/// <summary>
/// Export RSA private key
/// </summary>
/// <param name="rsa"></param>
/// <returns></returns>
/// <exception cref="ArgumentNullException"></exception>
public static byte[] ExportPkcs8PrivateKey(this RSA rsa)
{
if (rsa is null)
{
throw new ArgumentNullException(nameof(rsa));
}
return(Convert.FromBase64String(rsa.ToPkcs8PrivateString()));
}
