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Use DataReference to encrypt and decrypt multiple XML elements using different session keys

using System; using System.Xml; using System.Security.Cryptography; using System.Security.Cryptography.Xml; class Program {     static void Main(string[] args)     {         XmlDocument xmlDoc = new XmlDocument();         xmlDoc.PreserveWhitespace = true;         xmlDoc.Load("test.xml");         RSA rsaKey = new RSACryptoServiceProvider();         // Encrypt the "creditcard" element.         Encrypt(xmlDoc, "creditcard", "EncryptedElement1", rsaKey, "rsaKey");         // Encrypt the "creditcard2" element.         Encrypt(xmlDoc, "creditcard2", "EncryptedElement2", rsaKey, "rsaKey");         Console.WriteLine("Encrypted XML:");         Console.WriteLine(xmlDoc.OuterXml);         // Decrypt the "creditcard" element.         Decrypt(xmlDoc, rsaKey, "rsaKey");                  Console.WriteLine("Decrypted XML:");         Console.WriteLine(xmlDoc.OuterXml);         rsaKey.Clear();     }     public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, string EncryptionElementID, RSA Alg, string KeyName)     {         XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;         RijndaelManaged sessionKey = new RijndaelManaged();         sessionKey.KeySize = 256;         EncryptedXml eXml = new EncryptedXml();         byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, sessionKey, false);         EncryptedData edElement = new EncryptedData();         edElement.Type = EncryptedXml.XmlEncElementUrl;         edElement.Id = EncryptionElementID;         edElement.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncAES256Url);         EncryptedKey ek = new EncryptedKey();         byte[] encryptedKey = EncryptedXml.EncryptKey(sessionKey.Key, Alg, false);         ek.CipherData = new CipherData(encryptedKey);         ek.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncRSA15Url);         edElement.KeyInfo = new KeyInfo();         KeyInfoName kin = new KeyInfoName();         kin.Value = KeyName;         ek.KeyInfo.AddClause(kin);         DataReference dRef = new DataReference();         dRef.Uri = "#" + EncryptionElementID;         ek.AddReference(dRef);         edElement.KeyInfo.AddClause(new KeyInfoEncryptedKey(ek));         edElement.CipherData.CipherValue = encryptedElement;         EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);     }     public static void Decrypt(XmlDocument Doc, RSA Alg, string KeyName)     {         EncryptedXml exml = new EncryptedXml(Doc);         exml.AddKeyNameMapping(KeyName, Alg);         exml.DecryptDocument();     } } //  <root> //     <creditcard xmlns="myNamespace" Id="tag1"> //         <number>A</number> //         <expiry>02/02/2011</expiry> //     </creditcard> //     <creditcard2 xmlns="myNamespace" Id="tag2"> //         <number>2</number> //         <expiry>02/02/2012</expiry> //     </creditcard2> // </root>