*conn, error) {
+func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey) (*conn, error) {
 	localPeer, err := peer.IDFromPrivateKey(privKey)
 	if err != nil {
 		return nil, err
@@ -32,17 +32,17 @@ func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, rem
 	if err != nil {
 		return nil, err
 	}
-	local, err := toWebtransportMultiaddr(wconn.LocalAddr())
+	local, err := toWebtransportMultiaddr(wsess.LocalAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting local addr: %w", err)
 	}
-	remote, err := toWebtransportMultiaddr(wconn.RemoteAddr())
+	remote, err := toWebtransportMultiaddr(wsess.RemoteAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
 	}
 	return &conn{
 		transport:    tr,
-		wconn:        wconn,
+		wsess:        wsess,
 		privKey:      privKey,
 		localPeer:    localPeer,
 		remotePeer:   remotePeer,
@@ -55,7 +55,7 @@ func newConn(tr tpt.Transport, wconn *webtransport.Conn, privKey ic.PrivKey, rem
 var _ tpt.CapableConn = &conn{}
 
 func (c *conn) Close() error {
-	return c.wconn.Close()
+	return c.wsess.Close()
 }
 
 func (c *conn) IsClosed() bool {
@@ -63,12 +63,12 @@ func (c *conn) IsClosed() bool {
 }
 
 func (c *conn) OpenStream(ctx context.Context) (network.MuxedStream, error) {
-	str, err := c.wconn.OpenStreamSync(ctx)
+	str, err := c.wsess.OpenStreamSync(ctx)
 	return &stream{str}, err
 }
 
 func (c *conn) AcceptStream() (network.MuxedStream, error) {
-	str, err := c.wconn.AcceptStream(context.Background())
+	str, err := c.wsess.AcceptStream(context.Background())
 	return &stream{str}, err
 }
 
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 993354f965..6789a74542 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -122,16 +122,16 @@ func (l *listener) Accept() (tpt.CapableConn, error) {
 	}
 }
 
-func (l *listener) handshake(ctx context.Context, c *webtransport.Conn) (tpt.CapableConn, error) {
-	str, err := c.AcceptStream(ctx)
+func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (tpt.CapableConn, error) {
+	str, err := sess.AcceptStream(ctx)
 	if err != nil {
 		return nil, err
 	}
-	conn, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wconn: c}, "")
+	conn, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
 	if err != nil {
 		return nil, err
 	}
-	return newConn(l.transport, c, conn.LocalPrivateKey(), conn.RemotePublicKey())
+	return newConn(l.transport, sess, conn.LocalPrivateKey(), conn.RemotePublicKey())
 }
 
 func (l *listener) Addr() net.Addr {
diff --git a/p2p/transport/webtransport/stream.go b/p2p/transport/webtransport/stream.go
index fa34242b6c..6aa58cb8d8 100644
--- a/p2p/transport/webtransport/stream.go
+++ b/p2p/transport/webtransport/stream.go
@@ -15,17 +15,17 @@ const (
 
 type webtransportStream struct {
 	webtransport.Stream
-	wconn *webtransport.Conn
+	wsess *webtransport.Session
 }
 
 var _ net.Conn = &webtransportStream{}
 
 func (s *webtransportStream) LocalAddr() net.Addr {
-	return s.wconn.LocalAddr()
+	return s.wsess.LocalAddr()
 }
 
 func (s *webtransportStream) RemoteAddr() net.Addr {
-	return s.wconn.RemoteAddr()
+	return s.wsess.RemoteAddr()
 }
 
 type stream struct {
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 2596ba4dcd..29eb784788 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -16,13 +16,13 @@ import (
 
 	noise "github.com/libp2p/go-libp2p-noise"
 
+	logging "github.com/ipfs/go-log/v2"
+	"github.com/lucas-clemente/quic-go/http3"
+	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
-
-	logging "github.com/ipfs/go-log/v2"
-	"github.com/marten-seemann/webtransport-go"
 )
 
 var log = logging.Logger("webtransport")
@@ -56,7 +56,9 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 		pid:     id,
 		privKey: key,
 		dialer: webtransport.Dialer{
-			TLSClientConf: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
+			RoundTripper: &http3.RoundTripper{
+				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
+			},
 		},
 	}
 	noise, err := noise.New(key, noise.WithEarlyDataHandler(t.checkEarlyData))
@@ -117,7 +119,7 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if err != nil {
 		return nil, fmt.Errorf("failed to marshal WebTransport protobuf: %w", err)
 	}
-	sconn, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wconn: wconn}, p, msgBytes)
+	sconn, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: wconn}, p, msgBytes)
 	if err != nil {
 		return nil, err
 	}

From d155f115144d34d99bc2ca1bf727ffd1ae5a06c5 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 12:05:51 +0000
Subject: [PATCH 20/53] tighten multiaddr conversion logic

---
 p2p/transport/webtransport/multiaddr.go      |  8 ++++++--
 p2p/transport/webtransport/multiaddr_test.go | 21 ++++++++++++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 p2p/transport/webtransport/multiaddr_test.go

diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index 5560d90f68..9d79991938 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -1,6 +1,7 @@
 package libp2pwebtransport
 
 import (
+	"errors"
 	"net"
 
 	ma "github.com/multiformats/go-multiaddr"
@@ -13,9 +14,12 @@ var webtransportMA = ma.StringCast("/quic/webtransport")
 var webtransportMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC), mafmt.Base(ma.P_WEBTRANSPORT))
 
 func toWebtransportMultiaddr(na net.Addr) (ma.Multiaddr, error) {
-	udpMA, err := manet.FromNetAddr(na)
+	addr, err := manet.FromNetAddr(na)
 	if err != nil {
 		return nil, err
 	}
-	return udpMA.Encapsulate(webtransportMA), nil
+	if _, err := addr.ValueForProtocol(ma.P_UDP); err != nil {
+		return nil, errors.New("not a UDP address")
+	}
+	return addr.Encapsulate(webtransportMA), nil
 }
diff --git a/p2p/transport/webtransport/multiaddr_test.go b/p2p/transport/webtransport/multiaddr_test.go
new file mode 100644
index 0000000000..2098babbd0
--- /dev/null
+++ b/p2p/transport/webtransport/multiaddr_test.go
@@ -0,0 +1,21 @@
+package libp2pwebtransport
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestWebtransportMultiaddr(t *testing.T) {
+	t.Run("valid", func(t *testing.T) {
+		addr, err := toWebtransportMultiaddr(&net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 1337})
+		require.NoError(t, err)
+		require.Equal(t, "/ip4/127.0.0.1/udp/1337/quic/webtransport", addr.String())
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		_, err := toWebtransportMultiaddr(&net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 1337})
+		require.EqualError(t, err, "not a UDP address")
+	})
+}

From 106cbc3810f725241ca27bab54ac2c1fbe6fcd7c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 14:30:41 +0000
Subject: [PATCH 21/53] return the listener's HTTP handler as soon as the
 handshake completes

With the most recent webtransport-go, it's not necessary to block any more.
---
 p2p/transport/webtransport/listener.go | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 6789a74542..91767dac1c 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -97,9 +97,8 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 			return
 		}
 		cancel()
+		// TODO: think about what happens when this channel fills up
 		ln.queue <- conn
-		// We need to block until we're done with this WebTransport session.
-		<-c.Context().Done()
 	})
 	ln.server.H3.Handler = mux
 	go func() {

From ed5a2f58da861540ee5c31de955bbf8e064e81d7 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 11:30:49 +0000
Subject: [PATCH 22/53] use the resource manager when dialing

---
 p2p/transport/webtransport/transport.go      | 26 ++++++++++-
 p2p/transport/webtransport/transport_test.go | 45 ++++++++++++++++----
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 29eb784788..52b4e554a2 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -11,6 +11,7 @@ import (
 	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
+	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
@@ -37,6 +38,8 @@ type transport struct {
 
 	dialer webtransport.Dialer
 
+	rcmgr network.ResourceManager
+
 	listenOnce    sync.Once
 	listenOnceErr error
 	certManager   *certManager
@@ -47,7 +50,7 @@ type transport struct {
 var _ tpt.Transport = &transport{}
 var _ io.Closer = &transport{}
 
-func New(key ic.PrivKey) (tpt.Transport, error) {
+func New(key ic.PrivKey, rcmgr network.ResourceManager) (tpt.Transport, error) {
 	id, err := peer.IDFromPrivateKey(key)
 	if err != nil {
 		return nil, err
@@ -55,6 +58,7 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 	t := &transport{
 		pid:     id,
 		privKey: key,
+		rcmgr:   rcmgr,
 		dialer: webtransport.Dialer{
 			RoundTripper: &http3.RoundTripper{
 				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
@@ -70,6 +74,26 @@ func New(key ic.PrivKey) (tpt.Transport, error) {
 }
 
 func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
+	scope, err := t.rcmgr.OpenConnection(network.DirOutbound, false, raddr)
+	if err != nil {
+		log.Debugw("resource manager blocked outgoing connection", "peer", p, "addr", raddr, "error", err)
+		return nil, err
+	}
+	if err := scope.SetPeer(p); err != nil {
+		log.Debugw("resource manager blocked outgoing connection for peer", "peer", p, "addr", raddr, "error", err)
+		scope.Done()
+		return nil, err
+	}
+
+	conn, err := t.dial(ctx, raddr, p)
+	if err != nil {
+		scope.Done()
+		return nil, err
+	}
+	return conn, nil
+}
+
+func (t *transport) dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
 	_, addr, err := manet.DialArgs(raddr)
 	if err != nil {
 		return nil, err
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 4d640eb5d3..f27a4984e4 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -4,16 +4,20 @@ import (
 	"context"
 	"crypto/rand"
 	"crypto/sha256"
+	"errors"
 	"fmt"
 	"io"
-	"strings"
+	"net"
 	"testing"
 
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 
 	ic "github.com/libp2p/go-libp2p-core/crypto"
+	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 
+	"github.com/golang/mock/gomock"
+	mocknetwork "github.com/libp2p/go-libp2p-testing/mocks/network"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
@@ -51,7 +55,7 @@ func extractCertHashes(t *testing.T, addr ma.Multiaddr) []string {
 
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
-	tr, err := libp2pwebtransport.New(serverKey)
+	tr, err := libp2pwebtransport.New(serverKey, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
@@ -61,7 +65,7 @@ func TestTransport(t *testing.T) {
 	addrChan := make(chan ma.Multiaddr)
 	go func() {
 		_, clientKey := newIdentity(t)
-		tr2, err := libp2pwebtransport.New(clientKey)
+		tr2, err := libp2pwebtransport.New(clientKey, network.NullResourceManager)
 		require.NoError(t, err)
 		defer tr2.(io.Closer).Close()
 
@@ -76,7 +80,8 @@ func TestTransport(t *testing.T) {
 		// check RemoteMultiaddr
 		_, addr, err := manet.DialArgs(ln.Multiaddr())
 		require.NoError(t, err)
-		port := strings.Split(addr, ":")[1]
+		_, port, err := net.SplitHostPort(addr)
+		require.NoError(t, err)
 		require.Equal(t, ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/%s/quic/webtransport", port)), conn.RemoteMultiaddr())
 		addrChan <- conn.RemoteMultiaddr()
 	}()
@@ -93,7 +98,7 @@ func TestTransport(t *testing.T) {
 
 func TestHashVerification(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
-	tr, err := libp2pwebtransport.New(serverKey)
+	tr, err := libp2pwebtransport.New(serverKey, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
@@ -106,7 +111,7 @@ func TestHashVerification(t *testing.T) {
 	}()
 
 	_, clientKey := newIdentity(t)
-	tr2, err := libp2pwebtransport.New(clientKey)
+	tr2, err := libp2pwebtransport.New(clientKey, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr2.(io.Closer).Close()
 
@@ -152,7 +157,7 @@ func TestCanDial(t *testing.T) {
 	}
 
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key)
+	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -178,7 +183,7 @@ func TestListenAddrValidity(t *testing.T) {
 	}
 
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key)
+	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -195,7 +200,7 @@ func TestListenAddrValidity(t *testing.T) {
 
 func TestListenerAddrs(t *testing.T) {
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key)
+	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -208,3 +213,25 @@ func TestListenerAddrs(t *testing.T) {
 	hashes2 := extractCertHashes(t, ln2.Multiaddr())
 	require.Equal(t, hashes1, hashes2)
 }
+
+func TestResourceManagerDialing(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	rcmgr := mocknetwork.NewMockResourceManager(ctrl)
+
+	addr := ma.StringCast("/ip4/9.8.7.6/udp/1234/quic/webtransport")
+	p := peer.ID("foobar")
+
+	_, key := newIdentity(t)
+	tr, err := libp2pwebtransport.New(key, rcmgr)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+
+	scope := mocknetwork.NewMockConnManagementScope(ctrl)
+	rcmgr.EXPECT().OpenConnection(network.DirOutbound, false, addr).Return(scope, nil)
+	scope.EXPECT().SetPeer(p).Return(errors.New("denied"))
+	scope.EXPECT().Done()
+
+	_, err = tr.Dial(context.Background(), addr, p)
+	require.EqualError(t, err, "denied")
+}

From 468fd51967585a6da58fd63345082cf313c0a703 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 11:33:19 +0000
Subject: [PATCH 23/53] move the HTTP handler to a separate method on the
 listener

---
 p2p/transport/webtransport/listener.go | 40 ++++++++++++++------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 91767dac1c..50af8879c1 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -81,25 +81,7 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte("Hello, world!"))
 	})
-	mux.HandleFunc(webtransportHTTPEndpoint, func(w http.ResponseWriter, r *http.Request) {
-		// TODO: check ?type=multistream URL param
-		c, err := ln.server.Upgrade(w, r)
-		if err != nil {
-			w.WriteHeader(500)
-			return
-		}
-		ctx, cancel := context.WithTimeout(ln.ctx, handshakeTimeout)
-		conn, err := ln.handshake(ctx, c)
-		if err != nil {
-			cancel()
-			log.Debugw("handshake failed", "error", err)
-			c.Close()
-			return
-		}
-		cancel()
-		// TODO: think about what happens when this channel fills up
-		ln.queue <- conn
-	})
+	mux.HandleFunc(webtransportHTTPEndpoint, ln.httpHandler)
 	ln.server.H3.Handler = mux
 	go func() {
 		defer close(ln.serverClosed)
@@ -112,6 +94,26 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 	return ln, nil
 }
 
+func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
+	// TODO: check ?type=multistream URL param
+	c, err := l.server.Upgrade(w, r)
+	if err != nil {
+		w.WriteHeader(500)
+		return
+	}
+	ctx, cancel := context.WithTimeout(l.ctx, handshakeTimeout)
+	conn, err := l.handshake(ctx, c)
+	if err != nil {
+		cancel()
+		log.Debugw("handshake failed", "error", err)
+		c.Close()
+		return
+	}
+	cancel()
+	// TODO: think about what happens when this channel fills up
+	l.queue <- conn
+}
+
 func (l *listener) Accept() (tpt.CapableConn, error) {
 	select {
 	case <-l.ctx.Done():

From 2110e680dd0f8350fa5563ceacb67acb8ac7f5b6 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 12:11:05 +0000
Subject: [PATCH 24/53] add a function to convert a IP:port string to a
 WebTransport multiaddr

---
 p2p/transport/webtransport/multiaddr.go      | 17 +++++++++++++++++
 p2p/transport/webtransport/multiaddr_test.go | 20 ++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index 9d79991938..a61b1b8962 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -3,6 +3,7 @@ package libp2pwebtransport
 import (
 	"errors"
 	"net"
+	"strconv"
 
 	ma "github.com/multiformats/go-multiaddr"
 	mafmt "github.com/multiformats/go-multiaddr-fmt"
@@ -23,3 +24,19 @@ func toWebtransportMultiaddr(na net.Addr) (ma.Multiaddr, error) {
 	}
 	return addr.Encapsulate(webtransportMA), nil
 }
+
+func stringToWebtransportMultiaddr(str string) (ma.Multiaddr, error) {
+	host, portStr, err := net.SplitHostPort(str)
+	if err != nil {
+		return nil, err
+	}
+	port, err := strconv.ParseInt(portStr, 10, 32)
+	if err != nil {
+		return nil, err
+	}
+	ip := net.ParseIP(host)
+	if ip == nil {
+		return nil, errors.New("failed to parse IP")
+	}
+	return toWebtransportMultiaddr(&net.UDPAddr{IP: ip, Port: int(port)})
+}
diff --git a/p2p/transport/webtransport/multiaddr_test.go b/p2p/transport/webtransport/multiaddr_test.go
index 2098babbd0..5fc0432a33 100644
--- a/p2p/transport/webtransport/multiaddr_test.go
+++ b/p2p/transport/webtransport/multiaddr_test.go
@@ -19,3 +19,23 @@ func TestWebtransportMultiaddr(t *testing.T) {
 		require.EqualError(t, err, "not a UDP address")
 	})
 }
+
+func TestWebtransportMultiaddrFromString(t *testing.T) {
+	t.Run("valid", func(t *testing.T) {
+		addr, err := stringToWebtransportMultiaddr("1.2.3.4:60042")
+		require.NoError(t, err)
+		require.Equal(t, "/ip4/1.2.3.4/udp/60042/quic/webtransport", addr.String())
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		for _, addr := range [...]string{
+			"1.2.3.4",        // missing port
+			"1.2.3.4:123456", // invalid port
+			":1234",          // missing IP
+			"foobar",
+		} {
+			_, err := stringToWebtransportMultiaddr(addr)
+			require.Error(t, err)
+		}
+	})
+}

From f55a4ffc9a6e7bae7be6d4ddfe5d400c0d8ca504 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 15:19:45 +0000
Subject: [PATCH 25/53] use the resource manager when accepting connections

---
 p2p/transport/webtransport/listener.go       | 32 ++++++++++-
 p2p/transport/webtransport/transport.go      |  2 +-
 p2p/transport/webtransport/transport_test.go | 56 ++++++++++++++++++++
 3 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 50af8879c1..ef21c23ffb 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/libp2p/go-libp2p-core/network"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
 	noise "github.com/libp2p/go-libp2p-noise"
@@ -27,6 +28,7 @@ type listener struct {
 	transport   tpt.Transport
 	noise       *noise.Transport
 	certManager *certManager
+	rcmgr       network.ResourceManager
 
 	server webtransport.Server
 
@@ -43,7 +45,7 @@ type listener struct {
 
 var _ tpt.Listener = &listener{}
 
-func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager) (tpt.Listener, error) {
+func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager, rcmgr network.ResourceManager) (tpt.Listener, error) {
 	network, addr, err := manet.DialArgs(laddr)
 	if err != nil {
 		return nil, err
@@ -64,6 +66,7 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 		transport:    transport,
 		noise:        noise,
 		certManager:  certManager,
+		rcmgr:        rcmgr,
 		queue:        make(chan tpt.CapableConn, queueLen),
 		serverClosed: make(chan struct{}),
 		addr:         udpConn.LocalAddr(),
@@ -95,10 +98,28 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 }
 
 func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
+	remoteMultiaddr, err := stringToWebtransportMultiaddr(r.RemoteAddr)
+	if err != nil {
+		// This should never happen.
+		log.Errorw("converting remote address failed", "remote", r.RemoteAddr, "error", err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	connScope, err := l.rcmgr.OpenConnection(network.DirInbound, false, remoteMultiaddr)
+	if err != nil {
+		log.Debugw("resource manager blocked incoming connection", "addr", r.RemoteAddr, "error", err)
+		w.WriteHeader(http.StatusServiceUnavailable)
+		return
+	}
+
 	// TODO: check ?type=multistream URL param
 	c, err := l.server.Upgrade(w, r)
 	if err != nil {
+		log.Debugw("upgrade failed", "error", err)
+		// TODO: think about the status code to use here
 		w.WriteHeader(500)
+		connScope.Done()
 		return
 	}
 	ctx, cancel := context.WithTimeout(l.ctx, handshakeTimeout)
@@ -107,9 +128,18 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 		cancel()
 		log.Debugw("handshake failed", "error", err)
 		c.Close()
+		connScope.Done()
 		return
 	}
 	cancel()
+
+	if err := connScope.SetPeer(conn.RemotePeer()); err != nil {
+		log.Debugw("resource manager blocked incoming connection for peer", "peer", conn.RemotePeer(), "addr", r.RemoteAddr, "error", err)
+		conn.Close()
+		connScope.Done()
+		return
+	}
+
 	// TODO: think about what happens when this channel fills up
 	l.queue <- conn
 }
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 52b4e554a2..0d825076b2 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -193,7 +193,7 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 	if t.listenOnceErr != nil {
 		return nil, t.listenOnceErr
 	}
-	return newListener(laddr, t, t.noise, t.certManager)
+	return newListener(laddr, t, t.noise, t.certManager, t.rcmgr)
 }
 
 func (t *transport) Protocols() []int {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index f27a4984e4..8f8b70fb8e 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -235,3 +235,59 @@ func TestResourceManagerDialing(t *testing.T) {
 	_, err = tr.Dial(context.Background(), addr, p)
 	require.EqualError(t, err, "denied")
 }
+
+func TestResourceManagerListening(t *testing.T) {
+	clientID, key := newIdentity(t)
+	cl, err := libp2pwebtransport.New(key, network.NullResourceManager)
+	require.NoError(t, err)
+	defer cl.(io.Closer).Close()
+
+	t.Run("blocking the connection", func(t *testing.T) {
+		serverID, key := newIdentity(t)
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		rcmgr := mocknetwork.NewMockResourceManager(ctrl)
+		tr, err := libp2pwebtransport.New(key, rcmgr)
+		require.NoError(t, err)
+		ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+		require.NoError(t, err)
+		defer ln.Close()
+
+		rcmgr.EXPECT().OpenConnection(network.DirInbound, false, gomock.Any()).DoAndReturn(func(_ network.Direction, _ bool, addr ma.Multiaddr) (network.ConnManagementScope, error) {
+			_, err := addr.ValueForProtocol(ma.P_WEBTRANSPORT)
+			require.NoError(t, err, "expected a WebTransport multiaddr")
+			_, addrStr, err := manet.DialArgs(addr)
+			require.NoError(t, err)
+			host, _, err := net.SplitHostPort(addrStr)
+			require.NoError(t, err)
+			require.Equal(t, "127.0.0.1", host)
+			return nil, errors.New("denied")
+		})
+
+		_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+		require.EqualError(t, err, "received status 503")
+	})
+
+	t.Run("blocking the peer", func(t *testing.T) {
+		serverID, key := newIdentity(t)
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		rcmgr := mocknetwork.NewMockResourceManager(ctrl)
+		tr, err := libp2pwebtransport.New(key, rcmgr)
+		require.NoError(t, err)
+		ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+		require.NoError(t, err)
+		defer ln.Close()
+
+		scope := mocknetwork.NewMockConnManagementScope(ctrl)
+		rcmgr.EXPECT().OpenConnection(network.DirInbound, false, gomock.Any()).Return(scope, nil)
+		scope.EXPECT().SetPeer(clientID).Return(errors.New("denied"))
+		scope.EXPECT().Done()
+
+		// The handshake will complete, but the server will immediately close the connection.
+		conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+		require.NoError(t, err)
+		_, err = conn.AcceptStream()
+		require.Error(t, err)
+	})
+}

From 3b13c8342d30ede876dac413c02b918599cb180e Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 16:24:24 +0000
Subject: [PATCH 26/53] move extraction of certificate hashes to a separate
 function

---
 p2p/transport/webtransport/multiaddr.go      | 26 +++++++++++
 p2p/transport/webtransport/multiaddr_test.go | 47 ++++++++++++++++++++
 p2p/transport/webtransport/transport.go      | 22 ++-------
 p2p/transport/webtransport/transport_test.go |  6 +--
 4 files changed, 79 insertions(+), 22 deletions(-)

diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index a61b1b8962..7b6df2ba25 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -2,12 +2,15 @@ package libp2pwebtransport
 
 import (
 	"errors"
+	"fmt"
 	"net"
 	"strconv"
 
 	ma "github.com/multiformats/go-multiaddr"
 	mafmt "github.com/multiformats/go-multiaddr-fmt"
 	manet "github.com/multiformats/go-multiaddr/net"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 )
 
 var webtransportMA = ma.StringCast("/quic/webtransport")
@@ -40,3 +43,26 @@ func stringToWebtransportMultiaddr(str string) (ma.Multiaddr, error) {
 	}
 	return toWebtransportMultiaddr(&net.UDPAddr{IP: ip, Port: int(port)})
 }
+
+func extractCertHashes(addr ma.Multiaddr) ([]multihash.DecodedMultihash, error) {
+	certHashesStr := make([]string, 0, 2)
+	ma.ForEach(addr, func(c ma.Component) bool {
+		if c.Protocol().Code == ma.P_CERTHASH {
+			certHashesStr = append(certHashesStr, c.Value())
+		}
+		return true
+	})
+	certHashes := make([]multihash.DecodedMultihash, 0, len(certHashesStr))
+	for _, s := range certHashesStr {
+		_, ch, err := multibase.Decode(s)
+		if err != nil {
+			return nil, fmt.Errorf("failed to multibase-decode certificate hash: %w", err)
+		}
+		dh, err := multihash.Decode(ch)
+		if err != nil {
+			return nil, fmt.Errorf("failed to multihash-decode certificate hash: %w", err)
+		}
+		certHashes = append(certHashes, *dh)
+	}
+	return certHashes, nil
+}
diff --git a/p2p/transport/webtransport/multiaddr_test.go b/p2p/transport/webtransport/multiaddr_test.go
index 5fc0432a33..7c95b00d01 100644
--- a/p2p/transport/webtransport/multiaddr_test.go
+++ b/p2p/transport/webtransport/multiaddr_test.go
@@ -1,9 +1,13 @@
 package libp2pwebtransport
 
 import (
+	"fmt"
 	"net"
 	"testing"
 
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 	"github.com/stretchr/testify/require"
 )
 
@@ -39,3 +43,46 @@ func TestWebtransportMultiaddrFromString(t *testing.T) {
 		}
 	})
 }
+
+func encodeCertHash(t *testing.T, b []byte, mh uint64, mb multibase.Encoding) string {
+	t.Helper()
+	h, err := multihash.Encode(b, mh)
+	require.NoError(t, err)
+	str, err := multibase.Encode(mb, h)
+	require.NoError(t, err)
+	return str
+}
+
+func TestExtractCertHashes(t *testing.T) {
+	fooHash := encodeCertHash(t, []byte("foo"), multihash.SHA2_256, multibase.Base58BTC)
+	barHash := encodeCertHash(t, []byte("bar"), multihash.BLAKE2B_MAX, multibase.Base32)
+
+	// valid cases
+	for _, tc := range [...]struct {
+		addr   string
+		hashes []string
+	}{
+		{addr: "/ip4/127.0.0.1/udp/1234/quic/webtransport"},
+		{addr: fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s", fooHash), hashes: []string{"foo"}},
+		{addr: fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s/certhash/%s", fooHash, barHash), hashes: []string{"foo", "bar"}},
+	} {
+		ch, err := extractCertHashes(ma.StringCast(tc.addr))
+		require.NoError(t, err)
+		require.Len(t, ch, len(tc.hashes))
+		for i, h := range tc.hashes {
+			require.Equal(t, h, string(ch[i].Digest))
+		}
+	}
+
+	// invalid cases
+	for _, tc := range [...]struct {
+		addr string
+		err  string
+	}{
+		{addr: fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s", fooHash[:len(fooHash)-1]), err: "failed to multihash-decode certificate hash"},
+	} {
+		_, err := extractCertHashes(ma.StringCast(tc.addr))
+		require.Error(t, err)
+		require.Contains(t, err.Error(), tc.err)
+	}
+}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 0d825076b2..2d2ffcfb6f 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -22,7 +22,6 @@ import (
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
-	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
 )
 
@@ -99,24 +98,9 @@ func (t *transport) dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		return nil, err
 	}
 	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
-	certHashesStr := make([]string, 0, 2)
-	ma.ForEach(raddr, func(c ma.Component) bool {
-		if c.Protocol().Code == ma.P_CERTHASH {
-			certHashesStr = append(certHashesStr, c.Value())
-		}
-		return true
-	})
-	var certHashes []multihash.DecodedMultihash
-	for _, s := range certHashesStr {
-		_, ch, err := multibase.Decode(s)
-		if err != nil {
-			return nil, fmt.Errorf("failed to multibase-decode certificate hash: %w", err)
-		}
-		dh, err := multihash.Decode(ch)
-		if err != nil {
-			return nil, fmt.Errorf("failed to multihash-decode certificate hash: %w", err)
-		}
-		certHashes = append(certHashes, *dh)
+	certHashes, err := extractCertHashes(raddr)
+	if err != nil {
+		return nil, err
 	}
 	rsp, wconn, err := t.dialer.Dial(ctx, url, nil)
 	if err != nil {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 8f8b70fb8e..115c7f1030 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -42,7 +42,7 @@ func randomMultihash(t *testing.T) string {
 	return s
 }
 
-func extractCertHashes(t *testing.T, addr ma.Multiaddr) []string {
+func extractCertHashes(addr ma.Multiaddr) []string {
 	var certHashesStr []string
 	ma.ForEach(addr, func(c ma.Component) bool {
 		if c.Protocol().Code == ma.P_CERTHASH {
@@ -208,9 +208,9 @@ func TestListenerAddrs(t *testing.T) {
 	require.NoError(t, err)
 	ln2, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
-	hashes1 := extractCertHashes(t, ln1.Multiaddr())
+	hashes1 := extractCertHashes(ln1.Multiaddr())
 	require.Len(t, hashes1, 1)
-	hashes2 := extractCertHashes(t, ln2.Multiaddr())
+	hashes2 := extractCertHashes(ln2.Multiaddr())
 	require.Equal(t, hashes1, hashes2)
 }
 

From c7149b3be4b74a160c52271ccbda241d19e6219d Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 18:49:40 +0000
Subject: [PATCH 27/53] pass the connection scope to the connection (#11)

---
 p2p/transport/webtransport/conn.go           | 15 +++----
 p2p/transport/webtransport/listener.go       | 29 +++++++------
 p2p/transport/webtransport/transport.go      | 45 +++++++++++++-------
 p2p/transport/webtransport/transport_test.go | 15 ++++++-
 4 files changed, 63 insertions(+), 41 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index 90ae154b8c..3478d39db1 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -21,9 +21,10 @@ type conn struct {
 	local, remote         ma.Multiaddr
 	privKey               ic.PrivKey
 	remotePubKey          ic.PubKey
+	scope                 network.ConnScope
 }
 
-func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey) (*conn, error) {
+func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey, scope network.ConnScope) (*conn, error) {
 	localPeer, err := peer.IDFromPrivateKey(privKey)
 	if err != nil {
 		return nil, err
@@ -49,6 +50,7 @@ func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey,
 		remotePubKey: remotePubKey,
 		local:        local,
 		remote:       remote,
+		scope:        scope,
 	}, nil
 }
 
@@ -78,12 +80,5 @@ func (c *conn) RemotePeer() peer.ID           { return c.remotePeer }
 func (c *conn) RemotePublicKey() ic.PubKey    { return c.remotePubKey }
 func (c *conn) LocalMultiaddr() ma.Multiaddr  { return c.local }
 func (c *conn) RemoteMultiaddr() ma.Multiaddr { return c.remote }
-
-func (c *conn) Scope() network.ConnScope {
-	// TODO implement me
-	panic("implement me")
-}
-
-func (c *conn) Transport() tpt.Transport {
-	return c.transport
-}
+func (c *conn) Scope() network.ConnScope      { return c.scope }
+func (c *conn) Transport() tpt.Transport      { return c.transport }
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index ef21c23ffb..739c230ca6 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -114,7 +114,7 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// TODO: check ?type=multistream URL param
-	c, err := l.server.Upgrade(w, r)
+	sess, err := l.server.Upgrade(w, r)
 	if err != nil {
 		log.Debugw("upgrade failed", "error", err)
 		// TODO: think about the status code to use here
@@ -123,25 +123,32 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	ctx, cancel := context.WithTimeout(l.ctx, handshakeTimeout)
-	conn, err := l.handshake(ctx, c)
+	sconn, err := l.handshake(ctx, sess)
 	if err != nil {
 		cancel()
 		log.Debugw("handshake failed", "error", err)
-		c.Close()
+		sess.Close()
 		connScope.Done()
 		return
 	}
 	cancel()
 
-	if err := connScope.SetPeer(conn.RemotePeer()); err != nil {
-		log.Debugw("resource manager blocked incoming connection for peer", "peer", conn.RemotePeer(), "addr", r.RemoteAddr, "error", err)
-		conn.Close()
+	if err := connScope.SetPeer(sconn.RemotePeer()); err != nil {
+		log.Debugw("resource manager blocked incoming connection for peer", "peer", sconn.RemotePeer(), "addr", r.RemoteAddr, "error", err)
+		sess.Close()
+		connScope.Done()
+		return
+	}
+
+	c, err := newConn(l.transport, sess, sconn.LocalPrivateKey(), sconn.RemotePublicKey(), connScope)
+	if err != nil {
+		sess.Close()
 		connScope.Done()
 		return
 	}
 
 	// TODO: think about what happens when this channel fills up
-	l.queue <- conn
+	l.queue <- c
 }
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
@@ -153,16 +160,12 @@ func (l *listener) Accept() (tpt.CapableConn, error) {
 	}
 }
 
-func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (tpt.CapableConn, error) {
+func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (network.ConnSecurity, error) {
 	str, err := sess.AcceptStream(ctx)
 	if err != nil {
 		return nil, err
 	}
-	conn, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
-	if err != nil {
-		return nil, err
-	}
-	return newConn(l.transport, sess, conn.LocalPrivateKey(), conn.RemotePublicKey())
+	return l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
 }
 
 func (l *listener) Addr() net.Addr {
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 2d2ffcfb6f..640221a9b1 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	manet "github.com/multiformats/go-multiaddr/net"
 	"io"
 	"sync"
 	"time"
@@ -21,7 +22,6 @@ import (
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
-	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multihash"
 )
 
@@ -73,6 +73,15 @@ func New(key ic.PrivKey, rcmgr network.ResourceManager) (tpt.Transport, error) {
 }
 
 func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
+	_, addr, err := manet.DialArgs(raddr)
+	if err != nil {
+		return nil, err
+	}
+	certHashes, err := extractCertHashes(raddr)
+	if err != nil {
+		return nil, err
+	}
+
 	scope, err := t.rcmgr.OpenConnection(network.DirOutbound, false, raddr)
 	if err != nil {
 		log.Debugw("resource manager blocked outgoing connection", "peer", p, "addr", raddr, "error", err)
@@ -84,32 +93,40 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		return nil, err
 	}
 
-	conn, err := t.dial(ctx, raddr, p)
+	sess, err := t.dial(ctx, addr)
 	if err != nil {
 		scope.Done()
 		return nil, err
 	}
-	return conn, nil
-}
-
-func (t *transport) dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tpt.CapableConn, error) {
-	_, addr, err := manet.DialArgs(raddr)
+	sconn, err := t.upgrade(ctx, sess, p, certHashes)
 	if err != nil {
+		sess.Close()
+		scope.Done()
 		return nil, err
 	}
-	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
-	certHashes, err := extractCertHashes(raddr)
+	c, err := newConn(t, sess, t.privKey, sconn.RemotePublicKey(), scope)
 	if err != nil {
+		sess.Close()
+		scope.Done()
 		return nil, err
 	}
-	rsp, wconn, err := t.dialer.Dial(ctx, url, nil)
+	return c, nil
+}
+
+func (t *transport) dial(ctx context.Context, addr string) (*webtransport.Session, error) {
+	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
+	rsp, sess, err := t.dialer.Dial(ctx, url, nil)
 	if err != nil {
 		return nil, err
 	}
 	if rsp.StatusCode < 200 || rsp.StatusCode > 299 {
 		return nil, fmt.Errorf("invalid response status code: %d", rsp.StatusCode)
 	}
-	str, err := wconn.OpenStreamSync(ctx)
+	return sess, err
+}
+
+func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p peer.ID, certHashes []multihash.DecodedMultihash) (network.ConnSecurity, error) {
+	str, err := sess.OpenStreamSync(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -127,11 +144,7 @@ func (t *transport) dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if err != nil {
 		return nil, fmt.Errorf("failed to marshal WebTransport protobuf: %w", err)
 	}
-	sconn, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: wconn}, p, msgBytes)
-	if err != nil {
-		return nil, err
-	}
-	return newConn(t, wconn, t.privKey, sconn.RemotePublicKey())
+	return t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: sess}, p, msgBytes)
 }
 
 func (t *transport) checkEarlyData(b []byte) error {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 115c7f1030..7ddcff9ffa 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"testing"
+	"time"
 
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 
@@ -287,7 +288,17 @@ func TestResourceManagerListening(t *testing.T) {
 		// The handshake will complete, but the server will immediately close the connection.
 		conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
 		require.NoError(t, err)
-		_, err = conn.AcceptStream()
-		require.Error(t, err)
+		defer conn.Close()
+		done := make(chan struct{})
+		go func() {
+			defer close(done)
+			_, err = conn.AcceptStream()
+			require.Error(t, err)
+		}()
+		select {
+		case <-done:
+		case <-time.After(5 * time.Second):
+			t.Fatal("timeout")
+		}
 	})
 }

From 69341f6e33172e8be86bcc5a7f3b6cd144a0710a Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 21:44:22 +0000
Subject: [PATCH 28/53] properly implement conn.IsClosed (#13)

---
 p2p/transport/webtransport/conn.go           | 24 ++++++++------------
 p2p/transport/webtransport/transport_test.go |  3 +++
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index 3478d39db1..2efc263fbf 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -15,7 +15,7 @@ import (
 
 type conn struct {
 	transport tpt.Transport
-	wsess     *webtransport.Session
+	session   *webtransport.Session
 
 	localPeer, remotePeer peer.ID
 	local, remote         ma.Multiaddr
@@ -24,7 +24,7 @@ type conn struct {
 	scope                 network.ConnScope
 }
 
-func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey, scope network.ConnScope) (*conn, error) {
+func newConn(tr tpt.Transport, sess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey, scope network.ConnScope) (*conn, error) {
 	localPeer, err := peer.IDFromPrivateKey(privKey)
 	if err != nil {
 		return nil, err
@@ -33,17 +33,17 @@ func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey,
 	if err != nil {
 		return nil, err
 	}
-	local, err := toWebtransportMultiaddr(wsess.LocalAddr())
+	local, err := toWebtransportMultiaddr(sess.LocalAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting local addr: %w", err)
 	}
-	remote, err := toWebtransportMultiaddr(wsess.RemoteAddr())
+	remote, err := toWebtransportMultiaddr(sess.RemoteAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
 	}
 	return &conn{
 		transport:    tr,
-		wsess:        wsess,
+		session:      sess,
 		privKey:      privKey,
 		localPeer:    localPeer,
 		remotePeer:   remotePeer,
@@ -56,24 +56,18 @@ func newConn(tr tpt.Transport, wsess *webtransport.Session, privKey ic.PrivKey,
 
 var _ tpt.CapableConn = &conn{}
 
-func (c *conn) Close() error {
-	return c.wsess.Close()
-}
-
-func (c *conn) IsClosed() bool {
-	panic("implement me")
-}
-
 func (c *conn) OpenStream(ctx context.Context) (network.MuxedStream, error) {
-	str, err := c.wsess.OpenStreamSync(ctx)
+	str, err := c.session.OpenStreamSync(ctx)
 	return &stream{str}, err
 }
 
 func (c *conn) AcceptStream() (network.MuxedStream, error) {
-	str, err := c.wsess.AcceptStream(context.Background())
+	str, err := c.session.AcceptStream(context.Background())
 	return &stream{str}, err
 }
 
+func (c *conn) Close() error                  { return c.session.Close() }
+func (c *conn) IsClosed() bool                { return c.session.Context().Err() != nil }
 func (c *conn) LocalPeer() peer.ID            { return c.localPeer }
 func (c *conn) LocalPrivateKey() ic.PrivKey   { return c.privKey }
 func (c *conn) RemotePeer() peer.ID           { return c.remotePeer }
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 7ddcff9ffa..397664c5b6 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -89,12 +89,15 @@ func TestTransport(t *testing.T) {
 
 	conn, err := ln.Accept()
 	require.NoError(t, err)
+	require.False(t, conn.IsClosed())
 	str, err := conn.AcceptStream()
 	require.NoError(t, err)
 	data, err := io.ReadAll(str)
 	require.NoError(t, err)
 	require.Equal(t, "foobar", string(data))
 	require.Equal(t, <-addrChan, conn.LocalMultiaddr())
+	require.NoError(t, conn.Close())
+	require.True(t, conn.IsClosed())
 }
 
 func TestHashVerification(t *testing.T) {

From ecc1eff49d77ac8e025662f9aed6d227f4d23e1d Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 21:48:20 +0000
Subject: [PATCH 29/53] refactor the conn constructor

---
 p2p/transport/webtransport/conn.go      | 64 ++++++-------------------
 p2p/transport/webtransport/listener.go  | 32 +++++++++----
 p2p/transport/webtransport/transport.go | 47 ++++++++++++++----
 3 files changed, 74 insertions(+), 69 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index 2efc263fbf..a8f73b079d 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -2,60 +2,32 @@ package libp2pwebtransport
 
 import (
 	"context"
-	"fmt"
-
-	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/network"
-	"github.com/libp2p/go-libp2p-core/peer"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
 	"github.com/marten-seemann/webtransport-go"
-	ma "github.com/multiformats/go-multiaddr"
 )
 
 type conn struct {
+	connSecurityMultiaddrs
+
 	transport tpt.Transport
 	session   *webtransport.Session
 
-	localPeer, remotePeer peer.ID
-	local, remote         ma.Multiaddr
-	privKey               ic.PrivKey
-	remotePubKey          ic.PubKey
-	scope                 network.ConnScope
+	scope network.ConnScope
 }
 
-func newConn(tr tpt.Transport, sess *webtransport.Session, privKey ic.PrivKey, remotePubKey ic.PubKey, scope network.ConnScope) (*conn, error) {
-	localPeer, err := peer.IDFromPrivateKey(privKey)
-	if err != nil {
-		return nil, err
-	}
-	remotePeer, err := peer.IDFromPublicKey(remotePubKey)
-	if err != nil {
-		return nil, err
-	}
-	local, err := toWebtransportMultiaddr(sess.LocalAddr())
-	if err != nil {
-		return nil, fmt.Errorf("error determiniting local addr: %w", err)
-	}
-	remote, err := toWebtransportMultiaddr(sess.RemoteAddr())
-	if err != nil {
-		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
-	}
+var _ tpt.CapableConn = &conn{}
+
+func newConn(tr tpt.Transport, sess *webtransport.Session, sconn connSecurityMultiaddrs, scope network.ConnScope) *conn {
 	return &conn{
-		transport:    tr,
-		session:      sess,
-		privKey:      privKey,
-		localPeer:    localPeer,
-		remotePeer:   remotePeer,
-		remotePubKey: remotePubKey,
-		local:        local,
-		remote:       remote,
-		scope:        scope,
-	}, nil
+		connSecurityMultiaddrs: sconn,
+		transport:              tr,
+		session:                sess,
+		scope:                  scope,
+	}
 }
 
-var _ tpt.CapableConn = &conn{}
-
 func (c *conn) OpenStream(ctx context.Context) (network.MuxedStream, error) {
 	str, err := c.session.OpenStreamSync(ctx)
 	return &stream{str}, err
@@ -66,13 +38,7 @@ func (c *conn) AcceptStream() (network.MuxedStream, error) {
 	return &stream{str}, err
 }
 
-func (c *conn) Close() error                  { return c.session.Close() }
-func (c *conn) IsClosed() bool                { return c.session.Context().Err() != nil }
-func (c *conn) LocalPeer() peer.ID            { return c.localPeer }
-func (c *conn) LocalPrivateKey() ic.PrivKey   { return c.privKey }
-func (c *conn) RemotePeer() peer.ID           { return c.remotePeer }
-func (c *conn) RemotePublicKey() ic.PubKey    { return c.remotePubKey }
-func (c *conn) LocalMultiaddr() ma.Multiaddr  { return c.local }
-func (c *conn) RemoteMultiaddr() ma.Multiaddr { return c.remote }
-func (c *conn) Scope() network.ConnScope      { return c.scope }
-func (c *conn) Transport() tpt.Transport      { return c.transport }
+func (c *conn) Close() error             { return c.session.Close() }
+func (c *conn) IsClosed() bool           { return c.session.Context().Err() != nil }
+func (c *conn) Scope() network.ConnScope { return c.scope }
+func (c *conn) Transport() tpt.Transport { return c.transport }
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 739c230ca6..73794f2f3c 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
+	"fmt"
 	"net"
 	"net/http"
 	"time"
@@ -140,15 +141,8 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	c, err := newConn(l.transport, sess, sconn.LocalPrivateKey(), sconn.RemotePublicKey(), connScope)
-	if err != nil {
-		sess.Close()
-		connScope.Done()
-		return
-	}
-
 	// TODO: think about what happens when this channel fills up
-	l.queue <- c
+	l.queue <- newConn(l.transport, sess, sconn, connScope)
 }
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
@@ -160,12 +154,30 @@ func (l *listener) Accept() (tpt.CapableConn, error) {
 	}
 }
 
-func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (network.ConnSecurity, error) {
+func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (connSecurityMultiaddrs, error) {
+	local, err := toWebtransportMultiaddr(sess.LocalAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting local addr: %w", err)
+	}
+	remote, err := toWebtransportMultiaddr(sess.RemoteAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
+	}
+
 	str, err := sess.AcceptStream(ctx)
 	if err != nil {
 		return nil, err
 	}
-	return l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
+	c, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
+	if err != nil {
+		return nil, err
+	}
+
+	return &connSecurityMultiaddrsImpl{
+		ConnSecurity: c,
+		local:        local,
+		remote:       remote,
+	}, nil
 }
 
 func (l *listener) Addr() net.Addr {
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 640221a9b1..9fae27f27a 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	manet "github.com/multiformats/go-multiaddr/net"
 	"io"
 	"sync"
 	"time"
@@ -22,6 +21,7 @@ import (
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multihash"
 )
 
@@ -31,6 +31,21 @@ const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
 const certValidity = 14 * 24 * time.Hour
 
+type connSecurityMultiaddrs interface {
+	network.ConnMultiaddrs
+	network.ConnSecurity
+}
+
+type connSecurityMultiaddrsImpl struct {
+	network.ConnSecurity
+	local, remote ma.Multiaddr
+}
+
+var _ connSecurityMultiaddrs = &connSecurityMultiaddrsImpl{}
+
+func (c *connSecurityMultiaddrsImpl) LocalMultiaddr() ma.Multiaddr  { return c.local }
+func (c *connSecurityMultiaddrsImpl) RemoteMultiaddr() ma.Multiaddr { return c.remote }
+
 type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
@@ -104,13 +119,8 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		scope.Done()
 		return nil, err
 	}
-	c, err := newConn(t, sess, t.privKey, sconn.RemotePublicKey(), scope)
-	if err != nil {
-		sess.Close()
-		scope.Done()
-		return nil, err
-	}
-	return c, nil
+
+	return newConn(t, sess, sconn, scope), nil
 }
 
 func (t *transport) dial(ctx context.Context, addr string) (*webtransport.Session, error) {
@@ -125,7 +135,16 @@ func (t *transport) dial(ctx context.Context, addr string) (*webtransport.Sessio
 	return sess, err
 }
 
-func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p peer.ID, certHashes []multihash.DecodedMultihash) (network.ConnSecurity, error) {
+func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p peer.ID, certHashes []multihash.DecodedMultihash) (connSecurityMultiaddrs, error) {
+	local, err := toWebtransportMultiaddr(sess.LocalAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting local addr: %w", err)
+	}
+	remote, err := toWebtransportMultiaddr(sess.RemoteAddr())
+	if err != nil {
+		return nil, fmt.Errorf("error determiniting remote addr: %w", err)
+	}
+
 	str, err := sess.OpenStreamSync(ctx)
 	if err != nil {
 		return nil, err
@@ -144,7 +163,15 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 	if err != nil {
 		return nil, fmt.Errorf("failed to marshal WebTransport protobuf: %w", err)
 	}
-	return t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: sess}, p, msgBytes)
+	c, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: sess}, p, msgBytes)
+	if err != nil {
+		return nil, err
+	}
+	return &connSecurityMultiaddrsImpl{
+		ConnSecurity: c,
+		local:        local,
+		remote:       remote,
+	}, nil
 }
 
 func (t *transport) checkEarlyData(b []byte) error {

From 2c6fc83df04675e5cef93d6461d37bf898bcd6c8 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 22:00:49 +0000
Subject: [PATCH 30/53] implement connection gating for dials

---
 .../mock_connection_gater_test.go             | 109 ++++++++++++++++++
 p2p/transport/webtransport/transport.go       |  10 +-
 p2p/transport/webtransport/transport_test.go  |  57 +++++++--
 3 files changed, 164 insertions(+), 12 deletions(-)
 create mode 100644 p2p/transport/webtransport/mock_connection_gater_test.go

diff --git a/p2p/transport/webtransport/mock_connection_gater_test.go b/p2p/transport/webtransport/mock_connection_gater_test.go
new file mode 100644
index 0000000000..071ed7494f
--- /dev/null
+++ b/p2p/transport/webtransport/mock_connection_gater_test.go
@@ -0,0 +1,109 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/libp2p/go-libp2p-core/connmgr (interfaces: ConnectionGater)
+
+// Package libp2pwebtransport_test is a generated GoMock package.
+package libp2pwebtransport_test
+
+import (
+	reflect "reflect"
+
+	gomock "github.com/golang/mock/gomock"
+	control "github.com/libp2p/go-libp2p-core/control"
+	network "github.com/libp2p/go-libp2p-core/network"
+	peer "github.com/libp2p/go-libp2p-core/peer"
+	multiaddr "github.com/multiformats/go-multiaddr"
+)
+
+// MockConnectionGater is a mock of ConnectionGater interface.
+type MockConnectionGater struct {
+	ctrl     *gomock.Controller
+	recorder *MockConnectionGaterMockRecorder
+}
+
+// MockConnectionGaterMockRecorder is the mock recorder for MockConnectionGater.
+type MockConnectionGaterMockRecorder struct {
+	mock *MockConnectionGater
+}
+
+// NewMockConnectionGater creates a new mock instance.
+func NewMockConnectionGater(ctrl *gomock.Controller) *MockConnectionGater {
+	mock := &MockConnectionGater{ctrl: ctrl}
+	mock.recorder = &MockConnectionGaterMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockConnectionGater) EXPECT() *MockConnectionGaterMockRecorder {
+	return m.recorder
+}
+
+// InterceptAccept mocks base method.
+func (m *MockConnectionGater) InterceptAccept(arg0 network.ConnMultiaddrs) bool {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "InterceptAccept", arg0)
+	ret0, _ := ret[0].(bool)
+	return ret0
+}
+
+// InterceptAccept indicates an expected call of InterceptAccept.
+func (mr *MockConnectionGaterMockRecorder) InterceptAccept(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "InterceptAccept", reflect.TypeOf((*MockConnectionGater)(nil).InterceptAccept), arg0)
+}
+
+// InterceptAddrDial mocks base method.
+func (m *MockConnectionGater) InterceptAddrDial(arg0 peer.ID, arg1 multiaddr.Multiaddr) bool {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "InterceptAddrDial", arg0, arg1)
+	ret0, _ := ret[0].(bool)
+	return ret0
+}
+
+// InterceptAddrDial indicates an expected call of InterceptAddrDial.
+func (mr *MockConnectionGaterMockRecorder) InterceptAddrDial(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "InterceptAddrDial", reflect.TypeOf((*MockConnectionGater)(nil).InterceptAddrDial), arg0, arg1)
+}
+
+// InterceptPeerDial mocks base method.
+func (m *MockConnectionGater) InterceptPeerDial(arg0 peer.ID) bool {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "InterceptPeerDial", arg0)
+	ret0, _ := ret[0].(bool)
+	return ret0
+}
+
+// InterceptPeerDial indicates an expected call of InterceptPeerDial.
+func (mr *MockConnectionGaterMockRecorder) InterceptPeerDial(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "InterceptPeerDial", reflect.TypeOf((*MockConnectionGater)(nil).InterceptPeerDial), arg0)
+}
+
+// InterceptSecured mocks base method.
+func (m *MockConnectionGater) InterceptSecured(arg0 network.Direction, arg1 peer.ID, arg2 network.ConnMultiaddrs) bool {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "InterceptSecured", arg0, arg1, arg2)
+	ret0, _ := ret[0].(bool)
+	return ret0
+}
+
+// InterceptSecured indicates an expected call of InterceptSecured.
+func (mr *MockConnectionGaterMockRecorder) InterceptSecured(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "InterceptSecured", reflect.TypeOf((*MockConnectionGater)(nil).InterceptSecured), arg0, arg1, arg2)
+}
+
+// InterceptUpgraded mocks base method.
+func (m *MockConnectionGater) InterceptUpgraded(arg0 network.Conn) (bool, control.DisconnectReason) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "InterceptUpgraded", arg0)
+	ret0, _ := ret[0].(bool)
+	ret1, _ := ret[1].(control.DisconnectReason)
+	return ret0, ret1
+}
+
+// InterceptUpgraded indicates an expected call of InterceptUpgraded.
+func (mr *MockConnectionGaterMockRecorder) InterceptUpgraded(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "InterceptUpgraded", reflect.TypeOf((*MockConnectionGater)(nil).InterceptUpgraded), arg0)
+}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 9fae27f27a..834412df36 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -10,6 +10,7 @@ import (
 
 	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
 
+	"github.com/libp2p/go-libp2p-core/connmgr"
 	ic "github.com/libp2p/go-libp2p-core/crypto"
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
@@ -53,6 +54,7 @@ type transport struct {
 	dialer webtransport.Dialer
 
 	rcmgr network.ResourceManager
+	gater connmgr.ConnectionGater
 
 	listenOnce    sync.Once
 	listenOnceErr error
@@ -64,7 +66,7 @@ type transport struct {
 var _ tpt.Transport = &transport{}
 var _ io.Closer = &transport{}
 
-func New(key ic.PrivKey, rcmgr network.ResourceManager) (tpt.Transport, error) {
+func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceManager) (tpt.Transport, error) {
 	id, err := peer.IDFromPrivateKey(key)
 	if err != nil {
 		return nil, err
@@ -73,6 +75,7 @@ func New(key ic.PrivKey, rcmgr network.ResourceManager) (tpt.Transport, error) {
 		pid:     id,
 		privKey: key,
 		rcmgr:   rcmgr,
+		gater:   gater,
 		dialer: webtransport.Dialer{
 			RoundTripper: &http3.RoundTripper{
 				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
@@ -119,6 +122,11 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		scope.Done()
 		return nil, err
 	}
+	if t.gater != nil && !t.gater.InterceptSecured(network.DirOutbound, p, sconn) {
+		// TODO: can we close with a specific error here?
+		sess.Close()
+		return nil, fmt.Errorf("secured connection gated")
+	}
 
 	return newConn(t, sess, sconn, scope), nil
 }
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 397664c5b6..ff73e0f9d8 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -56,7 +56,7 @@ func extractCertHashes(addr ma.Multiaddr) []string {
 
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
-	tr, err := libp2pwebtransport.New(serverKey, network.NullResourceManager)
+	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
@@ -66,7 +66,7 @@ func TestTransport(t *testing.T) {
 	addrChan := make(chan ma.Multiaddr)
 	go func() {
 		_, clientKey := newIdentity(t)
-		tr2, err := libp2pwebtransport.New(clientKey, network.NullResourceManager)
+		tr2, err := libp2pwebtransport.New(clientKey, nil, network.NullResourceManager)
 		require.NoError(t, err)
 		defer tr2.(io.Closer).Close()
 
@@ -102,7 +102,7 @@ func TestTransport(t *testing.T) {
 
 func TestHashVerification(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
-	tr, err := libp2pwebtransport.New(serverKey, network.NullResourceManager)
+	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
@@ -115,7 +115,7 @@ func TestHashVerification(t *testing.T) {
 	}()
 
 	_, clientKey := newIdentity(t)
-	tr2, err := libp2pwebtransport.New(clientKey, network.NullResourceManager)
+	tr2, err := libp2pwebtransport.New(clientKey, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr2.(io.Closer).Close()
 
@@ -161,7 +161,7 @@ func TestCanDial(t *testing.T) {
 	}
 
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
+	tr, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -187,7 +187,7 @@ func TestListenAddrValidity(t *testing.T) {
 	}
 
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
+	tr, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -204,7 +204,7 @@ func TestListenAddrValidity(t *testing.T) {
 
 func TestListenerAddrs(t *testing.T) {
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key, network.NullResourceManager)
+	tr, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -227,7 +227,7 @@ func TestResourceManagerDialing(t *testing.T) {
 	p := peer.ID("foobar")
 
 	_, key := newIdentity(t)
-	tr, err := libp2pwebtransport.New(key, rcmgr)
+	tr, err := libp2pwebtransport.New(key, nil, rcmgr)
 	require.NoError(t, err)
 	defer tr.(io.Closer).Close()
 
@@ -242,7 +242,7 @@ func TestResourceManagerDialing(t *testing.T) {
 
 func TestResourceManagerListening(t *testing.T) {
 	clientID, key := newIdentity(t)
-	cl, err := libp2pwebtransport.New(key, network.NullResourceManager)
+	cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
 	require.NoError(t, err)
 	defer cl.(io.Closer).Close()
 
@@ -251,7 +251,7 @@ func TestResourceManagerListening(t *testing.T) {
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 		rcmgr := mocknetwork.NewMockResourceManager(ctrl)
-		tr, err := libp2pwebtransport.New(key, rcmgr)
+		tr, err := libp2pwebtransport.New(key, nil, rcmgr)
 		require.NoError(t, err)
 		ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 		require.NoError(t, err)
@@ -277,7 +277,7 @@ func TestResourceManagerListening(t *testing.T) {
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 		rcmgr := mocknetwork.NewMockResourceManager(ctrl)
-		tr, err := libp2pwebtransport.New(key, rcmgr)
+		tr, err := libp2pwebtransport.New(key, nil, rcmgr)
 		require.NoError(t, err)
 		ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 		require.NoError(t, err)
@@ -305,3 +305,38 @@ func TestResourceManagerListening(t *testing.T) {
 		}
 	})
 }
+
+// TODO: unify somehow. We do the same in libp2pquic.
+//go:generate sh -c "mockgen -package libp2pwebtransport_test -destination mock_connection_gater_test.go github.com/libp2p/go-libp2p-core/connmgr ConnectionGater && goimports -w mock_connection_gater_test.go"
+
+func TestConnectionGaterDialing(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	connGater := NewMockConnectionGater(ctrl)
+
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	defer ln.Close()
+
+	connGater.EXPECT().InterceptSecured(network.DirOutbound, serverID, gomock.Any()).Do(func(_ network.Direction, _ peer.ID, addrs network.ConnMultiaddrs) {
+		expected := ln.Multiaddr()
+		for {
+			_, err := expected.ValueForProtocol(ma.P_CERTHASH)
+			if err != nil {
+				break
+			}
+			expected, _ = ma.SplitLast(expected)
+		}
+		require.Equal(t, expected, addrs.RemoteMultiaddr())
+	})
+	_, key := newIdentity(t)
+	cl, err := libp2pwebtransport.New(key, connGater, network.NullResourceManager)
+	require.NoError(t, err)
+	defer cl.(io.Closer).Close()
+	_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+	require.EqualError(t, err, "secured connection gated")
+}

From a508e940049967c94b0a74d008a31f83eb32a55b Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 22:21:26 +0000
Subject: [PATCH 31/53] implement InterceptAccept connection gating

---
 p2p/transport/webtransport/listener.go       | 14 ++++--
 p2p/transport/webtransport/transport.go      | 17 +++++---
 p2p/transport/webtransport/transport_test.go | 46 ++++++++++++++++----
 3 files changed, 57 insertions(+), 20 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 73794f2f3c..9409612dcf 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/libp2p/go-libp2p-core/connmgr"
 	"github.com/libp2p/go-libp2p-core/network"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
@@ -30,6 +31,7 @@ type listener struct {
 	noise       *noise.Transport
 	certManager *certManager
 	rcmgr       network.ResourceManager
+	gater       connmgr.ConnectionGater
 
 	server webtransport.Server
 
@@ -46,7 +48,7 @@ type listener struct {
 
 var _ tpt.Listener = &listener{}
 
-func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager, rcmgr network.ResourceManager) (tpt.Listener, error) {
+func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager, gater connmgr.ConnectionGater, rcmgr network.ResourceManager) (tpt.Listener, error) {
 	network, addr, err := manet.DialArgs(laddr)
 	if err != nil {
 		return nil, err
@@ -68,6 +70,7 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 		noise:        noise,
 		certManager:  certManager,
 		rcmgr:        rcmgr,
+		gater:        gater,
 		queue:        make(chan tpt.CapableConn, queueLen),
 		serverClosed: make(chan struct{}),
 		addr:         udpConn.LocalAddr(),
@@ -106,6 +109,10 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
+	if l.gater != nil && !l.gater.InterceptAccept(&connMultiaddrs{local: l.multiaddr, remote: remoteMultiaddr}) {
+		w.WriteHeader(http.StatusForbidden)
+		return
+	}
 
 	connScope, err := l.rcmgr.OpenConnection(network.DirInbound, false, remoteMultiaddr)
 	if err != nil {
@@ -174,9 +181,8 @@ func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (c
 	}
 
 	return &connSecurityMultiaddrsImpl{
-		ConnSecurity: c,
-		local:        local,
-		remote:       remote,
+		ConnSecurity:   c,
+		ConnMultiaddrs: &connMultiaddrs{local: local, remote: remote},
 	}, nil
 }
 
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 834412df36..c20c4c47ed 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -39,13 +39,17 @@ type connSecurityMultiaddrs interface {
 
 type connSecurityMultiaddrsImpl struct {
 	network.ConnSecurity
+	network.ConnMultiaddrs
+}
+
+type connMultiaddrs struct {
 	local, remote ma.Multiaddr
 }
 
-var _ connSecurityMultiaddrs = &connSecurityMultiaddrsImpl{}
+var _ network.ConnMultiaddrs = &connMultiaddrs{}
 
-func (c *connSecurityMultiaddrsImpl) LocalMultiaddr() ma.Multiaddr  { return c.local }
-func (c *connSecurityMultiaddrsImpl) RemoteMultiaddr() ma.Multiaddr { return c.remote }
+func (c *connMultiaddrs) LocalMultiaddr() ma.Multiaddr  { return c.local }
+func (c *connMultiaddrs) RemoteMultiaddr() ma.Multiaddr { return c.remote }
 
 type transport struct {
 	privKey ic.PrivKey
@@ -176,9 +180,8 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 		return nil, err
 	}
 	return &connSecurityMultiaddrsImpl{
-		ConnSecurity: c,
-		local:        local,
-		remote:       remote,
+		ConnSecurity:   c,
+		ConnMultiaddrs: &connMultiaddrs{local: local, remote: remote},
 	}, nil
 }
 
@@ -225,7 +228,7 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 	if t.listenOnceErr != nil {
 		return nil, t.listenOnceErr
 	}
-	return newListener(laddr, t, t.noise, t.certManager, t.rcmgr)
+	return newListener(laddr, t, t.noise, t.certManager, t.gater, t.rcmgr)
 }
 
 func (t *transport) Protocols() []int {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index ff73e0f9d8..c317adbd63 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -54,6 +54,16 @@ func extractCertHashes(addr ma.Multiaddr) []string {
 	return certHashesStr
 }
 
+func stripCertHashes(addr ma.Multiaddr) ma.Multiaddr {
+	for {
+		_, err := addr.ValueForProtocol(ma.P_CERTHASH)
+		if err != nil {
+			return addr
+		}
+		addr, _ = ma.SplitLast(addr)
+	}
+}
+
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
@@ -323,15 +333,7 @@ func TestConnectionGaterDialing(t *testing.T) {
 	defer ln.Close()
 
 	connGater.EXPECT().InterceptSecured(network.DirOutbound, serverID, gomock.Any()).Do(func(_ network.Direction, _ peer.ID, addrs network.ConnMultiaddrs) {
-		expected := ln.Multiaddr()
-		for {
-			_, err := expected.ValueForProtocol(ma.P_CERTHASH)
-			if err != nil {
-				break
-			}
-			expected, _ = ma.SplitLast(expected)
-		}
-		require.Equal(t, expected, addrs.RemoteMultiaddr())
+		require.Equal(t, stripCertHashes(ln.Multiaddr()), addrs.RemoteMultiaddr())
 	})
 	_, key := newIdentity(t)
 	cl, err := libp2pwebtransport.New(key, connGater, network.NullResourceManager)
@@ -340,3 +342,29 @@ func TestConnectionGaterDialing(t *testing.T) {
 	_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
 	require.EqualError(t, err, "secured connection gated")
 }
+
+func TestConnectionGaterInterceptAccept(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	connGater := NewMockConnectionGater(ctrl)
+
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey, connGater, network.NullResourceManager)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	defer ln.Close()
+
+	connGater.EXPECT().InterceptAccept(gomock.Any()).Do(func(addrs network.ConnMultiaddrs) {
+		require.Equal(t, stripCertHashes(ln.Multiaddr()), addrs.LocalMultiaddr())
+		require.NotEqual(t, stripCertHashes(ln.Multiaddr()), addrs.RemoteMultiaddr())
+	})
+
+	_, key := newIdentity(t)
+	cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
+	require.NoError(t, err)
+	defer cl.(io.Closer).Close()
+	_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+	require.EqualError(t, err, "received status 403")
+}

From 7e8ca3ac06fbe0c514d3a7f95758b69c8fd33074 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 9 Jul 2022 22:25:58 +0000
Subject: [PATCH 32/53] implement InterceptSecured for accepted connections

---
 p2p/transport/webtransport/listener.go       |  7 ++++
 p2p/transport/webtransport/transport_test.go | 40 ++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 9409612dcf..bb762f7d7a 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -141,6 +141,13 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	cancel()
 
+	if l.gater != nil && !l.gater.InterceptSecured(network.DirInbound, sconn.RemotePeer(), sconn) {
+		// TODO: can we close with a specific error here?
+		sess.Close()
+		connScope.Done()
+		return
+	}
+
 	if err := connScope.SetPeer(sconn.RemotePeer()); err != nil {
 		log.Debugw("resource manager blocked incoming connection for peer", "peer", sconn.RemotePeer(), "addr", r.RemoteAddr, "error", err)
 		sess.Close()
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index c317adbd63..8540cabd9b 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -368,3 +368,43 @@ func TestConnectionGaterInterceptAccept(t *testing.T) {
 	_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
 	require.EqualError(t, err, "received status 403")
 }
+
+func TestConnectionGaterInterceptSecured(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	connGater := NewMockConnectionGater(ctrl)
+
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey, connGater, network.NullResourceManager)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	defer ln.Close()
+
+	clientID, key := newIdentity(t)
+	cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
+	require.NoError(t, err)
+	defer cl.(io.Closer).Close()
+
+	connGater.EXPECT().InterceptAccept(gomock.Any()).Return(true)
+	connGater.EXPECT().InterceptSecured(network.DirInbound, clientID, gomock.Any()).Do(func(_ network.Direction, _ peer.ID, addrs network.ConnMultiaddrs) {
+		require.Equal(t, stripCertHashes(ln.Multiaddr()), addrs.LocalMultiaddr())
+		require.NotEqual(t, stripCertHashes(ln.Multiaddr()), addrs.RemoteMultiaddr())
+	})
+	// The handshake will complete, but the server will immediately close the connection.
+	conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+	require.NoError(t, err)
+	defer conn.Close()
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		_, err = conn.AcceptStream()
+		require.Error(t, err)
+	}()
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		t.Fatal("timeout")
+	}
+}

From 851e6ba1716c978e91c48966bf35f476755d0d7f Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 10 Jul 2022 12:36:39 +0000
Subject: [PATCH 33/53] verify the hash of the server's certificate (#16)

---
 .../webtransport/cert_manager_test.go         |  14 +-
 p2p/transport/webtransport/crypto.go          |  50 ++++++-
 p2p/transport/webtransport/crypto_test.go     | 128 ++++++++++++++++++
 p2p/transport/webtransport/transport.go       |  24 ++--
 p2p/transport/webtransport/transport_test.go  |   1 +
 5 files changed, 199 insertions(+), 18 deletions(-)
 create mode 100644 p2p/transport/webtransport/crypto_test.go

diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
index 3d9c881d4e..cb55a56ddc 100644
--- a/p2p/transport/webtransport/cert_manager_test.go
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -1,16 +1,22 @@
 package libp2pwebtransport
 
 import (
-	"github.com/multiformats/go-multibase"
-	"github.com/multiformats/go-multihash"
+	"crypto/sha256"
+	"crypto/tls"
 	"os"
 	"testing"
 	"time"
 
 	ma "github.com/multiformats/go-multiaddr"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 	"github.com/stretchr/testify/require"
 )
 
+func certificateHashFromTLSConfig(c *tls.Config) [32]byte {
+	return sha256.Sum256(c.Certificates[0].Certificate[0])
+}
+
 func splitMultiaddr(addr ma.Multiaddr) []ma.Component {
 	var components []ma.Component
 	ma.ForEach(addr, func(c ma.Component) bool {
@@ -44,7 +50,7 @@ func TestInitialCert(t *testing.T) {
 	components := splitMultiaddr(addr)
 	require.Len(t, components, 1)
 	require.Equal(t, ma.P_CERTHASH, components[0].Protocol().Code)
-	hash := certificateHash(conf)
+	hash := certificateHashFromTLSConfig(conf)
 	require.Equal(t, hash[:], certHashFromComponent(t, components[0]))
 }
 
@@ -71,6 +77,6 @@ func TestCertRenewal(t *testing.T) {
 	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, certValidity/2, 10*time.Millisecond)
 	newConf := m.GetConfig()
 	// check that the new config now matches the second component
-	hash := certificateHash(newConf)
+	hash := certificateHashFromTLSConfig(newConf)
 	require.Equal(t, hash[:], certHashFromComponent(t, components[1]))
 }
diff --git a/p2p/transport/webtransport/crypto.go b/p2p/transport/webtransport/crypto.go
index f30943c6f6..9bb7f7a330 100644
--- a/p2p/transport/webtransport/crypto.go
+++ b/p2p/transport/webtransport/crypto.go
@@ -1,6 +1,7 @@
 package libp2pwebtransport
 
 import (
+	"bytes"
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
@@ -9,13 +10,13 @@ import (
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/binary"
+	"errors"
+	"fmt"
 	"math/big"
 	"time"
-)
 
-func certificateHash(c *tls.Config) [32]byte {
-	return sha256.Sum256(c.Certificates[0].Certificate[0])
-}
+	"github.com/multiformats/go-multihash"
+)
 
 func getTLSConf(start, end time.Time) (*tls.Config, error) {
 	cert, priv, err := generateCert(start, end)
@@ -61,3 +62,44 @@ func generateCert(start, end time.Time) (*x509.Certificate, *ecdsa.PrivateKey, e
 	}
 	return ca, caPrivateKey, nil
 }
+
+func verifyRawCerts(rawCerts [][]byte, certHashes []multihash.DecodedMultihash) error {
+	if len(rawCerts) < 1 {
+		return errors.New("no cert")
+	}
+	leaf := rawCerts[len(rawCerts)-1]
+	// The W3C WebTransport specification currently only allows SHA-256 certificates for serverCertificateHashes.
+	hash := sha256.Sum256(leaf)
+	var verified bool
+	for _, h := range certHashes {
+		if h.Code == multihash.SHA2_256 && bytes.Equal(h.Digest, hash[:]) {
+			verified = true
+			break
+		}
+	}
+	if !verified {
+		digests := make([][]byte, 0, len(certHashes))
+		for _, h := range certHashes {
+			digests = append(digests, h.Digest)
+		}
+		return fmt.Errorf("cert hash not found: %#x (expected: %#x)", hash, digests)
+	}
+
+	cert, err := x509.ParseCertificate(leaf)
+	if err != nil {
+		return err
+	}
+	// TODO: is this the best (and complete?) way to identify RSA certificates?
+	switch cert.SignatureAlgorithm {
+	case x509.SHA1WithRSA, x509.SHA256WithRSA, x509.SHA384WithRSA, x509.SHA512WithRSA, x509.MD2WithRSA, x509.MD5WithRSA:
+		return errors.New("cert uses RSA")
+	}
+	if l := cert.NotAfter.Sub(cert.NotBefore); l > 14*24*time.Hour {
+		return fmt.Errorf("cert must not be valid for longer than 14 days (NotBefore: %s, NotAfter: %s, Length: %s)", cert.NotBefore, cert.NotAfter, l)
+	}
+	now := time.Now()
+	if now.Before(cert.NotBefore) || now.After(cert.NotAfter) {
+		return fmt.Errorf("cert not valid (NotBefore: %s, NotAfter: %s)", cert.NotBefore, cert.NotAfter)
+	}
+	return nil
+}
diff --git a/p2p/transport/webtransport/crypto_test.go b/p2p/transport/webtransport/crypto_test.go
new file mode 100644
index 0000000000..c69c578b92
--- /dev/null
+++ b/p2p/transport/webtransport/crypto_test.go
@@ -0,0 +1,128 @@
+package libp2pwebtransport
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"fmt"
+	"math/big"
+	mrand "math/rand"
+	"testing"
+	"time"
+
+	"github.com/multiformats/go-multihash"
+	"github.com/stretchr/testify/require"
+)
+
+func sha256Multihash(t *testing.T, b []byte) multihash.DecodedMultihash {
+	t.Helper()
+	hash := sha256.Sum256(b)
+	h, err := multihash.Encode(hash[:], multihash.SHA2_256)
+	require.NoError(t, err)
+	dh, err := multihash.Decode(h)
+	require.NoError(t, err)
+	return *dh
+}
+
+func generateCertWithKey(t *testing.T, key crypto.PrivateKey, start, end time.Time) *x509.Certificate {
+	t.Helper()
+	certTempl := &x509.Certificate{
+		SerialNumber:          big.NewInt(int64(mrand.Uint64())),
+		Subject:               pkix.Name{},
+		NotBefore:             start,
+		NotAfter:              end,
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+	}
+	caBytes, err := x509.CreateCertificate(rand.Reader, certTempl, certTempl, key.(interface{ Public() crypto.PublicKey }).Public(), key)
+	require.NoError(t, err)
+	ca, err := x509.ParseCertificate(caBytes)
+	require.NoError(t, err)
+	return ca
+}
+
+func TestCertificateVerification(t *testing.T) {
+	now := time.Now()
+	ecdsaKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	require.NoError(t, err)
+	rsaKey, err := rsa.GenerateKey(rand.Reader, 1024)
+	require.NoError(t, err)
+
+	t.Run("accepting a valid cert", func(t *testing.T) {
+		validCert := generateCertWithKey(t, ecdsaKey, now, now.Add(14*24*time.Hour))
+		require.NoError(t, verifyRawCerts([][]byte{validCert.Raw}, []multihash.DecodedMultihash{sha256Multihash(t, validCert.Raw)}))
+	})
+
+	for _, tc := range [...]struct {
+		name   string
+		cert   *x509.Certificate
+		errStr string
+	}{
+		{
+			name:   "validitity period too long",
+			cert:   generateCertWithKey(t, ecdsaKey, now, now.Add(15*24*time.Hour)),
+			errStr: "cert must not be valid for longer than 14 days",
+		},
+		{
+			name:   "uses RSA key",
+			cert:   generateCertWithKey(t, rsaKey, now, now.Add(14*24*time.Hour)),
+			errStr: "RSA",
+		},
+		{
+			name:   "expired certificate",
+			cert:   generateCertWithKey(t, ecdsaKey, now.Add(-14*24*time.Hour), now),
+			errStr: "cert not valid",
+		},
+		{
+			name:   "not yet valid",
+			cert:   generateCertWithKey(t, ecdsaKey, now.Add(time.Hour), now.Add(time.Hour+14*24*time.Hour)),
+			errStr: "cert not valid",
+		},
+	} {
+		tc := tc
+		t.Run(fmt.Sprintf("rejecting invalid certificates: %s", tc.name), func(t *testing.T) {
+			err := verifyRawCerts([][]byte{tc.cert.Raw}, []multihash.DecodedMultihash{sha256Multihash(t, tc.cert.Raw)})
+			require.Error(t, err)
+			require.Contains(t, err.Error(), tc.errStr)
+		})
+	}
+
+	for _, tc := range [...]struct {
+		name   string
+		certs  [][]byte
+		hashes []multihash.DecodedMultihash
+		errStr string
+	}{
+		{
+			name:   "no certificates",
+			hashes: []multihash.DecodedMultihash{sha256Multihash(t, []byte("foobar"))},
+			errStr: "no cert",
+		},
+		{
+			name:   "certificate not parseable",
+			certs:  [][]byte{[]byte("foobar")},
+			hashes: []multihash.DecodedMultihash{sha256Multihash(t, []byte("foobar"))},
+			errStr: "x509: malformed certificate",
+		},
+		{
+			name:   "hash mismatch",
+			certs:  [][]byte{generateCertWithKey(t, ecdsaKey, now, now.Add(15*24*time.Hour)).Raw},
+			hashes: []multihash.DecodedMultihash{sha256Multihash(t, []byte("foobar"))},
+			errStr: "cert hash not found",
+		},
+	} {
+		tc := tc
+		t.Run(fmt.Sprintf("rejecting invalid certificates: %s", tc.name), func(t *testing.T) {
+			err := verifyRawCerts(tc.certs, tc.hashes)
+			require.Error(t, err)
+			require.Contains(t, err.Error(), tc.errStr)
+		})
+	}
+}
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index c20c4c47ed..68938565cb 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -3,6 +3,7 @@ package libp2pwebtransport
 import (
 	"context"
 	"crypto/tls"
+	"crypto/x509"
 	"fmt"
 	"io"
 	"sync"
@@ -55,8 +56,6 @@ type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
 
-	dialer webtransport.Dialer
-
 	rcmgr network.ResourceManager
 	gater connmgr.ConnectionGater
 
@@ -80,11 +79,6 @@ func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceMa
 		privKey: key,
 		rcmgr:   rcmgr,
 		gater:   gater,
-		dialer: webtransport.Dialer{
-			RoundTripper: &http3.RoundTripper{
-				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // TODO: verify certificate,
-			},
-		},
 	}
 	noise, err := noise.New(key, noise.WithEarlyDataHandler(t.checkEarlyData))
 	if err != nil {
@@ -115,7 +109,7 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 		return nil, err
 	}
 
-	sess, err := t.dial(ctx, addr)
+	sess, err := t.dial(ctx, addr, certHashes)
 	if err != nil {
 		scope.Done()
 		return nil, err
@@ -135,9 +129,19 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	return newConn(t, sess, sconn, scope), nil
 }
 
-func (t *transport) dial(ctx context.Context, addr string) (*webtransport.Session, error) {
+func (t *transport) dial(ctx context.Context, addr string, certHashes []multihash.DecodedMultihash) (*webtransport.Session, error) {
 	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
-	rsp, sess, err := t.dialer.Dial(ctx, url, nil)
+	dialer := webtransport.Dialer{
+		RoundTripper: &http3.RoundTripper{
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: true, // this is not insecure. We verify the certificate ourselves.
+				VerifyPeerCertificate: func(rawCerts [][]byte, _ [][]*x509.Certificate) error {
+					return verifyRawCerts(rawCerts, certHashes)
+				},
+			},
+		},
+	}
+	rsp, sess, err := dialer.Dial(ctx, url, nil)
 	if err != nil {
 		return nil, err
 	}
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 8540cabd9b..3bc6d27efc 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -145,6 +145,7 @@ func TestHashVerification(t *testing.T) {
 
 		_, err := tr2.Dial(context.Background(), addr, serverID)
 		require.Error(t, err)
+		require.Contains(t, err.Error(), "CRYPTO_ERROR (0x12a): cert hash not found")
 	})
 
 	t.Run("fails when adding a wrong hash", func(t *testing.T) {

From f0dbd3e7e740b4466b38073e59e13f9b523b6e33 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 10 Jul 2022 13:01:21 +0000
Subject: [PATCH 34/53] fix flaky resource manager test (#19)

---
 p2p/transport/webtransport/transport_test.go | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 3bc6d27efc..d85fcb828f 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -294,23 +294,29 @@ func TestResourceManagerListening(t *testing.T) {
 		require.NoError(t, err)
 		defer ln.Close()
 
+		serverDone := make(chan struct{})
 		scope := mocknetwork.NewMockConnManagementScope(ctrl)
 		rcmgr.EXPECT().OpenConnection(network.DirInbound, false, gomock.Any()).Return(scope, nil)
 		scope.EXPECT().SetPeer(clientID).Return(errors.New("denied"))
-		scope.EXPECT().Done()
+		scope.EXPECT().Done().Do(func() { close(serverDone) })
 
 		// The handshake will complete, but the server will immediately close the connection.
 		conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
 		require.NoError(t, err)
 		defer conn.Close()
-		done := make(chan struct{})
+		clientDone := make(chan struct{})
 		go func() {
-			defer close(done)
+			defer close(clientDone)
 			_, err = conn.AcceptStream()
 			require.Error(t, err)
 		}()
 		select {
-		case <-done:
+		case <-clientDone:
+		case <-time.After(5 * time.Second):
+			t.Fatal("timeout")
+		}
+		select {
+		case <-serverDone:
 		case <-time.After(5 * time.Second):
 			t.Fatal("timeout")
 		}

From d626e806968e1014a268d13d00a89290a2b17e58 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 10 Jul 2022 20:49:27 +0000
Subject: [PATCH 35/53] move connection interface to conn.go

---
 p2p/transport/webtransport/conn.go      | 21 +++++++++++++++++++++
 p2p/transport/webtransport/transport.go | 19 -------------------
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index a8f73b079d..409cea3383 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -2,12 +2,33 @@ package libp2pwebtransport
 
 import (
 	"context"
+
 	"github.com/libp2p/go-libp2p-core/network"
 	tpt "github.com/libp2p/go-libp2p-core/transport"
 
 	"github.com/marten-seemann/webtransport-go"
+	ma "github.com/multiformats/go-multiaddr"
 )
 
+type connSecurityMultiaddrs interface {
+	network.ConnMultiaddrs
+	network.ConnSecurity
+}
+
+type connSecurityMultiaddrsImpl struct {
+	network.ConnSecurity
+	network.ConnMultiaddrs
+}
+
+type connMultiaddrs struct {
+	local, remote ma.Multiaddr
+}
+
+var _ network.ConnMultiaddrs = &connMultiaddrs{}
+
+func (c *connMultiaddrs) LocalMultiaddr() ma.Multiaddr  { return c.local }
+func (c *connMultiaddrs) RemoteMultiaddr() ma.Multiaddr { return c.remote }
+
 type conn struct {
 	connSecurityMultiaddrs
 
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 68938565cb..5438e259b7 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -33,25 +33,6 @@ const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
 const certValidity = 14 * 24 * time.Hour
 
-type connSecurityMultiaddrs interface {
-	network.ConnMultiaddrs
-	network.ConnSecurity
-}
-
-type connSecurityMultiaddrsImpl struct {
-	network.ConnSecurity
-	network.ConnMultiaddrs
-}
-
-type connMultiaddrs struct {
-	local, remote ma.Multiaddr
-}
-
-var _ network.ConnMultiaddrs = &connMultiaddrs{}
-
-func (c *connMultiaddrs) LocalMultiaddr() ma.Multiaddr  { return c.local }
-func (c *connMultiaddrs) RemoteMultiaddr() ma.Multiaddr { return c.remote }
-
 type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID

From ebcb51309fc6825a6f8cde3fb2cb3df316e7822e Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 10 Jul 2022 21:19:25 +0000
Subject: [PATCH 36/53] use a mock clock in cert manager tests (#20)

---
 p2p/transport/webtransport/cert_manager.go    | 17 +++++++------
 .../webtransport/cert_manager_test.go         | 25 +++++++++++--------
 p2p/transport/webtransport/transport.go       | 21 ++++++++++++++--
 3 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index f2a0afd04e..8ca5b85913 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/benbjohnson/clock"
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
@@ -40,6 +41,7 @@ func newCertConfig(start, end time.Time, conf *tls.Config) (*certConfig, error)
 //    We continue to remember the hash of (1) for validation during the Noise handshake for another 4 days,
 //    as the client might be connecting with a cached address.
 type certManager struct {
+	clock     clock.Clock
 	ctx       context.Context
 	ctxCancel context.CancelFunc
 	refCount  sync.WaitGroup
@@ -53,18 +55,22 @@ type certManager struct {
 	addrComp      ma.Multiaddr
 }
 
-func newCertManager(certValidity time.Duration) (*certManager, error) {
+func newCertManager(clock clock.Clock, certValidity time.Duration) (*certManager, error) {
 	m := &certManager{
+		clock:        clock,
 		certValidity: certValidity,
 	}
 	m.ctx, m.ctxCancel = context.WithCancel(context.Background())
 	if err := m.init(); err != nil {
 		return nil, err
 	}
+
+	t := m.clock.Ticker(m.certValidity * 4 / 9) // make sure we're a bit faster than 1/2
 	m.refCount.Add(1)
 	go func() {
 		defer m.refCount.Done()
-		if err := m.background(); err != nil {
+		defer t.Stop()
+		if err := m.background(t); err != nil {
 			log.Fatal(err)
 		}
 	}()
@@ -72,7 +78,7 @@ func newCertManager(certValidity time.Duration) (*certManager, error) {
 }
 
 func (m *certManager) init() error {
-	start := time.Now()
+	start := m.clock.Now()
 	end := start.Add(m.certValidity)
 	tlsConf, err := getTLSConf(start, end)
 	if err != nil {
@@ -86,10 +92,7 @@ func (m *certManager) init() error {
 	return m.cacheAddrComponent()
 }
 
-func (m *certManager) background() error {
-	t := time.NewTicker(m.certValidity * 4 / 9) // make sure we're a bit faster than 1/2
-	defer t.Stop()
-
+func (m *certManager) background(t *clock.Ticker) error {
 	for {
 		select {
 		case <-m.ctx.Done():
diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
index cb55a56ddc..84cb93510a 100644
--- a/p2p/transport/webtransport/cert_manager_test.go
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -3,10 +3,11 @@ package libp2pwebtransport
 import (
 	"crypto/sha256"
 	"crypto/tls"
-	"os"
+	"fmt"
 	"testing"
 	"time"
 
+	"github.com/benbjohnson/clock"
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
@@ -37,15 +38,17 @@ func certHashFromComponent(t *testing.T, comp ma.Component) []byte {
 }
 
 func TestInitialCert(t *testing.T) {
-	m, err := newCertManager(certValidity)
+	cl := clock.NewMock()
+	cl.Add(1234567 * time.Hour)
+	m, err := newCertManager(cl, certValidity)
 	require.NoError(t, err)
 	defer m.Close()
 
 	conf := m.GetConfig()
 	require.Len(t, conf.Certificates, 1)
 	cert := conf.Certificates[0]
-	require.WithinDuration(t, time.Now(), cert.Leaf.NotBefore, time.Second)
-	require.WithinDuration(t, time.Now().Add(certValidity), cert.Leaf.NotAfter, time.Second)
+	require.Equal(t, cl.Now().UTC(), cert.Leaf.NotBefore)
+	require.Equal(t, cl.Now().Add(certValidity).UTC(), cert.Leaf.NotAfter)
 	addr := m.AddrComponent()
 	components := splitMultiaddr(addr)
 	require.Len(t, components, 1)
@@ -55,18 +58,17 @@ func TestInitialCert(t *testing.T) {
 }
 
 func TestCertRenewal(t *testing.T) {
-	var certValidity = 300 * time.Millisecond
-	if os.Getenv("CI") != "" {
-		certValidity = 2 * time.Second
-	}
-	m, err := newCertManager(certValidity)
+	cl := clock.NewMock()
+	m, err := newCertManager(cl, certValidity)
 	require.NoError(t, err)
 	defer m.Close()
 
 	firstConf := m.GetConfig()
 	require.Len(t, splitMultiaddr(m.AddrComponent()), 1)
 	// wait for a new certificate to be generated
-	require.Eventually(t, func() bool { return len(splitMultiaddr(m.AddrComponent())) > 1 }, certValidity/2, 10*time.Millisecond)
+	fmt.Println("add time")
+	cl.Add(certValidity / 2)
+	require.Eventually(t, func() bool { return len(splitMultiaddr(m.AddrComponent())) > 1 }, 200*time.Millisecond, 10*time.Millisecond)
 	// the actual config used should still be the same, we're just advertising the hash of the next config
 	components := splitMultiaddr(m.AddrComponent())
 	require.Len(t, components, 2)
@@ -74,7 +76,8 @@ func TestCertRenewal(t *testing.T) {
 		require.Equal(t, ma.P_CERTHASH, c.Protocol().Code)
 	}
 	require.Equal(t, firstConf, m.GetConfig())
-	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, certValidity/2, 10*time.Millisecond)
+	cl.Add(certValidity / 2)
+	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, 200*time.Millisecond, 10*time.Millisecond)
 	newConf := m.GetConfig()
 	// check that the new config now matches the second component
 	hash := certificateHashFromTLSConfig(newConf)
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 5438e259b7..f27fcfdb99 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -19,6 +19,7 @@ import (
 
 	noise "github.com/libp2p/go-libp2p-noise"
 
+	"github.com/benbjohnson/clock"
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
@@ -33,9 +34,19 @@ const webtransportHTTPEndpoint = "/.well-known/libp2p-webtransport"
 
 const certValidity = 14 * 24 * time.Hour
 
+type Option func(*transport) error
+
+func WithClock(cl clock.Clock) Option {
+	return func(t *transport) error {
+		t.clock = cl
+		return nil
+	}
+}
+
 type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
+	clock   clock.Clock
 
 	rcmgr network.ResourceManager
 	gater connmgr.ConnectionGater
@@ -50,7 +61,7 @@ type transport struct {
 var _ tpt.Transport = &transport{}
 var _ io.Closer = &transport{}
 
-func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceManager) (tpt.Transport, error) {
+func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceManager, opts ...Option) (tpt.Transport, error) {
 	id, err := peer.IDFromPrivateKey(key)
 	if err != nil {
 		return nil, err
@@ -60,6 +71,12 @@ func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceMa
 		privKey: key,
 		rcmgr:   rcmgr,
 		gater:   gater,
+		clock:   clock.New(),
+	}
+	for _, opt := range opts {
+		if err := opt(t); err != nil {
+			return nil, err
+		}
 	}
 	noise, err := noise.New(key, noise.WithEarlyDataHandler(t.checkEarlyData))
 	if err != nil {
@@ -208,7 +225,7 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 		return nil, fmt.Errorf("cannot listen on non-WebTransport addr: %s", laddr)
 	}
 	t.listenOnce.Do(func() {
-		t.certManager, t.listenOnceErr = newCertManager(certValidity)
+		t.certManager, t.listenOnceErr = newCertManager(t.clock, certValidity)
 	})
 	if t.listenOnceErr != nil {
 		return nil, t.listenOnceErr

From 9f2e830b65500721934073fb31c21e44c1f1fcce Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 10 Jul 2022 21:22:45 +0000
Subject: [PATCH 37/53] remove member variable for certificate validity from
 cert manager

---
 p2p/transport/webtransport/cert_manager.go      | 15 +++++----------
 p2p/transport/webtransport/cert_manager_test.go |  6 ++----
 p2p/transport/webtransport/transport.go         |  2 +-
 3 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index 8ca5b85913..a797b55085 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -46,8 +46,6 @@ type certManager struct {
 	ctxCancel context.CancelFunc
 	refCount  sync.WaitGroup
 
-	certValidity time.Duration // so we can set it in tests
-
 	mx            sync.Mutex
 	lastConfig    *certConfig // initially nil
 	currentConfig *certConfig
@@ -55,17 +53,14 @@ type certManager struct {
 	addrComp      ma.Multiaddr
 }
 
-func newCertManager(clock clock.Clock, certValidity time.Duration) (*certManager, error) {
-	m := &certManager{
-		clock:        clock,
-		certValidity: certValidity,
-	}
+func newCertManager(clock clock.Clock) (*certManager, error) {
+	m := &certManager{clock: clock}
 	m.ctx, m.ctxCancel = context.WithCancel(context.Background())
 	if err := m.init(); err != nil {
 		return nil, err
 	}
 
-	t := m.clock.Ticker(m.certValidity * 4 / 9) // make sure we're a bit faster than 1/2
+	t := m.clock.Ticker(certValidity * 4 / 9) // make sure we're a bit faster than 1/2
 	m.refCount.Add(1)
 	go func() {
 		defer m.refCount.Done()
@@ -79,7 +74,7 @@ func newCertManager(clock clock.Clock, certValidity time.Duration) (*certManager
 
 func (m *certManager) init() error {
 	start := m.clock.Now()
-	end := start.Add(m.certValidity)
+	end := start.Add(certValidity)
 	tlsConf, err := getTLSConf(start, end)
 	if err != nil {
 		return err
@@ -98,7 +93,7 @@ func (m *certManager) background(t *clock.Ticker) error {
 		case <-m.ctx.Done():
 			return nil
 		case start := <-t.C:
-			end := start.Add(m.certValidity)
+			end := start.Add(certValidity)
 			tlsConf, err := getTLSConf(start, end)
 			if err != nil {
 				return err
diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
index 84cb93510a..69cd7163da 100644
--- a/p2p/transport/webtransport/cert_manager_test.go
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -3,7 +3,6 @@ package libp2pwebtransport
 import (
 	"crypto/sha256"
 	"crypto/tls"
-	"fmt"
 	"testing"
 	"time"
 
@@ -40,7 +39,7 @@ func certHashFromComponent(t *testing.T, comp ma.Component) []byte {
 func TestInitialCert(t *testing.T) {
 	cl := clock.NewMock()
 	cl.Add(1234567 * time.Hour)
-	m, err := newCertManager(cl, certValidity)
+	m, err := newCertManager(cl)
 	require.NoError(t, err)
 	defer m.Close()
 
@@ -59,14 +58,13 @@ func TestInitialCert(t *testing.T) {
 
 func TestCertRenewal(t *testing.T) {
 	cl := clock.NewMock()
-	m, err := newCertManager(cl, certValidity)
+	m, err := newCertManager(cl)
 	require.NoError(t, err)
 	defer m.Close()
 
 	firstConf := m.GetConfig()
 	require.Len(t, splitMultiaddr(m.AddrComponent()), 1)
 	// wait for a new certificate to be generated
-	fmt.Println("add time")
 	cl.Add(certValidity / 2)
 	require.Eventually(t, func() bool { return len(splitMultiaddr(m.AddrComponent())) > 1 }, 200*time.Millisecond, 10*time.Millisecond)
 	// the actual config used should still be the same, we're just advertising the hash of the next config
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index f27fcfdb99..c32d1059a3 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -225,7 +225,7 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 		return nil, fmt.Errorf("cannot listen on non-WebTransport addr: %s", laddr)
 	}
 	t.listenOnce.Do(func() {
-		t.certManager, t.listenOnceErr = newCertManager(t.clock, certValidity)
+		t.certManager, t.listenOnceErr = newCertManager(t.clock)
 	})
 	if t.listenOnceErr != nil {
 		return nil, t.listenOnceErr

From ff5aa304a0aca38967f4a2378bd233fb360f8a64 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 12 Jul 2022 10:43:19 +0000
Subject: [PATCH 38/53] simplify certificate generation

---
 p2p/transport/webtransport/cert_manager.go | 25 ++++++++--------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index a797b55085..519a89d88e 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -16,15 +16,16 @@ import (
 )
 
 type certConfig struct {
-	start, end time.Time
-	tlsConf    *tls.Config
-	sha256     [32]byte // cached from the tlsConf
+	tlsConf *tls.Config
+	sha256  [32]byte // cached from the tlsConf
 }
 
-func newCertConfig(start, end time.Time, conf *tls.Config) (*certConfig, error) {
+func newCertConfig(start, end time.Time) (*certConfig, error) {
+	conf, err := getTLSConf(start, end)
+	if err != nil {
+		return nil, err
+	}
 	return &certConfig{
-		start:   start,
-		end:     end,
 		tlsConf: conf,
 		sha256:  sha256.Sum256(conf.Certificates[0].Leaf.Raw),
 	}, nil
@@ -75,11 +76,7 @@ func newCertManager(clock clock.Clock) (*certManager, error) {
 func (m *certManager) init() error {
 	start := m.clock.Now()
 	end := start.Add(certValidity)
-	tlsConf, err := getTLSConf(start, end)
-	if err != nil {
-		return err
-	}
-	cc, err := newCertConfig(start, end, tlsConf)
+	cc, err := newCertConfig(start, end)
 	if err != nil {
 		return err
 	}
@@ -94,11 +91,7 @@ func (m *certManager) background(t *clock.Ticker) error {
 			return nil
 		case start := <-t.C:
 			end := start.Add(certValidity)
-			tlsConf, err := getTLSConf(start, end)
-			if err != nil {
-				return err
-			}
-			cc, err := newCertConfig(start, end, tlsConf)
+			cc, err := newCertConfig(start, end)
 			if err != nil {
 				return err
 			}

From 2823159a99d45518a94db48f9942fa54005f2797 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 16 Jul 2022 10:22:10 +0000
Subject: [PATCH 39/53] optimize expiry periods of certificates (#21)

---
 p2p/transport/webtransport/cert_manager.go    | 106 ++++++++++--------
 .../webtransport/cert_manager_test.go         |  53 ++++++---
 p2p/transport/webtransport/transport_test.go  |  13 ++-
 3 files changed, 105 insertions(+), 67 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index 519a89d88e..c46a60b666 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -15,11 +15,19 @@ import (
 	"github.com/multiformats/go-multihash"
 )
 
+// Allow for a bit of clock skew.
+// When we generate a certificate, the NotBefore time is set to clockSkewAllowance before the current time.
+// Similarly, we stop using a certificate one clockSkewAllowance before its expiry time.
+const clockSkewAllowance = time.Hour
+
 type certConfig struct {
 	tlsConf *tls.Config
 	sha256  [32]byte // cached from the tlsConf
 }
 
+func (c *certConfig) Start() time.Time { return c.tlsConf.Certificates[0].Leaf.NotBefore }
+func (c *certConfig) End() time.Time   { return c.tlsConf.Certificates[0].Leaf.NotAfter }
+
 func newCertConfig(start, end time.Time) (*certConfig, error) {
 	conf, err := getTLSConf(start, end)
 	if err != nil {
@@ -32,22 +40,17 @@ func newCertConfig(start, end time.Time) (*certConfig, error) {
 }
 
 // Certificate renewal logic:
-// 0. To simplify the math, assume the certificate is valid for 10 days (in real life: 14 days).
-// 1. On startup, we generate the first certificate (1).
-// 2. After 4 days, we generate a second certificate (2).
-//    We don't use that certificate yet, but we advertise the hashes of (1) and (2).
-//    That allows clients to connect to us using addresses that are 4 days old.
-// 3. After another 4 days, we now actually start using (2).
-//    We also generate a third certificate (3), and start advertising the hashes of (2) and (3).
-//    We continue to remember the hash of (1) for validation during the Noise handshake for another 4 days,
-//    as the client might be connecting with a cached address.
+// 1. On startup, we generate one cert that is valid from now (-1h, to allow for clock skew), and another
+//    cert that is valid from the expiry date of the first certificate (again, with allowance for clock skew).
+// 2. Once we reach 1h before expiry of the first certificate, we switch over to the second certificate.
+//    At the same time, we stop advertising the certhash of the first cert and generate the next cert.
 type certManager struct {
 	clock     clock.Clock
 	ctx       context.Context
 	ctxCancel context.CancelFunc
 	refCount  sync.WaitGroup
 
-	mx            sync.Mutex
+	mx            sync.RWMutex
 	lastConfig    *certConfig // initially nil
 	currentConfig *certConfig
 	nextConfig    *certConfig // nil until we have passed half the certValidity of the current config
@@ -61,64 +64,71 @@ func newCertManager(clock clock.Clock) (*certManager, error) {
 		return nil, err
 	}
 
-	t := m.clock.Ticker(certValidity * 4 / 9) // make sure we're a bit faster than 1/2
-	m.refCount.Add(1)
-	go func() {
-		defer m.refCount.Done()
-		defer t.Stop()
-		if err := m.background(t); err != nil {
-			log.Fatal(err)
-		}
-	}()
+	m.background()
 	return m, nil
 }
 
 func (m *certManager) init() error {
-	start := m.clock.Now()
-	end := start.Add(certValidity)
-	cc, err := newCertConfig(start, end)
+	start := m.clock.Now().Add(-clockSkewAllowance)
+	var err error
+	m.nextConfig, err = newCertConfig(start, start.Add(certValidity))
 	if err != nil {
 		return err
 	}
-	m.currentConfig = cc
+	return m.rollConfig()
+}
+
+func (m *certManager) rollConfig() error {
+	// We stop using the current certificate clockSkewAllowance before its expiry time.
+	// At this point, the next certificate needs to be valid for one clockSkewAllowance.
+	nextStart := m.nextConfig.End().Add(-2 * clockSkewAllowance)
+	c, err := newCertConfig(nextStart, nextStart.Add(certValidity))
+	if err != nil {
+		return err
+	}
+	m.lastConfig = m.currentConfig
+	m.currentConfig = m.nextConfig
+	m.nextConfig = c
 	return m.cacheAddrComponent()
 }
 
-func (m *certManager) background(t *clock.Ticker) error {
-	for {
-		select {
-		case <-m.ctx.Done():
-			return nil
-		case start := <-t.C:
-			end := start.Add(certValidity)
-			cc, err := newCertConfig(start, end)
-			if err != nil {
-				return err
-			}
-			m.mx.Lock()
-			if m.nextConfig != nil {
-				m.lastConfig = m.currentConfig
-				m.currentConfig = m.nextConfig
-			}
-			m.nextConfig = cc
-			if err := m.cacheAddrComponent(); err != nil {
+func (m *certManager) background() {
+	d := m.currentConfig.End().Add(-clockSkewAllowance).Sub(m.clock.Now())
+	log.Debugw("setting timer", "duration", d.String())
+	t := m.clock.Timer(d)
+	m.refCount.Add(1)
+
+	go func() {
+		defer m.refCount.Done()
+		defer t.Stop()
+
+		for {
+			select {
+			case <-m.ctx.Done():
+				return
+			case now := <-t.C:
+				m.mx.Lock()
+				if err := m.rollConfig(); err != nil {
+					log.Errorw("rolling config failed", "error", err)
+				}
+				d := m.currentConfig.End().Add(-clockSkewAllowance).Sub(now)
+				log.Debugw("rolling certificates", "next", d.String())
+				t.Reset(d)
 				m.mx.Unlock()
-				return err
 			}
-			m.mx.Unlock()
 		}
-	}
+	}()
 }
 
 func (m *certManager) GetConfig() *tls.Config {
-	m.mx.Lock()
-	defer m.mx.Unlock()
+	m.mx.RLock()
+	defer m.mx.RUnlock()
 	return m.currentConfig.tlsConf
 }
 
 func (m *certManager) AddrComponent() ma.Multiaddr {
-	m.mx.Lock()
-	defer m.mx.Unlock()
+	m.mx.RLock()
+	defer m.mx.RUnlock()
 	return m.addrComp
 }
 
diff --git a/p2p/transport/webtransport/cert_manager_test.go b/p2p/transport/webtransport/cert_manager_test.go
index 69cd7163da..3f2328fbb7 100644
--- a/p2p/transport/webtransport/cert_manager_test.go
+++ b/p2p/transport/webtransport/cert_manager_test.go
@@ -46,14 +46,15 @@ func TestInitialCert(t *testing.T) {
 	conf := m.GetConfig()
 	require.Len(t, conf.Certificates, 1)
 	cert := conf.Certificates[0]
-	require.Equal(t, cl.Now().UTC(), cert.Leaf.NotBefore)
-	require.Equal(t, cl.Now().Add(certValidity).UTC(), cert.Leaf.NotAfter)
+	require.Equal(t, cl.Now().Add(-clockSkewAllowance).UTC(), cert.Leaf.NotBefore)
+	require.Equal(t, cert.Leaf.NotBefore.Add(certValidity), cert.Leaf.NotAfter)
 	addr := m.AddrComponent()
 	components := splitMultiaddr(addr)
-	require.Len(t, components, 1)
+	require.Len(t, components, 2)
 	require.Equal(t, ma.P_CERTHASH, components[0].Protocol().Code)
 	hash := certificateHashFromTLSConfig(conf)
 	require.Equal(t, hash[:], certHashFromComponent(t, components[0]))
+	require.Equal(t, ma.P_CERTHASH, components[1].Protocol().Code)
 }
 
 func TestCertRenewal(t *testing.T) {
@@ -63,21 +64,39 @@ func TestCertRenewal(t *testing.T) {
 	defer m.Close()
 
 	firstConf := m.GetConfig()
-	require.Len(t, splitMultiaddr(m.AddrComponent()), 1)
+	first := splitMultiaddr(m.AddrComponent())
+	require.Len(t, first, 2)
+	require.NotEqual(t, first[0].Value(), first[1].Value(), "the hashes should differ")
 	// wait for a new certificate to be generated
-	cl.Add(certValidity / 2)
-	require.Eventually(t, func() bool { return len(splitMultiaddr(m.AddrComponent())) > 1 }, 200*time.Millisecond, 10*time.Millisecond)
-	// the actual config used should still be the same, we're just advertising the hash of the next config
-	components := splitMultiaddr(m.AddrComponent())
-	require.Len(t, components, 2)
-	for _, c := range components {
+	cl.Add(certValidity - 2*clockSkewAllowance - time.Second)
+	require.Never(t, func() bool {
+		for i, c := range splitMultiaddr(m.AddrComponent()) {
+			if c.Value() != first[i].Value() {
+				return true
+			}
+		}
+		return false
+	}, 100*time.Millisecond, 10*time.Millisecond)
+	cl.Add(2 * time.Second)
+	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, 200*time.Millisecond, 10*time.Millisecond)
+	secondConf := m.GetConfig()
+
+	second := splitMultiaddr(m.AddrComponent())
+	require.Len(t, second, 2)
+	for _, c := range second {
 		require.Equal(t, ma.P_CERTHASH, c.Protocol().Code)
 	}
-	require.Equal(t, firstConf, m.GetConfig())
-	cl.Add(certValidity / 2)
-	require.Eventually(t, func() bool { return m.GetConfig() != firstConf }, 200*time.Millisecond, 10*time.Millisecond)
-	newConf := m.GetConfig()
-	// check that the new config now matches the second component
-	hash := certificateHashFromTLSConfig(newConf)
-	require.Equal(t, hash[:], certHashFromComponent(t, components[1]))
+	// check that the 2nd certificate from the beginning was rolled over to be the 1st certificate
+	require.Equal(t, first[1].Value(), second[0].Value())
+	require.NotEqual(t, first[0].Value(), second[1].Value())
+
+	cl.Add(certValidity - 2*clockSkewAllowance + time.Second)
+	require.Eventually(t, func() bool { return m.GetConfig() != secondConf }, 200*time.Millisecond, 10*time.Millisecond)
+	third := splitMultiaddr(m.AddrComponent())
+	require.Len(t, third, 2)
+	for _, c := range third {
+		require.Equal(t, ma.P_CERTHASH, c.Protocol().Code)
+	}
+	// check that the 2nd certificate from the beginning was rolled over to be the 1st certificate
+	require.Equal(t, second[1].Value(), third[0].Value())
 }
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index d85fcb828f..61cd245138 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -140,7 +140,16 @@ func TestHashVerification(t *testing.T) {
 
 	t.Run("fails using only a wrong hash", func(t *testing.T) {
 		// replace the certificate hash in the multiaddr with a fake hash
-		addr, _ := ma.SplitLast(ln.Multiaddr())
+		addr := ln.Multiaddr()
+		// strip off all certhash components
+		for {
+			a, comp := ma.SplitLast(addr)
+			if comp.Protocol().Code != ma.P_CERTHASH {
+				break
+			}
+			addr = a
+		}
+
 		addr = addr.Encapsulate(foobarHash)
 
 		_, err := tr2.Dial(context.Background(), addr, serverID)
@@ -224,7 +233,7 @@ func TestListenerAddrs(t *testing.T) {
 	ln2, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
 	require.NoError(t, err)
 	hashes1 := extractCertHashes(ln1.Multiaddr())
-	require.Len(t, hashes1, 1)
+	require.Len(t, hashes1, 2)
 	hashes2 := extractCertHashes(ln2.Multiaddr())
 	require.Equal(t, hashes1, hashes2)
 }

From d74921df0a4be3b73241b26236c4ff6b36b0f5d0 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 16 Jul 2022 13:55:57 +0000
Subject: [PATCH 40/53] make it possible to use a custom tls.Config for
 listening and dialing (#22)

---
 p2p/transport/webtransport/listener.go       |  49 ++++----
 p2p/transport/webtransport/transport.go      |  68 +++++++---
 p2p/transport/webtransport/transport_test.go | 123 ++++++++++++++++---
 3 files changed, 184 insertions(+), 56 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index bb762f7d7a..872e65804b 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -27,11 +27,13 @@ const queueLen = 16
 const handshakeTimeout = 10 * time.Second
 
 type listener struct {
-	transport   tpt.Transport
-	noise       *noise.Transport
-	certManager *certManager
-	rcmgr       network.ResourceManager
-	gater       connmgr.ConnectionGater
+	transport     tpt.Transport
+	noise         *noise.Transport
+	certManager   *certManager
+	staticTLSConf *tls.Config
+
+	rcmgr network.ResourceManager
+	gater connmgr.ConnectionGater
 
 	server webtransport.Server
 
@@ -48,7 +50,7 @@ type listener struct {
 
 var _ tpt.Listener = &listener{}
 
-func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager, gater connmgr.ConnectionGater, rcmgr network.ResourceManager) (tpt.Listener, error) {
+func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Transport, certManager *certManager, tlsConf *tls.Config, gater connmgr.ConnectionGater, rcmgr network.ResourceManager) (tpt.Listener, error) {
 	network, addr, err := manet.DialArgs(laddr)
 	if err != nil {
 		return nil, err
@@ -65,23 +67,23 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 	if err != nil {
 		return nil, err
 	}
+	if tlsConf == nil {
+		tlsConf = &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
+			return certManager.GetConfig(), nil
+		}}
+	}
 	ln := &listener{
-		transport:    transport,
-		noise:        noise,
-		certManager:  certManager,
-		rcmgr:        rcmgr,
-		gater:        gater,
-		queue:        make(chan tpt.CapableConn, queueLen),
-		serverClosed: make(chan struct{}),
-		addr:         udpConn.LocalAddr(),
-		multiaddr:    localMultiaddr,
-		server: webtransport.Server{
-			H3: http3.Server{
-				TLSConfig: &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
-					return certManager.GetConfig(), nil
-				}},
-			},
-		},
+		transport:     transport,
+		noise:         noise,
+		certManager:   certManager,
+		staticTLSConf: tlsConf,
+		rcmgr:         rcmgr,
+		gater:         gater,
+		queue:         make(chan tpt.CapableConn, queueLen),
+		serverClosed:  make(chan struct{}),
+		addr:          udpConn.LocalAddr(),
+		multiaddr:     localMultiaddr,
+		server:        webtransport.Server{H3: http3.Server{TLSConfig: tlsConf}},
 	}
 	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
 	mux := http.NewServeMux()
@@ -198,6 +200,9 @@ func (l *listener) Addr() net.Addr {
 }
 
 func (l *listener) Multiaddr() ma.Multiaddr {
+	if l.certManager == nil {
+		return l.multiaddr
+	}
 	return l.multiaddr.Encapsulate(l.certManager.AddrComponent())
 }
 
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index c32d1059a3..e027e1fe8f 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"crypto/x509"
+	"errors"
 	"fmt"
 	"io"
 	"sync"
@@ -43,6 +44,27 @@ func WithClock(cl clock.Clock) Option {
 	}
 }
 
+// WithTLSConfig sets a tls.Config used for listening.
+// When used, the certificate from that config will be used, and no /certhash will be added to the listener's multiaddr.
+// This is most useful when running a listener that has a valid (CA-signed) certificate.
+func WithTLSConfig(c *tls.Config) Option {
+	return func(t *transport) error {
+		t.staticTLSConf = c
+		return nil
+	}
+}
+
+// WithTLSClientConfig sets a custom tls.Config used for dialing.
+// This option is most useful for setting a custom tls.Config.RootCAs certificate pool.
+// When dialing a multiaddr that contains a /certhash component, this library will set InsecureSkipVerify and
+// overwrite the VerifyPeerCertificate callback.
+func WithTLSClientConfig(c *tls.Config) Option {
+	return func(t *transport) error {
+		t.tlsClientConf = c
+		return nil
+	}
+}
+
 type transport struct {
 	privKey ic.PrivKey
 	pid     peer.ID
@@ -54,6 +76,8 @@ type transport struct {
 	listenOnce    sync.Once
 	listenOnceErr error
 	certManager   *certManager
+	staticTLSConf *tls.Config
+	tlsClientConf *tls.Config
 
 	noise *noise.Transport
 }
@@ -129,15 +153,21 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 
 func (t *transport) dial(ctx context.Context, addr string, certHashes []multihash.DecodedMultihash) (*webtransport.Session, error) {
 	url := fmt.Sprintf("https://%s%s", addr, webtransportHTTPEndpoint)
+	var tlsConf *tls.Config
+	if t.tlsClientConf != nil {
+		tlsConf = t.tlsClientConf.Clone()
+	} else {
+		tlsConf = &tls.Config{}
+	}
+
+	if len(certHashes) > 0 {
+		tlsConf.InsecureSkipVerify = true // this is not insecure. We verify the certificate ourselves.
+		tlsConf.VerifyPeerCertificate = func(rawCerts [][]byte, _ [][]*x509.Certificate) error {
+			return verifyRawCerts(rawCerts, certHashes)
+		}
+	}
 	dialer := webtransport.Dialer{
-		RoundTripper: &http3.RoundTripper{
-			TLSClientConfig: &tls.Config{
-				InsecureSkipVerify: true, // this is not insecure. We verify the certificate ourselves.
-				VerifyPeerCertificate: func(rawCerts [][]byte, _ [][]*x509.Certificate) error {
-					return verifyRawCerts(rawCerts, certHashes)
-				},
-			},
-		},
+		RoundTripper: &http3.RoundTripper{TLSClientConfig: tlsConf},
 	}
 	rsp, sess, err := dialer.Dial(ctx, url, nil)
 	if err != nil {
@@ -193,6 +223,14 @@ func (t *transport) checkEarlyData(b []byte) error {
 		return fmt.Errorf("failed to unmarshal early data protobuf: %w", err)
 	}
 	hashes := make([]multihash.DecodedMultihash, 0, len(msg.CertHashes))
+
+	if t.staticTLSConf != nil {
+		if len(hashes) > 0 {
+			return errors.New("using static TLS config, didn't expect any certificate hashes")
+		}
+		return nil
+	}
+
 	for _, h := range msg.CertHashes {
 		dh, err := multihash.Decode(h)
 		if err != nil {
@@ -224,13 +262,15 @@ func (t *transport) Listen(laddr ma.Multiaddr) (tpt.Listener, error) {
 	if !webtransportMatcher.Matches(laddr) {
 		return nil, fmt.Errorf("cannot listen on non-WebTransport addr: %s", laddr)
 	}
-	t.listenOnce.Do(func() {
-		t.certManager, t.listenOnceErr = newCertManager(t.clock)
-	})
-	if t.listenOnceErr != nil {
-		return nil, t.listenOnceErr
+	if t.staticTLSConf == nil {
+		t.listenOnce.Do(func() {
+			t.certManager, t.listenOnceErr = newCertManager(t.clock)
+		})
+		if t.listenOnceErr != nil {
+			return nil, t.listenOnceErr
+		}
 	}
-	return newListener(laddr, t, t.noise, t.certManager, t.gater, t.rcmgr)
+	return newListener(laddr, t, t.noise, t.certManager, t.staticTLSConf, t.gater, t.rcmgr)
 }
 
 func (t *transport) Protocols() []int {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 61cd245138..e83cac02e5 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -2,12 +2,19 @@ package libp2pwebtransport_test
 
 import (
 	"context"
+	"crypto/ecdsa"
+	"crypto/elliptic"
 	"crypto/rand"
 	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
 	"errors"
 	"fmt"
 	"io"
+	"math/big"
 	"net"
+	"strings"
 	"testing"
 	"time"
 
@@ -64,6 +71,19 @@ func stripCertHashes(addr ma.Multiaddr) ma.Multiaddr {
 	}
 }
 
+// create a /certhash multiaddr component using the SHA256 of foobar
+func getCerthashComponent(t *testing.T, b []byte) ma.Multiaddr {
+	t.Helper()
+	h := sha256.Sum256(b)
+	mh, err := multihash.Encode(h[:], multihash.SHA2_256)
+	require.NoError(t, err)
+	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
+	require.NoError(t, err)
+	ha, err := ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
+	require.NoError(t, err)
+	return ha
+}
+
 func TestTransport(t *testing.T) {
 	serverID, serverKey := newIdentity(t)
 	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
@@ -129,29 +149,11 @@ func TestHashVerification(t *testing.T) {
 	require.NoError(t, err)
 	defer tr2.(io.Closer).Close()
 
-	// create a hash component using the SHA256 of foobar
-	h := sha256.Sum256([]byte("foobar"))
-	mh, err := multihash.Encode(h[:], multihash.SHA2_256)
-	require.NoError(t, err)
-	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
-	require.NoError(t, err)
-	foobarHash, err := ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
-	require.NoError(t, err)
+	foobarHash := getCerthashComponent(t, []byte("foobar"))
 
 	t.Run("fails using only a wrong hash", func(t *testing.T) {
 		// replace the certificate hash in the multiaddr with a fake hash
-		addr := ln.Multiaddr()
-		// strip off all certhash components
-		for {
-			a, comp := ma.SplitLast(addr)
-			if comp.Protocol().Code != ma.P_CERTHASH {
-				break
-			}
-			addr = a
-		}
-
-		addr = addr.Encapsulate(foobarHash)
-
+		addr := stripCertHashes(ln.Multiaddr()).Encapsulate(foobarHash)
 		_, err := tr2.Dial(context.Background(), addr, serverID)
 		require.Error(t, err)
 		require.Contains(t, err.Error(), "CRYPTO_ERROR (0x12a): cert hash not found")
@@ -424,3 +426,84 @@ func TestConnectionGaterInterceptSecured(t *testing.T) {
 		t.Fatal("timeout")
 	}
 }
+
+func getTLSConf(t *testing.T, ip net.IP, start, end time.Time) *tls.Config {
+	t.Helper()
+	certTempl := &x509.Certificate{
+		SerialNumber:          big.NewInt(1234),
+		Subject:               pkix.Name{Organization: []string{"webtransport"}},
+		NotBefore:             start,
+		NotAfter:              end,
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+		IPAddresses:           []net.IP{ip},
+	}
+	priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	require.NoError(t, err)
+	caBytes, err := x509.CreateCertificate(rand.Reader, certTempl, certTempl, &priv.PublicKey, priv)
+	require.NoError(t, err)
+	cert, err := x509.ParseCertificate(caBytes)
+	require.NoError(t, err)
+	return &tls.Config{
+		Certificates: []tls.Certificate{{
+			Certificate: [][]byte{cert.Raw},
+			PrivateKey:  priv,
+			Leaf:        cert,
+		}},
+	}
+}
+
+func TestStaticTLSConf(t *testing.T) {
+	tlsConf := getTLSConf(t, net.ParseIP("127.0.0.1"), time.Now(), time.Now().Add(365*24*time.Hour))
+
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager, libp2pwebtransport.WithTLSConfig(tlsConf))
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	defer ln.Close()
+	require.Empty(t, extractCertHashes(ln.Multiaddr()), "listener address shouldn't contain any certhash")
+
+	t.Run("fails when the certificate is invalid", func(t *testing.T) {
+		_, key := newIdentity(t)
+		cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
+		require.NoError(t, err)
+		defer cl.(io.Closer).Close()
+
+		_, err = cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+		require.Error(t, err)
+		if !strings.Contains(err.Error(), "certificate is not trusted") &&
+			!strings.Contains(err.Error(), "certificate signed by unknown authority") {
+			t.Fatalf("expected a certificate error, got %+v", err)
+		}
+	})
+
+	t.Run("fails when dialing with a wrong certhash", func(t *testing.T) {
+		_, key := newIdentity(t)
+		cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
+		require.NoError(t, err)
+		defer cl.(io.Closer).Close()
+
+		addr := ln.Multiaddr().Encapsulate(getCerthashComponent(t, []byte("foo")))
+		_, err = cl.Dial(context.Background(), addr, serverID)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "cert hash not found")
+	})
+
+	t.Run("accepts a valid TLS certificate", func(t *testing.T) {
+		_, key := newIdentity(t)
+		store := x509.NewCertPool()
+		store.AddCert(tlsConf.Certificates[0].Leaf)
+		tlsConf := &tls.Config{RootCAs: store}
+		cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager, libp2pwebtransport.WithTLSClientConfig(tlsConf))
+		require.NoError(t, err)
+		defer cl.(io.Closer).Close()
+
+		conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+		require.NoError(t, err)
+		defer conn.Close()
+	})
+}

From 60a40710abe6857ff277683dca486dbb473c50e2 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 29 Aug 2022 17:44:52 +0300
Subject: [PATCH 41/53] chore: update CI to Go 1.18 / 1.19, update
 webtransport-go to v0.1.0

---
 p2p/transport/webtransport/cert_manager.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index c46a60b666..6fc363281d 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -40,10 +40,10 @@ func newCertConfig(start, end time.Time) (*certConfig, error) {
 }
 
 // Certificate renewal logic:
-// 1. On startup, we generate one cert that is valid from now (-1h, to allow for clock skew), and another
-//    cert that is valid from the expiry date of the first certificate (again, with allowance for clock skew).
-// 2. Once we reach 1h before expiry of the first certificate, we switch over to the second certificate.
-//    At the same time, we stop advertising the certhash of the first cert and generate the next cert.
+//  1. On startup, we generate one cert that is valid from now (-1h, to allow for clock skew), and another
+//     cert that is valid from the expiry date of the first certificate (again, with allowance for clock skew).
+//  2. Once we reach 1h before expiry of the first certificate, we switch over to the second certificate.
+//     At the same time, we stop advertising the certhash of the first cert and generate the next cert.
 type certManager struct {
 	clock     clock.Clock
 	ctx       context.Context

From 4ce4e4f05edd9ba28650f08d4b9ada7bff8f6362 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 3 Sep 2022 11:57:25 +0300
Subject: [PATCH 42/53] only use positive numbers for x509.Certificate serial
 numbers

---
 p2p/transport/webtransport/crypto.go      | 7 +++++--
 p2p/transport/webtransport/crypto_test.go | 6 +++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/p2p/transport/webtransport/crypto.go b/p2p/transport/webtransport/crypto.go
index 9bb7f7a330..0ea71323af 100644
--- a/p2p/transport/webtransport/crypto.go
+++ b/p2p/transport/webtransport/crypto.go
@@ -37,9 +37,12 @@ func generateCert(start, end time.Time) (*x509.Certificate, *ecdsa.PrivateKey, e
 	if _, err := rand.Read(b); err != nil {
 		return nil, nil, err
 	}
-	serial := binary.BigEndian.Uint64(b)
+	serial := int64(binary.BigEndian.Uint64(b))
+	if serial < 0 {
+		serial = -serial
+	}
 	certTempl := &x509.Certificate{
-		SerialNumber:          big.NewInt(int64(serial)),
+		SerialNumber:          big.NewInt(serial),
 		Subject:               pkix.Name{},
 		NotBefore:             start,
 		NotAfter:              end,
diff --git a/p2p/transport/webtransport/crypto_test.go b/p2p/transport/webtransport/crypto_test.go
index c69c578b92..d6d106202a 100644
--- a/p2p/transport/webtransport/crypto_test.go
+++ b/p2p/transport/webtransport/crypto_test.go
@@ -31,8 +31,12 @@ func sha256Multihash(t *testing.T, b []byte) multihash.DecodedMultihash {
 
 func generateCertWithKey(t *testing.T, key crypto.PrivateKey, start, end time.Time) *x509.Certificate {
 	t.Helper()
+	serial := int64(mrand.Uint64())
+	if serial < 0 {
+		serial = -serial
+	}
 	certTempl := &x509.Certificate{
-		SerialNumber:          big.NewInt(int64(mrand.Uint64())),
+		SerialNumber:          big.NewInt(serial),
 		Subject:               pkix.Name{},
 		NotBefore:             start,
 		NotAfter:              end,

From 3521b4fae8c1e930bdf1b895a123a9eb7037f34f Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 3 Sep 2022 12:07:15 +0300
Subject: [PATCH 43/53] chore: update go-multiaddr to v0.6.0

---
 p2p/transport/webtransport/multiaddr_test.go | 12 ------------
 p2p/transport/webtransport/transport_test.go |  5 ++++-
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/p2p/transport/webtransport/multiaddr_test.go b/p2p/transport/webtransport/multiaddr_test.go
index 7c95b00d01..3af1ce56e2 100644
--- a/p2p/transport/webtransport/multiaddr_test.go
+++ b/p2p/transport/webtransport/multiaddr_test.go
@@ -73,16 +73,4 @@ func TestExtractCertHashes(t *testing.T) {
 			require.Equal(t, h, string(ch[i].Digest))
 		}
 	}
-
-	// invalid cases
-	for _, tc := range [...]struct {
-		addr string
-		err  string
-	}{
-		{addr: fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s", fooHash[:len(fooHash)-1]), err: "failed to multihash-decode certificate hash"},
-	} {
-		_, err := extractCertHashes(ma.StringCast(tc.addr))
-		require.Error(t, err)
-		require.Contains(t, err.Error(), tc.err)
-	}
 }
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index e83cac02e5..d436af4bd2 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -43,9 +43,12 @@ func newIdentity(t *testing.T) (peer.ID, ic.PrivKey) {
 }
 
 func randomMultihash(t *testing.T) string {
+	t.Helper()
 	b := make([]byte, 16)
 	rand.Read(b)
-	s, err := multibase.Encode(multibase.Base32hex, b)
+	h, err := multihash.Encode(b, multihash.KECCAK_224)
+	require.NoError(t, err)
+	s, err := multibase.Encode(multibase.Base32hex, h)
 	require.NoError(t, err)
 	return s
 }

From 97e739f0a872abf72f75c26549aa70870140ddd9 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 3 Sep 2022 13:52:50 +0300
Subject: [PATCH 44/53] update to the current master of go-libp2p (#23)

---
 p2p/transport/webtransport/conn.go            |  4 +-
 p2p/transport/webtransport/listener.go        | 75 +++++++++++++------
 .../mock_connection_gater_test.go             |  8 +-
 .../webtransport/noise_early_data.go          | 34 +++++++++
 p2p/transport/webtransport/stream.go          |  2 +-
 p2p/transport/webtransport/transport.go       | 48 ++++--------
 p2p/transport/webtransport/transport_test.go  | 10 +--
 7 files changed, 113 insertions(+), 68 deletions(-)
 create mode 100644 p2p/transport/webtransport/noise_early_data.go

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index 409cea3383..f68595293f 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -3,8 +3,8 @@ package libp2pwebtransport
 import (
 	"context"
 
-	"github.com/libp2p/go-libp2p-core/network"
-	tpt "github.com/libp2p/go-libp2p-core/transport"
+	"github.com/libp2p/go-libp2p/core/network"
+	tpt "github.com/libp2p/go-libp2p/core/transport"
 
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 872e65804b..4c87512d29 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -5,15 +5,16 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
+	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
+	"github.com/multiformats/go-multihash"
 	"net"
 	"net/http"
 	"time"
 
-	"github.com/libp2p/go-libp2p-core/connmgr"
-	"github.com/libp2p/go-libp2p-core/network"
-	tpt "github.com/libp2p/go-libp2p-core/transport"
-
-	noise "github.com/libp2p/go-libp2p-noise"
+	"github.com/libp2p/go-libp2p/core/connmgr"
+	"github.com/libp2p/go-libp2p/core/network"
+	tpt "github.com/libp2p/go-libp2p/core/transport"
+	"github.com/libp2p/go-libp2p/p2p/security/noise"
 
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
@@ -27,10 +28,11 @@ const queueLen = 16
 const handshakeTimeout = 10 * time.Second
 
 type listener struct {
-	transport     tpt.Transport
-	noise         *noise.Transport
-	certManager   *certManager
-	staticTLSConf *tls.Config
+	transport       tpt.Transport
+	noise           *noise.Transport
+	certManager     *certManager
+	tlsConf         *tls.Config
+	isStaticTLSConf bool
 
 	rcmgr network.ResourceManager
 	gater connmgr.ConnectionGater
@@ -67,23 +69,25 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 	if err != nil {
 		return nil, err
 	}
+	isStaticTLSConf := tlsConf != nil
 	if tlsConf == nil {
 		tlsConf = &tls.Config{GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
 			return certManager.GetConfig(), nil
 		}}
 	}
 	ln := &listener{
-		transport:     transport,
-		noise:         noise,
-		certManager:   certManager,
-		staticTLSConf: tlsConf,
-		rcmgr:         rcmgr,
-		gater:         gater,
-		queue:         make(chan tpt.CapableConn, queueLen),
-		serverClosed:  make(chan struct{}),
-		addr:          udpConn.LocalAddr(),
-		multiaddr:     localMultiaddr,
-		server:        webtransport.Server{H3: http3.Server{TLSConfig: tlsConf}},
+		transport:       transport,
+		noise:           noise,
+		certManager:     certManager,
+		tlsConf:         tlsConf,
+		isStaticTLSConf: isStaticTLSConf,
+		rcmgr:           rcmgr,
+		gater:           gater,
+		queue:           make(chan tpt.CapableConn, queueLen),
+		serverClosed:    make(chan struct{}),
+		addr:            udpConn.LocalAddr(),
+		multiaddr:       localMultiaddr,
+		server:          webtransport.Server{H3: http3.Server{TLSConfig: tlsConf}},
 	}
 	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
 	mux := http.NewServeMux()
@@ -184,7 +188,11 @@ func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (c
 	if err != nil {
 		return nil, err
 	}
-	c, err := l.noise.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
+	n, err := l.noise.WithSessionOptions(noise.EarlyData(newEarlyDataReceiver(l.checkEarlyData)))
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize Noise session: %w", err)
+	}
+	c, err := n.SecureInbound(ctx, &webtransportStream{Stream: str, wsess: sess}, "")
 	if err != nil {
 		return nil, err
 	}
@@ -195,6 +203,31 @@ func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (c
 	}, nil
 }
 
+func (l *listener) checkEarlyData(b []byte) error {
+	var msg pb.WebTransport
+	if err := msg.Unmarshal(b); err != nil {
+		fmt.Println(1)
+		return fmt.Errorf("failed to unmarshal early data protobuf: %w", err)
+	}
+
+	if l.isStaticTLSConf {
+		if len(msg.CertHashes) > 0 {
+			return errors.New("using static TLS config, didn't expect any certificate hashes")
+		}
+		return nil
+	}
+
+	hashes := make([]multihash.DecodedMultihash, 0, len(msg.CertHashes))
+	for _, h := range msg.CertHashes {
+		dh, err := multihash.Decode(h)
+		if err != nil {
+			return fmt.Errorf("failed to decode hash: %w", err)
+		}
+		hashes = append(hashes, *dh)
+	}
+	return l.certManager.Verify(hashes)
+}
+
 func (l *listener) Addr() net.Addr {
 	return l.addr
 }
diff --git a/p2p/transport/webtransport/mock_connection_gater_test.go b/p2p/transport/webtransport/mock_connection_gater_test.go
index 071ed7494f..c6e7dbaad6 100644
--- a/p2p/transport/webtransport/mock_connection_gater_test.go
+++ b/p2p/transport/webtransport/mock_connection_gater_test.go
@@ -1,5 +1,5 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/libp2p/go-libp2p-core/connmgr (interfaces: ConnectionGater)
+// Source: github.com/libp2p/go-libp2p/core/connmgr (interfaces: ConnectionGater)
 
 // Package libp2pwebtransport_test is a generated GoMock package.
 package libp2pwebtransport_test
@@ -8,9 +8,9 @@ import (
 	reflect "reflect"
 
 	gomock "github.com/golang/mock/gomock"
-	control "github.com/libp2p/go-libp2p-core/control"
-	network "github.com/libp2p/go-libp2p-core/network"
-	peer "github.com/libp2p/go-libp2p-core/peer"
+	control "github.com/libp2p/go-libp2p/core/control"
+	network "github.com/libp2p/go-libp2p/core/network"
+	peer "github.com/libp2p/go-libp2p/core/peer"
 	multiaddr "github.com/multiformats/go-multiaddr"
 )
 
diff --git a/p2p/transport/webtransport/noise_early_data.go b/p2p/transport/webtransport/noise_early_data.go
new file mode 100644
index 0000000000..ec01c6d7a2
--- /dev/null
+++ b/p2p/transport/webtransport/noise_early_data.go
@@ -0,0 +1,34 @@
+package libp2pwebtransport
+
+import (
+	"context"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/libp2p/go-libp2p/p2p/security/noise"
+	"net"
+)
+
+type earlyDataHandler struct {
+	earlyData []byte
+	receive   func([]byte) error
+}
+
+var _ noise.EarlyDataHandler = &earlyDataHandler{}
+
+func newEarlyDataSender(earlyData []byte) noise.EarlyDataHandler {
+	return &earlyDataHandler{earlyData: earlyData}
+}
+
+func newEarlyDataReceiver(receive func([]byte) error) noise.EarlyDataHandler {
+	return &earlyDataHandler{receive: receive}
+}
+
+func (e *earlyDataHandler) Send(context.Context, net.Conn, peer.ID) []byte {
+	return e.earlyData
+}
+
+func (e *earlyDataHandler) Received(_ context.Context, _ net.Conn, b []byte) error {
+	if e.receive == nil {
+		return nil
+	}
+	return e.receive(b)
+}
diff --git a/p2p/transport/webtransport/stream.go b/p2p/transport/webtransport/stream.go
index 6aa58cb8d8..ff17b3083f 100644
--- a/p2p/transport/webtransport/stream.go
+++ b/p2p/transport/webtransport/stream.go
@@ -6,7 +6,7 @@ import (
 
 	"github.com/marten-seemann/webtransport-go"
 
-	"github.com/libp2p/go-libp2p-core/network"
+	"github.com/libp2p/go-libp2p/core/network"
 )
 
 const (
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index e027e1fe8f..faa13db86c 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"crypto/x509"
-	"errors"
 	"fmt"
 	"io"
 	"sync"
@@ -12,13 +11,12 @@ import (
 
 	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
 
-	"github.com/libp2p/go-libp2p-core/connmgr"
-	ic "github.com/libp2p/go-libp2p-core/crypto"
-	"github.com/libp2p/go-libp2p-core/network"
-	"github.com/libp2p/go-libp2p-core/peer"
-	tpt "github.com/libp2p/go-libp2p-core/transport"
-
-	noise "github.com/libp2p/go-libp2p-noise"
+	"github.com/libp2p/go-libp2p/core/connmgr"
+	ic "github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
+	"github.com/libp2p/go-libp2p/core/peer"
+	tpt "github.com/libp2p/go-libp2p/core/transport"
+	"github.com/libp2p/go-libp2p/p2p/security/noise"
 
 	"github.com/benbjohnson/clock"
 	logging "github.com/ipfs/go-log/v2"
@@ -102,11 +100,11 @@ func New(key ic.PrivKey, gater connmgr.ConnectionGater, rcmgr network.ResourceMa
 			return nil, err
 		}
 	}
-	noise, err := noise.New(key, noise.WithEarlyDataHandler(t.checkEarlyData))
+	n, err := noise.New(key)
 	if err != nil {
 		return nil, err
 	}
-	t.noise = noise
+	t.noise = n
 	return t, nil
 }
 
@@ -207,7 +205,11 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 	if err != nil {
 		return nil, fmt.Errorf("failed to marshal WebTransport protobuf: %w", err)
 	}
-	c, err := t.noise.SecureOutboundWithEarlyData(ctx, &webtransportStream{Stream: str, wsess: sess}, p, msgBytes)
+	n, err := t.noise.WithSessionOptions(noise.EarlyData(newEarlyDataSender(msgBytes)))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create Noise transport: %w", err)
+	}
+	c, err := n.SecureOutbound(ctx, &webtransportStream{Stream: str, wsess: sess}, p)
 	if err != nil {
 		return nil, err
 	}
@@ -217,30 +219,6 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 	}, nil
 }
 
-func (t *transport) checkEarlyData(b []byte) error {
-	var msg pb.WebTransport
-	if err := msg.Unmarshal(b); err != nil {
-		return fmt.Errorf("failed to unmarshal early data protobuf: %w", err)
-	}
-	hashes := make([]multihash.DecodedMultihash, 0, len(msg.CertHashes))
-
-	if t.staticTLSConf != nil {
-		if len(hashes) > 0 {
-			return errors.New("using static TLS config, didn't expect any certificate hashes")
-		}
-		return nil
-	}
-
-	for _, h := range msg.CertHashes {
-		dh, err := multihash.Decode(h)
-		if err != nil {
-			return fmt.Errorf("failed to decode hash: %w", err)
-		}
-		hashes = append(hashes, *dh)
-	}
-	return t.certManager.Verify(hashes)
-}
-
 func (t *transport) CanDial(addr ma.Multiaddr) bool {
 	var numHashes int
 	ma.ForEach(addr, func(c ma.Component) bool {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index d436af4bd2..02f065bc8c 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -20,12 +20,12 @@ import (
 
 	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
 
-	ic "github.com/libp2p/go-libp2p-core/crypto"
-	"github.com/libp2p/go-libp2p-core/network"
-	"github.com/libp2p/go-libp2p-core/peer"
+	ic "github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
+	mocknetwork "github.com/libp2p/go-libp2p/core/network/mocks"
+	"github.com/libp2p/go-libp2p/core/peer"
 
 	"github.com/golang/mock/gomock"
-	mocknetwork "github.com/libp2p/go-libp2p-testing/mocks/network"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
@@ -338,7 +338,7 @@ func TestResourceManagerListening(t *testing.T) {
 }
 
 // TODO: unify somehow. We do the same in libp2pquic.
-//go:generate sh -c "mockgen -package libp2pwebtransport_test -destination mock_connection_gater_test.go github.com/libp2p/go-libp2p-core/connmgr ConnectionGater && goimports -w mock_connection_gater_test.go"
+//go:generate sh -c "mockgen -package libp2pwebtransport_test -destination mock_connection_gater_test.go github.com/libp2p/go-libp2p/core/connmgr ConnectionGater && goimports -w mock_connection_gater_test.go"
 
 func TestConnectionGaterDialing(t *testing.T) {
 	ctrl := gomock.NewController(t)

From 0295df00740b877e14a3c7dae91e2e0e61cc62e9 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 09:44:35 +0300
Subject: [PATCH 45/53] remove Hello World HTTP endpoint

---
 p2p/transport/webtransport/listener.go | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 4c87512d29..02ee9ace04 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -91,9 +91,6 @@ func newListener(laddr ma.Multiaddr, transport tpt.Transport, noise *noise.Trans
 	}
 	ln.ctx, ln.ctxCancel = context.WithCancel(context.Background())
 	mux := http.NewServeMux()
-	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte("Hello, world!"))
-	})
 	mux.HandleFunc(webtransportHTTPEndpoint, ln.httpHandler)
 	ln.server.H3.Handler = mux
 	go func() {

From c783884fb105d218d470321e5b675c5f0db61f46 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 10:12:41 +0300
Subject: [PATCH 46/53] add a link to the certificate hashes section of the w3c
 WebTransport spec

---
 p2p/transport/webtransport/transport.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index faa13db86c..b960083a17 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -159,7 +159,9 @@ func (t *transport) dial(ctx context.Context, addr string, certHashes []multihas
 	}
 
 	if len(certHashes) > 0 {
-		tlsConf.InsecureSkipVerify = true // this is not insecure. We verify the certificate ourselves.
+		// This is not insecure. We verify the certificate ourselves.
+		// See https://www.w3.org/TR/webtransport/#certificate-hashes.
+		tlsConf.InsecureSkipVerify = true
 		tlsConf.VerifyPeerCertificate = func(rawCerts [][]byte, _ [][]*x509.Certificate) error {
 			return verifyRawCerts(rawCerts, certHashes)
 		}

From ef657d6d7ce25e2ebe0e03081a1cb727b343f5af Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 10:14:22 +0300
Subject: [PATCH 47/53] make addrComponentForCert a pure function

---
 p2p/transport/webtransport/cert_manager.go | 17 ++---------------
 p2p/transport/webtransport/multiaddr.go    | 12 ++++++++++++
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/p2p/transport/webtransport/cert_manager.go b/p2p/transport/webtransport/cert_manager.go
index 6fc363281d..c005d448bc 100644
--- a/p2p/transport/webtransport/cert_manager.go
+++ b/p2p/transport/webtransport/cert_manager.go
@@ -11,7 +11,6 @@ import (
 
 	"github.com/benbjohnson/clock"
 	ma "github.com/multiformats/go-multiaddr"
-	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
 )
 
@@ -147,12 +146,12 @@ func (m *certManager) Verify(hashes []multihash.DecodedMultihash) error {
 }
 
 func (m *certManager) cacheAddrComponent() error {
-	addr, err := m.addrComponentForCert(m.currentConfig.sha256[:])
+	addr, err := addrComponentForCert(m.currentConfig.sha256[:])
 	if err != nil {
 		return err
 	}
 	if m.nextConfig != nil {
-		comp, err := m.addrComponentForCert(m.nextConfig.sha256[:])
+		comp, err := addrComponentForCert(m.nextConfig.sha256[:])
 		if err != nil {
 			return err
 		}
@@ -162,18 +161,6 @@ func (m *certManager) cacheAddrComponent() error {
 	return nil
 }
 
-func (m *certManager) addrComponentForCert(hash []byte) (ma.Multiaddr, error) {
-	mh, err := multihash.Encode(hash, multihash.SHA2_256)
-	if err != nil {
-		return nil, err
-	}
-	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
-	if err != nil {
-		return nil, err
-	}
-	return ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
-}
-
 func (m *certManager) Close() error {
 	m.ctxCancel()
 	m.refCount.Wait()
diff --git a/p2p/transport/webtransport/multiaddr.go b/p2p/transport/webtransport/multiaddr.go
index 7b6df2ba25..7789a3d1de 100644
--- a/p2p/transport/webtransport/multiaddr.go
+++ b/p2p/transport/webtransport/multiaddr.go
@@ -66,3 +66,15 @@ func extractCertHashes(addr ma.Multiaddr) ([]multihash.DecodedMultihash, error)
 	}
 	return certHashes, nil
 }
+
+func addrComponentForCert(hash []byte) (ma.Multiaddr, error) {
+	mh, err := multihash.Encode(hash, multihash.SHA2_256)
+	if err != nil {
+		return nil, err
+	}
+	certStr, err := multibase.Encode(multibase.Base58BTC, mh)
+	if err != nil {
+		return nil, err
+	}
+	return ma.NewComponent(ma.ProtocolWithCode(ma.P_CERTHASH).Name, certStr)
+}

From d2b47dd53951d196e8051cbe5a7eb6055ebe3840 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 10:19:30 +0300
Subject: [PATCH 48/53] remove the unneeded connSecurityMultiaddrs interface

---
 p2p/transport/webtransport/conn.go      | 11 +++--------
 p2p/transport/webtransport/listener.go  |  4 ++--
 p2p/transport/webtransport/transport.go |  4 ++--
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/p2p/transport/webtransport/conn.go b/p2p/transport/webtransport/conn.go
index f68595293f..e4d30e4a5c 100644
--- a/p2p/transport/webtransport/conn.go
+++ b/p2p/transport/webtransport/conn.go
@@ -10,12 +10,7 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 )
 
-type connSecurityMultiaddrs interface {
-	network.ConnMultiaddrs
-	network.ConnSecurity
-}
-
-type connSecurityMultiaddrsImpl struct {
+type connSecurityMultiaddrs struct {
 	network.ConnSecurity
 	network.ConnMultiaddrs
 }
@@ -30,7 +25,7 @@ func (c *connMultiaddrs) LocalMultiaddr() ma.Multiaddr  { return c.local }
 func (c *connMultiaddrs) RemoteMultiaddr() ma.Multiaddr { return c.remote }
 
 type conn struct {
-	connSecurityMultiaddrs
+	*connSecurityMultiaddrs
 
 	transport tpt.Transport
 	session   *webtransport.Session
@@ -40,7 +35,7 @@ type conn struct {
 
 var _ tpt.CapableConn = &conn{}
 
-func newConn(tr tpt.Transport, sess *webtransport.Session, sconn connSecurityMultiaddrs, scope network.ConnScope) *conn {
+func newConn(tr tpt.Transport, sess *webtransport.Session, sconn *connSecurityMultiaddrs, scope network.ConnScope) *conn {
 	return &conn{
 		connSecurityMultiaddrs: sconn,
 		transport:              tr,
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 02ee9ace04..4985b9e6ec 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -171,7 +171,7 @@ func (l *listener) Accept() (tpt.CapableConn, error) {
 	}
 }
 
-func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (connSecurityMultiaddrs, error) {
+func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (*connSecurityMultiaddrs, error) {
 	local, err := toWebtransportMultiaddr(sess.LocalAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting local addr: %w", err)
@@ -194,7 +194,7 @@ func (l *listener) handshake(ctx context.Context, sess *webtransport.Session) (c
 		return nil, err
 	}
 
-	return &connSecurityMultiaddrsImpl{
+	return &connSecurityMultiaddrs{
 		ConnSecurity:   c,
 		ConnMultiaddrs: &connMultiaddrs{local: local, remote: remote},
 	}, nil
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index b960083a17..04effa9748 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -179,7 +179,7 @@ func (t *transport) dial(ctx context.Context, addr string, certHashes []multihas
 	return sess, err
 }
 
-func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p peer.ID, certHashes []multihash.DecodedMultihash) (connSecurityMultiaddrs, error) {
+func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p peer.ID, certHashes []multihash.DecodedMultihash) (*connSecurityMultiaddrs, error) {
 	local, err := toWebtransportMultiaddr(sess.LocalAddr())
 	if err != nil {
 		return nil, fmt.Errorf("error determiniting local addr: %w", err)
@@ -215,7 +215,7 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 	if err != nil {
 		return nil, err
 	}
-	return &connSecurityMultiaddrsImpl{
+	return &connSecurityMultiaddrs{
 		ConnSecurity:   c,
 		ConnMultiaddrs: &connMultiaddrs{local: local, remote: remote},
 	}, nil

From 86a058d8484700b8c24bdb39a48c0096ec8f9093 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 10:21:56 +0300
Subject: [PATCH 49/53] close the scope when the connection gater intercepts

---
 p2p/transport/webtransport/transport.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 04effa9748..62761edde5 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -143,6 +143,7 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	if t.gater != nil && !t.gater.InterceptSecured(network.DirOutbound, p, sconn) {
 		// TODO: can we close with a specific error here?
 		sess.Close()
+		scope.Done()
 		return nil, fmt.Errorf("secured connection gated")
 	}
 

From f49dd4f3229c567d5f867c64093444dd6177e7c7 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 10:52:54 +0300
Subject: [PATCH 50/53] clarify comment about certificate hash verification

---
 p2p/transport/webtransport/transport.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index 62761edde5..b6434c7b7b 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -195,7 +195,8 @@ func (t *transport) upgrade(ctx context.Context, sess *webtransport.Session, p p
 		return nil, err
 	}
 
-	// Now run a Noise handshake (using early data) and verify the cert hash.
+	// Now run a Noise handshake (using early data) and send all the certificate hashes that we would have accepted.
+	// The server will verify that it advertised all of these certificate hashes.
 	msg := pb.WebTransport{CertHashes: make([][]byte, 0, len(certHashes))}
 	for _, certHash := range certHashes {
 		h, err := multihash.Encode(certHash.Digest, certHash.Code)

From 7714b04df5e7302a847ebdaae37635c47629162e Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 11:51:13 +0300
Subject: [PATCH 51/53] drop incoming sessions when the accept queue fills up
 (#24)

---
 p2p/transport/webtransport/listener.go       |  9 ++++--
 p2p/transport/webtransport/transport_test.go | 32 ++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 4985b9e6ec..902bba9f27 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -158,8 +158,13 @@ func (l *listener) httpHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// TODO: think about what happens when this channel fills up
-	l.queue <- newConn(l.transport, sess, sconn, connScope)
+	select {
+	case l.queue <- newConn(l.transport, sess, sconn, connScope):
+	default:
+		log.Debugw("accept queue full, dropping incoming connection", "peer", sconn.RemotePeer(), "addr", r.RemoteAddr, "error", err)
+		sess.Close()
+		connScope.Done()
+	}
 }
 
 func (l *listener) Accept() (tpt.CapableConn, error) {
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 02f065bc8c..ab9649b0a3 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -24,6 +24,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/network"
 	mocknetwork "github.com/libp2p/go-libp2p/core/network/mocks"
 	"github.com/libp2p/go-libp2p/core/peer"
+	tpt "github.com/libp2p/go-libp2p/core/transport"
 
 	"github.com/golang/mock/gomock"
 	ma "github.com/multiformats/go-multiaddr"
@@ -510,3 +511,34 @@ func TestStaticTLSConf(t *testing.T) {
 		defer conn.Close()
 	})
 }
+
+func TestAcceptQueueFilledUp(t *testing.T) {
+	serverID, serverKey := newIdentity(t)
+	tr, err := libp2pwebtransport.New(serverKey, nil, network.NullResourceManager)
+	require.NoError(t, err)
+	defer tr.(io.Closer).Close()
+	ln, err := tr.Listen(ma.StringCast("/ip4/127.0.0.1/udp/0/quic/webtransport"))
+	require.NoError(t, err)
+	defer ln.Close()
+
+	newConn := func() (tpt.CapableConn, error) {
+		t.Helper()
+		_, key := newIdentity(t)
+		cl, err := libp2pwebtransport.New(key, nil, network.NullResourceManager)
+		require.NoError(t, err)
+		defer cl.(io.Closer).Close()
+		return cl.Dial(context.Background(), ln.Multiaddr(), serverID)
+	}
+
+	for i := 0; i < 16; i++ {
+		conn, err := newConn()
+		require.NoError(t, err)
+		defer conn.Close()
+	}
+
+	conn, err := newConn()
+	if err == nil {
+		_, err = conn.AcceptStream()
+	}
+	require.Error(t, err)
+}

From 98ff0c65518a9abfdca6a5efa8902ac0a2f275f3 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 12:30:55 +0300
Subject: [PATCH 52/53] fix CanDial for addresses that don't contain any
 certificate hashes (#25)

---
 p2p/transport/webtransport/transport.go      | 5 ++---
 p2p/transport/webtransport/transport_test.go | 9 +++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index b6434c7b7b..d674f3de19 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -231,9 +231,8 @@ func (t *transport) CanDial(addr ma.Multiaddr) bool {
 		}
 		return true
 	})
-	if numHashes == 0 {
-		return false
-	}
+	// Remove the /certhash components from the multiaddr.
+	// If the multiaddr doesn't contain any certhashes, the node might have a CA-signed certificate.
 	for i := 0; i < numHashes; i++ {
 		addr, _ = ma.SplitLast(addr)
 	}
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index ab9649b0a3..6713ec7af1 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -177,13 +177,13 @@ func TestCanDial(t *testing.T) {
 		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),
 		ma.StringCast("/ip6/b16b:8255:efc6:9cd5:1a54:ee86:2d7a:c2e6/udp/1234/quic/webtransport/certhash/" + randomMultihash(t)),
 		ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s/certhash/%s/certhash/%s", randomMultihash(t), randomMultihash(t), randomMultihash(t))),
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport"), // no certificate hash
 	}
 
 	invalid := []ma.Multiaddr{
-		ma.StringCast("/ip4/127.0.0.1/udp/1234"),                   // missing webtransport
-		ma.StringCast("/ip4/127.0.0.1/udp/1234/webtransport"),      // missing quic
-		ma.StringCast("/ip4/127.0.0.1/tcp/1234/webtransport"),      // WebTransport over TCP? Is this a joke?
-		ma.StringCast("/ip4/127.0.0.1/udp/1234/quic/webtransport"), // missing certificate hash
+		ma.StringCast("/ip4/127.0.0.1/udp/1234"),              // missing webtransport
+		ma.StringCast("/ip4/127.0.0.1/udp/1234/webtransport"), // missing quic
+		ma.StringCast("/ip4/127.0.0.1/tcp/1234/webtransport"), // WebTransport over TCP? Is this a joke?
 	}
 
 	_, key := newIdentity(t)
@@ -506,6 +506,7 @@ func TestStaticTLSConf(t *testing.T) {
 		require.NoError(t, err)
 		defer cl.(io.Closer).Close()
 
+		require.True(t, cl.CanDial(ln.Multiaddr()))
 		conn, err := cl.Dial(context.Background(), ln.Multiaddr(), serverID)
 		require.NoError(t, err)
 		defer conn.Close()

From 73b3d566f3a30acb33a285a6ecb37d94f0d5422d Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 7 Sep 2022 12:34:32 +0300
Subject: [PATCH 53/53] webtransport: adjust import paths

---
 go.mod                                       | 5 ++++-
 go.sum                                       | 6 ++++++
 p2p/transport/webtransport/listener.go       | 4 ++--
 p2p/transport/webtransport/transport.go      | 3 +--
 p2p/transport/webtransport/transport_test.go | 4 +---
 5 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/go.mod b/go.mod
index 64b2a600b3..20221b2805 100644
--- a/go.mod
+++ b/go.mod
@@ -33,6 +33,7 @@ require (
 	github.com/libp2p/zeroconf/v2 v2.2.0
 	github.com/lucas-clemente/quic-go v0.29.0
 	github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd
+	github.com/marten-seemann/webtransport-go v0.1.0
 	github.com/mikioh/tcpinfo v0.0.0-20190314235526-30a79bb1804b
 	github.com/minio/sha256-simd v1.0.0
 	github.com/mr-tron/base58 v1.2.0
@@ -40,6 +41,7 @@ require (
 	github.com/multiformats/go-multiaddr v0.6.0
 	github.com/multiformats/go-multiaddr-dns v0.3.1
 	github.com/multiformats/go-multiaddr-fmt v0.1.0
+	github.com/multiformats/go-multibase v0.1.1
 	github.com/multiformats/go-multicodec v0.5.0
 	github.com/multiformats/go-multihash v0.2.1
 	github.com/multiformats/go-multistream v0.3.3
@@ -81,6 +83,7 @@ require (
 	github.com/klauspost/cpuid/v2 v2.1.0 // indirect
 	github.com/koron/go-ssdp v0.0.3 // indirect
 	github.com/libp2p/go-cidranger v1.1.0 // indirect
+	github.com/marten-seemann/qpack v0.2.1 // indirect
 	github.com/marten-seemann/qtls-go1-18 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-19 v0.1.0 // indirect
 	github.com/mattn/go-isatty v0.0.16 // indirect
@@ -89,7 +92,6 @@ require (
 	github.com/miekg/dns v1.1.50 // indirect
 	github.com/mikioh/tcpopt v0.0.0-20190314235656-172688c1accc // indirect
 	github.com/multiformats/go-base36 v0.1.0 // indirect
-	github.com/multiformats/go-multibase v0.1.1 // indirect
 	github.com/nxadm/tail v1.4.8 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
 	github.com/opencontainers/runtime-spec v1.0.2 // indirect
@@ -107,6 +109,7 @@ require (
 	golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e // indirect
 	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
 	golang.org/x/net v0.0.0-20220812174116-3211cb980234 // indirect
+	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/tools v0.1.12 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
diff --git a/go.sum b/go.sum
index 402c81cfc4..3bc941c299 100644
--- a/go.sum
+++ b/go.sum
@@ -321,12 +321,16 @@ github.com/lucas-clemente/quic-go v0.29.0/go.mod h1:CTcNfLYJS2UuRNB+zcNlgvkjBhxX
 github.com/lunixbochs/vtclean v1.0.0/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm/+2c2E2WMI=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mailru/easyjson v0.0.0-20190312143242-1de009706dbe/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
+github.com/marten-seemann/qpack v0.2.1 h1:jvTsT/HpCn2UZJdP+UUB53FfUUgeOyG5K1ns0OJOGVs=
+github.com/marten-seemann/qpack v0.2.1/go.mod h1:F7Gl5L1jIgN1D11ucXefiuJS9UMVP2opoCp2jDKb7wc=
 github.com/marten-seemann/qtls-go1-18 v0.1.2 h1:JH6jmzbduz0ITVQ7ShevK10Av5+jBEKAHMntXmIV7kM=
 github.com/marten-seemann/qtls-go1-18 v0.1.2/go.mod h1:mJttiymBAByA49mhlNZZGrH5u1uXYZJ+RW28Py7f4m4=
 github.com/marten-seemann/qtls-go1-19 v0.1.0 h1:rLFKD/9mp/uq1SYGYuVZhm83wkmU95pK5df3GufyYYU=
 github.com/marten-seemann/qtls-go1-19 v0.1.0/go.mod h1:5HTDWtVudo/WFsHKRNuOhWlbdjrfs5JHrYb0wIJqGpI=
 github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd h1:br0buuQ854V8u83wA0rVZ8ttrq5CpaPZdvrK0LP2lOk=
 github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd/go.mod h1:QuCEs1Nt24+FYQEqAAncTDPJIuGs+LxK1MCiFL25pMU=
+github.com/marten-seemann/webtransport-go v0.1.0 h1:tKknMOI+9fmMTPRJv3Fz7XpDq67Tg8Va8B1QEE+qaZw=
+github.com/marten-seemann/webtransport-go v0.1.0/go.mod h1:CACJOFSohYRmnqHWHWZ2rpTr9MfA0pNqOSkpqb6J/+w=
 github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
@@ -393,6 +397,7 @@ github.com/nxadm/tail v1.4.8/go.mod h1:+ncqLTQzXmGhMZNUePPaPqPvBxHAIsmXswZKocGu+
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
+github.com/onsi/ginkgo v1.14.0/go.mod h1:iSB4RoI2tjJc9BBv4NKIKWKya62Rps+oPG/Lv9klQyY=
 github.com/onsi/ginkgo v1.16.5 h1:8xi0RTUf59SOSfEtZMvwTvXYMzG4gV23XVHOZiXNtnE=
 github.com/onsi/ginkgo v1.16.5/go.mod h1:+E8gABHa3K6zRBolWtd+ROzc/U5bkGt0FwiG042wbpU=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
@@ -695,6 +700,7 @@ golang.org/x/sys v0.0.0-20200331124033-c3d80250170d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200501052902-10377860bb8e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200511232937-7e40ca221e25/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200523222454-059865788121/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200615200032-f1bc736245b1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
diff --git a/p2p/transport/webtransport/listener.go b/p2p/transport/webtransport/listener.go
index 902bba9f27..ca8fe1cf35 100644
--- a/p2p/transport/webtransport/listener.go
+++ b/p2p/transport/webtransport/listener.go
@@ -5,8 +5,6 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
-	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
-	"github.com/multiformats/go-multihash"
 	"net"
 	"net/http"
 	"time"
@@ -15,11 +13,13 @@ import (
 	"github.com/libp2p/go-libp2p/core/network"
 	tpt "github.com/libp2p/go-libp2p/core/transport"
 	"github.com/libp2p/go-libp2p/p2p/security/noise"
+	pb "github.com/libp2p/go-libp2p/p2p/transport/webtransport/pb"
 
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/marten-seemann/webtransport-go"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
+	"github.com/multiformats/go-multihash"
 )
 
 var errClosed = errors.New("closed")
diff --git a/p2p/transport/webtransport/transport.go b/p2p/transport/webtransport/transport.go
index d674f3de19..03cacb133c 100644
--- a/p2p/transport/webtransport/transport.go
+++ b/p2p/transport/webtransport/transport.go
@@ -9,14 +9,13 @@ import (
 	"sync"
 	"time"
 
-	pb "github.com/marten-seemann/go-libp2p-webtransport/pb"
-
 	"github.com/libp2p/go-libp2p/core/connmgr"
 	ic "github.com/libp2p/go-libp2p/core/crypto"
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
 	tpt "github.com/libp2p/go-libp2p/core/transport"
 	"github.com/libp2p/go-libp2p/p2p/security/noise"
+	pb "github.com/libp2p/go-libp2p/p2p/transport/webtransport/pb"
 
 	"github.com/benbjohnson/clock"
 	logging "github.com/ipfs/go-log/v2"
diff --git a/p2p/transport/webtransport/transport_test.go b/p2p/transport/webtransport/transport_test.go
index 6713ec7af1..92680fafbe 100644
--- a/p2p/transport/webtransport/transport_test.go
+++ b/p2p/transport/webtransport/transport_test.go
@@ -18,20 +18,18 @@ import (
 	"testing"
 	"time"
 
-	libp2pwebtransport "github.com/marten-seemann/go-libp2p-webtransport"
-
 	ic "github.com/libp2p/go-libp2p/core/crypto"
 	"github.com/libp2p/go-libp2p/core/network"
 	mocknetwork "github.com/libp2p/go-libp2p/core/network/mocks"
 	"github.com/libp2p/go-libp2p/core/peer"
 	tpt "github.com/libp2p/go-libp2p/core/transport"
+	libp2pwebtransport "github.com/libp2p/go-libp2p/p2p/transport/webtransport"
 
 	"github.com/golang/mock/gomock"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
 	"github.com/multiformats/go-multibase"
 	"github.com/multiformats/go-multihash"
-
 	"github.com/stretchr/testify/require"
 )