ref: 2cdc6577ef8a251bf1740439cf5bfc47050dab41
dir: /third_party/boringssl/src/ssl/test/runner/handshake_client.go/
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package runner
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rsa"
"crypto/subtle"
"crypto/x509"
"errors"
"fmt"
"io"
"math/big"
"net"
"time"
"boringssl.googlesource.com/boringssl/ssl/test/runner/hpke"
)
const echBadPayloadByte = 0xff
type clientHandshakeState struct {
c *Conn
serverHello *serverHelloMsg
hello *clientHelloMsg
innerHello *clientHelloMsg
echHPKEContext *hpke.Context
suite *cipherSuite
finishedHash finishedHash
keyShares map[CurveID]ecdhCurve
masterSecret []byte
session *ClientSessionState
finishedBytes []byte
peerPublicKey crypto.PublicKey
}
func mapClientHelloVersion(vers uint16, isDTLS bool) uint16 {
if !isDTLS {
return vers
}
switch vers {
case VersionTLS12:
return VersionDTLS12
case VersionTLS10:
return VersionDTLS10
}
panic("Unknown ClientHello version.")
}
// replaceClientHello returns a new clientHelloMsg which serializes to |in|, but
// with key shares copied from |hello|. This allows sending an exact
// externally-specified ClientHello in tests. However, we use |hello|'s key
// shares. This ensures we have the private keys to complete the handshake. Note
// this function does not update internal handshake state, so the test must be
// configured compatibly with |in|.
func replaceClientHello(hello *clientHelloMsg, in []byte) (*clientHelloMsg, error) {
copied := append([]byte{}, in...)
newHello := new(clientHelloMsg)
if !newHello.unmarshal(copied) {
return nil, errors.New("tls: invalid ClientHello")
}
// Replace |newHellos|'s key shares with those of |hello|. For simplicity,
// we require their lengths match, which is satisfied by matching the
// DefaultCurves setting to the selection in the replacement ClientHello.
bb := newByteBuilder()
hello.marshalKeyShares(bb)
keyShares := bb.finish()
if len(keyShares) != len(newHello.keySharesRaw) {
return nil, errors.New("tls: ClientHello key share length is inconsistent with DefaultCurves setting")
}
// |newHello.keySharesRaw| aliases |copied|.
copy(newHello.keySharesRaw, keyShares)
newHello.keyShares = hello.keyShares
return newHello, nil
}
func (c *Conn) clientHandshake() error {
if c.config == nil {
c.config = defaultConfig()
}
if len(c.config.ServerName) == 0 && !c.config.InsecureSkipVerify {
return errors.New("tls: either ServerName or InsecureSkipVerify must be specified in the tls.Config")
}
c.sendHandshakeSeq = 0
c.recvHandshakeSeq = 0
hs := &clientHandshakeState{
c: c,
keyShares: make(map[CurveID]ecdhCurve),
}
// Pick a session to resume.
var session *ClientSessionState
var cacheKey string
sessionCache := c.config.ClientSessionCache
if sessionCache != nil {
// Try to resume a previously negotiated TLS session, if
// available.
cacheKey = clientSessionCacheKey(c.conn.RemoteAddr(), c.config)
// TODO(nharper): Support storing more than one session
// ticket for TLS 1.3.
candidateSession, ok := sessionCache.Get(cacheKey)
if ok {
ticketOk := !c.config.SessionTicketsDisabled || candidateSession.sessionTicket == nil
// Check that the ciphersuite/version used for the
// previous session are still valid.
cipherSuiteOk := false
if candidateSession.vers <= VersionTLS12 {
for _, id := range c.config.cipherSuites() {
if id == candidateSession.cipherSuite.id {
cipherSuiteOk = true
break
}
}
} else {
// TLS 1.3 allows the cipher to change on
// resumption.
cipherSuiteOk = true
}
_, versOk := c.config.isSupportedVersion(candidateSession.wireVersion, c.isDTLS)
if ticketOk && versOk && cipherSuiteOk {
session = candidateSession
hs.session = session
}
}
}
// Set up ECH parameters.
var err error
var earlyHello *clientHelloMsg
if c.config.ClientECHConfig != nil {
if c.config.ClientECHConfig.KEM != hpke.X25519WithHKDFSHA256 {
return errors.New("tls: unsupported KEM type in ECHConfig")
}
echCipherSuite, ok := chooseECHCipherSuite(c.config.ClientECHConfig, c.config)
if !ok {
return errors.New("tls: did not find compatible cipher suite in ECHConfig")
}
info := []byte("tls ech\x00")
info = append(info, c.config.ClientECHConfig.Raw...)
var echEnc []byte
hs.echHPKEContext, echEnc, err = hpke.SetupBaseSenderX25519(echCipherSuite.KDF, echCipherSuite.AEAD, c.config.ClientECHConfig.PublicKey, info, nil)
if err != nil {
return errors.New("tls: ech: failed to set up client's HPKE sender context")
}
hs.innerHello, err = hs.createClientHello(nil, nil)
if err != nil {
return err
}
hs.hello, err = hs.createClientHello(hs.innerHello, echEnc)
if err != nil {
return err
}
earlyHello = hs.innerHello
} else {
hs.hello, err = hs.createClientHello(nil, nil)
if err != nil {
return err
}
earlyHello = hs.hello
}
if len(earlyHello.pskIdentities) == 0 || c.config.Bugs.SendEarlyData == nil {
earlyHello = nil
}
if c.config.Bugs.SendV2ClientHello {
hs.hello.isV2ClientHello = true
// The V2ClientHello "challenge" field is variable-length and is
// left-padded or truncated to become the SSL3/TLS random.
challengeLength := c.config.Bugs.V2ClientHelloChallengeLength
if challengeLength == 0 {
challengeLength = len(hs.hello.random)
}
if challengeLength <= len(hs.hello.random) {
skip := len(hs.hello.random) - challengeLength
for i := 0; i < skip; i++ {
hs.hello.random[i] = 0
}
hs.hello.v2Challenge = hs.hello.random[skip:]
} else {
hs.hello.v2Challenge = make([]byte, challengeLength)
copy(hs.hello.v2Challenge, hs.hello.random)
if _, err := io.ReadFull(c.config.rand(), hs.hello.v2Challenge[len(hs.hello.random):]); err != nil {
c.sendAlert(alertInternalError)
return fmt.Errorf("tls: short read from Rand: %s", err)
}
}
c.writeV2Record(hs.hello.marshal())
} else {
helloBytes := hs.hello.marshal()
var appendToHello byte
if c.config.Bugs.PartialClientFinishedWithClientHello {
appendToHello = typeFinished
} else if c.config.Bugs.PartialEndOfEarlyDataWithClientHello {
appendToHello = typeEndOfEarlyData
} else if c.config.Bugs.PartialSecondClientHelloAfterFirst {
appendToHello = typeClientHello
} else if c.config.Bugs.PartialClientKeyExchangeWithClientHello {
appendToHello = typeClientKeyExchange
}
if appendToHello != 0 {
c.writeRecord(recordTypeHandshake, append(helloBytes[:len(helloBytes):len(helloBytes)], appendToHello))
} else {
c.writeRecord(recordTypeHandshake, helloBytes)
}
}
c.flushHandshake()
if err := c.simulatePacketLoss(nil); err != nil {
return err
}
if c.config.Bugs.SendEarlyAlert {
c.sendAlert(alertHandshakeFailure)
}
if c.config.Bugs.SendFakeEarlyDataLength > 0 {
c.sendFakeEarlyData(c.config.Bugs.SendFakeEarlyDataLength)
}
// Derive early write keys and set Conn state to allow early writes.
if earlyHello != nil {
finishedHash := newFinishedHash(session.wireVersion, c.isDTLS, session.cipherSuite)
finishedHash.addEntropy(session.secret)
finishedHash.Write(earlyHello.marshal())
if !c.config.Bugs.SkipChangeCipherSpec {
c.wireVersion = session.wireVersion
c.vers = VersionTLS13
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
c.wireVersion = 0
c.vers = 0
}
earlyTrafficSecret := finishedHash.deriveSecret(earlyTrafficLabel)
c.earlyExporterSecret = finishedHash.deriveSecret(earlyExporterLabel)
c.useOutTrafficSecret(encryptionEarlyData, session.wireVersion, session.cipherSuite, earlyTrafficSecret)
for _, earlyData := range c.config.Bugs.SendEarlyData {
if _, err := c.writeRecord(recordTypeApplicationData, earlyData); err != nil {
return err
}
}
}
msg, err := c.readHandshake()
if err != nil {
return err
}
if c.isDTLS {
helloVerifyRequest, ok := msg.(*helloVerifyRequestMsg)
if ok {
if helloVerifyRequest.vers != VersionDTLS10 {
// Per RFC 6347, the version field in
// HelloVerifyRequest SHOULD be always DTLS
// 1.0. Enforce this for testing purposes.
return errors.New("dtls: bad HelloVerifyRequest version")
}
hs.hello.raw = nil
hs.hello.cookie = helloVerifyRequest.cookie
c.writeRecord(recordTypeHandshake, hs.hello.marshal())
c.flushHandshake()
if err := c.simulatePacketLoss(nil); err != nil {
return err
}
msg, err = c.readHandshake()
if err != nil {
return err
}
}
}
// The first message is either ServerHello or HelloRetryRequest, either of
// which determines the version and cipher suite.
var serverWireVersion, suiteID uint16
switch m := msg.(type) {
case *helloRetryRequestMsg:
serverWireVersion = m.vers
suiteID = m.cipherSuite
case *serverHelloMsg:
serverWireVersion = m.vers
suiteID = m.cipherSuite
default:
c.sendAlert(alertUnexpectedMessage)
return fmt.Errorf("tls: received unexpected message of type %T when waiting for HelloRetryRequest or ServerHello", msg)
}
serverVersion, ok := c.config.isSupportedVersion(serverWireVersion, c.isDTLS)
if !ok {
c.sendAlert(alertProtocolVersion)
return fmt.Errorf("tls: server selected unsupported protocol version %x", c.vers)
}
c.wireVersion = serverWireVersion
c.vers = serverVersion
c.haveVers = true
// We only implement enough of SSL 3.0 to test that the server doesn't:
// we can send a ClientHello and attempt to read a ServerHello. The server
// should respond with a protocol_version alert and not get this far.
if c.vers == VersionSSL30 {
return errors.New("tls: server selected SSL 3.0")
}
cipherSuites := hs.hello.cipherSuites
if hs.innerHello != nil && c.config.Bugs.MinimalClientHelloOuter {
// hs.hello has a placeholder list of ciphers if testing with
// MinimalClientHelloOuter, so we use hs.innerHello instead. (We do not
// attempt to support actual different cipher suite preferences between
// the two.)
cipherSuites = hs.innerHello.cipherSuites
}
hs.suite = mutualCipherSuite(cipherSuites, suiteID)
if hs.suite == nil {
c.sendAlert(alertHandshakeFailure)
return fmt.Errorf("tls: server selected an unsupported cipher suite")
}
hs.finishedHash = newFinishedHash(c.wireVersion, c.isDTLS, hs.suite)
hs.finishedHash.WriteHandshake(hs.hello.marshal(), hs.c.sendHandshakeSeq-1)
if c.vers >= VersionTLS13 {
if err := hs.doTLS13Handshake(msg); err != nil {
return err
}
} else {
hs.serverHello, ok = msg.(*serverHelloMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(hs.serverHello, msg)
}
if isAllZero(hs.serverHello.random) {
// If the server forgets to fill in the server random, it will
// likely be all zero.
return errors.New("tls: ServerHello random was all zero")
}
hs.writeServerHash(hs.serverHello.marshal())
if c.config.Bugs.EarlyChangeCipherSpec > 0 {
hs.establishKeys()
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
}
if hs.serverHello.compressionMethod != compressionNone {
c.sendAlert(alertUnexpectedMessage)
return errors.New("tls: server selected unsupported compression format")
}
err = hs.processServerExtensions(&hs.serverHello.extensions)
if err != nil {
return err
}
isResume, err := hs.processServerHello()
if err != nil {
return err
}
if isResume {
if c.config.Bugs.EarlyChangeCipherSpec == 0 {
if err := hs.establishKeys(); err != nil {
return err
}
}
if err := hs.readSessionTicket(); err != nil {
return err
}
if err := hs.readFinished(c.firstFinished[:]); err != nil {
return err
}
if err := hs.sendFinished(nil, isResume); err != nil {
return err
}
} else {
if err := hs.doFullHandshake(); err != nil {
return err
}
if err := hs.establishKeys(); err != nil {
return err
}
if err := hs.sendFinished(c.firstFinished[:], isResume); err != nil {
return err
}
// Most retransmits are triggered by a timeout, but the final
// leg of the handshake is retransmited upon re-receiving a
// Finished.
if err := c.simulatePacketLoss(func() {
c.sendHandshakeSeq--
c.writeRecord(recordTypeHandshake, hs.finishedBytes)
c.flushHandshake()
}); err != nil {
return err
}
if err := hs.readSessionTicket(); err != nil {
return err
}
if err := hs.readFinished(nil); err != nil {
return err
}
}
if sessionCache != nil && hs.session != nil && session != hs.session {
if c.config.Bugs.RequireSessionTickets && len(hs.session.sessionTicket) == 0 {
return errors.New("tls: new session used session IDs instead of tickets")
}
if c.config.Bugs.RequireSessionIDs && len(hs.session.sessionID) == 0 {
return errors.New("tls: new session used session tickets instead of IDs")
}
sessionCache.Put(cacheKey, hs.session)
}
c.didResume = isResume
c.exporterSecret = hs.masterSecret
}
c.handshakeComplete = true
c.cipherSuite = hs.suite
copy(c.clientRandom[:], hs.hello.random)
copy(c.serverRandom[:], hs.serverHello.random)
return nil
}
func chooseECHCipherSuite(echConfig *ECHConfig, config *Config) (HPKECipherSuite, bool) {
if echConfig.KEM != hpke.X25519WithHKDFSHA256 {
return HPKECipherSuite{}, false
}
for _, wantSuite := range config.echCipherSuitePreferences() {
if config.Bugs.IgnoreECHConfigCipherPreferences {
return wantSuite, true
}
for _, cipherSuite := range echConfig.CipherSuites {
if cipherSuite == wantSuite {
return cipherSuite, true
}
}
}
return HPKECipherSuite{}, false
}
// createClientHello creates a new ClientHello message. If |innerHello| is not
// nil, this is a ClientHelloOuter that should contain an encrypted |innerHello|
// with |echEnc| as the encapsulated public key. Otherwise, the ClientHello
// should reflect the connection's true preferences.
func (hs *clientHandshakeState) createClientHello(innerHello *clientHelloMsg, echEnc []byte) (*clientHelloMsg, error) {
c := hs.c
nextProtosLength := 0
for _, proto := range c.config.NextProtos {
if l := len(proto); l > 255 {
return nil, errors.New("tls: invalid NextProtos value")
} else {
nextProtosLength += 1 + l
}
}
if nextProtosLength > 0xffff {
return nil, errors.New("tls: NextProtos values too large")
}
quicTransportParams := c.config.QUICTransportParams
quicTransportParamsLegacy := c.config.QUICTransportParams
if !c.config.QUICTransportParamsUseLegacyCodepoint.IncludeStandard() {
quicTransportParams = nil
}
if !c.config.QUICTransportParamsUseLegacyCodepoint.IncludeLegacy() {
quicTransportParamsLegacy = nil
}
isInner := innerHello == nil && hs.echHPKEContext != nil
minVersion := c.config.minVersion(c.isDTLS)
maxVersion := c.config.maxVersion(c.isDTLS)
// The ClientHelloInner may not offer TLS 1.2 or below.
requireTLS13 := isInner && !c.config.Bugs.AllowTLS12InClientHelloInner
if requireTLS13 && minVersion < VersionTLS13 {
minVersion = VersionTLS13
if minVersion > maxVersion {
return nil, errors.New("tls: ECH requires TLS 1.3")
}
}
hello := &clientHelloMsg{
isDTLS: c.isDTLS,
compressionMethods: []uint8{compressionNone},
random: make([]byte, 32),
ocspStapling: !c.config.Bugs.NoOCSPStapling,
sctListSupported: !c.config.Bugs.NoSignedCertificateTimestamps,
supportedCurves: c.config.curvePreferences(),
supportedPoints: []uint8{pointFormatUncompressed},
nextProtoNeg: len(c.config.NextProtos) > 0,
secureRenegotiation: []byte{},
alpnProtocols: c.config.NextProtos,
quicTransportParams: quicTransportParams,
quicTransportParamsLegacy: quicTransportParamsLegacy,
duplicateExtension: c.config.Bugs.DuplicateExtension,
channelIDSupported: c.config.ChannelID != nil,
extendedMasterSecret: maxVersion >= VersionTLS10,
srtpProtectionProfiles: c.config.SRTPProtectionProfiles,
srtpMasterKeyIdentifier: c.config.Bugs.SRTPMasterKeyIdentifer,
customExtension: c.config.Bugs.CustomExtension,
omitExtensions: c.config.Bugs.OmitExtensions,
emptyExtensions: c.config.Bugs.EmptyExtensions,
delegatedCredentials: !c.config.Bugs.DisableDelegatedCredentials,
}
// Translate the bugs that modify ClientHello extension order into a
// list of prefix extensions. The marshal function will try these
// extensions before any others, followed by any remaining extensions in
// the default order.
if c.config.Bugs.PSKBinderFirst && !c.config.Bugs.OnlyCorruptSecondPSKBinder {
hello.prefixExtensions = append(hello.prefixExtensions, extensionPreSharedKey)
}
if c.config.Bugs.SwapNPNAndALPN {
hello.prefixExtensions = append(hello.prefixExtensions, extensionALPN)
hello.prefixExtensions = append(hello.prefixExtensions, extensionNextProtoNeg)
}
// Configure ech_outer_extensions.
if isInner {
hello.outerExtensions = c.config.ECHOuterExtensions
// If |OnlyCompressSecondClientHelloInner| is set, we still configure
// |hello.outerExtensions| for ordering, so that we do not introduce an
// unsolicited change across HelloRetryRequest.
hello.reorderOuterExtensionsWithoutCompressing = c.config.Bugs.OnlyCompressSecondClientHelloInner
} else {
// Compressed extensions must appear in the same relative order between
// ClientHelloInner and ClientHelloOuter. For simplicity, we default to
// forcing their order to match, but the caller can override this with
// either valid or invalid explicit orders.
if c.config.Bugs.ECHOuterExtensionOrder != nil {
hello.prefixExtensions = append(hello.prefixExtensions, c.config.Bugs.ECHOuterExtensionOrder...)
} else {
hello.prefixExtensions = append(hello.prefixExtensions, c.config.ECHOuterExtensions...)
}
}
if maxVersion >= VersionTLS13 {
hello.vers = mapClientHelloVersion(VersionTLS12, c.isDTLS)
if !c.config.Bugs.OmitSupportedVersions {
hello.supportedVersions = c.config.supportedVersions(c.isDTLS, requireTLS13)
}
hello.pskKEModes = []byte{pskDHEKEMode}
} else {
hello.vers = mapClientHelloVersion(maxVersion, c.isDTLS)
}
if c.config.Bugs.SendClientVersion != 0 {
hello.vers = c.config.Bugs.SendClientVersion
}
if len(c.config.Bugs.SendSupportedVersions) > 0 {
hello.supportedVersions = c.config.Bugs.SendSupportedVersions
}
if innerHello != nil {
hello.serverName = c.config.ClientECHConfig.PublicName
} else {
hello.serverName = c.config.ServerName
}
disableEMS := c.config.Bugs.NoExtendedMasterSecret
if c.cipherSuite != nil {
disableEMS = c.config.Bugs.NoExtendedMasterSecretOnRenegotiation
}
if disableEMS {
hello.extendedMasterSecret = false
}
if c.config.Bugs.NoSupportedCurves {
hello.supportedCurves = nil
}
if c.config.Bugs.SendPSKKeyExchangeModes != nil {
hello.pskKEModes = c.config.Bugs.SendPSKKeyExchangeModes
}
if c.config.Bugs.SendCompressionMethods != nil {
hello.compressionMethods = c.config.Bugs.SendCompressionMethods
}
if c.config.Bugs.SendSupportedPointFormats != nil {
hello.supportedPoints = c.config.Bugs.SendSupportedPointFormats
}
if len(c.clientVerify) > 0 && !c.config.Bugs.EmptyRenegotiationInfo {
if c.config.Bugs.BadRenegotiationInfo {
hello.secureRenegotiation = append(hello.secureRenegotiation, c.clientVerify...)
hello.secureRenegotiation[0] ^= 0x80
} else {
hello.secureRenegotiation = c.clientVerify
}
}
if c.config.Bugs.DuplicateCompressedCertAlgs {
hello.compressedCertAlgs = []uint16{1, 1}
} else if len(c.config.CertCompressionAlgs) > 0 {
hello.compressedCertAlgs = make([]uint16, 0, len(c.config.CertCompressionAlgs))
for id := range c.config.CertCompressionAlgs {
hello.compressedCertAlgs = append(hello.compressedCertAlgs, uint16(id))
}
}
if c.noRenegotiationInfo() {
hello.secureRenegotiation = nil
}
for protocol := range c.config.ApplicationSettings {
hello.alpsProtocols = append(hello.alpsProtocols, protocol)
}
if maxVersion >= VersionTLS13 {
// Use the same key shares between ClientHelloInner and ClientHelloOuter.
if innerHello != nil {
hello.hasKeyShares = innerHello.hasKeyShares
hello.keyShares = innerHello.keyShares
} else {
hello.hasKeyShares = true
hello.trailingKeyShareData = c.config.Bugs.TrailingKeyShareData
curvesToSend := c.config.defaultCurves()
for _, curveID := range hello.supportedCurves {
if !curvesToSend[curveID] {
continue
}
curve, ok := curveForCurveID(curveID, c.config)
if !ok {
continue
}
publicKey, err := curve.offer(c.config.rand())
if err != nil {
return nil, err
}
if c.config.Bugs.SendCurve != 0 {
curveID = c.config.Bugs.SendCurve
}
if c.config.Bugs.InvalidECDHPoint {
publicKey[0] ^= 0xff
}
hello.keyShares = append(hello.keyShares, keyShareEntry{
group: curveID,
keyExchange: publicKey,
})
hs.keyShares[curveID] = curve
if c.config.Bugs.DuplicateKeyShares {
hello.keyShares = append(hello.keyShares, hello.keyShares[len(hello.keyShares)-1])
}
}
if c.config.Bugs.MissingKeyShare {
hello.hasKeyShares = false
}
}
}
possibleCipherSuites := c.config.cipherSuites()
hello.cipherSuites = make([]uint16, 0, len(possibleCipherSuites))
NextCipherSuite:
for _, suiteID := range possibleCipherSuites {
for _, suite := range cipherSuites {
if suite.id != suiteID {
continue
}
// Don't advertise TLS 1.2-only cipher suites unless
// we're attempting TLS 1.2.
if maxVersion < VersionTLS12 && suite.flags&suiteTLS12 != 0 {
continue
}
hello.cipherSuites = append(hello.cipherSuites, suiteID)
continue NextCipherSuite
}
}
if c.config.Bugs.AdvertiseAllConfiguredCiphers {
hello.cipherSuites = possibleCipherSuites
}
if c.config.Bugs.SendRenegotiationSCSV {
hello.cipherSuites = append(hello.cipherSuites, renegotiationSCSV)
}
if c.config.Bugs.SendFallbackSCSV {
hello.cipherSuites = append(hello.cipherSuites, fallbackSCSV)
}
_, err := io.ReadFull(c.config.rand(), hello.random)
if err != nil {
c.sendAlert(alertInternalError)
return nil, errors.New("tls: short read from Rand: " + err.Error())
}
if maxVersion >= VersionTLS12 && !c.config.Bugs.NoSignatureAlgorithms {
hello.signatureAlgorithms = c.config.verifySignatureAlgorithms()
}
if c.config.ClientSessionCache != nil {
hello.ticketSupported = !c.config.SessionTicketsDisabled
}
session := hs.session
// ClientHelloOuter cannot offer sessions.
if innerHello != nil && !c.config.Bugs.OfferSessionInClientHelloOuter {
session = nil
}
if session != nil && c.config.time().Before(session.ticketExpiration) {
ticket := session.sessionTicket
if c.config.Bugs.FilterTicket != nil && len(ticket) > 0 {
// Copy the ticket so FilterTicket may act in-place.
ticket = make([]byte, len(session.sessionTicket))
copy(ticket, session.sessionTicket)
ticket, err = c.config.Bugs.FilterTicket(ticket)
if err != nil {
return nil, err
}
}
if session.vers >= VersionTLS13 || c.config.Bugs.SendBothTickets {
// TODO(nharper): Support sending more
// than one PSK identity.
ticketAge := uint32(c.config.time().Sub(session.ticketCreationTime) / time.Millisecond)
if c.config.Bugs.SendTicketAge != 0 {
ticketAge = uint32(c.config.Bugs.SendTicketAge / time.Millisecond)
}
psk := pskIdentity{
ticket: ticket,
obfuscatedTicketAge: session.ticketAgeAdd + ticketAge,
}
hello.pskIdentities = []pskIdentity{psk}
if c.config.Bugs.ExtraPSKIdentity {
hello.pskIdentities = append(hello.pskIdentities, psk)
}
}
if session.vers < VersionTLS13 || c.config.Bugs.SendBothTickets {
if ticket != nil {
hello.sessionTicket = ticket
// A random session ID is used to detect when the
// server accepted the ticket and is resuming a session
// (see RFC 5077).
sessionIDLen := 16
if c.config.Bugs.TicketSessionIDLength != 0 {
sessionIDLen = c.config.Bugs.TicketSessionIDLength
}
if c.config.Bugs.EmptyTicketSessionID {
sessionIDLen = 0
}
hello.sessionID = make([]byte, sessionIDLen)
if _, err := io.ReadFull(c.config.rand(), hello.sessionID); err != nil {
c.sendAlert(alertInternalError)
return nil, errors.New("tls: short read from Rand: " + err.Error())
}
} else {
hello.sessionID = session.sessionID
}
}
}
if innerHello == nil {
// Request compatibility mode from the client by sending a fake session
// ID. Although BoringSSL always enables compatibility mode, other
// implementations make it conditional on the ClientHello. We test
// BoringSSL's expected behavior with SendClientHelloSessionID.
if len(hello.sessionID) == 0 && maxVersion >= VersionTLS13 {
hello.sessionID = make([]byte, 32)
if _, err := io.ReadFull(c.config.rand(), hello.sessionID); err != nil {
c.sendAlert(alertInternalError)
return nil, errors.New("tls: short read from Rand: " + err.Error())
}
}
if c.config.Bugs.MockQUICTransport != nil && !c.config.Bugs.CompatModeWithQUIC {
hello.sessionID = []byte{}
}
if c.config.Bugs.SendClientHelloSessionID != nil {
hello.sessionID = c.config.Bugs.SendClientHelloSessionID
}
} else {
// ClientHelloOuter's session ID is copied from ClientHelloINnner.
hello.sessionID = innerHello.sessionID
}
if c.config.Bugs.SendCipherSuites != nil {
hello.cipherSuites = c.config.Bugs.SendCipherSuites
}
if innerHello == nil {
if len(hello.pskIdentities) > 0 && c.config.Bugs.SendEarlyData != nil {
hello.hasEarlyData = true
}
if c.config.Bugs.SendFakeEarlyDataLength > 0 {
hello.hasEarlyData = true
}
if c.config.Bugs.OmitEarlyDataExtension {
hello.hasEarlyData = false
}
} else {
hello.hasEarlyData = innerHello.hasEarlyData
}
if (isInner && !c.config.Bugs.OmitECHInner) || c.config.Bugs.AlwaysSendECHInner {
hello.echInner = true
hello.invalidECHInner = c.config.Bugs.SendInvalidECHInner
}
if innerHello != nil {
if err := hs.encryptClientHello(hello, innerHello, c.config.ClientECHConfig.ConfigID, echEnc); err != nil {
return nil, err
}
if c.config.Bugs.CorruptEncryptedClientHello {
if c.config.Bugs.NullAllCiphers {
hello.echOuter.payload = []byte{echBadPayloadByte}
} else {
hello.echOuter.payload[0] ^= 1
}
}
}
// PSK binders and ECH both must be computed last because they incorporate
// the rest of the ClientHello and conflict. ECH resolves this by forbidding
// clients from offering PSKs on ClientHelloOuter, but we still need to test
// servers handle it correctly so they tolerate GREASE. In other cases, we
// expect the server to reject ECH, so we put PSK last. Note this renders
// ECH undecryptable.
if len(hello.pskIdentities) > 0 {
version := session.wireVersion
// We may have a pre-1.3 session if SendBothTickets is set.
if session.vers < VersionTLS13 {
version = VersionTLS13
}
generatePSKBinders(version, hello, session, nil, nil, c.config)
}
if c.config.Bugs.SendClientHelloWithFixes != nil {
hello, err = replaceClientHello(hello, c.config.Bugs.SendClientHelloWithFixes)
if err != nil {
return nil, err
}
}
return hello, nil
}
// encryptClientHello encrypts |innerHello| using the specified HPKE context and
// adds the extension to |hello|.
func (hs *clientHandshakeState) encryptClientHello(hello, innerHello *clientHelloMsg, configID uint8, enc []byte) error {
c := hs.c
if c.config.Bugs.MinimalClientHelloOuter {
*hello = clientHelloMsg{
vers: VersionTLS12,
random: hello.random,
sessionID: hello.sessionID,
cipherSuites: []uint16{0x0a0a},
compressionMethods: hello.compressionMethods,
}
}
if c.config.Bugs.TruncateClientECHEnc {
enc = enc[:1]
}
encodedInner := innerHello.marshalForEncodedInner()
padding := make([]byte, c.config.Bugs.ClientECHPadding)
if c.config.Bugs.BadClientECHPadding {
padding[0] = 1
}
encodedInner = append(encodedInner, padding...)
// Encode ClientHelloOuter with a placeholder payload string.
payloadLength := len(encodedInner)
if !c.config.Bugs.NullAllCiphers {
payloadLength += hs.echHPKEContext.Overhead()
}
hello.echOuter = &echClientOuter{
kdfID: hs.echHPKEContext.KDF(),
aeadID: hs.echHPKEContext.AEAD(),
configID: configID,
enc: enc,
payload: make([]byte, payloadLength),
}
aad := hello.marshal()[4:] // Remove message header
hello.raw = nil
hello.echOuter.payload = hs.echHPKEContext.Seal(encodedInner, aad)
if c.config.Bugs.NullAllCiphers {
hello.echOuter.payload = encodedInner
}
if c.config.Bugs.RecordClientHelloInner != nil {
if err := c.config.Bugs.RecordClientHelloInner(encodedInner, hello.marshal()[4:]); err != nil {
return err
}
// ECH is normally the last extension added to |hello|, but, when
// OfferSessionInClientHelloOuter is enabled, we may modify it again.
hello.raw = nil
}
return nil
}
func (hs *clientHandshakeState) checkECHConfirmation(msg interface{}, hello *clientHelloMsg, finishedHash *finishedHash) bool {
var offset int
var raw, label []byte
if hrr, ok := msg.(*helloRetryRequestMsg); ok {
if hrr.echConfirmationOffset == 0 {
return false
}
raw = hrr.raw
label = echAcceptConfirmationHRRLabel
offset = hrr.echConfirmationOffset
} else {
raw = msg.(*serverHelloMsg).raw
label = echAcceptConfirmationLabel
offset = 4 + 2 + 32 - echAcceptConfirmationLength
}
withZeros := append(make([]byte, 0, len(raw)), raw...)
for i := 0; i < echAcceptConfirmationLength; i++ {
withZeros[i+offset] = 0
}
confirmation := finishedHash.echAcceptConfirmation(hello.random, label, withZeros)
return bytes.Equal(confirmation, raw[offset:offset+echAcceptConfirmationLength])
}
func (hs *clientHandshakeState) doTLS13Handshake(msg interface{}) error {
c := hs.c
// The first message may be a ServerHello or HelloRetryRequest.
helloRetryRequest, haveHelloRetryRequest := msg.(*helloRetryRequestMsg)
if haveHelloRetryRequest {
hs.finishedHash.UpdateForHelloRetryRequest()
}
// Determine whether the server accepted ECH and drop the unnecessary
// transcript.
if hs.innerHello != nil {
innerFinishedHash := newFinishedHash(c.wireVersion, c.isDTLS, hs.suite)
innerFinishedHash.WriteHandshake(hs.innerHello.marshal(), hs.c.sendHandshakeSeq-1)
if haveHelloRetryRequest {
innerFinishedHash.UpdateForHelloRetryRequest()
}
if hs.checkECHConfirmation(msg, hs.innerHello, &innerFinishedHash) {
c.echAccepted = true
// Replace the transcript. For now, leave hs.hello and hs.innerHello
// as-is. HelloRetryRequest requires both be available.
hs.finishedHash = innerFinishedHash
}
} else {
// When not offering ECH, test that the backend server does not (or does)
// send a confirmation as expected.
confirmed := hs.checkECHConfirmation(msg, hs.hello, &hs.finishedHash)
if hs.hello.echInner && !confirmed {
return fmt.Errorf("tls: server did not send ECH confirmation in %T when requested", msg)
} else if !hs.hello.echInner && confirmed {
return fmt.Errorf("tls: server sent ECH confirmation in %T when not requested", msg)
}
}
// Once the PRF hash is known, TLS 1.3 does not require a handshake buffer.
hs.finishedHash.discardHandshakeBuffer()
// The first server message must be followed by a ChangeCipherSpec.
c.expectTLS13ChangeCipherSpec = true
if haveHelloRetryRequest {
hs.writeServerHash(helloRetryRequest.marshal())
if c.config.Bugs.FailIfHelloRetryRequested {
return errors.New("tls: unexpected HelloRetryRequest")
}
// Explicitly read the ChangeCipherSpec now; it should
// be attached to the first flight, not the second flight.
if err := c.readTLS13ChangeCipherSpec(); err != nil {
return err
}
// Reset the encryption state, in case we sent 0-RTT data.
c.out.resetCipher()
if c.echAccepted {
if err := hs.applyHelloRetryRequest(helloRetryRequest, hs.innerHello, hs.hello); err != nil {
return err
}
hs.writeClientHash(hs.innerHello.marshal())
} else {
if err := hs.applyHelloRetryRequest(helloRetryRequest, hs.hello, nil); err != nil {
return err
}
hs.writeClientHash(hs.hello.marshal())
}
toWrite := hs.hello.marshal()
if c.config.Bugs.PartialSecondClientHelloAfterFirst {
// The first byte has already been sent.
toWrite = toWrite[1:]
}
if c.config.Bugs.InterleaveEarlyData {
c.sendFakeEarlyData(4)
c.writeRecord(recordTypeHandshake, toWrite[:16])
c.sendFakeEarlyData(4)
c.writeRecord(recordTypeHandshake, toWrite[16:])
} else if c.config.Bugs.PartialClientFinishedWithSecondClientHello {
toWrite = append(make([]byte, 0, len(toWrite)+1), toWrite...)
toWrite = append(toWrite, typeFinished)
c.writeRecord(recordTypeHandshake, toWrite)
} else {
c.writeRecord(recordTypeHandshake, toWrite)
}
c.flushHandshake()
if c.config.Bugs.SendEarlyDataOnSecondClientHello {
c.sendFakeEarlyData(4)
}
var err error
msg, err = c.readHandshake()
if err != nil {
return err
}
}
// We no longer need to retain two ClientHellos.
if c.echAccepted {
hs.hello = hs.innerHello
}
hs.innerHello = nil
var ok bool
hs.serverHello, ok = msg.(*serverHelloMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(hs.serverHello, msg)
}
if isAllZero(hs.serverHello.random) {
// If the server forgets to fill in the server random, it will
// likely be all zero.
return errors.New("tls: ServerHello random was all zero")
}
if c.wireVersion != hs.serverHello.vers {
c.sendAlert(alertIllegalParameter)
return fmt.Errorf("tls: server sent non-matching version %x vs %x", c.wireVersion, hs.serverHello.vers)
}
if hs.suite.id != hs.serverHello.cipherSuite {
c.sendAlert(alertIllegalParameter)
return fmt.Errorf("tls: server sent non-matching cipher suite %04x vs %04x", hs.suite.id, hs.serverHello.cipherSuite)
}
if haveHelloRetryRequest {
if helloRetryRequest.hasSelectedGroup && helloRetryRequest.selectedGroup != hs.serverHello.keyShare.group {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: ServerHello parameters did not match HelloRetryRequest")
}
// Both the ServerHello and HelloRetryRequest must have an ECH confirmation.
echConfirmed := hs.checkECHConfirmation(hs.serverHello, hs.hello, &hs.finishedHash)
if hs.hello.echInner && !echConfirmed {
return errors.New("tls: server did not send ECH confirmation in ServerHello when requested")
} else if !hs.hello.echInner && echConfirmed {
return errors.New("tls: server sent ECH confirmation in ServerHello when not requested")
}
}
if !bytes.Equal(hs.hello.sessionID, hs.serverHello.sessionID) {
return errors.New("tls: session IDs did not match.")
}
// Resolve PSK and compute the early secret.
zeroSecret := hs.finishedHash.zeroSecret()
pskSecret := zeroSecret
if hs.serverHello.hasPSKIdentity {
// We send at most one PSK identity.
if hs.session == nil || hs.serverHello.pskIdentity != 0 {
c.sendAlert(alertUnknownPSKIdentity)
return errors.New("tls: server sent unknown PSK identity")
}
if hs.session.cipherSuite.hash() != hs.suite.hash() {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server resumed an invalid session for the cipher suite")
}
pskSecret = hs.session.secret
c.didResume = true
}
hs.finishedHash.addEntropy(pskSecret)
if !hs.serverHello.hasKeyShare {
c.sendAlert(alertUnsupportedExtension)
return errors.New("tls: server omitted KeyShare on resumption.")
}
// Resolve ECDHE and compute the handshake secret.
ecdheSecret := zeroSecret
if !c.config.Bugs.MissingKeyShare && !c.config.Bugs.SecondClientHelloMissingKeyShare {
curve, ok := hs.keyShares[hs.serverHello.keyShare.group]
if !ok {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server selected an unsupported group")
}
c.curveID = hs.serverHello.keyShare.group
var err error
ecdheSecret, err = curve.finish(hs.serverHello.keyShare.keyExchange)
if err != nil {
return err
}
}
hs.finishedHash.nextSecret()
hs.finishedHash.addEntropy(ecdheSecret)
hs.writeServerHash(hs.serverHello.marshal())
// Derive handshake traffic keys and switch read key to handshake
// traffic key.
clientHandshakeTrafficSecret := hs.finishedHash.deriveSecret(clientHandshakeTrafficLabel)
serverHandshakeTrafficSecret := hs.finishedHash.deriveSecret(serverHandshakeTrafficLabel)
if err := c.useInTrafficSecret(encryptionHandshake, c.wireVersion, hs.suite, serverHandshakeTrafficSecret); err != nil {
return err
}
msg, err := c.readHandshake()
if err != nil {
return err
}
encryptedExtensions, ok := msg.(*encryptedExtensionsMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(encryptedExtensions, msg)
}
hs.writeServerHash(encryptedExtensions.marshal())
if !bytes.Equal(encryptedExtensions.extensions.echRetryConfigs, c.config.Bugs.ExpectECHRetryConfigs) {
return errors.New("tls: server sent ECH retry_configs with unexpected contents")
}
err = hs.processServerExtensions(&encryptedExtensions.extensions)
if err != nil {
return err
}
var chainToSend *Certificate
var certReq *certificateRequestMsg
if c.didResume {
// Copy over authentication from the session.
c.peerCertificates = hs.session.serverCertificates
c.sctList = hs.session.sctList
c.ocspResponse = hs.session.ocspResponse
} else {
msg, err := c.readHandshake()
if err != nil {
return err
}
var ok bool
certReq, ok = msg.(*certificateRequestMsg)
if ok {
if len(certReq.requestContext) != 0 {
return errors.New("tls: non-empty certificate request context sent in handshake")
}
if c.config.Bugs.ExpectNoCertificateAuthoritiesExtension && certReq.hasCAExtension {
return errors.New("tls: expected no certificate_authorities extension")
}
if c.config.Bugs.IgnorePeerSignatureAlgorithmPreferences {
certReq.signatureAlgorithms = c.config.signSignatureAlgorithms()
}
hs.writeServerHash(certReq.marshal())
chainToSend, err = selectClientCertificate(c, certReq)
if err != nil {
return err
}
msg, err = c.readHandshake()
if err != nil {
return err
}
}
var certMsg *certificateMsg
if compressedCertMsg, ok := msg.(*compressedCertificateMsg); ok {
hs.writeServerHash(compressedCertMsg.marshal())
alg, ok := c.config.CertCompressionAlgs[compressedCertMsg.algID]
if !ok {
c.sendAlert(alertBadCertificate)
return fmt.Errorf("tls: received certificate compressed with unknown algorithm %x", compressedCertMsg.algID)
}
decompressed := make([]byte, 4+int(compressedCertMsg.uncompressedLength))
if !alg.Decompress(decompressed[4:], compressedCertMsg.compressed) {
c.sendAlert(alertBadCertificate)
return fmt.Errorf("tls: failed to decompress certificate with algorithm %x", compressedCertMsg.algID)
}
certMsg = &certificateMsg{
hasRequestContext: true,
}
if !certMsg.unmarshal(decompressed) {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to parse decompressed certificate")
}
if expected := c.config.Bugs.ExpectedCompressedCert; expected != 0 && expected != compressedCertMsg.algID {
return fmt.Errorf("tls: expected certificate compressed with algorithm %x, but message used %x", expected, compressedCertMsg.algID)
}
if c.config.Bugs.ExpectUncompressedCert {
return errors.New("tls: compressed certificate received")
}
} else {
if certMsg, ok = msg.(*certificateMsg); !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(certMsg, msg)
}
hs.writeServerHash(certMsg.marshal())
if c.config.Bugs.ExpectedCompressedCert != 0 {
return errors.New("tls: uncompressed certificate received")
}
}
// Check for unsolicited extensions.
for i, cert := range certMsg.certificates {
if c.config.Bugs.NoOCSPStapling && cert.ocspResponse != nil {
c.sendAlert(alertUnsupportedExtension)
return errors.New("tls: unexpected OCSP response in the server certificate")
}
if c.config.Bugs.NoSignedCertificateTimestamps && cert.sctList != nil {
c.sendAlert(alertUnsupportedExtension)
return errors.New("tls: unexpected SCT list in the server certificate")
}
if i > 0 && c.config.Bugs.ExpectNoExtensionsOnIntermediate && (cert.ocspResponse != nil || cert.sctList != nil) {
c.sendAlert(alertUnsupportedExtension)
return errors.New("tls: unexpected extensions in the server certificate")
}
}
if err := hs.verifyCertificates(certMsg); err != nil {
return err
}
c.ocspResponse = certMsg.certificates[0].ocspResponse
c.sctList = certMsg.certificates[0].sctList
msg, err = c.readHandshake()
if err != nil {
return err
}
certVerifyMsg, ok := msg.(*certificateVerifyMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(certVerifyMsg, msg)
}
c.peerSignatureAlgorithm = certVerifyMsg.signatureAlgorithm
input := hs.finishedHash.certificateVerifyInput(serverCertificateVerifyContextTLS13)
err = verifyMessage(c.vers, hs.peerPublicKey, c.config, certVerifyMsg.signatureAlgorithm, input, certVerifyMsg.signature)
if err != nil {
return err
}
hs.writeServerHash(certVerifyMsg.marshal())
}
msg, err = c.readHandshake()
if err != nil {
return err
}
serverFinished, ok := msg.(*finishedMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(serverFinished, msg)
}
verify := hs.finishedHash.serverSum(serverHandshakeTrafficSecret)
if len(verify) != len(serverFinished.verifyData) ||
subtle.ConstantTimeCompare(verify, serverFinished.verifyData) != 1 {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server's Finished message was incorrect")
}
hs.writeServerHash(serverFinished.marshal())
// The various secrets do not incorporate the client's final leg, so
// derive them now before updating the handshake context.
hs.finishedHash.nextSecret()
hs.finishedHash.addEntropy(zeroSecret)
clientTrafficSecret := hs.finishedHash.deriveSecret(clientApplicationTrafficLabel)
serverTrafficSecret := hs.finishedHash.deriveSecret(serverApplicationTrafficLabel)
c.exporterSecret = hs.finishedHash.deriveSecret(exporterLabel)
// Switch to application data keys on read. In particular, any alerts
// from the client certificate are read over these keys.
if err := c.useInTrafficSecret(encryptionApplication, c.wireVersion, hs.suite, serverTrafficSecret); err != nil {
return err
}
// If we're expecting 0.5-RTT messages from the server, read them now.
var deferredTickets []*newSessionTicketMsg
if encryptedExtensions.extensions.hasEarlyData {
// BoringSSL will always send two tickets half-RTT when
// negotiating 0-RTT.
for i := 0; i < shimConfig.HalfRTTTickets; i++ {
msg, err := c.readHandshake()
if err != nil {
return fmt.Errorf("tls: error reading half-RTT ticket: %s", err)
}
newSessionTicket, ok := msg.(*newSessionTicketMsg)
if !ok {
return errors.New("tls: expected half-RTT ticket")
}
// Defer processing until the resumption secret is computed.
deferredTickets = append(deferredTickets, newSessionTicket)
}
for _, expectedMsg := range c.config.Bugs.ExpectHalfRTTData {
if err := c.readRecord(recordTypeApplicationData); err != nil {
return err
}
if !bytes.Equal(c.input.data[c.input.off:], expectedMsg) {
return errors.New("ExpectHalfRTTData: did not get expected message")
}
c.in.freeBlock(c.input)
c.input = nil
}
}
// Send EndOfEarlyData and then switch write key to handshake
// traffic key.
if encryptedExtensions.extensions.hasEarlyData && !c.config.Bugs.SkipEndOfEarlyData && c.config.Bugs.MockQUICTransport == nil {
if c.config.Bugs.SendStrayEarlyHandshake {
helloRequest := new(helloRequestMsg)
c.writeRecord(recordTypeHandshake, helloRequest.marshal())
}
endOfEarlyData := new(endOfEarlyDataMsg)
endOfEarlyData.nonEmpty = c.config.Bugs.NonEmptyEndOfEarlyData
hs.writeClientHash(endOfEarlyData.marshal())
if c.config.Bugs.PartialEndOfEarlyDataWithClientHello {
// The first byte has already been sent.
c.writeRecord(recordTypeHandshake, endOfEarlyData.marshal()[1:])
} else {
c.writeRecord(recordTypeHandshake, endOfEarlyData.marshal())
}
}
if !c.config.Bugs.SkipChangeCipherSpec && !hs.hello.hasEarlyData {
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
}
for i := 0; i < c.config.Bugs.SendExtraChangeCipherSpec; i++ {
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
}
c.useOutTrafficSecret(encryptionHandshake, c.wireVersion, hs.suite, clientHandshakeTrafficSecret)
// The client EncryptedExtensions message is sent if some extension uses it.
// (Currently only ALPS does.)
hasEncryptedExtensions := c.config.Bugs.AlwaysSendClientEncryptedExtensions
clientEncryptedExtensions := new(clientEncryptedExtensionsMsg)
if encryptedExtensions.extensions.hasApplicationSettings || (c.config.Bugs.SendApplicationSettingsWithEarlyData && c.hasApplicationSettings) {
hasEncryptedExtensions = true
if !c.config.Bugs.OmitClientApplicationSettings {
clientEncryptedExtensions.hasApplicationSettings = true
clientEncryptedExtensions.applicationSettings = c.localApplicationSettings
}
}
if c.config.Bugs.SendExtraClientEncryptedExtension {
hasEncryptedExtensions = true
clientEncryptedExtensions.customExtension = []byte{0}
}
if hasEncryptedExtensions && !c.config.Bugs.OmitClientEncryptedExtensions {
hs.writeClientHash(clientEncryptedExtensions.marshal())
c.writeRecord(recordTypeHandshake, clientEncryptedExtensions.marshal())
}
if certReq != nil && !c.config.Bugs.SkipClientCertificate {
certMsg := &certificateMsg{
hasRequestContext: true,
requestContext: certReq.requestContext,
}
if chainToSend != nil {
for _, certData := range chainToSend.Certificate {
certMsg.certificates = append(certMsg.certificates, certificateEntry{
data: certData,
extraExtension: c.config.Bugs.SendExtensionOnCertificate,
})
}
}
hs.writeClientHash(certMsg.marshal())
c.writeRecord(recordTypeHandshake, certMsg.marshal())
if chainToSend != nil {
certVerify := &certificateVerifyMsg{
hasSignatureAlgorithm: true,
}
// Determine the hash to sign.
privKey := chainToSend.PrivateKey
var err error
certVerify.signatureAlgorithm, err = selectSignatureAlgorithm(c.vers, privKey, c.config, certReq.signatureAlgorithms)
if err != nil {
c.sendAlert(alertInternalError)
return err
}
input := hs.finishedHash.certificateVerifyInput(clientCertificateVerifyContextTLS13)
certVerify.signature, err = signMessage(c.vers, privKey, c.config, certVerify.signatureAlgorithm, input)
if err != nil {
c.sendAlert(alertInternalError)
return err
}
if c.config.Bugs.SendSignatureAlgorithm != 0 {
certVerify.signatureAlgorithm = c.config.Bugs.SendSignatureAlgorithm
}
if !c.config.Bugs.SkipCertificateVerify {
hs.writeClientHash(certVerify.marshal())
c.writeRecord(recordTypeHandshake, certVerify.marshal())
}
}
}
if encryptedExtensions.extensions.channelIDRequested {
channelIDHash := crypto.SHA256.New()
channelIDHash.Write(hs.finishedHash.certificateVerifyInput(channelIDContextTLS13))
channelIDMsgBytes, err := hs.writeChannelIDMessage(channelIDHash.Sum(nil))
if err != nil {
return err
}
hs.writeClientHash(channelIDMsgBytes)
c.writeRecord(recordTypeHandshake, channelIDMsgBytes)
}
// Send a client Finished message.
finished := new(finishedMsg)
finished.verifyData = hs.finishedHash.clientSum(clientHandshakeTrafficSecret)
if c.config.Bugs.BadFinished {
finished.verifyData[0]++
}
hs.writeClientHash(finished.marshal())
if c.config.Bugs.PartialClientFinishedWithClientHello {
// The first byte has already been sent.
c.writeRecord(recordTypeHandshake, finished.marshal()[1:])
} else if c.config.Bugs.InterleaveEarlyData {
finishedBytes := finished.marshal()
c.sendFakeEarlyData(4)
c.writeRecord(recordTypeHandshake, finishedBytes[:1])
c.sendFakeEarlyData(4)
c.writeRecord(recordTypeHandshake, finishedBytes[1:])
} else {
c.writeRecord(recordTypeHandshake, finished.marshal())
}
if c.config.Bugs.SendExtraFinished {
c.writeRecord(recordTypeHandshake, finished.marshal())
}
c.flushHandshake()
// Switch to application data keys.
c.useOutTrafficSecret(encryptionApplication, c.wireVersion, hs.suite, clientTrafficSecret)
c.resumptionSecret = hs.finishedHash.deriveSecret(resumptionLabel)
for _, ticket := range deferredTickets {
if err := c.processTLS13NewSessionTicket(ticket, hs.suite); err != nil {
return err
}
}
return nil
}
// applyHelloRetryRequest updates |hello| in-place based on |helloRetryRequest|.
// If |outerHello| is not nil, |outerHello| will be updated to contain an
// encrypted copy of |hello|.
func (hs *clientHandshakeState) applyHelloRetryRequest(helloRetryRequest *helloRetryRequestMsg, hello, outerHello *clientHelloMsg) error {
c := hs.c
firstHelloBytes := hello.marshal()
if len(helloRetryRequest.cookie) > 0 {
hello.tls13Cookie = helloRetryRequest.cookie
}
if c.config.Bugs.MisinterpretHelloRetryRequestCurve != 0 {
helloRetryRequest.hasSelectedGroup = true
helloRetryRequest.selectedGroup = c.config.Bugs.MisinterpretHelloRetryRequestCurve
}
if helloRetryRequest.hasSelectedGroup {
var hrrCurveFound bool
group := helloRetryRequest.selectedGroup
for _, curveID := range hello.supportedCurves {
if group == curveID {
hrrCurveFound = true
break
}
}
if !hrrCurveFound || hs.keyShares[group] != nil {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: received invalid HelloRetryRequest")
}
curve, ok := curveForCurveID(group, c.config)
if !ok {
return errors.New("tls: Unable to get curve requested in HelloRetryRequest")
}
publicKey, err := curve.offer(c.config.rand())
if err != nil {
return err
}
hs.keyShares[group] = curve
hello.keyShares = []keyShareEntry{{
group: group,
keyExchange: publicKey,
}}
}
if c.config.Bugs.SecondClientHelloMissingKeyShare {
hello.hasKeyShares = false
}
if c.config.Bugs.OmitSecondECHInner {
hello.echInner = false
}
hello.hasEarlyData = c.config.Bugs.SendEarlyDataOnSecondClientHello
// The first ClientHello may have skipped this due to OnlyCorruptSecondPSKBinder.
if c.config.Bugs.PSKBinderFirst && c.config.Bugs.OnlyCorruptSecondPSKBinder {
hello.prefixExtensions = append(hello.prefixExtensions, extensionPreSharedKey)
}
// The first ClientHello may have set this due to OnlyCompressSecondClientHelloInner.
hello.reorderOuterExtensionsWithoutCompressing = false
if c.config.Bugs.OmitPSKsOnSecondClientHello {
hello.pskIdentities = nil
hello.pskBinders = nil
}
hello.raw = nil
if len(hello.pskIdentities) > 0 {
generatePSKBinders(c.wireVersion, hello, hs.session, firstHelloBytes, helloRetryRequest.marshal(), c.config)
}
if outerHello != nil {
outerHello.raw = nil
// We know the server has accepted ECH, so the ClientHelloOuter's fields
// are irrelevant. In the general case, the HelloRetryRequest may not
// even be valid for ClientHelloOuter. However, we copy the key shares
// from ClientHelloInner so they remain eligible for compression.
if !c.config.Bugs.MinimalClientHelloOuter {
outerHello.keyShares = hello.keyShares
}
if c.config.Bugs.OmitSecondEncryptedClientHello {
outerHello.echOuter = nil
} else {
configID := c.config.ClientECHConfig.ConfigID
if c.config.Bugs.CorruptSecondEncryptedClientHelloConfigID {
configID ^= 1
}
if err := hs.encryptClientHello(outerHello, hello, configID, nil); err != nil {
return err
}
if c.config.Bugs.CorruptSecondEncryptedClientHello {
if c.config.Bugs.NullAllCiphers {
outerHello.echOuter.payload = []byte{echBadPayloadByte}
} else {
outerHello.echOuter.payload[0] ^= 1
}
}
}
}
return nil
}
func (hs *clientHandshakeState) doFullHandshake() error {
c := hs.c
var leaf *x509.Certificate
if hs.suite.flags&suitePSK == 0 {
msg, err := c.readHandshake()
if err != nil {
return err
}
certMsg, ok := msg.(*certificateMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(certMsg, msg)
}
hs.writeServerHash(certMsg.marshal())
if err := hs.verifyCertificates(certMsg); err != nil {
return err
}
leaf = c.peerCertificates[0]
}
if hs.serverHello.extensions.ocspStapling {
msg, err := c.readHandshake()
if err != nil {
return err
}
cs, ok := msg.(*certificateStatusMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(cs, msg)
}
hs.writeServerHash(cs.marshal())
if cs.statusType == statusTypeOCSP {
c.ocspResponse = cs.response
}
}
msg, err := c.readHandshake()
if err != nil {
return err
}
keyAgreement := hs.suite.ka(c.vers)
skx, ok := msg.(*serverKeyExchangeMsg)
if ok {
hs.writeServerHash(skx.marshal())
err = keyAgreement.processServerKeyExchange(c.config, hs.hello, hs.serverHello, hs.peerPublicKey, skx)
if err != nil {
c.sendAlert(alertUnexpectedMessage)
return err
}
if ecdhe, ok := keyAgreement.(*ecdheKeyAgreement); ok {
c.curveID = ecdhe.curveID
}
c.peerSignatureAlgorithm = keyAgreement.peerSignatureAlgorithm()
msg, err = c.readHandshake()
if err != nil {
return err
}
}
var chainToSend *Certificate
var certRequested bool
certReq, ok := msg.(*certificateRequestMsg)
if ok {
certRequested = true
if c.config.Bugs.IgnorePeerSignatureAlgorithmPreferences {
certReq.signatureAlgorithms = c.config.signSignatureAlgorithms()
}
hs.writeServerHash(certReq.marshal())
chainToSend, err = selectClientCertificate(c, certReq)
if err != nil {
return err
}
msg, err = c.readHandshake()
if err != nil {
return err
}
}
shd, ok := msg.(*serverHelloDoneMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(shd, msg)
}
hs.writeServerHash(shd.marshal())
// If the server requested a certificate then we have to send a
// Certificate message in TLS, even if it's empty because we don't have
// a certificate to send.
if certRequested && !c.config.Bugs.SkipClientCertificate {
certMsg := new(certificateMsg)
if chainToSend != nil {
for _, certData := range chainToSend.Certificate {
certMsg.certificates = append(certMsg.certificates, certificateEntry{
data: certData,
})
}
}
hs.writeClientHash(certMsg.marshal())
c.writeRecord(recordTypeHandshake, certMsg.marshal())
}
preMasterSecret, ckx, err := keyAgreement.generateClientKeyExchange(c.config, hs.hello, leaf)
if err != nil {
c.sendAlert(alertInternalError)
return err
}
if ckx != nil {
if c.config.Bugs.EarlyChangeCipherSpec < 2 {
hs.writeClientHash(ckx.marshal())
}
if c.config.Bugs.PartialClientKeyExchangeWithClientHello {
// The first byte was already written.
c.writeRecord(recordTypeHandshake, ckx.marshal()[1:])
} else {
c.writeRecord(recordTypeHandshake, ckx.marshal())
}
}
if hs.serverHello.extensions.extendedMasterSecret {
hs.masterSecret = extendedMasterFromPreMasterSecret(c.vers, hs.suite, preMasterSecret, hs.finishedHash)
c.extendedMasterSecret = true
} else {
if c.config.Bugs.RequireExtendedMasterSecret {
return errors.New("tls: extended master secret required but not supported by peer")
}
hs.masterSecret = masterFromPreMasterSecret(c.vers, hs.suite, preMasterSecret, hs.hello.random, hs.serverHello.random)
}
if chainToSend != nil {
certVerify := &certificateVerifyMsg{
hasSignatureAlgorithm: c.vers >= VersionTLS12,
}
// Determine the hash to sign.
privKey := c.config.Certificates[0].PrivateKey
if certVerify.hasSignatureAlgorithm {
certVerify.signatureAlgorithm, err = selectSignatureAlgorithm(c.vers, privKey, c.config, certReq.signatureAlgorithms)
if err != nil {
c.sendAlert(alertInternalError)
return err
}
}
certVerify.signature, err = signMessage(c.vers, privKey, c.config, certVerify.signatureAlgorithm, hs.finishedHash.buffer)
if err == nil && c.config.Bugs.SendSignatureAlgorithm != 0 {
certVerify.signatureAlgorithm = c.config.Bugs.SendSignatureAlgorithm
}
if err != nil {
c.sendAlert(alertInternalError)
return errors.New("tls: failed to sign handshake with client certificate: " + err.Error())
}
if !c.config.Bugs.SkipCertificateVerify {
hs.writeClientHash(certVerify.marshal())
c.writeRecord(recordTypeHandshake, certVerify.marshal())
}
}
// flushHandshake will be called in sendFinished.
hs.finishedHash.discardHandshakeBuffer()
return nil
}
// delegatedCredentialSignedMessage returns the bytes that are signed in order
// to authenticate a delegated credential.
func delegatedCredentialSignedMessage(credBytes []byte, algorithm signatureAlgorithm, leafDER []byte) []byte {
// https://tools.ietf.org/html/draft-ietf-tls-subcerts-03#section-3
ret := make([]byte, 64, 128)
for i := range ret {
ret[i] = 0x20
}
ret = append(ret, []byte("TLS, server delegated credentials\x00")...)
ret = append(ret, leafDER...)
ret = append(ret, byte(algorithm>>8), byte(algorithm))
ret = append(ret, credBytes...)
return ret
}
func (hs *clientHandshakeState) verifyCertificates(certMsg *certificateMsg) error {
c := hs.c
if len(certMsg.certificates) == 0 {
c.sendAlert(alertIllegalParameter)
return errors.New("tls: no certificates sent")
}
var dc *delegatedCredential
certs := make([]*x509.Certificate, len(certMsg.certificates))
for i, certEntry := range certMsg.certificates {
cert, err := x509.ParseCertificate(certEntry.data)
if err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to parse certificate from server: " + err.Error())
}
certs[i] = cert
if certEntry.delegatedCredential != nil {
if c.config.Bugs.FailIfDelegatedCredentials {
c.sendAlert(alertIllegalParameter)
return errors.New("tls: unexpected delegated credential")
}
if i != 0 {
c.sendAlert(alertIllegalParameter)
return errors.New("tls: non-leaf certificate has a delegated credential")
}
if c.config.Bugs.DisableDelegatedCredentials {
c.sendAlert(alertIllegalParameter)
return errors.New("tls: server sent delegated credential without it being requested")
}
dc = certEntry.delegatedCredential
}
}
if !c.config.InsecureSkipVerify {
opts := x509.VerifyOptions{
Roots: c.config.RootCAs,
CurrentTime: c.config.time(),
DNSName: c.config.ServerName,
Intermediates: x509.NewCertPool(),
}
for i, cert := range certs {
if i == 0 {
continue
}
opts.Intermediates.AddCert(cert)
}
var err error
c.verifiedChains, err = certs[0].Verify(opts)
if err != nil {
c.sendAlert(alertBadCertificate)
return err
}
}
leafPublicKey := certs[0].PublicKey
switch leafPublicKey.(type) {
case *rsa.PublicKey, *ecdsa.PublicKey, ed25519.PublicKey:
break
default:
c.sendAlert(alertUnsupportedCertificate)
return fmt.Errorf("tls: server's certificate contains an unsupported type of public key: %T", leafPublicKey)
}
c.peerCertificates = certs
if dc != nil {
// Note that this doesn't check a) the delegated credential temporal
// validity nor b) that the certificate has the special OID asserted.
var err error
if hs.peerPublicKey, err = x509.ParsePKIXPublicKey(dc.pkixPublicKey); err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to parse public key from delegated credential: " + err.Error())
}
verifier, err := getSigner(c.vers, hs.peerPublicKey, c.config, dc.algorithm, true)
if err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to get verifier for delegated credential: " + err.Error())
}
if err := verifier.verifyMessage(leafPublicKey, delegatedCredentialSignedMessage(dc.signedBytes, dc.algorithm, certs[0].Raw), dc.signature); err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to verify delegated credential: " + err.Error())
}
} else if c.config.Bugs.ExpectDelegatedCredentials {
c.sendAlert(alertInternalError)
return errors.New("tls: delegated credentials missing")
} else {
hs.peerPublicKey = leafPublicKey
}
return nil
}
func (hs *clientHandshakeState) establishKeys() error {
c := hs.c
clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
keysFromMasterSecret(c.vers, hs.suite, hs.masterSecret, hs.hello.random, hs.serverHello.random, hs.suite.macLen, hs.suite.keyLen, hs.suite.ivLen(c.vers))
var clientCipher, serverCipher interface{}
var clientHash, serverHash macFunction
if hs.suite.cipher != nil {
clientCipher = hs.suite.cipher(clientKey, clientIV, false /* not for reading */)
clientHash = hs.suite.mac(c.vers, clientMAC)
serverCipher = hs.suite.cipher(serverKey, serverIV, true /* for reading */)
serverHash = hs.suite.mac(c.vers, serverMAC)
} else {
clientCipher = hs.suite.aead(c.vers, clientKey, clientIV)
serverCipher = hs.suite.aead(c.vers, serverKey, serverIV)
}
c.in.prepareCipherSpec(c.wireVersion, serverCipher, serverHash)
c.out.prepareCipherSpec(c.wireVersion, clientCipher, clientHash)
return nil
}
func (hs *clientHandshakeState) processServerExtensions(serverExtensions *serverExtensions) error {
c := hs.c
if c.vers < VersionTLS13 {
if c.config.Bugs.RequireRenegotiationInfo && serverExtensions.secureRenegotiation == nil {
return errors.New("tls: renegotiation extension missing")
}
if len(c.clientVerify) > 0 && !c.noRenegotiationInfo() {
var expectedRenegInfo []byte
expectedRenegInfo = append(expectedRenegInfo, c.clientVerify...)
expectedRenegInfo = append(expectedRenegInfo, c.serverVerify...)
if !bytes.Equal(serverExtensions.secureRenegotiation, expectedRenegInfo) {
c.sendAlert(alertHandshakeFailure)
return fmt.Errorf("tls: renegotiation mismatch")
}
}
} else if serverExtensions.secureRenegotiation != nil {
return errors.New("tls: renegotiation info sent in TLS 1.3")
}
if expected := c.config.Bugs.ExpectedCustomExtension; expected != nil {
if serverExtensions.customExtension != *expected {
return fmt.Errorf("tls: bad custom extension contents %q", serverExtensions.customExtension)
}
}
clientDidNPN := hs.hello.nextProtoNeg
clientDidALPN := len(hs.hello.alpnProtocols) > 0
serverHasNPN := serverExtensions.nextProtoNeg
serverHasALPN := len(serverExtensions.alpnProtocol) > 0
if !clientDidNPN && serverHasNPN {
c.sendAlert(alertHandshakeFailure)
return errors.New("server advertised unrequested NPN extension")
}
if !clientDidALPN && serverHasALPN {
c.sendAlert(alertHandshakeFailure)
return errors.New("server advertised unrequested ALPN extension")
}
if serverHasNPN && serverHasALPN {
c.sendAlert(alertHandshakeFailure)
return errors.New("server advertised both NPN and ALPN extensions")
}
if serverHasALPN {
c.clientProtocol = serverExtensions.alpnProtocol
c.clientProtocolFallback = false
c.usedALPN = true
}
if serverHasNPN && c.vers >= VersionTLS13 {
c.sendAlert(alertHandshakeFailure)
return errors.New("server advertised NPN over TLS 1.3")
}
if !hs.hello.channelIDSupported && serverExtensions.channelIDRequested {
c.sendAlert(alertHandshakeFailure)
return errors.New("server advertised unrequested Channel ID extension")
}
if serverExtensions.extendedMasterSecret && c.vers >= VersionTLS13 {
return errors.New("tls: server advertised extended master secret over TLS 1.3")
}
if serverExtensions.ticketSupported && c.vers >= VersionTLS13 {
return errors.New("tls: server advertised ticket extension over TLS 1.3")
}
if serverExtensions.ocspStapling && c.vers >= VersionTLS13 {
return errors.New("tls: server advertised OCSP in ServerHello over TLS 1.3")
}
if serverExtensions.ocspStapling && c.config.Bugs.NoOCSPStapling {
return errors.New("tls: server advertised unrequested OCSP extension")
}
if len(serverExtensions.sctList) > 0 && c.vers >= VersionTLS13 {
return errors.New("tls: server advertised SCTs in ServerHello over TLS 1.3")
}
if len(serverExtensions.sctList) > 0 && c.config.Bugs.NoSignedCertificateTimestamps {
return errors.New("tls: server advertised unrequested SCTs")
}
if serverExtensions.srtpProtectionProfile != 0 {
if serverExtensions.srtpMasterKeyIdentifier != "" {
return errors.New("tls: server selected SRTP MKI value")
}
found := false
for _, p := range c.config.SRTPProtectionProfiles {
if p == serverExtensions.srtpProtectionProfile {
found = true
break
}
}
if !found {
return errors.New("tls: server advertised unsupported SRTP profile")
}
c.srtpProtectionProfile = serverExtensions.srtpProtectionProfile
}
if c.vers >= VersionTLS13 && c.didResume {
if c.config.Bugs.ExpectEarlyDataAccepted && !serverExtensions.hasEarlyData {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server did not accept early data when expected")
}
if !c.config.Bugs.ExpectEarlyDataAccepted && serverExtensions.hasEarlyData {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server accepted early data when not expected")
}
} else if serverExtensions.hasEarlyData {
return errors.New("tls: server accepted early data when not resuming")
}
if len(serverExtensions.quicTransportParams) > 0 {
if c.vers < VersionTLS13 {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server sent QUIC transport params for TLS version less than 1.3")
}
c.quicTransportParams = serverExtensions.quicTransportParams
}
if len(serverExtensions.quicTransportParamsLegacy) > 0 {
if c.vers < VersionTLS13 {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server sent QUIC transport params for TLS version less than 1.3")
}
c.quicTransportParamsLegacy = serverExtensions.quicTransportParamsLegacy
}
if serverExtensions.hasApplicationSettings {
if c.vers < VersionTLS13 {
return errors.New("tls: server sent application settings at invalid version")
}
if serverExtensions.hasEarlyData {
return errors.New("tls: server sent application settings with 0-RTT")
}
if !serverHasALPN {
return errors.New("tls: server sent application settings without ALPN")
}
settings, ok := c.config.ApplicationSettings[serverExtensions.alpnProtocol]
if !ok {
return errors.New("tls: server sent application settings for invalid protocol")
}
c.hasApplicationSettings = true
c.localApplicationSettings = settings
c.peerApplicationSettings = serverExtensions.applicationSettings
} else if serverExtensions.hasEarlyData {
// 0-RTT connections inherit application settings from the session.
c.hasApplicationSettings = hs.session.hasApplicationSettings
c.localApplicationSettings = hs.session.localApplicationSettings
c.peerApplicationSettings = hs.session.peerApplicationSettings
}
return nil
}
func (hs *clientHandshakeState) serverResumedSession() bool {
// If the server responded with the same sessionID then it means the
// sessionTicket is being used to resume a TLS session.
//
// Note that, if hs.hello.sessionID is a non-nil empty array, this will
// accept an empty session ID from the server as resumption. See
// EmptyTicketSessionID.
return hs.session != nil && hs.hello.sessionID != nil &&
bytes.Equal(hs.serverHello.sessionID, hs.hello.sessionID)
}
func (hs *clientHandshakeState) processServerHello() (bool, error) {
c := hs.c
// Check for downgrade signals in the server random, per RFC 8446, section 4.1.3.
gotDowngrade := hs.serverHello.random[len(hs.serverHello.random)-8:]
if !c.config.Bugs.IgnoreTLS13DowngradeRandom {
if c.config.maxVersion(c.isDTLS) >= VersionTLS13 {
if bytes.Equal(gotDowngrade, downgradeTLS13) {
c.sendAlert(alertProtocolVersion)
return false, errors.New("tls: downgrade from TLS 1.3 detected")
}
}
if c.vers <= VersionTLS11 && c.config.maxVersion(c.isDTLS) >= VersionTLS12 {
if bytes.Equal(gotDowngrade, downgradeTLS12) {
c.sendAlert(alertProtocolVersion)
return false, errors.New("tls: downgrade from TLS 1.2 detected")
}
}
}
if bytes.Equal(gotDowngrade, downgradeJDK11) != c.config.Bugs.ExpectJDK11DowngradeRandom {
c.sendAlert(alertProtocolVersion)
if c.config.Bugs.ExpectJDK11DowngradeRandom {
return false, errors.New("tls: server did not send a JDK 11 downgrade signal")
}
return false, errors.New("tls: server sent an unexpected JDK 11 downgrade signal")
}
if c.config.Bugs.ExpectOmitExtensions && !hs.serverHello.omitExtensions {
return false, errors.New("tls: ServerHello did not omit extensions")
}
if hs.serverResumedSession() {
// For test purposes, assert that the server never accepts the
// resumption offer on renegotiation.
if c.cipherSuite != nil && c.config.Bugs.FailIfResumeOnRenego {
return false, errors.New("tls: server resumed session on renegotiation")
}
if hs.serverHello.extensions.sctList != nil {
return false, errors.New("tls: server sent SCT extension on session resumption")
}
if hs.serverHello.extensions.ocspStapling {
return false, errors.New("tls: server sent OCSP extension on session resumption")
}
// Restore masterSecret and peerCerts from previous state
hs.masterSecret = hs.session.secret
c.peerCertificates = hs.session.serverCertificates
c.extendedMasterSecret = hs.session.extendedMasterSecret
c.sctList = hs.session.sctList
c.ocspResponse = hs.session.ocspResponse
hs.finishedHash.discardHandshakeBuffer()
return true, nil
}
if hs.serverHello.extensions.sctList != nil {
c.sctList = hs.serverHello.extensions.sctList
}
return false, nil
}
func (hs *clientHandshakeState) readFinished(out []byte) error {
c := hs.c
c.readRecord(recordTypeChangeCipherSpec)
if err := c.in.error(); err != nil {
return err
}
msg, err := c.readHandshake()
if err != nil {
return err
}
serverFinished, ok := msg.(*finishedMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(serverFinished, msg)
}
if c.config.Bugs.EarlyChangeCipherSpec == 0 {
verify := hs.finishedHash.serverSum(hs.masterSecret)
if len(verify) != len(serverFinished.verifyData) ||
subtle.ConstantTimeCompare(verify, serverFinished.verifyData) != 1 {
c.sendAlert(alertHandshakeFailure)
return errors.New("tls: server's Finished message was incorrect")
}
}
c.serverVerify = append(c.serverVerify[:0], serverFinished.verifyData...)
copy(out, serverFinished.verifyData)
hs.writeServerHash(serverFinished.marshal())
return nil
}
func (hs *clientHandshakeState) readSessionTicket() error {
c := hs.c
// Create a session with no server identifier. Either a
// session ID or session ticket will be attached.
session := &ClientSessionState{
vers: c.vers,
wireVersion: c.wireVersion,
cipherSuite: hs.suite,
secret: hs.masterSecret,
handshakeHash: hs.finishedHash.Sum(),
serverCertificates: c.peerCertificates,
sctList: c.sctList,
ocspResponse: c.ocspResponse,
ticketExpiration: c.config.time().Add(time.Duration(7 * 24 * time.Hour)),
}
if !hs.serverHello.extensions.ticketSupported {
if c.config.Bugs.ExpectNewTicket {
return errors.New("tls: expected new ticket")
}
if hs.session == nil && len(hs.serverHello.sessionID) > 0 {
session.sessionID = hs.serverHello.sessionID
hs.session = session
}
return nil
}
if c.config.Bugs.ExpectNoNewSessionTicket {
return errors.New("tls: received unexpected NewSessionTicket")
}
msg, err := c.readHandshake()
if err != nil {
return err
}
sessionTicketMsg, ok := msg.(*newSessionTicketMsg)
if !ok {
c.sendAlert(alertUnexpectedMessage)
return unexpectedMessageError(sessionTicketMsg, msg)
}
session.sessionTicket = sessionTicketMsg.ticket
hs.session = session
hs.writeServerHash(sessionTicketMsg.marshal())
return nil
}
func (hs *clientHandshakeState) sendFinished(out []byte, isResume bool) error {
c := hs.c
var postCCSMsgs [][]byte
seqno := hs.c.sendHandshakeSeq
if hs.serverHello.extensions.nextProtoNeg {
nextProto := new(nextProtoMsg)
proto, fallback := mutualProtocol(c.config.NextProtos, hs.serverHello.extensions.nextProtos)
nextProto.proto = proto
c.clientProtocol = proto
c.clientProtocolFallback = fallback
nextProtoBytes := nextProto.marshal()
hs.finishedHash.WriteHandshake(nextProtoBytes, seqno)
seqno++
postCCSMsgs = append(postCCSMsgs, nextProtoBytes)
}
if hs.serverHello.extensions.channelIDRequested {
var resumeHash []byte
if isResume {
resumeHash = hs.session.handshakeHash
}
channelIDMsgBytes, err := hs.writeChannelIDMessage(hs.finishedHash.hashForChannelID(resumeHash))
if err != nil {
return err
}
hs.finishedHash.WriteHandshake(channelIDMsgBytes, seqno)
seqno++
postCCSMsgs = append(postCCSMsgs, channelIDMsgBytes)
}
finished := new(finishedMsg)
if c.config.Bugs.EarlyChangeCipherSpec == 2 {
finished.verifyData = hs.finishedHash.clientSum(nil)
} else {
finished.verifyData = hs.finishedHash.clientSum(hs.masterSecret)
}
copy(out, finished.verifyData)
if c.config.Bugs.BadFinished {
finished.verifyData[0]++
}
c.clientVerify = append(c.clientVerify[:0], finished.verifyData...)
hs.finishedBytes = finished.marshal()
hs.finishedHash.WriteHandshake(hs.finishedBytes, seqno)
if c.config.Bugs.PartialClientFinishedWithClientHello {
// The first byte has already been written.
postCCSMsgs = append(postCCSMsgs, hs.finishedBytes[1:])
} else {
postCCSMsgs = append(postCCSMsgs, hs.finishedBytes)
}
if c.config.Bugs.FragmentAcrossChangeCipherSpec {
c.writeRecord(recordTypeHandshake, postCCSMsgs[0][:5])
postCCSMsgs[0] = postCCSMsgs[0][5:]
} else if c.config.Bugs.SendUnencryptedFinished {
c.writeRecord(recordTypeHandshake, postCCSMsgs[0])
postCCSMsgs = postCCSMsgs[1:]
}
if !c.config.Bugs.SkipChangeCipherSpec &&
c.config.Bugs.EarlyChangeCipherSpec == 0 {
ccs := []byte{1}
if c.config.Bugs.BadChangeCipherSpec != nil {
ccs = c.config.Bugs.BadChangeCipherSpec
}
c.writeRecord(recordTypeChangeCipherSpec, ccs)
}
if c.config.Bugs.AppDataAfterChangeCipherSpec != nil {
c.writeRecord(recordTypeApplicationData, c.config.Bugs.AppDataAfterChangeCipherSpec)
}
if c.config.Bugs.AlertAfterChangeCipherSpec != 0 {
c.sendAlert(c.config.Bugs.AlertAfterChangeCipherSpec)
return errors.New("tls: simulating post-CCS alert")
}
if !c.config.Bugs.SkipFinished {
for _, msg := range postCCSMsgs {
c.writeRecord(recordTypeHandshake, msg)
}
if c.config.Bugs.SendExtraFinished {
c.writeRecord(recordTypeHandshake, finished.marshal())
}
}
if !isResume || !c.config.Bugs.PackAppDataWithHandshake {
c.flushHandshake()
}
return nil
}
func (hs *clientHandshakeState) writeChannelIDMessage(channelIDHash []byte) ([]byte, error) {
c := hs.c
channelIDMsg := new(channelIDMsg)
if c.config.ChannelID.Curve != elliptic.P256() {
return nil, fmt.Errorf("tls: Channel ID is not on P-256.")
}
r, s, err := ecdsa.Sign(c.config.rand(), c.config.ChannelID, channelIDHash)
if err != nil {
return nil, err
}
channelID := make([]byte, 128)
writeIntPadded(channelID[0:32], c.config.ChannelID.X)
writeIntPadded(channelID[32:64], c.config.ChannelID.Y)
writeIntPadded(channelID[64:96], r)
writeIntPadded(channelID[96:128], s)
if c.config.Bugs.InvalidChannelIDSignature {
channelID[64] ^= 1
}
channelIDMsg.channelID = channelID
c.channelID = &c.config.ChannelID.PublicKey
return channelIDMsg.marshal(), nil
}
func (hs *clientHandshakeState) writeClientHash(msg []byte) {
// writeClientHash is called before writeRecord.
hs.finishedHash.WriteHandshake(msg, hs.c.sendHandshakeSeq)
}
func (hs *clientHandshakeState) writeServerHash(msg []byte) {
// writeServerHash is called after readHandshake.
hs.finishedHash.WriteHandshake(msg, hs.c.recvHandshakeSeq-1)
}
// selectClientCertificate selects a certificate for use with the given
// certificate, or none if none match. It may return a particular certificate or
// nil on success, or an error on internal error.
func selectClientCertificate(c *Conn, certReq *certificateRequestMsg) (*Certificate, error) {
if len(c.config.Certificates) == 0 {
return nil, nil
}
// The test is assumed to have configured the certificate it meant to
// send.
if len(c.config.Certificates) > 1 {
return nil, errors.New("tls: multiple certificates configured")
}
return &c.config.Certificates[0], nil
}
// clientSessionCacheKey returns a key used to cache sessionTickets that could
// be used to resume previously negotiated TLS sessions with a server.
func clientSessionCacheKey(serverAddr net.Addr, config *Config) string {
if len(config.ServerName) > 0 {
return config.ServerName
}
return serverAddr.String()
}
// mutualProtocol finds the mutual Next Protocol Negotiation or ALPN protocol
// given list of possible protocols and a list of the preference order. The
// first list must not be empty. It returns the resulting protocol and flag
// indicating if the fallback case was reached.
func mutualProtocol(protos, preferenceProtos []string) (string, bool) {
for _, s := range preferenceProtos {
for _, c := range protos {
if s == c {
return s, false
}
}
}
return protos[0], true
}
// writeIntPadded writes x into b, padded up with leading zeros as
// needed.
func writeIntPadded(b []byte, x *big.Int) {
for i := range b {
b[i] = 0
}
xb := x.Bytes()
copy(b[len(b)-len(xb):], xb)
}
func generatePSKBinders(version uint16, hello *clientHelloMsg, session *ClientSessionState, firstClientHello, helloRetryRequest []byte, config *Config) {
maybeCorruptBinder := !config.Bugs.OnlyCorruptSecondPSKBinder || len(firstClientHello) > 0
binderLen := session.cipherSuite.hash().Size()
numBinders := 1
if maybeCorruptBinder {
if config.Bugs.SendNoPSKBinder {
// The binders may have been set from the previous
// ClientHello.
hello.pskBinders = nil
return
}
if config.Bugs.SendShortPSKBinder {
binderLen--
}
if config.Bugs.SendExtraPSKBinder {
numBinders++
}
}
// Fill hello.pskBinders with appropriate length arrays of zeros so the
// length prefixes are correct when computing the binder over the truncated
// ClientHello message.
hello.pskBinders = make([][]byte, numBinders)
for i := range hello.pskBinders {
hello.pskBinders[i] = make([]byte, binderLen)
}
helloBytes := hello.marshal()
binderSize := len(hello.pskBinders)*(binderLen+1) + 2
truncatedHello := helloBytes[:len(helloBytes)-binderSize]
binder := computePSKBinder(session.secret, version, resumptionPSKBinderLabel, session.cipherSuite, firstClientHello, helloRetryRequest, truncatedHello)
if maybeCorruptBinder {
if config.Bugs.SendShortPSKBinder {
binder = binder[:binderLen]
}
if config.Bugs.SendInvalidPSKBinder {
binder[0] ^= 1
}
}
for i := range hello.pskBinders {
hello.pskBinders[i] = binder
}
hello.raw = nil
}