public static void FirmarXadesEPES(XmlDocument xmlDoc, X509Certificate2 cert)
{
// Precondiciones.
if (xmlDoc == null)
{
throw new ArgumentException("xmlDoc");
}
if (cert == null)
{
throw new ArgumentException("Cert");
}
//
String keyInfoID = "keyinfoID";
String signedPropertiestypeID = "SignedPropertiestypeID";
String signatureID = "FacturaeSignatureID";
// Creo el objeto de la firma.
XadesSignedXml signedXml = new XadesSignedXml(xmlDoc);
// Añado la clave privada.
signedXml.SigningKey = cert.PrivateKey;
// Creo una referencia al documento, se pasa "" para decir que es todo el documento
Reference reference = new Reference();
reference.Uri = "";
// Añado transformacion a enveloped a la referencia.
reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
// Añado la referencia al objeto de la firma.
signedXml.AddReference(reference);
// Creo una referencia al keyInfo
Reference keyInfoReference = new Reference();
keyInfoReference.Uri = "#" + keyInfoID;
signedXml.AddReference(keyInfoReference);
//referencia al SignedProperiestype
Reference signedProperiestypeReference = new Reference();
signedProperiestypeReference.Uri = "#" + signedPropertiestypeID;
signedProperiestypeReference.Type = "http://uri.etsi.org/01903#SignedProperties";
signedProperiestypeReference.AddTransform(new XmlDsigExcC14NTransform());
signedXml.AddReference(signedProperiestypeReference);
// Añado la informacion del certificado
KeyInfo keyInfo = new KeyInfo();
keyInfo.Id = keyInfoID;
keyInfo.AddClause(new KeyInfoX509Data(cert));
signedXml.KeyInfo = keyInfo;
//info extra para xades-epes
QualifyingPropertiesType qualifyingProperties = new QualifyingPropertiesType();
qualifyingProperties.Target = "#" + signatureID;
qualifyingProperties.SignedProperties = new SignedPropertiesType();
qualifyingProperties.SignedProperties.Id = signedPropertiestypeID;
qualifyingProperties.SignedProperties.SignedSignatureProperties = new SignedSignaturePropertiesType();
qualifyingProperties.SignedProperties.SignedSignatureProperties.SigningTime = DateTime.Today;
qualifyingProperties.SignedProperties.SignedSignatureProperties.SignaturePolicyIdentifier = new SignaturePolicyIdentifierType();
SignaturePolicyIdType signaturePolicyIdType = new SignaturePolicyIdType();
signaturePolicyIdType.SigPolicyId = new ObjectIdentifierType();
signaturePolicyIdType.SigPolicyId.Identifier = new IdentifierType();
signaturePolicyIdType.SigPolicyId.Identifier.Value = "http://www.facturae.es/politica_de_firma_formato_facturae/politica_de_firma_formato_facturae_v3_1.pdf";
signaturePolicyIdType.SigPolicyId.Description = "facturae31";
signaturePolicyIdType.SigPolicyHash = new DigestAlgAndValueType();
signaturePolicyIdType.SigPolicyHash.DigestMethod = new DigestMethodType();
signaturePolicyIdType.SigPolicyHash.DigestMethod.Algorithm = "http://www.w3.org/2000/09/xmldsig#sha1";
signaturePolicyIdType.SigPolicyHash.DigestValue = Convert.FromBase64String("Ohixl6upD6av8N7pEvDABhEL6hM=");
qualifyingProperties.SignedProperties.SignedSignatureProperties.SignaturePolicyIdentifier.Item = signaturePolicyIdType;
signedXml.AddQualifyingPropertiesObject(qualifyingProperties);
// Proceso la firma.
signedXml.ComputeSignature();
// Obtengo la representación de la firma en Xml.
XmlElement xmlDigitalSignature = signedXml.GetXml();
// Añado el xml de la firma al documento original.
xmlDoc.DocumentElement.AppendChild(xmlDoc.ImportNode(xmlDigitalSignature, true));
}