namedCurveOID := new(asn1.ObjectIdentifier)
		if !paramsDer.ReadASN1ObjectIdentifier(namedCurveOID) {
			return nil, errors.New("x509: invalid ECDSA parameters")
		}
		namedCurve := namedCurveFromOID(*namedCurveOID)
		if namedCurve == nil {
			return nil, errors.New("x509: unsupported elliptic curve")
		}
		x, y := elliptic.Unmarshal(namedCurve, der)
		if x == nil {