switch k := priv.(type) {
		case *rsa.PrivateKey:
			return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
		case *ecdsa.PrivateKey:
			b, err := x509.MarshalECPrivateKey(k)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Unable to marshal ECDSA private key: %v", err)
				os.Exit(2)
			}
			return &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
		default:
			return nil

pkg crypto/tls, const VersionTLS12 = 771
pkg crypto/tls, const VersionTLS12 ideal-int
pkg crypto/tls, type Config struct, MaxVersion uint16
pkg crypto/tls, type Config struct, MinVersion uint16
pkg crypto/x509, func MarshalECPrivateKey(*ecdsa.PrivateKey) ([]uint8, error)
pkg crypto/x509, type Certificate struct, CRLDistributionPoints []string
pkg crypto/x509, type Certificate struct, Extensions []pkix.Extension