System.Security.Cryptography.RSA.FromXmlString C# (CSharp) Method

        public override void FromXmlString(string xmlString)
        {
            throw new PlatformNotSupportedException();
        }

        /// <summary>
        /// Signiert ein Xml-Document.
        /// </summary>
        /// <param name="xDoc">Das Dokument welches die Daten enthält die signiert werden sollen.</param>
        /// <param name="privateKey">Der private Schlüssel.</param>
        /// <returns>Gibt ein Xml Element mit den Signierten daten zurück.</returns>
        public static XmlElement SignXmlDocument(XmlDocument xDoc, string privateKey)
        {
            var signedXml = new SignedXml();

            System.Security.Cryptography.RSA pvk = System.Security.Cryptography.RSA.Create();
            pvk.FromXmlString(privateKey);
            signedXml.SigningKey = pvk;

            var dataObject = new DataObject();

            dataObject.Id   = "content";
            dataObject.Data = xDoc.ChildNodes;

            signedXml.AddObject(dataObject);

            var reference = new Reference();

            reference.Uri = "#content";

            signedXml.AddReference(reference);

            var keyinfo = new KeyInfo();

            keyinfo.AddClause(new RSAKeyValue(pvk));
            signedXml.KeyInfo = keyinfo;

            signedXml.ComputeSignature();

            return(signedXml.GetXml());
        }