cloudflared/connection/quic_test.go
chungthuang e2064c820f TUN-8592: Use metadata from the edge to determine if request body is empty for QUIC transport
If the metadata is missing, fallback to decide based on protocol, http
method, transferring and content length
2024-10-07 10:51:21 -05:00

899 lines
22 KiB
Go

package connection
import (
"bytes"
"context"
"crypto/rand"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"encoding/pem"
"fmt"
"io"
"math/big"
"net"
"net/http"
"net/url"
"os"
"strings"
"testing"
"time"
"github.com/gobwas/ws/wsutil"
"github.com/google/uuid"
"github.com/pkg/errors"
"github.com/quic-go/quic-go"
"github.com/rs/zerolog"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"github.com/cloudflare/cloudflared/datagramsession"
cfdquic "github.com/cloudflare/cloudflared/quic"
"github.com/cloudflare/cloudflared/tracing"
"github.com/cloudflare/cloudflared/tunnelrpc/pogs"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
rpcquic "github.com/cloudflare/cloudflared/tunnelrpc/quic"
)
var (
testTLSServerConfig = GenerateTLSConfig()
testQUICConfig = &quic.Config{
KeepAlivePeriod: 5 * time.Second,
EnableDatagrams: true,
}
defaultQUICTimeout = 30 * time.Second
)
var _ ReadWriteAcker = (*streamReadWriteAcker)(nil)
// TestQUICServer tests if a quic server accepts and responds to a quic client with the acceptance protocol.
// It also serves as a demonstration for communication with the QUIC connection started by a cloudflared.
func TestQUICServer(t *testing.T) {
// This is simply a sample websocket frame message.
wsBuf := &bytes.Buffer{}
wsutil.WriteClientBinary(wsBuf, []byte("Hello"))
var tests = []struct {
desc string
dest string
connectionType pogs.ConnectionType
metadata []pogs.Metadata
message []byte
expectedResponse []byte
}{
{
desc: "test http proxy",
dest: "/ok",
connectionType: pogs.ConnectionTypeHTTP,
metadata: []pogs.Metadata{
{
Key: "HttpHeader:Cf-Ray",
Val: "123123123",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "GET",
},
},
expectedResponse: []byte("OK"),
},
{
desc: "test http body request streaming",
dest: "/slow_echo_body",
connectionType: pogs.ConnectionTypeHTTP,
metadata: []pogs.Metadata{
{
Key: "HttpHeader:Cf-Ray",
Val: "123123123",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "POST",
},
{
Key: "HttpHeader:Content-Length",
Val: "24",
},
},
message: []byte("This is the message body"),
expectedResponse: []byte("This is the message body"),
},
{
desc: "test ws proxy",
dest: "/ws/echo",
connectionType: pogs.ConnectionTypeWebsocket,
metadata: []pogs.Metadata{
{
Key: "HttpHeader:Cf-Cloudflared-Proxy-Connection-Upgrade",
Val: "Websocket",
},
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
message: wsBuf.Bytes(),
expectedResponse: []byte{0x82, 0x5, 0x48, 0x65, 0x6c, 0x6c, 0x6f},
},
{
desc: "test tcp proxy",
connectionType: pogs.ConnectionTypeTCP,
metadata: []pogs.Metadata{},
message: []byte("Here is some tcp data"),
expectedResponse: []byte("Here is some tcp data"),
},
}
for i, test := range tests {
test := test // capture range variable
t.Run(test.desc, func(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
// Start a UDP Listener for QUIC.
udpAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:0")
require.NoError(t, err)
udpListener, err := net.ListenUDP(udpAddr.Network(), udpAddr)
require.NoError(t, err)
defer udpListener.Close()
quicTransport := &quic.Transport{Conn: udpListener, ConnectionIDLength: 16}
quicListener, err := quicTransport.Listen(testTLSServerConfig, testQUICConfig)
require.NoError(t, err)
serverDone := make(chan struct{})
go func() {
quicServer(
ctx, t, quicListener, test.dest, test.connectionType, test.metadata, test.message, test.expectedResponse,
)
close(serverDone)
}()
qc := testQUICConnection(udpListener.LocalAddr(), t, uint8(i))
connDone := make(chan struct{})
go func() {
qc.Serve(ctx)
close(connDone)
}()
<-serverDone
cancel()
<-connDone
})
}
}
type fakeControlStream struct {
ControlStreamHandler
}
func (fakeControlStream) ServeControlStream(ctx context.Context, rw io.ReadWriteCloser, connOptions *pogs.ConnectionOptions, tunnelConfigGetter TunnelConfigJSONGetter) error {
<-ctx.Done()
return nil
}
func (fakeControlStream) IsStopped() bool {
return true
}
func quicServer(
ctx context.Context,
t *testing.T,
listener *quic.Listener,
dest string,
connectionType pogs.ConnectionType,
metadata []pogs.Metadata,
message []byte,
expectedResponse []byte,
) {
session, err := listener.Accept(ctx)
require.NoError(t, err)
quicStream, err := session.OpenStreamSync(context.Background())
require.NoError(t, err)
stream := cfdquic.NewSafeStreamCloser(quicStream, defaultQUICTimeout, &log)
reqClientStream := rpcquic.RequestClientStream{ReadWriteCloser: stream}
err = reqClientStream.WriteConnectRequestData(dest, connectionType, metadata...)
require.NoError(t, err)
_, err = reqClientStream.ReadConnectResponseData()
require.NoError(t, err)
if message != nil {
// ALPN successful. Write data.
_, err := stream.Write(message)
require.NoError(t, err)
}
response := make([]byte, len(expectedResponse))
_, err = stream.Read(response)
if err != io.EOF {
require.NoError(t, err)
}
// For now it is an echo server. Verify if the same data is returned.
assert.Equal(t, expectedResponse, response)
}
type mockOriginProxyWithRequest struct{}
func (moc *mockOriginProxyWithRequest) ProxyHTTP(w ResponseWriter, tr *tracing.TracedHTTPRequest, isWebsocket bool) error {
// These are a series of crude tests to ensure the headers and http related data is transferred from
// metadata.
r := tr.Request
if r.Method == "" {
return errors.New("method not sent")
}
if r.Host == "" {
return errors.New("host not sent")
}
if len(r.Header) == 0 {
return errors.New("headers not set")
}
if isWebsocket {
return wsEchoEndpoint(w, r)
}
switch r.URL.Path {
case "/ok":
originRespEndpoint(w, http.StatusOK, []byte(http.StatusText(http.StatusOK)))
case "/slow_echo_body":
time.Sleep(5)
fallthrough
case "/echo_body":
resp := &http.Response{
StatusCode: http.StatusOK,
}
_ = w.WriteRespHeaders(resp.StatusCode, resp.Header)
io.Copy(w, r.Body)
case "/error":
return fmt.Errorf("Failed to proxy to origin")
default:
originRespEndpoint(w, http.StatusNotFound, []byte("page not found"))
}
return nil
}
func TestBuildHTTPRequest(t *testing.T) {
var tests = []struct {
name string
connectRequest *pogs.ConnectRequest
body io.ReadCloser
req *http.Request
}{
{
name: "check if http.Request is built correctly with content length",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Cf-Cloudflared-Proxy-Connection-Upgrade",
Val: "Websocket",
},
{
Key: "HttpHeader:Content-Length",
Val: "514",
},
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
},
req: &http.Request{
Method: "get",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
"Content-Length": []string{"514"},
},
ContentLength: 514,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if content length isn't part of request headers, then it's not set",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Cf-Cloudflared-Proxy-Connection-Upgrade",
Val: "Websocket",
},
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
},
req: &http.Request{
Method: "get",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
},
ContentLength: 0,
Host: "cf.host",
Body: http.NoBody,
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if content length is 0, but transfer-encoding is chunked, body is not nil",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHeader:Transfer-Encoding",
Val: "chunked",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
},
req: &http.Request{
Method: "get",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
"Transfer-Encoding": []string{"chunked"},
},
ContentLength: 0,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if content length is 0, but transfer-encoding is gzip,chunked, body is not nil",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHeader:Transfer-Encoding",
Val: "gzip,chunked",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
},
req: &http.Request{
Method: "get",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
"Transfer-Encoding": []string{"gzip,chunked"},
},
ContentLength: 0,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if content length is 0, and connect request is a websocket, body is not nil",
connectRequest: &pogs.ConnectRequest{
Type: pogs.ConnectionTypeWebsocket,
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "get",
},
},
},
req: &http.Request{
Method: "get",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
},
ContentLength: 0,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if edge sends the body is empty hint, set body to empty",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "put",
},
{
Key: HTTPRequestBodyHintKey,
Val: RequestBodyHintEmpty.String(),
},
},
},
req: &http.Request{
Method: "put",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
},
ContentLength: 0,
Host: "cf.host",
Body: http.NoBody,
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if edge sends the body has data hint, don't set body to empty",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "put",
},
{
Key: HTTPRequestBodyHintKey,
Val: RequestBodyHintHasData.String(),
},
},
},
req: &http.Request{
Method: "put",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
},
ContentLength: 0,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
{
name: "if the http method usually has body, don't set body to empty",
connectRequest: &pogs.ConnectRequest{
Dest: "http://test.com",
Metadata: []pogs.Metadata{
{
Key: "HttpHeader:Another-Header",
Val: "Misc",
},
{
Key: "HttpHost",
Val: "cf.host",
},
{
Key: "HttpMethod",
Val: "post",
},
},
},
req: &http.Request{
Method: "post",
URL: &url.URL{
Scheme: "http",
Host: "test.com",
},
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{
"Another-Header": []string{"Misc"},
},
ContentLength: 0,
Host: "cf.host",
Body: io.NopCloser(&bytes.Buffer{}),
},
body: io.NopCloser(&bytes.Buffer{}),
},
}
log := zerolog.Nop()
for _, test := range tests {
test := test // capture range variable
t.Run(test.name, func(t *testing.T) {
req, err := buildHTTPRequest(context.Background(), test.connectRequest, test.body, 0, &log)
assert.NoError(t, err)
test.req = test.req.WithContext(req.Context())
assert.Equal(t, test.req, req.Request)
})
}
}
func (moc *mockOriginProxyWithRequest) ProxyTCP(ctx context.Context, rwa ReadWriteAcker, tcpRequest *TCPRequest) error {
rwa.AckConnection("")
io.Copy(rwa, rwa)
return nil
}
func TestServeUDPSession(t *testing.T) {
// Start a UDP Listener for QUIC.
udpAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:0")
require.NoError(t, err)
udpListener, err := net.ListenUDP(udpAddr.Network(), udpAddr)
require.NoError(t, err)
defer udpListener.Close()
ctx, cancel := context.WithCancel(context.Background())
val := udpListener.LocalAddr()
// Establish QUIC connection with edge
edgeQUICSessionChan := make(chan quic.Connection)
go func() {
earlyListener, err := quic.Listen(udpListener, testTLSServerConfig, testQUICConfig)
require.NoError(t, err)
edgeQUICSession, err := earlyListener.Accept(ctx)
require.NoError(t, err)
edgeQUICSessionChan <- edgeQUICSession
}()
// Random index to avoid reusing port
qc := testQUICConnection(val, t, 28)
go qc.Serve(ctx)
edgeQUICSession := <-edgeQUICSessionChan
serveSession(ctx, qc, edgeQUICSession, closedByOrigin, io.EOF.Error(), t)
serveSession(ctx, qc, edgeQUICSession, closedByTimeout, datagramsession.SessionIdleErr(time.Millisecond*50).Error(), t)
serveSession(ctx, qc, edgeQUICSession, closedByRemote, "eyeball closed connection", t)
cancel()
}
func TestNopCloserReadWriterCloseBeforeEOF(t *testing.T) {
readerWriter := nopCloserReadWriter{ReadWriteCloser: &mockReaderNoopWriter{Reader: strings.NewReader("123456789")}}
buffer := make([]byte, 5)
n, err := readerWriter.Read(buffer)
require.NoError(t, err)
require.Equal(t, n, 5)
// close
require.NoError(t, readerWriter.Close())
// read should get error
n, err = readerWriter.Read(buffer)
require.Equal(t, n, 0)
require.Equal(t, err, fmt.Errorf("closed by handler"))
}
func TestNopCloserReadWriterCloseAfterEOF(t *testing.T) {
readerWriter := nopCloserReadWriter{ReadWriteCloser: &mockReaderNoopWriter{Reader: strings.NewReader("123456789")}}
buffer := make([]byte, 20)
n, err := readerWriter.Read(buffer)
require.NoError(t, err)
require.Equal(t, n, 9)
// force another read to read eof
_, err = readerWriter.Read(buffer)
require.Equal(t, err, io.EOF)
// close
require.NoError(t, readerWriter.Close())
// read should get EOF still
n, err = readerWriter.Read(buffer)
require.Equal(t, n, 0)
require.Equal(t, err, io.EOF)
}
func TestCreateUDPConnReuseSourcePort(t *testing.T) {
logger := zerolog.Nop()
conn, err := createUDPConnForConnIndex(0, nil, &logger)
require.NoError(t, err)
getPortFunc := func(conn *net.UDPConn) int {
addr := conn.LocalAddr().(*net.UDPAddr)
return addr.Port
}
initialPort := getPortFunc(conn)
// close conn
conn.Close()
// should get the same port as before.
conn, err = createUDPConnForConnIndex(0, nil, &logger)
require.NoError(t, err)
require.Equal(t, initialPort, getPortFunc(conn))
// new index, should get a different port
conn1, err := createUDPConnForConnIndex(1, nil, &logger)
require.NoError(t, err)
require.NotEqual(t, initialPort, getPortFunc(conn1))
// not closing the conn and trying to obtain a new conn for same index should give a different random port
conn, err = createUDPConnForConnIndex(0, nil, &logger)
require.NoError(t, err)
require.NotEqual(t, initialPort, getPortFunc(conn))
}
func serveSession(ctx context.Context, qc *QUICConnection, edgeQUICSession quic.Connection, closeType closeReason, expectedReason string, t *testing.T) {
var (
payload = []byte(t.Name())
)
sessionID := uuid.New()
cfdConn, originConn := net.Pipe()
// Registers and run a new session
session, err := qc.sessionManager.RegisterSession(ctx, sessionID, cfdConn)
require.NoError(t, err)
sessionDone := make(chan struct{})
go func() {
qc.serveUDPSession(session, time.Millisecond*50)
close(sessionDone)
}()
// Send a message to the quic session on edge side, it should be deumx to this datagram v2 session
muxedPayload, err := cfdquic.SuffixSessionID(sessionID, payload)
require.NoError(t, err)
muxedPayload, err = cfdquic.SuffixType(muxedPayload, cfdquic.DatagramTypeUDP)
require.NoError(t, err)
err = edgeQUICSession.SendDatagram(muxedPayload)
require.NoError(t, err)
readBuffer := make([]byte, len(payload)+1)
n, err := originConn.Read(readBuffer)
require.NoError(t, err)
require.Equal(t, len(payload), n)
require.True(t, bytes.Equal(payload, readBuffer[:n]))
// Close connection to terminate session
switch closeType {
case closedByOrigin:
originConn.Close()
case closedByRemote:
err = qc.UnregisterUdpSession(ctx, sessionID, expectedReason)
require.NoError(t, err)
case closedByTimeout:
}
if closeType != closedByRemote {
// Session was not closed by remote, so closeUDPSession should be invoked to unregister from remote
unregisterFromEdgeChan := make(chan struct{})
sessionRPCServer := &mockSessionRPCServer{
sessionID: sessionID,
unregisterReason: expectedReason,
calledUnregisterChan: unregisterFromEdgeChan,
}
go runRPCServer(ctx, edgeQUICSession, sessionRPCServer, nil, t)
<-unregisterFromEdgeChan
}
<-sessionDone
}
type closeReason uint8
const (
closedByOrigin closeReason = iota
closedByRemote
closedByTimeout
)
func runRPCServer(ctx context.Context, session quic.Connection, sessionRPCServer pogs.SessionManager, configRPCServer pogs.ConfigurationManager, t *testing.T) {
stream, err := session.AcceptStream(ctx)
require.NoError(t, err)
if stream.StreamID() == 0 {
// Skip the first stream, it's the control stream of the QUIC connection
stream, err = session.AcceptStream(ctx)
require.NoError(t, err)
}
ss := rpcquic.NewCloudflaredServer(
func(_ context.Context, _ *rpcquic.RequestServerStream) error {
return nil
},
sessionRPCServer,
configRPCServer,
10*time.Second,
)
err = ss.Serve(ctx, stream)
assert.NoError(t, err)
}
type mockSessionRPCServer struct {
sessionID uuid.UUID
unregisterReason string
calledUnregisterChan chan struct{}
}
func (s mockSessionRPCServer) RegisterUdpSession(ctx context.Context, sessionID uuid.UUID, dstIP net.IP, dstPort uint16, closeIdleAfter time.Duration, traceContext string) (*pogs.RegisterUdpSessionResponse, error) {
return nil, fmt.Errorf("mockSessionRPCServer doesn't implement RegisterUdpSession")
}
func (s mockSessionRPCServer) UnregisterUdpSession(ctx context.Context, sessionID uuid.UUID, reason string) error {
if s.sessionID != sessionID {
return fmt.Errorf("expect session ID %s, got %s", s.sessionID, sessionID)
}
if s.unregisterReason != reason {
return fmt.Errorf("expect unregister reason %s, got %s", s.unregisterReason, reason)
}
close(s.calledUnregisterChan)
return nil
}
func testQUICConnection(udpListenerAddr net.Addr, t *testing.T, index uint8) *QUICConnection {
tlsClientConfig := &tls.Config{
InsecureSkipVerify: true,
NextProtos: []string{"argotunnel"},
}
// Start a mock httpProxy
log := zerolog.New(os.Stdout)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
qc, err := NewQUICConnection(
ctx,
testQUICConfig,
udpListenerAddr,
nil,
index,
tlsClientConfig,
&mockOrchestrator{originProxy: &mockOriginProxyWithRequest{}},
&tunnelpogs.ConnectionOptions{},
fakeControlStream{},
&log,
nil,
15*time.Second,
0*time.Second,
0*time.Second,
)
require.NoError(t, err)
return qc
}
type mockReaderNoopWriter struct {
io.Reader
}
func (m *mockReaderNoopWriter) Write(p []byte) (n int, err error) {
return len(p), nil
}
func (m *mockReaderNoopWriter) Close() error {
return nil
}
// GenerateTLSConfig sets up a bare-bones TLS config for a QUIC server
func GenerateTLSConfig() *tls.Config {
key, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
panic(err)
}
template := x509.Certificate{SerialNumber: big.NewInt(1)}
certDER, err := x509.CreateCertificate(rand.Reader, &template, &template, &key.PublicKey, key)
if err != nil {
panic(err)
}
keyPEM := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key)})
certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: certDER})
tlsCert, err := tls.X509KeyPair(certPEM, keyPEM)
if err != nil {
panic(err)
}
return &tls.Config{
Certificates: []tls.Certificate{tlsCert},
NextProtos: []string{"argotunnel"},
}
}