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 {

	oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
	oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
	oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
)

func namedCurveFromOID(oid asn1.ObjectIdentifier) elliptic.Curve {
	switch {
	case oid.Equal(oidNamedCurveP224):
		return elliptic.P224()
	case oid.Equal(oidNamedCurveP256):
		return elliptic.P256()