【cert】verify the certs

func validCert(certs *generator.Artifacts, dnsName string) bool {
	if certs == nil || certs.Cert == nil || certs.Key == nil || certs.CACert == nil {
		return false
	}

	// Verify key and cert are valid pair
	_, err := tls.X509KeyPair(certs.Cert, certs.Key)
	if err != nil {
		return false
	}

	// Verify cert is good for desired DNS name and signed by CA and will be valid for desired period of time.
	pool := x509.NewCertPool()
	if !pool.AppendCertsFromPEM(certs.CACert) {
		return false
	}
	block, _ := pem.Decode(certs.Cert)
	if block == nil {
		return false
	}
	cert, err := x509.ParseCertificate(block.Bytes)
	if err != nil {
		return false
	}
	ops := x509.VerifyOptions{
		DNSName:     dnsName,
		Roots:       pool,
		CurrentTime: time.Now().AddDate(0, 6, 0),
	}
	_, err = cert.Verify(ops)
	return err == nil
}

pkgwebhookutilwritercertwriter.go