make the idle_timeout transport parameter optional

internal/handshake/transport_parameter_test.go

@@ -160,12 +160,6 @@ var _ = Describe("Transport Parameters", func() {
 				Expect(params.StatelessResetToken).To(Equal(statelessResetToken))
 			})
 
-			It("rejects the parameters if the idle_timeout is missing", func() {
-				delete(parameters, idleTimeoutParameterID)
-				err := params.unmarshal(marshal(parameters))
-				Expect(err).To(MatchError("missing parameter"))
-			})
-
 			It("doesn't allow values below the minimum remote idle timeout", func() {
 				t := 2 * time.Second
 				Expect(t).To(BeNumerically("<", protocol.MinRemoteIdleTimeout))

internal/handshake/transport_parameters.go

@@ -3,7 +3,6 @@ package handshake
 import (
 	"bytes"
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"time"
 
@@ -97,8 +96,6 @@ func (p *TransportParameters) getHelloMap() map[Tag][]byte {
 }
 
 func (p *TransportParameters) unmarshal(data []byte) error {
-	var foundIdleTimeout bool
-
 	for len(data) >= 4 {
 		paramID := binary.BigEndian.Uint16(data[:2])
 		paramLen := int(binary.BigEndian.Uint16(data[2:4]))
@@ -128,7 +125,6 @@ func (p *TransportParameters) unmarshal(data []byte) error {
 			}
 			p.MaxUniStreams = binary.BigEndian.Uint16(data[:2])
 		case idleTimeoutParameterID:
-			foundIdleTimeout = true
 			if paramLen != 2 {
 				return fmt.Errorf("wrong length for idle_timeout: %d (expected 2)", paramLen)
 			}
@@ -159,9 +155,6 @@ func (p *TransportParameters) unmarshal(data []byte) error {
 	if len(data) != 0 {
 		return fmt.Errorf("should have read all data. Still have %d bytes", len(data))
 	}
-	if !foundIdleTimeout {
-		return errors.New("missing parameter")
-	}
 	return nil
 }