/// <summary>
/// ImportParameters will replace the existing key that ECDsaCng is working with by creating a
/// new CngKey. If the parameters contains only Q, then only a public key will be imported.
/// If the parameters also contains D, then a full key pair will be imported.
/// The parameters Curve value specifies the type of the curve to import.
/// </summary>
/// <exception cref="CryptographicException">
/// if <paramref name="parameters" /> does not contain valid values.
/// </exception>
/// <exception cref="NotSupportedException">
/// if <paramref name="parameters" /> references a curve that cannot be imported.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// if <paramref name="parameters" /> references a curve that is not supported by this platform.
/// </exception>
public override void ImportParameters(ECParameters parameters)
{
parameters.Validate();
ThrowIfDisposed();
ECCurve curve = parameters.Curve;
bool includePrivateParameters = (parameters.D != null);
if (curve.IsPrime)
{
byte[] ecExplicitBlob = ECCng.GetPrimeCurveBlob(ref parameters, ecdh: false);
ImportFullKeyBlob(ecExplicitBlob, includePrivateParameters);
}
else if (curve.IsNamed)
{
// FriendlyName is required; an attempt was already made to default it in ECCurve
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value.ToString()));
}
byte[] ecNamedCurveBlob = ECCng.GetNamedCurveBlob(ref parameters, ecdh: false);
ImportKeyBlob(ecNamedCurveBlob, curve.Oid.FriendlyName, includePrivateParameters);
}
else
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
}