Implements Stateless Reset parsing

agents/parse_agent.go

@@ -108,10 +108,18 @@ func (a *ParsingAgent) Run(conn *Connection) {
 						payload := cryptoState.Read.Decrypt(ciphertext[hLen:], uint64(header.PacketNumber()), ciphertext[:hLen])
 						if payload == nil {
 							a.Logger.Printf("Could not decrypt packet {type=%s, number=%d}\n", header.PacketType().String(), header.PacketNumber())
-							break packetSelect
+							statelessResetToken := ciphertext[len(ciphertext)-16:]
+							if bytes.Equal(statelessResetToken, conn.TLSTPHandler.ReceivedParameters.StatelessResetToken) {
+								a.Logger.Println("Received a Stateless Reset packet")
+								cleartext = ciphertext
+								packet = ReadStatelessResetPacket(bytes.NewReader(ciphertext))
+							} else {
+								break packetSelect
+							}
+						} else {
+							cleartext = append(append(cleartext, ic.Payload[off:off+hLen]...), payload...)
+							packet = ReadProtectedPacket(bytes.NewReader(cleartext), a.conn)
 						}
-						cleartext = append(append(cleartext, ic.Payload[off:off+hLen]...), payload...)
-						packet = ReadProtectedPacket(bytes.NewReader(cleartext), a.conn)
 						consumed = len(ic.Payload)
 					case Retry:
 						cleartext = ciphertext

packets.go

@@ -375,3 +375,21 @@ func NewZeroRTTProtectedPacket(conn *Connection) *ZeroRTTProtectedPacket {
 	return p
 }
 
+type StatelessResetPacket struct {
+	abstractPacket
+	UnpredictableBits []byte
+	StatelessResetToken [16]byte
+}
+func (*StatelessResetPacket) ShouldBeAcknowledged() bool { return false }
+func (*StatelessResetPacket) PNSpace() PNSpace { return PNSpaceNoSpace }
+func (p *StatelessResetPacket) Pointer() unsafe.Pointer { return unsafe.Pointer(p) }
+func (*StatelessResetPacket) EncryptionLevel() EncryptionLevel { return EncryptionLevelNone }
+func ( StatelessResetPacket) EncodePayload() []byte { return nil }
+
+func ReadStatelessResetPacket(buffer *bytes.Reader) *StatelessResetPacket {
+	p := new(StatelessResetPacket)
+	p.UnpredictableBits = make([]byte, buffer.Len() - len(p.StatelessResetToken))
+	buffer.Read(p.UnpredictableBits)
+	buffer.Read(p.StatelessResetToken[:])
+	return p
+}

qlog/qt2qlog/qt2qlog.go

@@ -30,7 +30,7 @@ func ConvertPacket(p Packet) *qlog.Packet {
 	}
 	// TODO handle PacketSize computation here
 	switch p.(type) {
-	case *VersionNegotiationPacket, *RetryPacket:
+	case *VersionNegotiationPacket, *RetryPacket, *StatelessResetPacket:
 	default:
 		j.Header.PacketNumber = uint64(p.Header().PacketNumber())
 	}