add fuzzing for transport parameters

fuzzing/transportparameters/cmd/corpus.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"math"
+	"math/rand"
+	"net"
+	"os"
+	"time"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+
+	"github.com/lucas-clemente/quic-go/internal/wire"
+)
+
+func getRandomData(l int) []byte {
+	b := make([]byte, l)
+	rand.Read(b)
+	return b
+}
+
+func getRandomValue() uint64 {
+	maxVals := []int64{math.MaxUint8 / 4, math.MaxUint16 / 4, math.MaxUint32 / 4, math.MaxUint64 / 4}
+	return uint64(rand.Int63n(maxVals[int(rand.Int31n(4))]))
+}
+
+func main() {
+	rand.Seed(1337)
+	for i := 0; i < 20; i++ {
+		tp := &wire.TransportParameters{
+			InitialMaxStreamDataBidiLocal:  protocol.ByteCount(getRandomValue()),
+			InitialMaxStreamDataBidiRemote: protocol.ByteCount(getRandomValue()),
+			InitialMaxStreamDataUni:        protocol.ByteCount(getRandomValue()),
+			InitialMaxData:                 protocol.ByteCount(getRandomValue()),
+			MaxAckDelay:                    time.Duration(getRandomValue()),
+			AckDelayExponent:               uint8(getRandomValue()),
+			DisableActiveMigration:         getRandomValue()%2 == 0,
+			MaxUDPPayloadSize:              protocol.ByteCount(getRandomValue()),
+			MaxUniStreamNum:                protocol.StreamNum(getRandomValue()),
+			MaxBidiStreamNum:               protocol.StreamNum(getRandomValue()),
+			MaxIdleTimeout:                 time.Duration(getRandomValue()),
+			ActiveConnectionIDLimit:        getRandomValue(),
+		}
+		if rand.Int()%2 == 0 {
+			tp.OriginalDestinationConnectionID = protocol.ConnectionID(getRandomData(rand.Intn(50)))
+		}
+		if rand.Int()%2 == 0 {
+			tp.InitialSourceConnectionID = protocol.ConnectionID(getRandomData(rand.Intn(50)))
+		}
+		if rand.Int()%2 == 0 {
+			connID := protocol.ConnectionID(getRandomData(rand.Intn(50)))
+			tp.RetrySourceConnectionID = &connID
+		}
+		if rand.Int()%2 == 0 {
+			var token protocol.StatelessResetToken
+			rand.Read(token[:])
+			tp.StatelessResetToken = &token
+		}
+		if rand.Int()%2 == 0 {
+			var token protocol.StatelessResetToken
+			rand.Read(token[:])
+			tp.PreferredAddress = &wire.PreferredAddress{
+				IPv4:                net.IPv4(uint8(rand.Int()), uint8(rand.Int()), uint8(rand.Int()), uint8(rand.Int())),
+				IPv4Port:            uint16(rand.Int()),
+				IPv6:                net.IP(getRandomData(16)),
+				IPv6Port:            uint16(rand.Int()),
+				ConnectionID:        protocol.ConnectionID(getRandomData(rand.Intn(25))),
+				StatelessResetToken: token,
+			}
+		}
+		pers := protocol.PerspectiveServer
+		if rand.Int()%2 == 0 {
+			pers = protocol.PerspectiveClient
+		}
+		if err := writeCorpusFile(fmt.Sprintf("tp%d", i), tp.Marshal(pers)); err != nil {
+			log.Fatal(err)
+		}
+	}
+}
+
+func writeCorpusFile(name string, data []byte) error {
+	file, err := os.Create("corpus/" + name)
+	if err != nil {
+		return err
+	}
+	data = append(getRandomData(2), data...)
+	if _, err := file.Write(data); err != nil {
+		return err
+	}
+	return file.Close()
+}

fuzzing/transportparameters/fuzz.go

@@ -0,0 +1,56 @@
+package transportparameters
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/wire"
+)
+
+//go:generate go run ./cmd/corpus.go
+func Fuzz(data []byte) int {
+	if len(data) <= 1 {
+		return 0
+	}
+
+	if data[0]%2 == 0 {
+		return fuzzTransportParametersForSessionTicket(data[1:])
+	}
+	return fuzzTransportParameters(data[1:])
+}
+
+func fuzzTransportParameters(data []byte) int {
+	perspective := protocol.PerspectiveServer
+	if data[0]%2 == 1 {
+		perspective = protocol.PerspectiveServer
+	}
+	data = data[1:]
+
+	tp := &wire.TransportParameters{}
+	if err := tp.Unmarshal(data, perspective); err != nil {
+		return 0
+	}
+	_ = tp.String()
+
+	tp2 := &wire.TransportParameters{}
+	if err := tp2.Unmarshal(tp.Marshal(perspective), perspective); err != nil {
+		fmt.Printf("%#v\n", tp)
+		panic(err)
+	}
+	return 1
+}
+
+func fuzzTransportParametersForSessionTicket(data []byte) int {
+	tp := &wire.TransportParameters{}
+	if err := tp.UnmarshalFromSessionTicket(bytes.NewReader(data)); err != nil {
+		return 0
+	}
+	buf := &bytes.Buffer{}
+	tp.MarshalForSessionTicket(buf)
+	tp2 := &wire.TransportParameters{}
+	if err := tp2.UnmarshalFromSessionTicket(bytes.NewReader(buf.Bytes())); err != nil {
+		panic(err)
+	}
+	return 1
+}

internal/wire/transport_parameters.go

@@ -358,9 +358,11 @@ func (p *TransportParameters) Marshal(pers protocol.Perspective) []byte {
 	}
 	if pers == protocol.PerspectiveServer {
 		// stateless_reset_token
-		utils.WriteVarInt(b, uint64(statelessResetTokenParameterID))
-		utils.WriteVarInt(b, 16)
-		b.Write(p.StatelessResetToken[:])
+		if p.StatelessResetToken != nil {
+			utils.WriteVarInt(b, uint64(statelessResetTokenParameterID))
+			utils.WriteVarInt(b, 16)
+			b.Write(p.StatelessResetToken[:])
+		}
 		// original_destination_connection_id
 		utils.WriteVarInt(b, uint64(originalDestinationConnectionIDParameterID))
 		utils.WriteVarInt(b, uint64(p.OriginalDestinationConnectionID.Len()))