private void AddCodeCertificateExtensions(X509V3CertificateGenerator builder)
{
builder.AddExtension(X509Extensions.BasicConstraints, true, new BasicConstraints(false));
builder.AddExtension(X509Extensions.KeyUsage, true, new KeyUsage(KeyUsage.DigitalSignature | KeyUsage.NonRepudiation | KeyUsage.KeyEncipherment));
builder.AddExtension(X509Extensions.ExtendedKeyUsage, true, new ExtendedKeyUsage(KeyPurposeID.IdKPCodeSigning));
}