uquic/fuzzing/handshake/fuzz.go
2023-08-28 14:12:03 -06:00

422 lines
12 KiB
Go

package handshake
import (
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"errors"
"fmt"
"io"
"log"
"math"
mrand "math/rand"
"net"
"time"
tls "github.com/refraction-networking/utls"
"github.com/refraction-networking/uquic/fuzzing/internal/helper"
"github.com/refraction-networking/uquic/internal/handshake"
"github.com/refraction-networking/uquic/internal/protocol"
"github.com/refraction-networking/uquic/internal/utils"
"github.com/refraction-networking/uquic/internal/wire"
)
var (
cert, clientCert *tls.Certificate
certPool, clientCertPool *x509.CertPool
sessionTicketKey = [32]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32}
)
func init() {
priv, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
log.Fatal(err)
}
cert, certPool, err = helper.GenerateCertificate(priv)
if err != nil {
log.Fatal(err)
}
privClient, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
log.Fatal(err)
}
clientCert, clientCertPool, err = helper.GenerateCertificate(privClient)
if err != nil {
log.Fatal(err)
}
}
type messageType uint8
// TLS handshake message types.
const (
typeClientHello messageType = 1
typeServerHello messageType = 2
typeNewSessionTicket messageType = 4
typeEncryptedExtensions messageType = 8
typeCertificate messageType = 11
typeCertificateRequest messageType = 13
typeCertificateVerify messageType = 15
typeFinished messageType = 20
)
func (m messageType) String() string {
switch m {
case typeClientHello:
return "ClientHello"
case typeServerHello:
return "ServerHello"
case typeNewSessionTicket:
return "NewSessionTicket"
case typeEncryptedExtensions:
return "EncryptedExtensions"
case typeCertificate:
return "Certificate"
case typeCertificateRequest:
return "CertificateRequest"
case typeCertificateVerify:
return "CertificateVerify"
case typeFinished:
return "Finished"
default:
return fmt.Sprintf("unknown message type: %d", m)
}
}
// consumes 3 bits
func getClientAuth(rand uint8) tls.ClientAuthType {
switch rand {
default:
return tls.NoClientCert
case 0:
return tls.RequestClientCert
case 1:
return tls.RequireAnyClientCert
case 2:
return tls.VerifyClientCertIfGiven
case 3:
return tls.RequireAndVerifyClientCert
}
}
const (
alpn = "fuzzing"
alpnWrong = "wrong"
)
func toEncryptionLevel(n uint8) protocol.EncryptionLevel {
switch n % 3 {
default:
return protocol.EncryptionInitial
case 1:
return protocol.EncryptionHandshake
case 2:
return protocol.Encryption1RTT
}
}
func getTransportParameters(seed uint8) *wire.TransportParameters {
const maxVarInt = math.MaxUint64 / 4
r := mrand.New(mrand.NewSource(int64(seed)))
return &wire.TransportParameters{
ActiveConnectionIDLimit: 2,
InitialMaxData: protocol.ByteCount(r.Int63n(maxVarInt)),
InitialMaxStreamDataBidiLocal: protocol.ByteCount(r.Int63n(maxVarInt)),
InitialMaxStreamDataBidiRemote: protocol.ByteCount(r.Int63n(maxVarInt)),
InitialMaxStreamDataUni: protocol.ByteCount(r.Int63n(maxVarInt)),
}
}
// PrefixLen is the number of bytes used for configuration
const (
PrefixLen = 12
confLen = 5
)
// Fuzz fuzzes the TLS 1.3 handshake used by QUIC.
//
//go:generate go run ./cmd/corpus.go
func Fuzz(data []byte) int {
if len(data) < PrefixLen {
return -1
}
dataLen := len(data)
var runConfig1, runConfig2 [confLen]byte
copy(runConfig1[:], data)
data = data[confLen:]
messageConfig1 := data[0]
data = data[1:]
copy(runConfig2[:], data)
data = data[confLen:]
messageConfig2 := data[0]
data = data[1:]
if dataLen != len(data)+PrefixLen {
panic("incorrect configuration")
}
clientConf := &tls.Config{
MinVersion: tls.VersionTLS13,
ServerName: "localhost",
NextProtos: []string{alpn},
RootCAs: certPool,
}
useSessionTicketCache := helper.NthBit(runConfig1[0], 2)
if useSessionTicketCache {
clientConf.ClientSessionCache = tls.NewLRUClientSessionCache(5)
}
if val := runHandshake(runConfig1, messageConfig1, clientConf, data); val != 1 {
return val
}
return runHandshake(runConfig2, messageConfig2, clientConf, data)
}
func runHandshake(runConfig [confLen]byte, messageConfig uint8, clientConf *tls.Config, data []byte) int {
serverConf := &tls.Config{
MinVersion: tls.VersionTLS13,
Certificates: []tls.Certificate{*cert},
NextProtos: []string{alpn},
SessionTicketKey: sessionTicketKey,
}
// This sets the cipher suite for both client and server.
// The way crypto/tls is designed doesn't allow us to set different cipher suites for client and server.
resetCipherSuite := func() {}
switch (runConfig[0] >> 6) % 4 {
case 0:
resetCipherSuite = qtls.SetCipherSuite(tls.TLS_AES_128_GCM_SHA256)
case 1:
resetCipherSuite = qtls.SetCipherSuite(tls.TLS_AES_256_GCM_SHA384)
case 3:
resetCipherSuite = qtls.SetCipherSuite(tls.TLS_CHACHA20_POLY1305_SHA256)
default:
}
defer resetCipherSuite()
enable0RTTClient := helper.NthBit(runConfig[0], 0)
enable0RTTServer := helper.NthBit(runConfig[0], 1)
sendPostHandshakeMessageToClient := helper.NthBit(runConfig[0], 3)
sendPostHandshakeMessageToServer := helper.NthBit(runConfig[0], 4)
sendSessionTicket := helper.NthBit(runConfig[0], 5)
serverConf.ClientAuth = getClientAuth(runConfig[1] & 0b00000111)
serverConf.SessionTicketsDisabled = helper.NthBit(runConfig[1], 3)
if helper.NthBit(runConfig[2], 0) {
clientConf.RootCAs = x509.NewCertPool()
}
if helper.NthBit(runConfig[2], 1) {
serverConf.ClientCAs = clientCertPool
} else {
serverConf.ClientCAs = x509.NewCertPool()
}
if helper.NthBit(runConfig[2], 2) {
serverConf.GetConfigForClient = func(*tls.ClientHelloInfo) (*tls.Config, error) {
if helper.NthBit(runConfig[2], 3) {
return nil, errors.New("getting client config failed")
}
if helper.NthBit(runConfig[2], 4) {
return nil, nil
}
return serverConf, nil
}
}
if helper.NthBit(runConfig[2], 5) {
serverConf.GetCertificate = func(*tls.ClientHelloInfo) (*tls.Certificate, error) {
if helper.NthBit(runConfig[2], 6) {
return nil, errors.New("getting certificate failed")
}
if helper.NthBit(runConfig[2], 7) {
return nil, nil
}
return clientCert, nil // this certificate will be invalid
}
}
if helper.NthBit(runConfig[3], 0) {
serverConf.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
if helper.NthBit(runConfig[3], 1) {
return errors.New("certificate verification failed")
}
return nil
}
}
if helper.NthBit(runConfig[3], 2) {
clientConf.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
if helper.NthBit(runConfig[3], 3) {
return errors.New("certificate verification failed")
}
return nil
}
}
if helper.NthBit(runConfig[3], 4) {
serverConf.NextProtos = []string{alpnWrong}
}
if helper.NthBit(runConfig[3], 5) {
serverConf.NextProtos = []string{alpnWrong, alpn}
}
if helper.NthBit(runConfig[3], 6) {
serverConf.KeyLogWriter = io.Discard
}
if helper.NthBit(runConfig[3], 7) {
clientConf.KeyLogWriter = io.Discard
}
clientTP := getTransportParameters(runConfig[4] & 0x3)
if helper.NthBit(runConfig[4], 3) {
clientTP.MaxAckDelay = protocol.MaxMaxAckDelay + 5
}
serverTP := getTransportParameters(runConfig[4] & 0b00011000)
if helper.NthBit(runConfig[4], 3) {
serverTP.MaxAckDelay = protocol.MaxMaxAckDelay + 5
}
messageToReplace := messageConfig % 32
messageToReplaceEncLevel := toEncryptionLevel(messageConfig >> 6)
if len(data) == 0 {
return -1
}
client := handshake.NewCryptoSetupClient(
protocol.ConnectionID{},
clientTP,
clientConf,
enable0RTTClient,
utils.NewRTTStats(),
nil,
utils.DefaultLogger.WithPrefix("client"),
protocol.Version1,
)
if err := client.StartHandshake(); err != nil {
log.Fatal(err)
}
defer client.Close()
server := handshake.NewCryptoSetupServer(
protocol.ConnectionID{},
&net.UDPAddr{IP: net.IPv6loopback, Port: 1234},
&net.UDPAddr{IP: net.IPv6loopback, Port: 4321},
serverTP,
serverConf,
enable0RTTServer,
utils.NewRTTStats(),
nil,
utils.DefaultLogger.WithPrefix("server"),
protocol.Version1,
)
if err := server.StartHandshake(); err != nil {
log.Fatal(err)
}
defer server.Close()
var clientHandshakeComplete, serverHandshakeComplete bool
for {
var processedEvent bool
clientLoop:
for {
ev := client.NextEvent()
//nolint:exhaustive // only need to process a few events
switch ev.Kind {
case handshake.EventNoEvent:
if !processedEvent && !clientHandshakeComplete { // handshake stuck
return 1
}
break clientLoop
case handshake.EventWriteInitialData, handshake.EventWriteHandshakeData:
msg := ev.Data
encLevel := protocol.EncryptionInitial
if ev.Kind == handshake.EventWriteHandshakeData {
encLevel = protocol.EncryptionHandshake
}
if msg[0] == messageToReplace {
fmt.Printf("replacing %s message to the server with %s at %s\n", messageType(msg[0]), messageType(data[0]), messageToReplaceEncLevel)
msg = data
encLevel = messageToReplaceEncLevel
}
if err := server.HandleMessage(msg, encLevel); err != nil {
return 1
}
case handshake.EventHandshakeComplete:
clientHandshakeComplete = true
}
processedEvent = true
}
processedEvent = false
serverLoop:
for {
ev := server.NextEvent()
//nolint:exhaustive // only need to process a few events
switch ev.Kind {
case handshake.EventNoEvent:
if !processedEvent && !serverHandshakeComplete { // handshake stuck
return 1
}
break serverLoop
case handshake.EventWriteInitialData, handshake.EventWriteHandshakeData:
encLevel := protocol.EncryptionInitial
if ev.Kind == handshake.EventWriteHandshakeData {
encLevel = protocol.EncryptionHandshake
}
msg := ev.Data
if msg[0] == messageToReplace {
fmt.Printf("replacing %s message to the client with %s at %s\n", messageType(msg[0]), messageType(data[0]), messageToReplaceEncLevel)
msg = data
encLevel = messageToReplaceEncLevel
}
if err := client.HandleMessage(msg, encLevel); err != nil {
return 1
}
case handshake.EventHandshakeComplete:
serverHandshakeComplete = true
}
processedEvent = true
}
if serverHandshakeComplete && clientHandshakeComplete {
break
}
}
_ = client.ConnectionState()
_ = server.ConnectionState()
sealer, err := client.Get1RTTSealer()
if err != nil {
panic("expected to get a 1-RTT sealer")
}
opener, err := server.Get1RTTOpener()
if err != nil {
panic("expected to get a 1-RTT opener")
}
const msg = "Lorem ipsum dolor sit amet, consectetur adipiscing elit."
encrypted := sealer.Seal(nil, []byte(msg), 1337, []byte("foobar"))
decrypted, err := opener.Open(nil, encrypted, time.Time{}, 1337, protocol.KeyPhaseZero, []byte("foobar"))
if err != nil {
panic(fmt.Sprintf("Decrypting message failed: %s", err.Error()))
}
if string(decrypted) != msg {
panic("wrong message")
}
if sendSessionTicket && !serverConf.SessionTicketsDisabled {
ticket, err := server.GetSessionTicket()
if err != nil {
panic(err)
}
if ticket == nil {
panic("empty ticket")
}
client.HandleMessage(ticket, protocol.Encryption1RTT)
}
if sendPostHandshakeMessageToClient {
fmt.Println("sending post handshake message to the client at", messageToReplaceEncLevel)
client.HandleMessage(data, messageToReplaceEncLevel)
}
if sendPostHandshakeMessageToServer {
fmt.Println("sending post handshake message to the server at", messageToReplaceEncLevel)
server.HandleMessage(data, messageToReplaceEncLevel)
}
return 1
}