handshake_client_gm.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 tls

import (
	"bytes"
	"crypto"
	"crypto/ecdsa"
	"crypto/rsa"
	"crypto/subtle"
	"errors"
	"fmt"
	"github.com/Lcfling/cryptogm/sm2"
	"github.com/Lcfling/cryptogm/x509"
	"hash"
	"io"
	"sync/atomic"
)

type clientHandshakeStateGM struct {
	c            *Conn
	serverHello  *serverHelloMsg
	hello        *clientHelloMsg
	suite        *cipherSuite
	finishedHash finishedHash
	masterSecret []byte
	session      *ClientSessionState
}

func (c *Conn) makeClientHelloGM() (*clientHelloMsg, error) {
	config := c.config
	if len(config.ServerName) == 0 && !config.InsecureSkipVerify {
		return nil, errors.New("tls: either ServerName or InsecureSkipVerify must be specified in the tls.Config")
	}

	hello := &clientHelloMsg{
		vers:               config.GMSupport.GetVersion(),
		compressionMethods: []uint8{compressionNone},
		random:             make([]byte, 32),
	}

	if c.handshakes > 0 {
		hello.secureRenegotiation = c.clientFinished[:]
	}

	possibleCipherSuites := config.cipherSuites()
	hello.cipherSuites = make([]uint16, 0, len(possibleCipherSuites))

	for _, suiteId := range possibleCipherSuites {
		for _, suite := range config.GMSupport.cipherSuites() {
			if suite.id != suiteId {
				continue
			}
			hello.cipherSuites = append(hello.cipherSuites, suiteId)
			break
		}
	}

	_, err := io.ReadFull(config.rand(), hello.random)
	if err != nil {
		return nil, errors.New("tls: short read from Rand: " + err.Error())
	}

	// A random session ID is used to detect when the server accepted a ticket
	// and is resuming a session (see RFC 5077). In TLS 1.3, it's always set as
	// a compatibility measure (see RFC 8446, Section 4.1.2).
	if _, err := io.ReadFull(config.rand(), hello.sessionId); err != nil {
		return nil, errors.New("tls: short read from Rand: " + err.Error())
	}
	return hello, nil
}

// Does the handshake, either a full one or resumes old session. Requires hs.c,
// hs.hello, hs.serverHello, and, optionally, hs.session to be set.
func (hs *clientHandshakeStateGM) handshake() error {
	c := hs.c

	isResume, err := hs.processServerHello()
	if err != nil {
		return err
	}

	hs.finishedHash = newFinishedHashGM(hs.suite)

	// No signatures of the handshake are needed in a resumption.
	// Otherwise, in a full handshake, if we don't have any certificates
	// configured then we will never send a CertificateVerify message and
	// thus no signatures are needed in that case either.
	if isResume || (len(c.config.Certificates) == 0 && c.config.GetClientCertificate == nil) {
		hs.finishedHash.discardHandshakeBuffer()
	}

	hs.finishedHash.Write(hs.hello.marshal())
	hs.finishedHash.Write(hs.serverHello.marshal())

	c.buffering = true
	c.didResume = isResume
	if isResume {
		if err := hs.establishKeys(); err != nil {
			return err
		}
		if err := hs.readSessionTicket(); err != nil {
			return err
		}
		if err := hs.readFinished(c.serverFinished[:]); err != nil {
			return err
		}
		c.clientFinishedIsFirst = false
		// Make sure the connection is still being verified whether or not this
		// is a resumption. Resumptions currently don't reverify certificates so
		// they don't call verifyServerCertificate. See Issue 31641.
		if c.config.VerifyConnection != nil {
			if err := c.config.VerifyConnection(c.connectionStateLocked()); err != nil {
				c.sendAlert(alertBadCertificate)
				return err
			}
		}
		if err := hs.sendFinished(c.clientFinished[:]); err != nil {
			return err
		}
		if _, err := c.flush(); 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.clientFinished[:]); err != nil {
			return err
		}
		if _, err := c.flush(); err != nil {
			return err
		}
		c.clientFinishedIsFirst = true
		if err := hs.readSessionTicket(); err != nil {
			return err
		}
		if err := hs.readFinished(c.serverFinished[:]); err != nil {
			return err
		}
	}

	c.ekm = ekmFromMasterSecret(c.vers, hs.suite, hs.masterSecret, hs.hello.random, hs.serverHello.random)
	atomic.StoreUint32(&c.handshakeStatus, 1)

	return nil
}

func (hs *clientHandshakeStateGM) pickCipherSuite() error {
	if hs.suite = mutualCipherSuite(hs.hello.cipherSuites, hs.serverHello.cipherSuite); hs.suite == nil {
		hs.c.sendAlert(alertHandshakeFailure)
		return errors.New("tls: server chose an unconfigured cipher suite")
	}

	hs.c.cipherSuite = hs.suite.id
	return nil
}

func (hs *clientHandshakeStateGM) doFullHandshake() error {
	c := hs.c

	msg, err := c.readHandshake()
	if err != nil {
		return err
	}
	certMsg, ok := msg.(*certificateMsg)
	if !ok || len(certMsg.certificates) == 0 {
		c.sendAlert(alertUnexpectedMessage)
		return unexpectedMessageError(certMsg, msg)
	}
	hs.finishedHash.Write(certMsg.marshal())

	msg, err = c.readHandshake()
	if err != nil {
		return err
	}

	cs, ok := msg.(*certificateStatusMsg)
	if ok {
		// RFC4366 on Certificate Status Request:
		// The server MAY return a "certificate_status" message.

		if !hs.serverHello.ocspStapling {
			// If a server returns a "CertificateStatus" message, then the
			// server MUST have included an extension of type "status_request"
			// with empty "extension_data" in the extended server hello.

			c.sendAlert(alertUnexpectedMessage)
			return errors.New("tls: received unexpected CertificateStatus message")
		}
		hs.finishedHash.Write(cs.marshal())

		c.ocspResponse = cs.response

		msg, err = c.readHandshake()
		if err != nil {
			return err
		}
	}

	if c.handshakes == 0 {
		// If this is the first handshake on a connection, process and
		// (optionally) verify the server's certificates.
		if err := c.verifyServerCertificateGM(certMsg.certificates); err != nil {
			return err
		}
	} else {
		// This is a renegotiation handshake. We require that the
		// server's identity (i.e. leaf certificate) is unchanged and
		// thus any previous trust decision is still valid.
		//
		// See https://mitls.org/pages/attacks/3SHAKE for the
		// motivation behind this requirement.
		if !bytes.Equal(c.peerCertificates[0].Raw, certMsg.certificates[0]) {
			c.sendAlert(alertBadCertificate)
			return errors.New("tls: server's identity changed during renegotiation")
		}
	}

	keyAgreement := hs.suite.ka(c.vers)
	if ka, ok := keyAgreement.(*eccKeyAgreementGM); ok {
		// mod by syl only one cert
		//ka.encipherCert = c.peerCertificates[1]
		ka.encipherCert = c.peerCertificates[0]
	}
	skx, ok := msg.(*serverKeyExchangeMsg)
	if ok {
		hs.finishedHash.Write(skx.marshal())
		err = keyAgreement.processServerKeyExchange(c.config, hs.hello, hs.serverHello, c.peerCertificates[0], skx)
		if err != nil {
			c.sendAlert(alertUnexpectedMessage)
			return err
		}

		msg, err = c.readHandshake()
		if err != nil {
			return err
		}
	}

	var chainToSend *Certificate
	var certRequested bool
	certReq, ok := msg.(*certificateRequestMsgGM)
	if ok {
		certRequested = true
		hs.finishedHash.Write(certReq.marshal())

		cri := certificateRequestInfoFromMsgGM(c.vers, certReq)
		if chainToSend, err = c.getClientCertificateGM(cri); err != nil {
			c.sendAlert(alertInternalError)
			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.finishedHash.Write(shd.marshal())

	// If the server requested a certificate then we have to send a
	// Certificate message, even if it's empty because we don't have a
	// certificate to send.
	if certRequested {
		certMsg = new(certificateMsg)
		certMsg.certificates = chainToSend.Certificate
		hs.finishedHash.Write(certMsg.marshal())
		if _, err := c.writeRecord(recordTypeHandshake, certMsg.marshal()); err != nil {
			return err
		}
	}

	preMasterSecret, ckx, err := keyAgreement.generateClientKeyExchange(c.config, hs.hello, c.peerCertificates[0])
	if err != nil {
		c.sendAlert(alertInternalError)
		return err
	}
	if ckx != nil {
		hs.finishedHash.Write(ckx.marshal())
		if _, err := c.writeRecord(recordTypeHandshake, ckx.marshal()); err != nil {
			return err
		}
	}

	if chainToSend != nil && len(chainToSend.Certificate) > 0 {
		certVerify := &certificateVerifyMsg{}

		key, ok := chainToSend.PrivateKey.(crypto.Signer)
		if !ok {
			c.sendAlert(alertInternalError)
			return fmt.Errorf("tls: client certificate private key of type %T does not implement crypto.Signer", chainToSend.PrivateKey)
		}

		digest := hs.finishedHash.client.Sum(nil)

		certVerify.signature, err = key.Sign(c.config.rand(), digest, nil)
		if err != nil {
			c.sendAlert(alertInternalError)
			return err
		}

		hs.finishedHash.Write(certVerify.marshal())
		if _, err := c.writeRecord(recordTypeHandshake, certVerify.marshal()); err != nil {
			return err
		}
	}

	hs.masterSecret = masterFromPreMasterSecret(c.vers, hs.suite, preMasterSecret, hs.hello.random, hs.serverHello.random)
	if err := c.config.writeKeyLog(keyLogLabelTLS12, hs.hello.random, hs.masterSecret); err != nil {
		c.sendAlert(alertInternalError)
		return errors.New("tls: failed to write to key log: " + err.Error())
	}

	hs.finishedHash.discardHandshakeBuffer()

	return nil
}

func (hs *clientHandshakeStateGM) 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)
	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(clientMAC)
		serverCipher = hs.suite.cipher(serverKey, serverIV, true /* for reading */)
		serverHash = hs.suite.mac(serverMAC)
	} else {
		clientCipher = hs.suite.aead(clientKey, clientIV)
		serverCipher = hs.suite.aead(serverKey, serverIV)
	}

	c.in.prepareCipherSpec(c.vers, serverCipher, serverHash)
	c.out.prepareCipherSpec(c.vers, clientCipher, clientHash)
	return nil
}

func (hs *clientHandshakeStateGM) serverResumedSession() bool {
	// If the server responded with the same sessionId then it means the
	// sessionTicket is being used to resume a TLS session.
	return hs.session != nil && hs.hello.sessionId != nil &&
		bytes.Equal(hs.serverHello.sessionId, hs.hello.sessionId)
}

func (hs *clientHandshakeStateGM) processServerHello() (bool, error) {
	c := hs.c

	if err := hs.pickCipherSuite(); err != nil {
		return false, err
	}

	if hs.serverHello.compressionMethod != compressionNone {
		c.sendAlert(alertUnexpectedMessage)
		return false, errors.New("tls: server selected unsupported compression format")
	}

	if c.handshakes == 0 && hs.serverHello.secureRenegotiationSupported {
		c.secureRenegotiation = true
		if len(hs.serverHello.secureRenegotiation) != 0 {
			c.sendAlert(alertHandshakeFailure)
			return false, errors.New("tls: initial handshake had non-empty renegotiation extension")
		}
	}

	if c.handshakes > 0 && c.secureRenegotiation {
		var expectedSecureRenegotiation [24]byte
		copy(expectedSecureRenegotiation[:], c.clientFinished[:])
		copy(expectedSecureRenegotiation[12:], c.serverFinished[:])
		if !bytes.Equal(hs.serverHello.secureRenegotiation, expectedSecureRenegotiation[:]) {
			c.sendAlert(alertHandshakeFailure)
			return false, errors.New("tls: incorrect renegotiation extension contents")
		}
	}

	if hs.serverHello.alpnProtocol != "" {
		if len(hs.hello.alpnProtocols) == 0 {
			c.sendAlert(alertUnsupportedExtension)
			return false, errors.New("tls: server advertised unrequested ALPN extension")
		}
		if mutualProtocol([]string{hs.serverHello.alpnProtocol}, hs.hello.alpnProtocols) == "" {
			c.sendAlert(alertUnsupportedExtension)
			return false, errors.New("tls: server selected unadvertised ALPN protocol")
		}
		c.clientProtocol = hs.serverHello.alpnProtocol
	}

	c.scts = hs.serverHello.scts

	if !hs.serverResumedSession() {
		return false, nil
	}

	if hs.session.vers != c.vers {
		c.sendAlert(alertHandshakeFailure)
		return false, errors.New("tls: server resumed a session with a different version")
	}

	if hs.session.cipherSuite != hs.suite.id {
		c.sendAlert(alertHandshakeFailure)
		return false, errors.New("tls: server resumed a session with a different cipher suite")
	}

	// Restore masterSecret, peerCerts, and ocspResponse from previous state
	hs.masterSecret = hs.session.masterSecret
	c.peerCertificates = hs.session.serverCertificates
	c.verifiedChains = hs.session.verifiedChains
	c.ocspResponse = hs.session.ocspResponse
	// Let the ServerHello SCTs override the session SCTs from the original
	// connection, if any are provided
	if len(c.scts) == 0 && len(hs.session.scts) != 0 {
		c.scts = hs.session.scts
	}

	return true, nil
}

func (hs *clientHandshakeStateGM) readFinished(out []byte) error {
	c := hs.c

	if err := c.readChangeCipherSpec(); 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)
	}

	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")
	}
	hs.finishedHash.Write(serverFinished.marshal())
	copy(out, verify)
	return nil
}

func (hs *clientHandshakeStateGM) readSessionTicket() error {
	if !hs.serverHello.ticketSupported {
		return nil
	}

	c := hs.c
	msg, err := c.readHandshake()
	if err != nil {
		return err
	}
	sessionTicketMsg, ok := msg.(*newSessionTicketMsg)
	if !ok {
		c.sendAlert(alertUnexpectedMessage)
		return unexpectedMessageError(sessionTicketMsg, msg)
	}
	hs.finishedHash.Write(sessionTicketMsg.marshal())

	hs.session = &ClientSessionState{
		sessionTicket:      sessionTicketMsg.ticket,
		vers:               c.vers,
		cipherSuite:        hs.suite.id,
		masterSecret:       hs.masterSecret,
		serverCertificates: c.peerCertificates,
		verifiedChains:     c.verifiedChains,
		receivedAt:         c.config.time(),
		ocspResponse:       c.ocspResponse,
		scts:               c.scts,
	}

	return nil
}

func (hs *clientHandshakeStateGM) sendFinished(out []byte) error {
	c := hs.c

	if _, err := c.writeRecord(recordTypeChangeCipherSpec, []byte{1}); err != nil {
		return err
	}

	finished := new(finishedMsg)
	finished.verifyData = hs.finishedHash.clientSum(hs.masterSecret)
	hs.finishedHash.Write(finished.marshal())
	if _, err := c.writeRecord(recordTypeHandshake, finished.marshal()); err != nil {
		return err
	}
	copy(out, finished.verifyData)
	return nil
}

// verifyServerCertificate parses and verifies the provided chain, setting
// c.verifiedChains and c.peerCertificates or sending the appropriate alert.
func (c *Conn) verifyServerCertificateGM(certificates [][]byte) error {
	certs := make([]*x509.Certificate, len(certificates))
	for i, asn1Data := range certificates {
		cert, err := x509.ParseCertificate(asn1Data)
		if err != nil {
			c.sendAlert(alertBadCertificate)
			return errors.New("tls: failed to parse certificate from server: " + err.Error())
		}
		certs[i] = cert
	}

	if !c.config.InsecureSkipVerify {
		opts := x509.VerifyOptions{
			Roots:         c.config.RootCAs,
			CurrentTime:   c.config.time(),
			DNSName:       c.config.ServerName,
			Intermediates: x509.NewCertPool(),
		}
		if opts.Roots == nil {
			opts.Roots = x509.NewCertPool()
		}

		for _, rootca := range getCAs() {
			opts.Roots.AddCert(rootca)
		}
		for _, cert := range certs[2:] {
			opts.Intermediates.AddCert(cert)
		}
		var err error
		c.verifiedChains, err = certs[0].Verify(opts)
		if err != nil {
			c.sendAlert(alertBadCertificate)
			return err
		}
	}

	switch certs[0].PublicKey.(type) {
	case *sm2.PublicKey, *ecdsa.PublicKey, *rsa.PublicKey:
		break
	default:
		c.sendAlert(alertUnsupportedCertificate)
		return fmt.Errorf("tls: server's certificate contains an unsupported type of public key: %T", certs[0].PublicKey)
	}

	c.peerCertificates = certs

	if c.config.VerifyPeerCertificate != nil {
		if err := c.config.VerifyPeerCertificate(certificates, c.verifiedChains); err != nil {
			c.sendAlert(alertBadCertificate)
			return err
		}
	}

	if c.config.VerifyConnection != nil {
		if err := c.config.VerifyConnection(c.connectionStateLocked()); err != nil {
			c.sendAlert(alertBadCertificate)
			return err
		}
	}

	return nil
}

// certificateRequestInfoFromMsg generates a CertificateRequestInfo from a TLS
// <= 1.2 CertificateRequest, making an effort to fill in missing information.

func certificateRequestInfoFromMsgGM(vers uint16, certReq *certificateRequestMsgGM) *CertificateRequestInfo {

	var signatureSchemes []SignatureScheme
	cri := &CertificateRequestInfo{
		AcceptableCAs: certReq.certificateAuthorities,
		Version:       vers,
	}

	cri.SignatureSchemes = signatureSchemes

	// Filter the signature schemes based on the certificate types.
	// See RFC 5246, Section 7.4.4 (where it calls this "somewhat complicated").

	return cri
}
func (c *Conn) getClientCertificateGM(cri *CertificateRequestInfo) (*Certificate, error) {
	if c.config.GetClientCertificate != nil {
		return c.config.GetClientCertificate(cri)
	}

	for _, chain := range c.config.Certificates {
		if err := cri.SupportsCertificateGM(&chain); err != nil {
			continue
		}
		return &chain, nil
	}

	// No acceptable certificate found. Don't send a certificate.
	return new(Certificate), nil
}