private void AddIdentificacionPolitica(string path)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.Load(path);
            try
            {
                result = "";
                string uri = "http://www.w3.org/2000/09/xmldsig#";
                string URI = "http://uri.etsi.org/01903/v1.3.2#";

                XmlElement DigestMethod = xmlDoc.CreateElement("ds", "DigestMethod");
                XmlElement DigestValue = xmlDoc.CreateElement("ds", "DigestValue");

                XmlElement SignaturePolicyIdentifier = xmlDoc.CreateElement("xades", "SignaturePolicyIdentifier", URI);

                XmlElement SignaturePolicyId = xmlDoc.CreateElement("xades", "SignaturePolicyId", URI);
                SignaturePolicyIdentifier.AppendChild(SignaturePolicyId);

                XmlElement SigPolicyId = xmlDoc.CreateElement("xades", "SigPolicyId", URI);
                SignaturePolicyId.AppendChild(SigPolicyId);

                XmlElement Identifier = xmlDoc.CreateElement("xades", "Identifier", URI);
                Identifier.InnerText = "https://tribunet.hacienda.go.cr/docs/esquemas/2016/v4.1/Resolucion_Comprobantes_Electronicos_DGT-R-48-2016.pdf";
                SigPolicyId.AppendChild(Identifier);

                XmlElement SigPolicyHash = xmlDoc.CreateElement("xades", "SigPolicyHash", URI);
                SignaturePolicyId.AppendChild(SigPolicyHash);

                DigestMethod = xmlDoc.CreateElement("ds", "DigestMethod",uri);
                DigestMethod.SetAttribute("Algorithm", "http://www.w3.org/2001/04/xmlenc#sha256");
                DigestValue = xmlDoc.CreateElement("ds", "DigestValue",uri);
                byte[] shaCertificate = { 0x06, 0xb3, 0x90, 0xb6, 0x45, 0xbb, 0x68, 0x3a, 0xde, 0x72, 0x8e, 0xb8, 0xf9, 0x79, 0x27, 0xd9, 0x18, 0x01, 0x67, 0xdb };
                SHA256 sigPolicyHash = SHA256Managed.Create();
                byte[] sigPolicyHashValue = sigPolicyHash.ComputeHash(shaCertificate);
                DigestValue.InnerText = Convert.ToBase64String(sigPolicyHashValue);
                SigPolicyHash.AppendChild(DigestMethod);
                SigPolicyHash.AppendChild(DigestValue);

                xmlDoc.DocumentElement.AppendChild(xmlDoc.ImportNode(SignaturePolicyIdentifier, true));
                xmlDoc.Save(path);
            }
            catch (Exception ex ){ result = ex.ToString(); }

        }