Method sendClientCertificate

handshake_client_tls13.go:543–610

()

}

func (hs *clientHandshakeStateTLS13) sendClientCertificate() error {
	c := hs.c

	if hs.certReq == nil {
		return nil
	}

	cert, err := c.getClientCertificate(&CertificateRequestInfo{
		AcceptableCAs:    hs.certReq.certificateAuthorities,
		SignatureSchemes: hs.certReq.supportedSignatureAlgorithms,
		Version:          c.vers,
		ctx:              hs.ctx,
	})
	if err != nil {
		return err
	}

	certMsg := new(certificateMsgTLS13)

	certMsg.certificate = *cert
	certMsg.scts = hs.certReq.scts && len(cert.SignedCertificateTimestamps) > 0
	certMsg.ocspStapling = hs.certReq.ocspStapling && len(cert.OCSPStaple) > 0

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

	// If we sent an empty certificate message, skip the CertificateVerify.
	if len(cert.Certificate) == 0 {
		return nil
	}

	certVerifyMsg := new(certificateVerifyMsg)
	certVerifyMsg.hasSignatureAlgorithm = true

	certVerifyMsg.signatureAlgorithm, err = selectSignatureScheme(c.vers, cert, hs.certReq.supportedSignatureAlgorithms)
	if err != nil {
		// getClientCertificate returned a certificate incompatible with the
		// CertificateRequestInfo supported signature algorithms.
		c.sendAlert(alertHandshakeFailure)
		return err
	}

	sigType, sigHash, err := typeAndHashFromSignatureScheme(certVerifyMsg.signatureAlgorithm)
	if err != nil {
		return c.sendAlert(alertInternalError)
	}

	signed := signedMessage(sigHash, clientSignatureContext, hs.transcript)
	signOpts := crypto.SignerOpts(sigHash)
	if sigType == signatureRSAPSS {
		signOpts = &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash, Hash: sigHash}
	}
	sig, err := cert.PrivateKey.(crypto.Signer).Sign(c.config.rand(), signed, signOpts)
	if err != nil {
		c.sendAlert(alertInternalError)
		return errors.New("tls: failed to sign handshake: " + err.Error())