Microsoft.Xades.XadesSignedXml.ComputeSignature C# (CSharp) Method

        public new void ComputeSignature()
        {
            this.BuildDigestedReferences();
            AsymmetricAlgorithm signingKey = this.SigningKey;
            if (signingKey == null)
            {
                throw new CryptographicException("Cryptography_Xml_LoadKeyFailed");
            }
            if (this.SignedInfo.SignatureMethod == null)
            {
                if (!(signingKey is DSA))
                {
                    if (!(signingKey is RSA))
                    {
                        throw new CryptographicException("Cryptography_Xml_CreatedKeyFailed");
                    }
                    if (this.SignedInfo.SignatureMethod == null)
                    {
                        this.SignedInfo.SignatureMethod = "http://www.w3.org/2000/09/xmldsig#rsa-sha1";
                    }
                }
                else
                {
                    this.SignedInfo.SignatureMethod = "http://www.w3.org/2000/09/xmldsig#dsa-sha1";
                }
            }
            SignatureDescription description = CryptoConfig.CreateFromName(this.SignedInfo.SignatureMethod) as SignatureDescription;
            if (description == null)
            {
                throw new CryptographicException("Cryptography_Xml_SignatureDescriptionNotCreated");
            }
            HashAlgorithm hash = description.CreateDigest();
            if (hash == null)
            {
                throw new CryptographicException("Cryptography_Xml_CreateHashAlgorithmFailed");
            }
            //this.GetC14NDigest(hash);
            this.GetC14NDigest(hash, "ds");
            //
            this.m_signature.SignatureValue = description.CreateFormatter(signingKey).CreateSignature(hash);
        }

        /// <summary>
        /// Realiza la contrafirma de la firma actual
        /// </summary>
        /// <param name="certificate"></param>
        /// <param name="signMethod"></param>
        public void CounterSign(X509Certificate2 certificate, SignMethod? signMethod = null)
        {
            SetSignatureId();

            if (_xadesSignedXml == null)
            {
                throw new Exception("No hay ninguna firma XADES cargada previamente.");
            }

            if (certificate == null)
            {
                throw new Exception("Es necesario un certificado válido para la firma.");
            }

            if (signMethod.HasValue)
            {
                this.SignMethod = signMethod.Value;
            }

            _signCertificate = certificate;

            XadesSignedXml counterSignature = new XadesSignedXml(_document);

            SetCryptoServiceProvider();

            counterSignature.SigningKey = _rsaKey;

            Reference reference = new Reference();
            reference.Uri = "#" + _xadesSignedXml.SignatureValueId;
            reference.Id = "Reference-" + Guid.NewGuid().ToString();
            reference.Type = "http://uri.etsi.org/01903#CountersignedSignature";
            reference.AddTransform(new XmlDsigC14NTransform());
            counterSignature.AddReference(reference);
            _objectReference = reference.Id;

            KeyInfo keyInfo = new KeyInfo();
            keyInfo.Id = "KeyInfoId-" + _signatureId;
            keyInfo.AddClause(new KeyInfoX509Data((X509Certificate)_signCertificate));
            keyInfo.AddClause(new RSAKeyValue((RSA)_rsaKey));
            counterSignature.KeyInfo = keyInfo;

            Reference referenceKeyInfo = new Reference();
            referenceKeyInfo.Id = "ReferenceKeyInfo-" + _signatureId;
            referenceKeyInfo.Uri = "#KeyInfoId-" + _signatureId;
            counterSignature.AddReference(referenceKeyInfo);

            counterSignature.Signature.Id = _signatureId;
            counterSignature.SignatureValueId = _signatureValueId;

            XadesObject counterSignatureXadesObject = new XadesObject();
            counterSignatureXadesObject.Id = "CounterSignatureXadesObject-" + Guid.NewGuid().ToString();
            counterSignatureXadesObject.QualifyingProperties.Target = "#" + _signatureId;
            counterSignatureXadesObject.QualifyingProperties.SignedProperties.Id = "SignedProperties-" + _signatureId;

            AddSignatureProperties(counterSignatureXadesObject.QualifyingProperties.SignedProperties.SignedSignatureProperties,
                counterSignatureXadesObject.QualifyingProperties.SignedProperties.SignedDataObjectProperties,
                counterSignatureXadesObject.QualifyingProperties.UnsignedProperties.UnsignedSignatureProperties,
                "text/xml", _signCertificate);

            counterSignature.AddXadesObject(counterSignatureXadesObject);

            foreach (Reference signReference in counterSignature.SignedInfo.References)
            {
                signReference.DigestMethod = _refsMethodUri;
            }

            counterSignature.AddXadesNamespace = true;
            counterSignature.ComputeSignature();

            UnsignedProperties unsignedProperties = _xadesSignedXml.UnsignedProperties;
            unsignedProperties.UnsignedSignatureProperties.CounterSignatureCollection.Add(counterSignature);
            _xadesSignedXml.UnsignedProperties = unsignedProperties;

            UpdateDocument();

            _xadesSignedXml = new XadesSignedXml(_document);

            XmlNode xmlNode = _document.SelectSingleNode("//*[@Id='" + _signatureId + "']");

            _xadesSignedXml.LoadXml((XmlElement)xmlNode);
        }