1 // Copyright 2018 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
19 type clientHandshakeStateTLS13 struct {
22 serverHello *serverHelloMsg
24 ecdheKey *ecdh.PrivateKey
26 session *ClientSessionState
30 certReq *certificateRequestMsgTLS13
33 suite *cipherSuiteTLS13
36 trafficSecret []byte // client_application_traffic_secret_0
39 // handshake requires hs.c, hs.hello, hs.serverHello, hs.ecdheKey, and,
40 // optionally, hs.session, hs.earlySecret and hs.binderKey to be set.
41 func (hs *clientHandshakeStateTLS13) handshake() error {
45 return errors.New("tls: internal error: TLS 1.3 reached in FIPS mode")
48 // The server must not select TLS 1.3 in a renegotiation. See RFC 8446,
49 // sections 4.1.2 and 4.1.3.
51 c.sendAlert(alertProtocolVersion)
52 return errors.New("tls: server selected TLS 1.3 in a renegotiation")
55 // Consistency check on the presence of a keyShare and its parameters.
56 if hs.ecdheKey == nil || len(hs.hello.keyShares) != 1 {
57 return c.sendAlert(alertInternalError)
60 if err := hs.checkServerHelloOrHRR(); err != nil {
64 hs.transcript = hs.suite.hash.New()
66 if err := transcriptMsg(hs.hello, hs.transcript); err != nil {
70 if bytes.Equal(hs.serverHello.random, helloRetryRequestRandom) {
71 if err := hs.sendDummyChangeCipherSpec(); err != nil {
74 if err := hs.processHelloRetryRequest(); err != nil {
79 if err := transcriptMsg(hs.serverHello, hs.transcript); err != nil {
84 if err := hs.processServerHello(); err != nil {
87 if err := hs.sendDummyChangeCipherSpec(); err != nil {
90 if err := hs.establishHandshakeKeys(); err != nil {
93 if err := hs.readServerParameters(); err != nil {
96 if err := hs.readServerCertificate(); err != nil {
99 if err := hs.readServerFinished(); err != nil {
102 if err := hs.sendClientCertificate(); err != nil {
105 if err := hs.sendClientFinished(); err != nil {
108 if _, err := c.flush(); err != nil {
112 c.isHandshakeComplete.Store(true)
117 // checkServerHelloOrHRR does validity checks that apply to both ServerHello and
118 // HelloRetryRequest messages. It sets hs.suite.
119 func (hs *clientHandshakeStateTLS13) checkServerHelloOrHRR() error {
122 if hs.serverHello.supportedVersion == 0 {
123 c.sendAlert(alertMissingExtension)
124 return errors.New("tls: server selected TLS 1.3 using the legacy version field")
127 if hs.serverHello.supportedVersion != VersionTLS13 {
128 c.sendAlert(alertIllegalParameter)
129 return errors.New("tls: server selected an invalid version after a HelloRetryRequest")
132 if hs.serverHello.vers != VersionTLS12 {
133 c.sendAlert(alertIllegalParameter)
134 return errors.New("tls: server sent an incorrect legacy version")
137 if hs.serverHello.ocspStapling ||
138 hs.serverHello.ticketSupported ||
139 hs.serverHello.secureRenegotiationSupported ||
140 len(hs.serverHello.secureRenegotiation) != 0 ||
141 len(hs.serverHello.alpnProtocol) != 0 ||
142 len(hs.serverHello.scts) != 0 {
143 c.sendAlert(alertUnsupportedExtension)
144 return errors.New("tls: server sent a ServerHello extension forbidden in TLS 1.3")
147 if !bytes.Equal(hs.hello.sessionId, hs.serverHello.sessionId) {
148 c.sendAlert(alertIllegalParameter)
149 return errors.New("tls: server did not echo the legacy session ID")
152 if hs.serverHello.compressionMethod != compressionNone {
153 c.sendAlert(alertIllegalParameter)
154 return errors.New("tls: server selected unsupported compression format")
157 selectedSuite := mutualCipherSuiteTLS13(hs.hello.cipherSuites, hs.serverHello.cipherSuite)
158 if hs.suite != nil && selectedSuite != hs.suite {
159 c.sendAlert(alertIllegalParameter)
160 return errors.New("tls: server changed cipher suite after a HelloRetryRequest")
162 if selectedSuite == nil {
163 c.sendAlert(alertIllegalParameter)
164 return errors.New("tls: server chose an unconfigured cipher suite")
166 hs.suite = selectedSuite
167 c.cipherSuite = hs.suite.id
172 // sendDummyChangeCipherSpec sends a ChangeCipherSpec record for compatibility
173 // with middleboxes that didn't implement TLS correctly. See RFC 8446, Appendix D.4.
174 func (hs *clientHandshakeStateTLS13) sendDummyChangeCipherSpec() error {
175 if hs.c.quic != nil {
181 hs.sentDummyCCS = true
183 return hs.c.writeChangeCipherRecord()
186 // processHelloRetryRequest handles the HRR in hs.serverHello, modifies and
187 // resends hs.hello, and reads the new ServerHello into hs.serverHello.
188 func (hs *clientHandshakeStateTLS13) processHelloRetryRequest() error {
191 // The first ClientHello gets double-hashed into the transcript upon a
192 // HelloRetryRequest. (The idea is that the server might offload transcript
193 // storage to the client in the cookie.) See RFC 8446, Section 4.4.1.
194 chHash := hs.transcript.Sum(nil)
195 hs.transcript.Reset()
196 hs.transcript.Write([]byte{typeMessageHash, 0, 0, uint8(len(chHash))})
197 hs.transcript.Write(chHash)
198 if err := transcriptMsg(hs.serverHello, hs.transcript); err != nil {
202 // The only HelloRetryRequest extensions we support are key_share and
203 // cookie, and clients must abort the handshake if the HRR would not result
204 // in any change in the ClientHello.
205 if hs.serverHello.selectedGroup == 0 && hs.serverHello.cookie == nil {
206 c.sendAlert(alertIllegalParameter)
207 return errors.New("tls: server sent an unnecessary HelloRetryRequest message")
210 if hs.serverHello.cookie != nil {
211 hs.hello.cookie = hs.serverHello.cookie
214 if hs.serverHello.serverShare.group != 0 {
215 c.sendAlert(alertDecodeError)
216 return errors.New("tls: received malformed key_share extension")
219 // If the server sent a key_share extension selecting a group, ensure it's
220 // a group we advertised but did not send a key share for, and send a key
221 // share for it this time.
222 if curveID := hs.serverHello.selectedGroup; curveID != 0 {
224 for _, id := range hs.hello.supportedCurves {
231 c.sendAlert(alertIllegalParameter)
232 return errors.New("tls: server selected unsupported group")
234 if sentID, _ := curveIDForCurve(hs.ecdheKey.Curve()); sentID == curveID {
235 c.sendAlert(alertIllegalParameter)
236 return errors.New("tls: server sent an unnecessary HelloRetryRequest key_share")
238 if _, ok := curveForCurveID(curveID); !ok {
239 c.sendAlert(alertInternalError)
240 return errors.New("tls: CurvePreferences includes unsupported curve")
242 key, err := generateECDHEKey(c.config.rand(), curveID)
244 c.sendAlert(alertInternalError)
248 hs.hello.keyShares = []keyShare{{group: curveID, data: key.PublicKey().Bytes()}}
252 if len(hs.hello.pskIdentities) > 0 {
253 pskSuite := cipherSuiteTLS13ByID(hs.session.cipherSuite)
255 return c.sendAlert(alertInternalError)
257 if pskSuite.hash == hs.suite.hash {
258 // Update binders and obfuscated_ticket_age.
259 ticketAge := uint32(c.config.time().Sub(hs.session.receivedAt) / time.Millisecond)
260 hs.hello.pskIdentities[0].obfuscatedTicketAge = ticketAge + hs.session.ageAdd
262 transcript := hs.suite.hash.New()
263 transcript.Write([]byte{typeMessageHash, 0, 0, uint8(len(chHash))})
264 transcript.Write(chHash)
265 if err := transcriptMsg(hs.serverHello, transcript); err != nil {
268 helloBytes, err := hs.hello.marshalWithoutBinders()
272 transcript.Write(helloBytes)
273 pskBinders := [][]byte{hs.suite.finishedHash(hs.binderKey, transcript)}
274 if err := hs.hello.updateBinders(pskBinders); err != nil {
278 // Server selected a cipher suite incompatible with the PSK.
279 hs.hello.pskIdentities = nil
280 hs.hello.pskBinders = nil
284 if _, err := hs.c.writeHandshakeRecord(hs.hello, hs.transcript); err != nil {
288 // serverHelloMsg is not included in the transcript
289 msg, err := c.readHandshake(nil)
294 serverHello, ok := msg.(*serverHelloMsg)
296 c.sendAlert(alertUnexpectedMessage)
297 return unexpectedMessageError(serverHello, msg)
299 hs.serverHello = serverHello
301 if err := hs.checkServerHelloOrHRR(); err != nil {
308 func (hs *clientHandshakeStateTLS13) processServerHello() error {
311 if bytes.Equal(hs.serverHello.random, helloRetryRequestRandom) {
312 c.sendAlert(alertUnexpectedMessage)
313 return errors.New("tls: server sent two HelloRetryRequest messages")
316 if len(hs.serverHello.cookie) != 0 {
317 c.sendAlert(alertUnsupportedExtension)
318 return errors.New("tls: server sent a cookie in a normal ServerHello")
321 if hs.serverHello.selectedGroup != 0 {
322 c.sendAlert(alertDecodeError)
323 return errors.New("tls: malformed key_share extension")
326 if hs.serverHello.serverShare.group == 0 {
327 c.sendAlert(alertIllegalParameter)
328 return errors.New("tls: server did not send a key share")
330 if sentID, _ := curveIDForCurve(hs.ecdheKey.Curve()); hs.serverHello.serverShare.group != sentID {
331 c.sendAlert(alertIllegalParameter)
332 return errors.New("tls: server selected unsupported group")
335 if !hs.serverHello.selectedIdentityPresent {
339 if int(hs.serverHello.selectedIdentity) >= len(hs.hello.pskIdentities) {
340 c.sendAlert(alertIllegalParameter)
341 return errors.New("tls: server selected an invalid PSK")
344 if len(hs.hello.pskIdentities) != 1 || hs.session == nil {
345 return c.sendAlert(alertInternalError)
347 pskSuite := cipherSuiteTLS13ByID(hs.session.cipherSuite)
349 return c.sendAlert(alertInternalError)
351 if pskSuite.hash != hs.suite.hash {
352 c.sendAlert(alertIllegalParameter)
353 return errors.New("tls: server selected an invalid PSK and cipher suite pair")
358 c.peerCertificates = hs.session.serverCertificates
359 c.verifiedChains = hs.session.verifiedChains
360 c.ocspResponse = hs.session.ocspResponse
361 c.scts = hs.session.scts
365 func (hs *clientHandshakeStateTLS13) establishHandshakeKeys() error {
368 peerKey, err := hs.ecdheKey.Curve().NewPublicKey(hs.serverHello.serverShare.data)
370 c.sendAlert(alertIllegalParameter)
371 return errors.New("tls: invalid server key share")
373 sharedKey, err := hs.ecdheKey.ECDH(peerKey)
375 c.sendAlert(alertIllegalParameter)
376 return errors.New("tls: invalid server key share")
379 earlySecret := hs.earlySecret
381 earlySecret = hs.suite.extract(nil, nil)
384 handshakeSecret := hs.suite.extract(sharedKey,
385 hs.suite.deriveSecret(earlySecret, "derived", nil))
387 clientSecret := hs.suite.deriveSecret(handshakeSecret,
388 clientHandshakeTrafficLabel, hs.transcript)
389 c.out.setTrafficSecret(hs.suite, QUICEncryptionLevelHandshake, clientSecret)
390 serverSecret := hs.suite.deriveSecret(handshakeSecret,
391 serverHandshakeTrafficLabel, hs.transcript)
392 c.in.setTrafficSecret(hs.suite, QUICEncryptionLevelHandshake, serverSecret)
395 if c.hand.Len() != 0 {
396 c.sendAlert(alertUnexpectedMessage)
398 c.quicSetWriteSecret(QUICEncryptionLevelHandshake, hs.suite.id, clientSecret)
399 c.quicSetReadSecret(QUICEncryptionLevelHandshake, hs.suite.id, serverSecret)
402 err = c.config.writeKeyLog(keyLogLabelClientHandshake, hs.hello.random, clientSecret)
404 c.sendAlert(alertInternalError)
407 err = c.config.writeKeyLog(keyLogLabelServerHandshake, hs.hello.random, serverSecret)
409 c.sendAlert(alertInternalError)
413 hs.masterSecret = hs.suite.extract(nil,
414 hs.suite.deriveSecret(handshakeSecret, "derived", nil))
419 func (hs *clientHandshakeStateTLS13) readServerParameters() error {
422 msg, err := c.readHandshake(hs.transcript)
427 encryptedExtensions, ok := msg.(*encryptedExtensionsMsg)
429 c.sendAlert(alertUnexpectedMessage)
430 return unexpectedMessageError(encryptedExtensions, msg)
433 if err := checkALPN(hs.hello.alpnProtocols, encryptedExtensions.alpnProtocol, c.quic != nil); err != nil {
434 // RFC 8446 specifies that no_application_protocol is sent by servers, but
435 // does not specify how clients handle the selection of an incompatible protocol.
436 // RFC 9001 Section 8.1 specifies that QUIC clients send no_application_protocol
437 // in this case. Always sending no_application_protocol seems reasonable.
438 c.sendAlert(alertNoApplicationProtocol)
441 c.clientProtocol = encryptedExtensions.alpnProtocol
444 if encryptedExtensions.quicTransportParameters == nil {
445 // RFC 9001 Section 8.2.
446 c.sendAlert(alertMissingExtension)
447 return errors.New("tls: server did not send a quic_transport_parameters extension")
449 c.quicSetTransportParameters(encryptedExtensions.quicTransportParameters)
451 if encryptedExtensions.quicTransportParameters != nil {
452 c.sendAlert(alertUnsupportedExtension)
453 return errors.New("tls: server sent an unexpected quic_transport_parameters extension")
460 func (hs *clientHandshakeStateTLS13) readServerCertificate() error {
463 // Either a PSK or a certificate is always used, but not both.
464 // See RFC 8446, Section 4.1.1.
466 // Make sure the connection is still being verified whether or not this
467 // is a resumption. Resumptions currently don't reverify certificates so
468 // they don't call verifyServerCertificate. See Issue 31641.
469 if c.config.VerifyConnection != nil {
470 if err := c.config.VerifyConnection(c.connectionStateLocked()); err != nil {
471 c.sendAlert(alertBadCertificate)
478 msg, err := c.readHandshake(hs.transcript)
483 certReq, ok := msg.(*certificateRequestMsgTLS13)
487 msg, err = c.readHandshake(hs.transcript)
493 certMsg, ok := msg.(*certificateMsgTLS13)
495 c.sendAlert(alertUnexpectedMessage)
496 return unexpectedMessageError(certMsg, msg)
498 if len(certMsg.certificate.Certificate) == 0 {
499 c.sendAlert(alertDecodeError)
500 return errors.New("tls: received empty certificates message")
503 c.scts = certMsg.certificate.SignedCertificateTimestamps
504 c.ocspResponse = certMsg.certificate.OCSPStaple
506 if err := c.verifyServerCertificate(certMsg.certificate.Certificate); err != nil {
510 // certificateVerifyMsg is included in the transcript, but not until
511 // after we verify the handshake signature, since the state before
512 // this message was sent is used.
513 msg, err = c.readHandshake(nil)
518 certVerify, ok := msg.(*certificateVerifyMsg)
520 c.sendAlert(alertUnexpectedMessage)
521 return unexpectedMessageError(certVerify, msg)
524 // See RFC 8446, Section 4.4.3.
525 if !isSupportedSignatureAlgorithm(certVerify.signatureAlgorithm, supportedSignatureAlgorithms()) {
526 c.sendAlert(alertIllegalParameter)
527 return errors.New("tls: certificate used with invalid signature algorithm")
529 sigType, sigHash, err := typeAndHashFromSignatureScheme(certVerify.signatureAlgorithm)
531 return c.sendAlert(alertInternalError)
533 if sigType == signaturePKCS1v15 || sigHash == crypto.SHA1 {
534 c.sendAlert(alertIllegalParameter)
535 return errors.New("tls: certificate used with invalid signature algorithm")
537 signed := signedMessage(sigHash, serverSignatureContext, hs.transcript)
538 if err := verifyHandshakeSignature(sigType, c.peerCertificates[0].PublicKey,
539 sigHash, signed, certVerify.signature); err != nil {
540 c.sendAlert(alertDecryptError)
541 return errors.New("tls: invalid signature by the server certificate: " + err.Error())
544 if err := transcriptMsg(certVerify, hs.transcript); err != nil {
551 func (hs *clientHandshakeStateTLS13) readServerFinished() error {
554 // finishedMsg is included in the transcript, but not until after we
555 // check the client version, since the state before this message was
556 // sent is used during verification.
557 msg, err := c.readHandshake(nil)
562 finished, ok := msg.(*finishedMsg)
564 c.sendAlert(alertUnexpectedMessage)
565 return unexpectedMessageError(finished, msg)
568 expectedMAC := hs.suite.finishedHash(c.in.trafficSecret, hs.transcript)
569 if !hmac.Equal(expectedMAC, finished.verifyData) {
570 c.sendAlert(alertDecryptError)
571 return errors.New("tls: invalid server finished hash")
574 if err := transcriptMsg(finished, hs.transcript); err != nil {
578 // Derive secrets that take context through the server Finished.
580 hs.trafficSecret = hs.suite.deriveSecret(hs.masterSecret,
581 clientApplicationTrafficLabel, hs.transcript)
582 serverSecret := hs.suite.deriveSecret(hs.masterSecret,
583 serverApplicationTrafficLabel, hs.transcript)
584 c.in.setTrafficSecret(hs.suite, QUICEncryptionLevelApplication, serverSecret)
586 err = c.config.writeKeyLog(keyLogLabelClientTraffic, hs.hello.random, hs.trafficSecret)
588 c.sendAlert(alertInternalError)
591 err = c.config.writeKeyLog(keyLogLabelServerTraffic, hs.hello.random, serverSecret)
593 c.sendAlert(alertInternalError)
597 c.ekm = hs.suite.exportKeyingMaterial(hs.masterSecret, hs.transcript)
602 func (hs *clientHandshakeStateTLS13) sendClientCertificate() error {
605 if hs.certReq == nil {
609 cert, err := c.getClientCertificate(&CertificateRequestInfo{
610 AcceptableCAs: hs.certReq.certificateAuthorities,
611 SignatureSchemes: hs.certReq.supportedSignatureAlgorithms,
619 certMsg := new(certificateMsgTLS13)
621 certMsg.certificate = *cert
622 certMsg.scts = hs.certReq.scts && len(cert.SignedCertificateTimestamps) > 0
623 certMsg.ocspStapling = hs.certReq.ocspStapling && len(cert.OCSPStaple) > 0
625 if _, err := hs.c.writeHandshakeRecord(certMsg, hs.transcript); err != nil {
629 // If we sent an empty certificate message, skip the CertificateVerify.
630 if len(cert.Certificate) == 0 {
634 certVerifyMsg := new(certificateVerifyMsg)
635 certVerifyMsg.hasSignatureAlgorithm = true
637 certVerifyMsg.signatureAlgorithm, err = selectSignatureScheme(c.vers, cert, hs.certReq.supportedSignatureAlgorithms)
639 // getClientCertificate returned a certificate incompatible with the
640 // CertificateRequestInfo supported signature algorithms.
641 c.sendAlert(alertHandshakeFailure)
645 sigType, sigHash, err := typeAndHashFromSignatureScheme(certVerifyMsg.signatureAlgorithm)
647 return c.sendAlert(alertInternalError)
650 signed := signedMessage(sigHash, clientSignatureContext, hs.transcript)
651 signOpts := crypto.SignerOpts(sigHash)
652 if sigType == signatureRSAPSS {
653 signOpts = &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash, Hash: sigHash}
655 sig, err := cert.PrivateKey.(crypto.Signer).Sign(c.config.rand(), signed, signOpts)
657 c.sendAlert(alertInternalError)
658 return errors.New("tls: failed to sign handshake: " + err.Error())
660 certVerifyMsg.signature = sig
662 if _, err := hs.c.writeHandshakeRecord(certVerifyMsg, hs.transcript); err != nil {
669 func (hs *clientHandshakeStateTLS13) sendClientFinished() error {
672 finished := &finishedMsg{
673 verifyData: hs.suite.finishedHash(c.out.trafficSecret, hs.transcript),
676 if _, err := hs.c.writeHandshakeRecord(finished, hs.transcript); err != nil {
680 c.out.setTrafficSecret(hs.suite, QUICEncryptionLevelApplication, hs.trafficSecret)
682 if !c.config.SessionTicketsDisabled && c.config.ClientSessionCache != nil {
683 c.resumptionSecret = hs.suite.deriveSecret(hs.masterSecret,
684 resumptionLabel, hs.transcript)
688 if c.hand.Len() != 0 {
689 c.sendAlert(alertUnexpectedMessage)
691 c.quicSetWriteSecret(QUICEncryptionLevelApplication, hs.suite.id, hs.trafficSecret)
697 func (c *Conn) handleNewSessionTicket(msg *newSessionTicketMsgTLS13) error {
699 c.sendAlert(alertUnexpectedMessage)
700 return errors.New("tls: received new session ticket from a client")
703 if c.config.SessionTicketsDisabled || c.config.ClientSessionCache == nil {
707 // See RFC 8446, Section 4.6.1.
708 if msg.lifetime == 0 {
711 lifetime := time.Duration(msg.lifetime) * time.Second
712 if lifetime > maxSessionTicketLifetime {
713 c.sendAlert(alertIllegalParameter)
714 return errors.New("tls: received a session ticket with invalid lifetime")
717 cipherSuite := cipherSuiteTLS13ByID(c.cipherSuite)
718 if cipherSuite == nil || c.resumptionSecret == nil {
719 return c.sendAlert(alertInternalError)
722 // Save the resumption_master_secret and nonce instead of deriving the PSK
723 // to do the least amount of work on NewSessionTicket messages before we
724 // know if the ticket will be used. Forward secrecy of resumed connections
725 // is guaranteed by the requirement for pskModeDHE.
726 session := &ClientSessionState{
727 sessionTicket: msg.label,
729 cipherSuite: c.cipherSuite,
730 masterSecret: c.resumptionSecret,
731 serverCertificates: c.peerCertificates,
732 verifiedChains: c.verifiedChains,
733 receivedAt: c.config.time(),
735 useBy: c.config.time().Add(lifetime),
737 ocspResponse: c.ocspResponse,
741 cacheKey := c.clientSessionCacheKey()
743 c.config.ClientSessionCache.Put(cacheKey, session)