Method readServerCertificate

handshake_client_tls13.go:613–703

()

}

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

	// Either a PSK or a certificate is always used, but not both.
	// See RFC 8446, Section 4.1.1.
	if hs.usingPSK {
		// 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
			}
		}
		return nil
	}

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

	certReq, ok := msg.(*certificateRequestMsgTLS13)
	if ok {
		hs.certReq = certReq

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

	certMsg, ok := msg.(*certificateMsgTLS13)
	if !ok {
		c.sendAlert(alertUnexpectedMessage)
		return unexpectedMessageError(certMsg, msg)
	}
	if len(certMsg.certificate.Certificate) == 0 {
		c.sendAlert(alertDecodeError)
		return errors.New("tls: received empty certificates message")
	}

	c.scts = certMsg.certificate.SignedCertificateTimestamps
	c.ocspResponse = certMsg.certificate.OCSPStaple

	if err := c.verifyServerCertificate(certMsg.certificate.Certificate); err != nil {
		return err
	}

	// certificateVerifyMsg is included in the transcript, but not until
	// after we verify the handshake signature, since the state before
	// this message was sent is used.
	msg, err = c.readHandshake(nil)
	if err != nil {
		return err
	}