EncryptedXml EncryptedXml EncryptedXml EncryptedXml Class

Definition

Represents the process model for implementing XML encryption.

public ref class EncryptedXml
public class EncryptedXml
type EncryptedXml = class
Public Class EncryptedXml
Inheritance
EncryptedXmlEncryptedXmlEncryptedXmlEncryptedXml

Examples

The following code example demonstrates how to create a simple utility class that uses the TripleDES algorithm to encrypt an XML document.

#using <System.Security.dll>
#using <System.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;

ref class TrippleDESDocumentEncryption
{
protected:
   XmlDocument^ docValue;
   TripleDES^ algValue;

public:
   TrippleDESDocumentEncryption( XmlDocument^ Doc, TripleDES^ Key )
   {
      if ( Doc != nullptr )
      {
         docValue = Doc;
      }
      else
      {
         throw gcnew ArgumentNullException( L"Doc" );
      }

      if ( Key != nullptr )
      {
         algValue = Key;
      }
      else
      {
         throw gcnew ArgumentNullException( L"Key" );
      }
   }


   property XmlDocument^ Doc
   {
      XmlDocument^ get()
      {
         return docValue;
      }

      void set( XmlDocument^ value )
      {
         docValue = value;
      }

   }

   property TripleDES^ Alg
   {
      TripleDES^ get()
      {
         return algValue;
      }

      void set( TripleDES^ value )
      {
         algValue = value;
      }

   }
   void Clear()
   {
      if ( algValue != nullptr )
      {
         algValue->Clear();
      }
      else
      {
         throw gcnew Exception( L"No TripleDES key was found to clear." );
      }
   }

   void Encrypt( String^ Element )
   {

      // Find the element by name and create a new
      // XmlElement object.
      XmlElement^ inputElement = dynamic_cast<XmlElement^>(docValue->GetElementsByTagName( Element )->Item( 0 ));

      // If the element was not found, throw an exception.
      if ( inputElement == nullptr )
      {
         throw gcnew Exception( L"The element was not found." );
      }


      // Create a new EncryptedXml object.
      EncryptedXml^ exml = gcnew EncryptedXml( docValue );

      // Encrypt the element using the symmetric key.
      array<Byte>^rgbOutput = exml->EncryptData( inputElement, algValue, false );

      // Create an EncryptedData object and populate it.
      EncryptedData^ ed = gcnew EncryptedData;

      // Specify the namespace URI for XML encryption elements.
      ed->Type = EncryptedXml::XmlEncElementUrl;

      // Specify the namespace URI for the TrippleDES algorithm.
      ed->EncryptionMethod = gcnew EncryptionMethod( EncryptedXml::XmlEncTripleDESUrl );

      // Create a CipherData element.
      ed->CipherData = gcnew CipherData;

      // Set the CipherData element to the value of the encrypted XML element.
      ed->CipherData->CipherValue = rgbOutput;

      // Replace the plaintext XML elemnt with an EncryptedData element.
      EncryptedXml::ReplaceElement( inputElement, ed, false );
   }

   void Decrypt()
   {

      // XmlElement object.
      XmlElement^ encryptedElement = dynamic_cast<XmlElement^>(docValue->GetElementsByTagName( L"EncryptedData" )->Item( 0 ));

      // If the EncryptedData element was not found, throw an exception.
      if ( encryptedElement == nullptr )
      {
         throw gcnew Exception( L"The EncryptedData element was not found." );
      }


      // Create an EncryptedData object and populate it.
      EncryptedData^ ed = gcnew EncryptedData;
      ed->LoadXml( encryptedElement );

      // Create a new EncryptedXml object.
      EncryptedXml^ exml = gcnew EncryptedXml;

      // Decrypt the element using the symmetric key.
      array<Byte>^rgbOutput = exml->DecryptData( ed, algValue );

      // Replace the encryptedData element with the plaintext XML elemnt.
      exml->ReplaceData( encryptedElement, rgbOutput );
   }

};

int main()
{

   // Create an XmlDocument object.
   XmlDocument^ xmlDoc = gcnew XmlDocument;

   // Load an XML file into the XmlDocument object.
   try
   {
      xmlDoc->PreserveWhitespace = true;
      xmlDoc->Load( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
      return 0;
   }


   // Create a new TripleDES key.
   TripleDESCryptoServiceProvider^ tDESkey = gcnew TripleDESCryptoServiceProvider;

   // Create a new instance of the TrippleDESDocumentEncryption object
   // defined in this sample.
   TrippleDESDocumentEncryption^ xmlTDES = gcnew TrippleDESDocumentEncryption( xmlDoc,tDESkey );
   try
   {

      // Encrypt the "creditcard" element.
      xmlTDES->Encrypt( L"creditcard" );

      // Display the encrypted XML to the console.
      Console::WriteLine( L"Encrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlTDES->Doc->OuterXml );

      // Decrypt the "creditcard" element.
      xmlTDES->Decrypt();

      // Display the encrypted XML to the console.
      Console::WriteLine();
      Console::WriteLine( L"Decrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlTDES->Doc->OuterXml );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
   }
   finally
   {

      // Clear the TripleDES key.
      xmlTDES->Clear();
   }

   return 1;
}

using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

	class Program
	{
		static void Main(string[] args)
		{

			// Create an XmlDocument object.
			XmlDocument xmlDoc = new XmlDocument();

			// Load an XML file into the XmlDocument object.
			try
			{
				xmlDoc.PreserveWhitespace = true;
				xmlDoc.Load("test.xml");
			}
			catch (Exception e)
			{
				Console.WriteLine(e.Message);
				return;
			}

			// Create a new TripleDES key. 
			TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();

			// Create a new instance of the TrippleDESDocumentEncryption object
			// defined in this sample.
			TrippleDESDocumentEncryption xmlTDES = new TrippleDESDocumentEncryption(xmlDoc, tDESkey);
			
			try
			{
				// Encrypt the "creditcard" element.
				xmlTDES.Encrypt("creditcard");

				// Display the encrypted XML to the console.
				Console.WriteLine("Encrypted XML:");
				Console.WriteLine();
				Console.WriteLine(xmlTDES.Doc.OuterXml);

				// Decrypt the "creditcard" element.
				xmlTDES.Decrypt();

				// Display the encrypted XML to the console.
				Console.WriteLine();
				Console.WriteLine("Decrypted XML:");
				Console.WriteLine();
				Console.WriteLine(xmlTDES.Doc.OuterXml);
			}
			catch (Exception e)
			{
				Console.WriteLine(e.Message);
			}
			finally
			{
				// Clear the TripleDES key.
				xmlTDES.Clear();
			}

		}

	}

class TrippleDESDocumentEncryption
{
	protected XmlDocument docValue;
	protected TripleDES algValue;

	public TrippleDESDocumentEncryption(XmlDocument Doc, TripleDES Key)
	{
		if (Doc != null)
		{
			docValue = Doc;
		}
		else
		{
			throw new ArgumentNullException("Doc");
		}

		if (Key != null)
		{

			algValue = Key;
		}
		else
		{
			throw new ArgumentNullException("Key");
		}
	}

	public XmlDocument Doc { set { docValue = value; } get { return docValue; } }
	public TripleDES Alg { set { algValue = value; } get { return algValue; } }

	public void Clear()
	{
		if (algValue != null)
		{
			algValue.Clear();
		}
		else
		{
			throw new Exception("No TripleDES key was found to clear.");
		}
	}

	public void Encrypt(string Element)
	{
		// Find the element by name and create a new
		// XmlElement object.
		XmlElement inputElement = docValue.GetElementsByTagName(Element)[0] as XmlElement;

		// If the element was not found, throw an exception.
		if (inputElement == null)
		{
			throw new Exception("The element was not found.");
		}

		// Create a new EncryptedXml object.
		EncryptedXml exml = new EncryptedXml(docValue);

		// Encrypt the element using the symmetric key.
		byte[] rgbOutput = exml.EncryptData(inputElement, algValue, false);

		// Create an EncryptedData object and populate it.
		EncryptedData ed = new EncryptedData();

		// Specify the namespace URI for XML encryption elements.
		ed.Type = EncryptedXml.XmlEncElementUrl;

		// Specify the namespace URI for the TrippleDES algorithm.
		ed.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl);

		// Create a CipherData element.
		ed.CipherData = new CipherData();

		// Set the CipherData element to the value of the encrypted XML element.
		ed.CipherData.CipherValue = rgbOutput;

		// Replace the plaintext XML elemnt with an EncryptedData element.
		EncryptedXml.ReplaceElement(inputElement, ed, false);
	}

	public void Decrypt()
	{

		// XmlElement object.
		XmlElement encryptedElement = docValue.GetElementsByTagName("EncryptedData")[0] as XmlElement;

		// If the EncryptedData element was not found, throw an exception.
		if (encryptedElement == null)
		{
			throw new Exception("The EncryptedData element was not found.");
		}

		// Create an EncryptedData object and populate it.
		EncryptedData ed = new EncryptedData();
		ed.LoadXml(encryptedElement);

		// Create a new EncryptedXml object.
		EncryptedXml exml = new EncryptedXml();

		// Decrypt the element using the symmetric key.
		byte[] rgbOutput = exml.DecryptData(ed, algValue);

		// Replace the encryptedData element with the plaintext XML elemnt.
		exml.ReplaceData(encryptedElement, rgbOutput);

	}

}
Imports System
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml



Module Program

    Sub Main(ByVal args() As String)

        ' Create an XmlDocument object.
        Dim xmlDoc As New XmlDocument()

        ' Load an XML file into the XmlDocument object.
        xmlDoc.PreserveWhitespace = True
        xmlDoc.Load("test.xml")


        ' Create a new TripleDES key. 
        Dim tDESkey As New TripleDESCryptoServiceProvider()

        ' Create a new instance of the TrippleDESDocumentEncryption object
        ' defined in this sample.
        Dim xmlTDES As New TrippleDESDocumentEncryption(xmlDoc, tDESkey)

        Try
            ' Encrypt the "creditcard" element.
            xmlTDES.Encrypt("creditcard")

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlTDES.Doc.OuterXml)

            ' Decrypt the "creditcard" element.
            xmlTDES.Decrypt()

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlTDES.Doc.OuterXml)
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the TripleDES key.
            xmlTDES.Clear()
        End Try

    End Sub 'Main 
End Module 'Program



Class TrippleDESDocumentEncryption
    Protected docValue As XmlDocument
    Protected algValue As TripleDES


    Public Sub New(ByVal Doc As XmlDocument, ByVal Key As TripleDES)
        If Not (Doc Is Nothing) Then
            docValue = Doc
        Else
            Throw New ArgumentNullException("Doc")
        End If

        If Not (Key Is Nothing) Then

            algValue = Key
        Else
            Throw New ArgumentNullException("Key")
        End If

    End Sub


    Public Property Doc() As XmlDocument
        Get
            Return docValue
        End Get
        Set(ByVal value As XmlDocument)
            docValue = value
        End Set
    End Property

    Public Property Alg() As TripleDES
        Get
            Return algValue
        End Get
        Set(ByVal value As TripleDES)
            algValue = value
        End Set
    End Property

    Public Sub Clear()
        If Not (algValue Is Nothing) Then
            algValue.Clear()
        Else
            Throw New Exception("No TripleDES key was found to clear.")
        End If

    End Sub


    Public Sub Encrypt(ByVal Element As String)
        ' Find the element by name and create a new
        ' XmlElement object.
        Dim inputElement As XmlElement = docValue.GetElementsByTagName(Element)(0)

        ' If the element was not found, throw an exception.
        If inputElement Is Nothing Then
            Throw New Exception("The element was not found.")
        End If

        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml(docValue)

        ' Encrypt the element using the symmetric key.
        Dim rgbOutput As Byte() = exml.EncryptData(inputElement, algValue, False)

        ' Create an EncryptedData object and populate it.
        Dim ed As New EncryptedData()

        ' Specify the namespace URI for XML encryption elements.
        ed.Type = EncryptedXml.XmlEncElementUrl

        ' Specify the namespace URI for the TrippleDES algorithm.
        ed.EncryptionMethod = New EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl)

        ' Create a CipherData element.
        ed.CipherData = New CipherData()

        ' Set the CipherData element to the value of the encrypted XML element.
        ed.CipherData.CipherValue = rgbOutput

        ' Replace the plaintext XML elemnt with an EncryptedData element.
        EncryptedXml.ReplaceElement(inputElement, ed, False)

    End Sub


    Public Sub Decrypt()

        ' XmlElement object.
        Dim encryptedElement As XmlElement = docValue.GetElementsByTagName("EncryptedData")(0)

        ' If the EncryptedData element was not found, throw an exception.
        If encryptedElement Is Nothing Then
            Throw New Exception("The EncryptedData element was not found.")
        End If

        ' Create an EncryptedData object and populate it.
        Dim ed As New EncryptedData()
        ed.LoadXml(encryptedElement)

        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml()

        ' Decrypt the element using the symmetric key.
        Dim rgbOutput As Byte() = exml.DecryptData(ed, algValue)

        ' Replace the encryptedData element with the plaintext XML elemnt.
        exml.ReplaceData(encryptedElement, rgbOutput)

    End Sub
End Class

The following code example demonstrates how to encrypt an XML document using a symmetric key. This example does not include any key information in the encrypted XML document.

#using <System.Security.dll>
#using <System.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
static void Encrypt( XmlDocument^ Doc, String^ ElementToEncrypt, SymmetricAlgorithm^ Alg )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( ElementToEncrypt == nullptr )
      throw gcnew ArgumentNullException( L"ElementToEncrypt" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );


   ////////////////////////////////////////////////
   // Find the specified element in the XmlDocument
   // object and create a new XmlElemnt object.
   ////////////////////////////////////////////////
   XmlElement^ elementToEncrypt = dynamic_cast<XmlElement^>(Doc->GetElementsByTagName( ElementToEncrypt )->Item( 0 ));

   // Throw an XmlException if the element was not found.
   if ( elementToEncrypt == nullptr )
   {
      throw gcnew XmlException( L"The specified element was not found" );
   }


   //////////////////////////////////////////////////
   // Create a new instance of the EncryptedXml class
   // and use it to encrypt the XmlElement with the
   // symmetric key.
   //////////////////////////////////////////////////
   EncryptedXml^ eXml = gcnew EncryptedXml;
   array<Byte>^encryptedElement = eXml->EncryptData( elementToEncrypt, Alg, false );

   ////////////////////////////////////////////////
   // Construct an EncryptedData object and populate
   // it with the desired encryption information.
   ////////////////////////////////////////////////
   EncryptedData^ edElement = gcnew EncryptedData;
   edElement->Type = EncryptedXml::XmlEncElementUrl;

   // Create an EncryptionMethod element so that the
   // receiver knows which algorithm to use for decryption.
   // Determine what kind of algorithm is being used and
   // supply the appropriate URL to the EncryptionMethod element.
   String^ encryptionMethod = nullptr;
   if ( dynamic_cast<TripleDES^>(Alg) )
   {
      encryptionMethod = EncryptedXml::XmlEncTripleDESUrl;
   }
   else
   if ( dynamic_cast<DES^>(Alg) )
   {
      encryptionMethod = EncryptedXml::XmlEncDESUrl;
   }
   else
   if ( dynamic_cast<Rijndael^>(Alg) )
   {
      switch ( Alg->KeySize )
      {
         case 128:
            encryptionMethod = EncryptedXml::XmlEncAES128Url;
            break;

         case 192:
            encryptionMethod = EncryptedXml::XmlEncAES192Url;
            break;

         case 256:
            encryptionMethod = EncryptedXml::XmlEncAES256Url;
            break;
      }
   }
   else
   {

      // Throw an exception if the transform is not in the previous categories
      throw gcnew CryptographicException( L"The specified algorithm is not supported for XML Encryption." );
   }



   edElement->EncryptionMethod = gcnew EncryptionMethod( encryptionMethod );

   // Add the encrypted element data to the
   // EncryptedData object.
   edElement->CipherData->CipherValue = encryptedElement;

   ////////////////////////////////////////////////////
   // Replace the element from the original XmlDocument
   // object with the EncryptedData element.
   ////////////////////////////////////////////////////
   EncryptedXml::ReplaceElement( elementToEncrypt, edElement, false );
}

static void Decrypt( XmlDocument^ Doc, SymmetricAlgorithm^ Alg )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );


   // Find the EncryptedData element in the XmlDocument.
   XmlElement^ encryptedElement = dynamic_cast<XmlElement^>(Doc->GetElementsByTagName( L"EncryptedData" )->Item( 0 ));

   // If the EncryptedData element was not found, throw an exception.
   if ( encryptedElement == nullptr )
   {
      throw gcnew XmlException( L"The EncryptedData element was not found." );
   }


   // Create an EncryptedData object and populate it.
   EncryptedData^ edElement = gcnew EncryptedData;
   edElement->LoadXml( encryptedElement );

   // Create a new EncryptedXml object.
   EncryptedXml^ exml = gcnew EncryptedXml;

   // Decrypt the element using the symmetric key.
   array<Byte>^rgbOutput = exml->DecryptData( edElement, Alg );

   // Replace the encryptedData element with the plaintext XML element.
   exml->ReplaceData( encryptedElement, rgbOutput );
}

int main()
{

   // Create an XmlDocument object.
   XmlDocument^ xmlDoc = gcnew XmlDocument;

   // Load an XML file into the XmlDocument object.
   try
   {
      xmlDoc->PreserveWhitespace = true;
      xmlDoc->Load( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
      return 0;
   }


   // Create a new TripleDES key.
   TripleDESCryptoServiceProvider^ tDESkey = gcnew TripleDESCryptoServiceProvider;
   try
   {

      // Encrypt the "creditcard" element.
      Encrypt( xmlDoc, L"creditcard", tDESkey );

      // Display the encrypted XML to the console.
      Console::WriteLine( L"Encrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );

      // Decrypt the "creditcard" element.
      Decrypt( xmlDoc, tDESkey );

      // Display the encrypted XML to the console.
      Console::WriteLine();
      Console::WriteLine( L"Decrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
   }
   finally
   {

      // Clear the TripleDES key.
      tDESkey->Clear();
   }

}

using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

class Program
{
    static void Main(string[] args)
    {

        // Create an XmlDocument object.
        XmlDocument xmlDoc = new XmlDocument();

        // Load an XML file into the XmlDocument object.
        try
        {
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.Load("test.xml");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            return;
        }

        // Create a new TripleDES key. 
        TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();


        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey);

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);

            // Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey);

            // Display the encrypted XML to the console.
            Console.WriteLine();
            Console.WriteLine("Decrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            // Clear the TripleDES key.
            tDESkey.Clear();
        }

    }

    public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, SymmetricAlgorithm Alg)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (ElementToEncrypt == null)
            throw new ArgumentNullException("ElementToEncrypt");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        ////////////////////////////////////////////////
        // Find the specified element in the XmlDocument
        // object and create a new XmlElemnt object.
        ////////////////////////////////////////////////

        XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

        // Throw an XmlException if the element was not found.
        if (elementToEncrypt == null)
        {
            throw new XmlException("The specified element was not found");

        }

        //////////////////////////////////////////////////
        // Create a new instance of the EncryptedXml class 
        // and use it to encrypt the XmlElement with the 
        // symmetric key.
        //////////////////////////////////////////////////

        EncryptedXml eXml = new EncryptedXml();

        byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, Alg, false);

        ////////////////////////////////////////////////
        // Construct an EncryptedData object and populate
        // it with the desired encryption information.
        ////////////////////////////////////////////////


        EncryptedData edElement = new EncryptedData();
        edElement.Type = EncryptedXml.XmlEncElementUrl;

        // Create an EncryptionMethod element so that the 
        // receiver knows which algorithm to use for decryption.
        // Determine what kind of algorithm is being used and
        // supply the appropriate URL to the EncryptionMethod element.

        string encryptionMethod = null;

        if (Alg is TripleDES)
        {
            encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
        }
        else if (Alg is DES)
        {
            encryptionMethod = EncryptedXml.XmlEncDESUrl;
        }
        else if (Alg is Rijndael)
        {
            switch (Alg.KeySize)
            {
                case 128:
                    encryptionMethod = EncryptedXml.XmlEncAES128Url;
                    break;
                case 192:
                    encryptionMethod = EncryptedXml.XmlEncAES192Url;
                    break;
                case 256:
                    encryptionMethod = EncryptedXml.XmlEncAES256Url;
                    break;
            }
        }
        else
        {
            // Throw an exception if the transform is not in the previous categories
            throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
        }

        edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);

        // Add the encrypted element data to the 
        // EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement;

        ////////////////////////////////////////////////////
        // Replace the element from the original XmlDocument
        // object with the EncryptedData element.
        ////////////////////////////////////////////////////

        EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);

    }

    public static void Decrypt(XmlDocument Doc, SymmetricAlgorithm Alg)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        // Find the EncryptedData element in the XmlDocument.
        XmlElement encryptedElement = Doc.GetElementsByTagName("EncryptedData")[0] as XmlElement;

        // If the EncryptedData element was not found, throw an exception.
        if (encryptedElement == null)
        {
            throw new XmlException("The EncryptedData element was not found.");
        }

        // Create an EncryptedData object and populate it.
        EncryptedData edElement = new EncryptedData();
        edElement.LoadXml(encryptedElement);

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml();

        // Decrypt the element using the symmetric key.
        byte[] rgbOutput = exml.DecryptData(edElement, Alg);

        // Replace the encryptedData element with the plaintext XML element.
        exml.ReplaceData(encryptedElement, rgbOutput);

    }


}
Imports System
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml



Module Program

    Sub Main(ByVal args() As String)

        ' Create an XmlDocument object.
        Dim xmlDoc As New XmlDocument()

        ' Load an XML file into the XmlDocument object.
        Try
            xmlDoc.PreserveWhitespace = True
            xmlDoc.Load("test.xml")
        Catch e As Exception
            Console.WriteLine(e.Message)
            Return
        End Try

        ' Create a new TripleDES key. 
        Dim tDESkey As New TripleDESCryptoServiceProvider()


        Try
            ' Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey)

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)

            ' Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey)

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the TripleDES key.
            tDESkey.Clear()
        End Try

    End Sub


    Sub Encrypt(ByVal Doc As XmlDocument, ByVal ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If ElementToEncrypt Is Nothing Then
            Throw New ArgumentNullException("ElementToEncrypt")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Find the specified element in the XmlDocument
        ' object and create a new XmlElemnt object.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(0)


        ' Throw an XmlException if the element was not found.
        If ElementToEncrypt Is Nothing Then
            Throw New XmlException("The specified element was not found")
        End If

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Create a new instance of the EncryptedXml class 
        ' and use it to encrypt the XmlElement with the 
        ' symmetric key.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim eXml As New EncryptedXml()

        Dim encryptedElement As Byte() = eXml.EncryptData(elementEncrypt, Alg, False)

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Construct an EncryptedData object and populate
        ' it with the desired encryption information.
        '''''''''''''''''''''''''''''''''''''''''''''''''''

        Dim edElement As New EncryptedData()
        edElement.Type = EncryptedXml.XmlEncElementUrl

        ' Create an EncryptionMethod element so that the 
        ' receiver knows which algorithm to use for decryption.
        ' Determine what kind of algorithm is being used and
        ' supply the appropriate URL to the EncryptionMethod element.
        Dim encryptionMethod As String = Nothing

        If TypeOf Alg Is TripleDES Then
            encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
        ElseIf TypeOf Alg Is DES Then
            encryptionMethod = EncryptedXml.XmlEncDESUrl
        ElseIf TypeOf Alg Is Rijndael Then
            Select Case Alg.KeySize
                Case 128
                    encryptionMethod = EncryptedXml.XmlEncAES128Url
                Case 192
                    encryptionMethod = EncryptedXml.XmlEncAES192Url
                Case 256
                    encryptionMethod = EncryptedXml.XmlEncAES256Url
            End Select
        Else
            ' Throw an exception if the transform is not in the previous categories
            Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
        End If

        edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)

        ' Add the encrypted element data to the 
        ' EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Replace the element from the original XmlDocument
        ' object with the EncryptedData element.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        EncryptedXml.ReplaceElement(elementEncrypt, edElement, False)

    End Sub 'Encrypt


    Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        ' Find the EncryptedData element in the XmlDocument.
        Dim encryptedElement As XmlElement = Doc.GetElementsByTagName("EncryptedData")(0)

        ' If the EncryptedData element was not found, throw an exception.
        If encryptedElement Is Nothing Then
            Throw New XmlException("The EncryptedData element was not found.")
        End If

        ' Create an EncryptedData object and populate it.
        Dim edElement As New EncryptedData()
        edElement.LoadXml(encryptedElement)

        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml()

        ' Decrypt the element using the symmetric key.
        Dim rgbOutput As Byte() = exml.DecryptData(edElement, Alg)

        ' Replace the encryptedData element with the plaintext XML element.
        exml.ReplaceData(encryptedElement, rgbOutput)

    End Sub
End Module

The following code example demonstrates how to encrypt an XML document using a symmetric key. This example embeds a key name in the encrypted XML document that the decrypting method uses to find the appropriate decryption key.

#using <System.Security.dll>
#using <System.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
static void Encrypt( XmlDocument^ Doc, String^ ElementToEncrypt, SymmetricAlgorithm^ Alg, String^ KeyName )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( ElementToEncrypt == nullptr )
      throw gcnew ArgumentNullException( L"ElementToEncrypt" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );


   ////////////////////////////////////////////////
   // Find the specified element in the XmlDocument
   // object and create a new XmlElemnt object.
   ////////////////////////////////////////////////
   XmlElement^ elementToEncrypt = dynamic_cast<XmlElement^>(Doc->GetElementsByTagName( ElementToEncrypt )->Item( 0 ));

   // Throw an XmlException if the element was not found.
   if ( elementToEncrypt == nullptr )
   {
      throw gcnew XmlException( L"The specified element was not found" );
   }


   //////////////////////////////////////////////////
   // Create a new instance of the EncryptedXml class
   // and use it to encrypt the XmlElement with the
   // symmetric key.
   //////////////////////////////////////////////////
   EncryptedXml^ eXml = gcnew EncryptedXml;
   array<Byte>^encryptedElement = eXml->EncryptData( elementToEncrypt, Alg, false );

   ////////////////////////////////////////////////
   // Construct an EncryptedData object and populate
   // it with the desired encryption information.
   ////////////////////////////////////////////////
   EncryptedData^ edElement = gcnew EncryptedData;
   edElement->Type = EncryptedXml::XmlEncElementUrl;

   // Create an EncryptionMethod element so that the
   // receiver knows which algorithm to use for decryption.
   // Determine what kind of algorithm is being used and
   // supply the appropriate URL to the EncryptionMethod element.
   String^ encryptionMethod = nullptr;
   if ( dynamic_cast<TripleDES^>(Alg) )
   {
      encryptionMethod = EncryptedXml::XmlEncTripleDESUrl;
   }
   else
   if ( dynamic_cast<DES^>(Alg) )
   {
      encryptionMethod = EncryptedXml::XmlEncDESUrl;
   }
   else
   if ( dynamic_cast<Rijndael^>(Alg) )
   {
      switch ( Alg->KeySize )
      {
         case 128:
            encryptionMethod = EncryptedXml::XmlEncAES128Url;
            break;

         case 192:
            encryptionMethod = EncryptedXml::XmlEncAES192Url;
            break;

         case 256:
            encryptionMethod = EncryptedXml::XmlEncAES256Url;
            break;
      }
   }
   else
   {

      // Throw an exception if the transform is not in the previous categories
      throw gcnew CryptographicException( L"The specified algorithm is not supported for XML Encryption." );
   }



   edElement->EncryptionMethod = gcnew EncryptionMethod( encryptionMethod );

   // Set the KeyInfo element to specify the
   // name of a key.
   // Create a new KeyInfo element.
   edElement->KeyInfo = gcnew KeyInfo;

   // Create a new KeyInfoName element.
   KeyInfoName^ kin = gcnew KeyInfoName;

   // Specify a name for the key.
   kin->Value = KeyName;

   // Add the KeyInfoName element.
   edElement->KeyInfo->AddClause( kin );

   // Add the encrypted element data to the
   // EncryptedData object.
   edElement->CipherData->CipherValue = encryptedElement;

   ////////////////////////////////////////////////////
   // Replace the element from the original XmlDocument
   // object with the EncryptedData element.
   ////////////////////////////////////////////////////
   EncryptedXml::ReplaceElement( elementToEncrypt, edElement, false );
}

static void Decrypt( XmlDocument^ Doc, SymmetricAlgorithm^ Alg, String^ KeyName )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );

   if ( KeyName == nullptr )
      throw gcnew ArgumentNullException( L"KeyName" );


   // Create a new EncryptedXml object.
   EncryptedXml^ exml = gcnew EncryptedXml( Doc );

   // Add a key-name mapping.
   // This method can only decrypt documents
   // that present the specified key name.
   exml->AddKeyNameMapping( KeyName, Alg );

   // Decrypt the element.
   exml->DecryptDocument();
}

int main()
{

   // Create an XmlDocument object.
   XmlDocument^ xmlDoc = gcnew XmlDocument;

   // Load an XML file into the XmlDocument object.
   try
   {
      xmlDoc->PreserveWhitespace = true;
      xmlDoc->Load( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
      return 0;
   }


   // Create a new TripleDES key.
   TripleDESCryptoServiceProvider^ tDESkey = gcnew TripleDESCryptoServiceProvider;
   try
   {

      // Encrypt the "creditcard" element.
      Encrypt( xmlDoc, L"creditcard", tDESkey, L"tDESKey" );

      // Display the encrypted XML to the console.
      Console::WriteLine( L"Encrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );

      // Decrypt the "creditcard" element.
      Decrypt( xmlDoc, tDESkey, L"tDESKey" );

      // Display the encrypted XML to the console.
      Console::WriteLine();
      Console::WriteLine( L"Decrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
   }
   finally
   {

      // Clear the TripleDES key.
      tDESkey->Clear();
   }
   return 1;
}
using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

class Program
{
    static void Main(string[] args)
    {

        // Create an XmlDocument object.
        XmlDocument xmlDoc = new XmlDocument();

        // Load an XML file into the XmlDocument object.
        try
        {
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.Load("test.xml");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            return;
        }

        // Create a new TripleDES key. 
        TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();


        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey, "tDESKey");

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);

            // Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey, "tDESKey");

            // Display the encrypted XML to the console.
            Console.WriteLine();
            Console.WriteLine("Decrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            // Clear the TripleDES key.
            tDESkey.Clear();
        }

    }

    public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, SymmetricAlgorithm Alg, string KeyName)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (ElementToEncrypt == null)
            throw new ArgumentNullException("ElementToEncrypt");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        ////////////////////////////////////////////////
        // Find the specified element in the XmlDocument
        // object and create a new XmlElemnt object.
        ////////////////////////////////////////////////

        XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

        // Throw an XmlException if the element was not found.
        if (elementToEncrypt == null)
        {
            throw new XmlException("The specified element was not found");

        }

        //////////////////////////////////////////////////
        // Create a new instance of the EncryptedXml class 
        // and use it to encrypt the XmlElement with the 
        // symmetric key.
        //////////////////////////////////////////////////

        EncryptedXml eXml = new EncryptedXml();

        byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, Alg, false);

        ////////////////////////////////////////////////
        // Construct an EncryptedData object and populate
        // it with the desired encryption information.
        ////////////////////////////////////////////////


        EncryptedData edElement = new EncryptedData();
        edElement.Type = EncryptedXml.XmlEncElementUrl;

        // Create an EncryptionMethod element so that the 
        // receiver knows which algorithm to use for decryption.
        // Determine what kind of algorithm is being used and
        // supply the appropriate URL to the EncryptionMethod element.

        string encryptionMethod = null;

        if (Alg is TripleDES)
        {
            encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
        }
        else if (Alg is DES)
        {
            encryptionMethod = EncryptedXml.XmlEncDESUrl;
        }
        else if (Alg is Rijndael)
        {
            switch (Alg.KeySize)
            {
                case 128:
                    encryptionMethod = EncryptedXml.XmlEncAES128Url;
                    break;
                case 192:
                    encryptionMethod = EncryptedXml.XmlEncAES192Url;
                    break;
                case 256:
                    encryptionMethod = EncryptedXml.XmlEncAES256Url;
                    break;
            }
        }
        else
        {
            // Throw an exception if the transform is not in the previous categories
            throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
        }

        edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);

        // Set the KeyInfo element to specify the
        // name of a key.

        // Create a new KeyInfo element.
        edElement.KeyInfo = new KeyInfo();

        // Create a new KeyInfoName element.
        KeyInfoName kin = new KeyInfoName();

        // Specify a name for the key.
        kin.Value = KeyName;

        // Add the KeyInfoName element.
        edElement.KeyInfo.AddClause(kin);

        // Add the encrypted element data to the 
        // EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement;

        ////////////////////////////////////////////////////
        // Replace the element from the original XmlDocument
        // object with the EncryptedData element.
        ////////////////////////////////////////////////////

        EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);

    }

    public static void Decrypt(XmlDocument Doc, SymmetricAlgorithm Alg, string KeyName)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (Alg == null)
            throw new ArgumentNullException("Alg");
        if (KeyName == null)
            throw new ArgumentNullException("KeyName");

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml(Doc);

        // Add a key-name mapping.
        // This method can only decrypt documents
        // that present the specified key name.
        exml.AddKeyNameMapping(KeyName, Alg);

        // Decrypt the element.
        exml.DecryptDocument();

    }


}
Imports System
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml



Module Program

    Sub Main(ByVal args() As String)

        ' Create an XmlDocument object.
        Dim xmlDoc As New XmlDocument()

        ' Load an XML file into the XmlDocument object.
        Try
            xmlDoc.PreserveWhitespace = True
            xmlDoc.Load("test.xml")
        Catch e As Exception
            Console.WriteLine(e.Message)
            Return
        End Try

        ' Create a new TripleDES key. 
        Dim tDESkey As New TripleDESCryptoServiceProvider()


        Try
            ' Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey, "tDESKey")

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)

            ' Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey, "tDESKey")

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the TripleDES key.
            tDESkey.Clear()
        End Try

    End Sub 'Main


    Sub Encrypt(ByVal Doc As XmlDocument, ByVal ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm, ByVal KeyName As String)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If ElementToEncrypt Is Nothing Then
            Throw New ArgumentNullException("ElementToEncrypt")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        '''''''''''''''''''''''''''''''''''''''''''''''''
        ' Find the specified element in the XmlDocument
        ' object and create a new XmlElemnt object.
        '''''''''''''''''''''''''''''''''''''''''''''''''
        Dim elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(0)
 

        ' Throw an XmlException if the element was not found.
        If elementToEncrypt Is Nothing Then
            Throw New XmlException("The specified element was not found")
        End If

        '''''''''''''''''''''''''''''''''''''''''''''''''
        ' Create a new instance of the EncryptedXml class 
        ' and use it to encrypt the XmlElement with the 
        ' symmetric key.
        '''''''''''''''''''''''''''''''''''''''''''''''''
        Dim eXml As New EncryptedXml()

        Dim encryptedElement As Byte() = eXml.EncryptData(elementEncrypt, Alg, False)

        '''''''''''''''''''''''''''''''''''''''''''''''''
        ' Construct an EncryptedData object and populate
        ' it with the desired encryption information.
        '''''''''''''''''''''''''''''''''''''''''''''''''

        Dim edElement As New EncryptedData()
        edElement.Type = EncryptedXml.XmlEncElementUrl

        ' Create an EncryptionMethod element so that the 
        ' receiver knows which algorithm to use for decryption.
        ' Determine what kind of algorithm is being used and
        ' supply the appropriate URL to the EncryptionMethod element.
        Dim encryptionMethod As String = Nothing

        If TypeOf Alg Is TripleDES Then
            encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
        ElseIf TypeOf Alg Is DES Then
            encryptionMethod = EncryptedXml.XmlEncDESUrl
        ElseIf TypeOf Alg Is Rijndael Then
            Select Case Alg.KeySize
                Case 128
                    encryptionMethod = EncryptedXml.XmlEncAES128Url
                Case 192
                    encryptionMethod = EncryptedXml.XmlEncAES192Url
                Case 256
                    encryptionMethod = EncryptedXml.XmlEncAES256Url
            End Select
        Else
            ' Throw an exception if the transform is not in the previous categories
            Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
        End If

        edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)

        ' Set the KeyInfo element to specify the
        ' name of a key.
        ' Create a new KeyInfo element.
        edElement.KeyInfo = New KeyInfo()

        ' Create a new KeyInfoName element.
        Dim kin As New KeyInfoName()

        ' Specify a name for the key.
        kin.Value = KeyName

        ' Add the KeyInfoName element.
        edElement.KeyInfo.AddClause(kin)

        ' Add the encrypted element data to the 
        ' EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement

        '''''''''''''''''''''''''''''''''''''''''''''''''
        ' Replace the element from the original XmlDocument
        ' object with the EncryptedData element.
        '''''''''''''''''''''''''''''''''''''''''''''''''
        EncryptedXml.ReplaceElement(elementEncrypt, edElement, False)

    End Sub


    Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm, ByVal KeyName As String)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        If KeyName Is Nothing Then
            Throw New ArgumentNullException("KeyName")
        End If
        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml(Doc)

        ' Add a key-name mapping.
        ' This method can only decrypt documents
        ' that present the specified key name.
        exml.AddKeyNameMapping(KeyName, Alg)

        ' Decrypt the element.
        exml.DecryptDocument()

    End Sub
End Module

The following code example demonstrates how to encrypt an XML document using an asymmetric key. This example creates a symmetric session key to encrypt the document and then uses the asymmetric key to embed an encrypted version of the session key into the XML document.

#using <System.Xml.dll>
#using <System.Security.dll>
#using <System.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
static void Encrypt( XmlDocument^ Doc, String^ ElementToEncrypt, RSA^ Alg, String^ KeyName )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( ElementToEncrypt == nullptr )
      throw gcnew ArgumentNullException( L"ElementToEncrypt" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );


   ////////////////////////////////////////////////
   // Find the specified element in the XmlDocument
   // object and create a new XmlElemnt object.
   ////////////////////////////////////////////////
   XmlElement^ elementToEncrypt = dynamic_cast<XmlElement^>(Doc->GetElementsByTagName( ElementToEncrypt )->Item( 0 ));

   // Throw an XmlException if the element was not found.
   if ( elementToEncrypt == nullptr )
   {
      throw gcnew XmlException( L"The specified element was not found" );
   }


   //////////////////////////////////////////////////
   // Create a new instance of the EncryptedXml class
   // and use it to encrypt the XmlElement with the
   // a new random symmetric key.
   //////////////////////////////////////////////////
   // Create a 256 bit Rijndael key.
   RijndaelManaged^ sessionKey = gcnew RijndaelManaged;
   sessionKey->KeySize = 256;
   EncryptedXml^ eXml = gcnew EncryptedXml;
   array<Byte>^encryptedElement = eXml->EncryptData( elementToEncrypt, sessionKey, false );

   ////////////////////////////////////////////////
   // Construct an EncryptedData object and populate
   // it with the desired encryption information.
   ////////////////////////////////////////////////
   EncryptedData^ edElement = gcnew EncryptedData;
   edElement->Type = EncryptedXml::XmlEncElementUrl;

   // Create an EncryptionMethod element so that the
   // receiver knows which algorithm to use for decryption.
   edElement->EncryptionMethod = gcnew EncryptionMethod( EncryptedXml::XmlEncAES256Url );

   // Encrypt the session key and add it to an EncryptedKey element.
   EncryptedKey^ ek = gcnew EncryptedKey;
   array<Byte>^encryptedKey = EncryptedXml::EncryptKey( sessionKey->Key, Alg, false );
   ek->CipherData = gcnew CipherData( encryptedKey );
   ek->EncryptionMethod = gcnew EncryptionMethod( EncryptedXml::XmlEncRSA15Url );

   // Set the KeyInfo element to specify the
   // name of the RSA key.
   // Create a new KeyInfo element.
   edElement->KeyInfo = gcnew KeyInfo;

   // Create a new KeyInfoName element.
   KeyInfoName^ kin = gcnew KeyInfoName;

   // Specify a name for the key.
   kin->Value = KeyName;

   // Add the KeyInfoName element to the
   // EncryptedKey object.
   ek->KeyInfo->AddClause( kin );

   // Add the encrypted key to the
   // EncryptedData object.
   edElement->KeyInfo->AddClause( gcnew KeyInfoEncryptedKey( ek ) );

   // Add the encrypted element data to the
   // EncryptedData object.
   edElement->CipherData->CipherValue = encryptedElement;

   ////////////////////////////////////////////////////
   // Replace the element from the original XmlDocument
   // object with the EncryptedData element.
   ////////////////////////////////////////////////////
   EncryptedXml::ReplaceElement( elementToEncrypt, edElement, false );
}

static void Decrypt( XmlDocument^ Doc, RSA^ Alg, String^ KeyName )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( Alg == nullptr )
      throw gcnew ArgumentNullException( L"Alg" );

   if ( KeyName == nullptr )
      throw gcnew ArgumentNullException( L"KeyName" );


   // Create a new EncryptedXml object.
   EncryptedXml^ exml = gcnew EncryptedXml( Doc );

   // Add a key-name mapping.
   // This method can only decrypt documents
   // that present the specified key name.
   exml->AddKeyNameMapping( KeyName, Alg );

   // Decrypt the element.
   exml->DecryptDocument();
}

int main()
{

   // Create an XmlDocument object.
   XmlDocument^ xmlDoc = gcnew XmlDocument;

   // Load an XML file into the XmlDocument object.
   try
   {
      xmlDoc->PreserveWhitespace = true;
      xmlDoc->Load( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
      return 0;
   }


   // Create a new RSA key.  This key will encrypt a symmetric key,
   // which will then be imbedded in the XML document.
   RSA^ rsaKey = gcnew RSACryptoServiceProvider;
   try
   {

      // Encrypt the "creditcard" element.
      Encrypt( xmlDoc, L"creditcard", rsaKey, L"rsaKey" );

      // Display the encrypted XML to the console.
      Console::WriteLine( L"Encrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );
	  xmlDoc->Save( L"test.xml" );

      // Decrypt the "creditcard" element.
      Decrypt( xmlDoc, rsaKey, L"rsaKey" );

      // Display the encrypted XML to the console.
      Console::WriteLine();
      Console::WriteLine( L"Decrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );
	  xmlDoc->Save( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
   }
   finally
   {

      // Clear the RSA key.
      rsaKey->Clear();
   }

   return 1;
}
using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

class Program
{
    static void Main(string[] args)
    {

        // Create an XmlDocument object.
        XmlDocument xmlDoc = new XmlDocument();

        // Load an XML file into the XmlDocument object.
        try
        {
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.Load("test.xml");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            return;
        }

        // Create a new RSA key.  This key will encrypt a symmetric key,
        // which will then be imbedded in the XML document.  
        RSA rsaKey = new RSACryptoServiceProvider();


        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", rsaKey, "rsaKey");

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
            xmlDoc.Save("test.xml");

            // Decrypt the "creditcard" element.
            Decrypt(xmlDoc, rsaKey, "rsaKey");
            xmlDoc.Save("test.xml");

            // Display the encrypted XML to the console.
            Console.WriteLine();
            Console.WriteLine("Decrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            // Clear the RSA key.
            rsaKey.Clear();
        }

    }

    public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, RSA Alg, string KeyName)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (ElementToEncrypt == null)
            throw new ArgumentNullException("ElementToEncrypt");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        ////////////////////////////////////////////////
        // Find the specified element in the XmlDocument
        // object and create a new XmlElemnt object.
        ////////////////////////////////////////////////

        XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

        // Throw an XmlException if the element was not found.
        if (elementToEncrypt == null)
        {
            throw new XmlException("The specified element was not found");

        }

        //////////////////////////////////////////////////
        // Create a new instance of the EncryptedXml class 
        // and use it to encrypt the XmlElement with the 
        // a new random symmetric key.
        //////////////////////////////////////////////////

        // Create a 256 bit Rijndael key.
        RijndaelManaged sessionKey = new RijndaelManaged();
        sessionKey.KeySize = 256;

        EncryptedXml eXml = new EncryptedXml();

        byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, sessionKey, false);

        ////////////////////////////////////////////////
        // Construct an EncryptedData object and populate
        // it with the desired encryption information.
        ////////////////////////////////////////////////


        EncryptedData edElement = new EncryptedData();
        edElement.Type = EncryptedXml.XmlEncElementUrl;

        // Create an EncryptionMethod element so that the 
        // receiver knows which algorithm to use for decryption.

        edElement.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncAES256Url);

        // Encrypt the session key and add it to an EncryptedKey element.
        EncryptedKey ek = new EncryptedKey();

        byte[] encryptedKey = EncryptedXml.EncryptKey(sessionKey.Key, Alg, false);

        ek.CipherData = new CipherData(encryptedKey);

        ek.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncRSA15Url);

        // Set the KeyInfo element to specify the
        // name of the RSA key.

        // Create a new KeyInfo element.
        edElement.KeyInfo = new KeyInfo();

        // Create a new KeyInfoName element.
        KeyInfoName kin = new KeyInfoName();

        // Specify a name for the key.
        kin.Value = KeyName;

        // Add the KeyInfoName element to the 
        // EncryptedKey object.
        ek.KeyInfo.AddClause(kin);

        // Add the encrypted key to the 
        // EncryptedData object.

        edElement.KeyInfo.AddClause(new KeyInfoEncryptedKey(ek));

        // Add the encrypted element data to the 
        // EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement;

        ////////////////////////////////////////////////////
        // Replace the element from the original XmlDocument
        // object with the EncryptedData element.
        ////////////////////////////////////////////////////

        EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);

    }

    public static void Decrypt(XmlDocument Doc, RSA Alg, string KeyName)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (Alg == null)
            throw new ArgumentNullException("Alg");
        if (KeyName == null)
            throw new ArgumentNullException("KeyName");

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml(Doc);

        // Add a key-name mapping.
        // This method can only decrypt documents
        // that present the specified key name.
        exml.AddKeyNameMapping(KeyName, Alg);

        // Decrypt the element.
        exml.DecryptDocument();

    }

}
Imports System
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml



Module Program

    Sub Main(ByVal args() As String)

        ' Create an XmlDocument object.
        Dim xmlDoc As New XmlDocument()

        ' Load an XML file into the XmlDocument object.
        Try
            xmlDoc.PreserveWhitespace = True
            xmlDoc.Load("test.xml")
        Catch e As Exception
            Console.WriteLine(e.Message)
            Return
        End Try

        ' Create a new RSA key.  This key will encrypt a symmetric key,
        ' which will then be imbedded in the XML document.  
        Dim rsaKey = New RSACryptoServiceProvider()


        Try
            ' Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", rsaKey, "rsaKey")

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
            xmlDoc.Save("test.xml")

            ' Decrypt the "creditcard" element.
            Decrypt(xmlDoc, rsaKey, "rsaKey")

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
            xmlDoc.Save("test.xml")
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the RSA key.
            rsaKey.Clear()
        End Try

    End Sub


    Sub Encrypt(ByVal Doc As XmlDocument, ByVal ElementToEncrypt As String, ByVal Alg As RSA, ByVal KeyName As String)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If ElementToEncrypt Is Nothing Then
            Throw New ArgumentNullException("ElementToEncrypt")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Find the specified element in the XmlDocument
        ' object and create a new XmlElemnt object.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(0)

        ' Throw an XmlException if the element was not found.
        If elementToEncrypt Is Nothing Then
            Throw New XmlException("The specified element was not found")
        End If

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Create a new instance of the EncryptedXml class 
        ' and use it to encrypt the XmlElement with the 
        ' a new random symmetric key.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Create a 256 bit Rijndael key.
        Dim sessionKey As New RijndaelManaged()
        sessionKey.KeySize = 256

        Dim eXml As New EncryptedXml()

        Dim encryptedElement As Byte() = eXml.EncryptData(elementEncrypt, sessionKey, False)

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Construct an EncryptedData object and populate
        ' it with the desired encryption information.
        '''''''''''''''''''''''''''''''''''''''''''''''''''

        Dim edElement As New EncryptedData()
        edElement.Type = EncryptedXml.XmlEncElementUrl

        ' Create an EncryptionMethod element so that the 
        ' receiver knows which algorithm to use for decryption.
        edElement.EncryptionMethod = New EncryptionMethod(EncryptedXml.XmlEncAES256Url)

        ' Encrypt the session key and add it to an EncryptedKey element.
        Dim ek As New EncryptedKey()

        Dim encryptedKey As Byte() = EncryptedXml.EncryptKey(sessionKey.Key, Alg, False)

        ek.CipherData = New CipherData(encryptedKey)

        ek.EncryptionMethod = New EncryptionMethod(EncryptedXml.XmlEncRSA15Url)

        ' Set the KeyInfo element to specify the
        ' name of the RSA key.
        ' Create a new KeyInfo element.
        edElement.KeyInfo = New KeyInfo()

        ' Create a new KeyInfoName element.
        Dim kin As New KeyInfoName()

        ' Specify a name for the key.
        kin.Value = KeyName

        ' Add the KeyInfoName element to the 
        ' EncryptedKey object.
        ek.KeyInfo.AddClause(kin)

        ' Add the encrypted key to the 
        ' EncryptedData object.
        edElement.KeyInfo.AddClause(New KeyInfoEncryptedKey(ek))

        ' Add the encrypted element data to the 
        ' EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Replace the element from the original XmlDocument
        ' object with the EncryptedData element.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        EncryptedXml.ReplaceElement(elementEncrypt, edElement, False)

    End Sub


    Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As RSA, ByVal KeyName As String)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If Alg Is Nothing Then
            Throw New ArgumentNullException("Alg")
        End If
        If KeyName Is Nothing Then
            Throw New ArgumentNullException("KeyName")
        End If
        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml(Doc)

        ' Add a key-name mapping.
        ' This method can only decrypt documents
        ' that present the specified key name.
        exml.AddKeyNameMapping(KeyName, Alg)

        ' Decrypt the element.
        exml.DecryptDocument()

    End Sub
End Module

The following code example demonstrates how to encrypt an XML document using an X.509 certificate. This example creates a symmetric session key to encrypt the document and then uses the X.509 certificate to embed an encrypted version of the session key into the XML document.

#using <System.Security.dll>
#using <System.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
using namespace System::Security::Cryptography::X509Certificates;
static void Encrypt( XmlDocument^ Doc, String^ ElementToEncrypt, X509Certificate2^ Cert )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );

   if ( ElementToEncrypt == nullptr )
      throw gcnew ArgumentNullException( L"ElementToEncrypt" );

   if ( Cert == nullptr )
      throw gcnew ArgumentNullException( L"Cert" );


   ////////////////////////////////////////////////
   // Find the specified element in the XmlDocument
   // object and create a new XmlElemnt object.
   ////////////////////////////////////////////////
   XmlElement^ elementToEncrypt = dynamic_cast<XmlElement^>(Doc->GetElementsByTagName( ElementToEncrypt )->Item( 0 ));

   // Throw an XmlException if the element was not found.
   if ( elementToEncrypt == nullptr )
   {
      throw gcnew XmlException( L"The specified element was not found" );
   }


   //////////////////////////////////////////////////
   // Create a new instance of the EncryptedXml class
   // and use it to encrypt the XmlElement with the
   // X.509 Certificate.
   //////////////////////////////////////////////////
   EncryptedXml^ eXml = gcnew EncryptedXml;

   // Encrypt the element.
   EncryptedData^ edElement = eXml->Encrypt( elementToEncrypt, Cert );

   ////////////////////////////////////////////////////
   // Replace the element from the original XmlDocument
   // object with the EncryptedData element.
   ////////////////////////////////////////////////////
   EncryptedXml::ReplaceElement( elementToEncrypt, edElement, false );
}

static void Decrypt( XmlDocument^ Doc )
{

   // Check the arguments.
   if ( Doc == nullptr )
      throw gcnew ArgumentNullException( L"Doc" );


   // Create a new EncryptedXml object.
   EncryptedXml^ exml = gcnew EncryptedXml( Doc );

   // Decrypt the XML document.
   exml->DecryptDocument();
}

int main()
{

   // Create an XmlDocument object.
   XmlDocument^ xmlDoc = gcnew XmlDocument;

   // Load an XML file into the XmlDocument object.
   try
   {
      xmlDoc->PreserveWhitespace = true;
      xmlDoc->Load( L"test.xml" );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
      return 0;
   }


   // Create a new X509Certificate2 object by loading
   // an X.509 certificate file.  To use XML encryption
   // with an X.509 certificate, use an X509Certificate2
   // object to encrypt, but use a certificate in a certificate
   // store to decrypt.
   // You can create a new test certificate file using the
   // makecert.exe tool.
   // Create an X509Certificate2 object for encryption.
   X509Certificate2^ cert = gcnew X509Certificate2( L"test.pfx" );

   // Put the certificate in certificate store for decryption.
   X509Store^ store = gcnew X509Store( StoreLocation::CurrentUser );
   store->Open( OpenFlags::ReadWrite );
   store->Add( cert );
   store->Close();
   try
   {

      // Encrypt the "creditcard" element.
      Encrypt( xmlDoc, L"creditcard", cert );

      // Display the encrypted XML to the console.
      Console::WriteLine( L"Encrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );

      // Decrypt the "creditcard" element.
      Decrypt( xmlDoc );

      // Display the encrypted XML to the console.
      Console::WriteLine();
      Console::WriteLine( L"Decrypted XML:" );
      Console::WriteLine();
      Console::WriteLine( xmlDoc->OuterXml );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( e->Message );
   }

   return 1;
}

using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Security.Cryptography.X509Certificates;

class Program
{
    static void Main(string[] args)
    {

        // Create an XmlDocument object.
        XmlDocument xmlDoc = new XmlDocument();

        // Load an XML file into the XmlDocument object.
        try
        {
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.Load("test.xml");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            return;
        }

        // Create a new X509Certificate2 object by loading
        // an X.509 certificate file.  To use XML encryption 
        // with an X.509 certificate, use an X509Certificate2 
        // object to encrypt, but use a certificate in a certificate
        // store to decrypt.

        // You can create a new test certificate file using the 
        // makecert.exe tool.

        // Create an X509Certificate2 object for encryption.
        X509Certificate2 cert = new X509Certificate2("test.pfx");

        // Put the certificate in certificate store for decryption.  
        X509Store store = new X509Store(StoreLocation.CurrentUser);

        store.Open(OpenFlags.ReadWrite);

        store.Add(cert);

        store.Close();


        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", cert);

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);

            // Decrypt the "creditcard" element.
            Decrypt(xmlDoc);

            // Display the encrypted XML to the console.
            Console.WriteLine();
            Console.WriteLine("Decrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }

    }

    public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, X509Certificate2 Cert)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (ElementToEncrypt == null)
            throw new ArgumentNullException("ElementToEncrypt");
        if (Cert == null)
            throw new ArgumentNullException("Cert");

        ////////////////////////////////////////////////
        // Find the specified element in the XmlDocument
        // object and create a new XmlElemnt object.
        ////////////////////////////////////////////////

        XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

        // Throw an XmlException if the element was not found.
        if (elementToEncrypt == null)
        {
            throw new XmlException("The specified element was not found");

        }

        //////////////////////////////////////////////////
        // Create a new instance of the EncryptedXml class 
        // and use it to encrypt the XmlElement with the 
        // X.509 Certificate.
        //////////////////////////////////////////////////

        EncryptedXml eXml = new EncryptedXml();

        // Encrypt the element.
        EncryptedData edElement = eXml.Encrypt(elementToEncrypt, Cert);


        ////////////////////////////////////////////////////
        // Replace the element from the original XmlDocument
        // object with the EncryptedData element.
        ////////////////////////////////////////////////////

        EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);

    }

    public static void Decrypt(XmlDocument Doc)
    {
        // Check the arguments.  
        if (Doc == null)
            throw new ArgumentNullException("Doc");

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml(Doc);

        // Decrypt the XML document.
        exml.DecryptDocument();

    }


}
Imports System
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.Security.Cryptography.X509Certificates



Module Program

    Sub Main(ByVal args() As String)

        ' Create an XmlDocument object.
        Dim xmlDoc As New XmlDocument()

        ' Load an XML file into the XmlDocument object.
        Try
            xmlDoc.PreserveWhitespace = True
            xmlDoc.Load("test.xml")
        Catch e As Exception
            Console.WriteLine(e.Message)
            Return
        End Try

        ' Create a new X509Certificate2 object by loading
        ' an X.509 certificate file.  To use XML encryption 
        ' with an X.509 certificate, use an X509Certificate2 
        ' object to encrypt, but use a certificate in a certificate
        ' store to decrypt.
        ' You can create a new test certificate file using the 
        ' makecert.exe tool.
        ' Create an X509Certificate2 object for encryption.
        Dim cert As New X509Certificate2("test.pfx")

        ' Put the certificate in certificate store for decryption.  
        Dim store As New X509Store(StoreLocation.CurrentUser)

        store.Open(OpenFlags.ReadWrite)

        store.Add(cert)

        store.Close()


        Try
            ' Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", cert)

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)

            ' Decrypt the "creditcard" element.
            Decrypt(xmlDoc)

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try

    End Sub


    Sub Encrypt(ByVal Doc As XmlDocument, ByVal ElementToEncrypt As String, ByVal Cert As X509Certificate2)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        If ElementToEncrypt Is Nothing Then
            Throw New ArgumentNullException("ElementToEncrypt")
        End If
        If Cert Is Nothing Then
            Throw New ArgumentNullException("Cert")
        End If
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Find the specified element in the XmlDocument
        ' object and create a new XmlElemnt object.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(0) 


        ' Throw an XmlException if the element was not found.
        If elementToEncrypt Is Nothing Then
            Throw New XmlException("The specified element was not found")
        End If

        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Create a new instance of the EncryptedXml class 
        ' and use it to encrypt the XmlElement with the 
        ' X.509 Certificate.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim eXml As New EncryptedXml()

        ' Encrypt the element.
        Dim edElement As EncryptedData = eXml.Encrypt(elementEncrypt, Cert)


        '''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Replace the element from the original XmlDocument
        ' object with the EncryptedData element.
        '''''''''''''''''''''''''''''''''''''''''''''''''''
        EncryptedXml.ReplaceElement(elementEncrypt, edElement, False)

    End Sub


    Sub Decrypt(ByVal Doc As XmlDocument)
        ' Check the arguments.  
        If Doc Is Nothing Then
            Throw New ArgumentNullException("Doc")
        End If
        ' Create a new EncryptedXml object.
        Dim exml As New EncryptedXml(Doc)

        ' Decrypt the XML document.
        exml.DecryptDocument()

    End Sub
End Module

Remarks

The EncryptedXml class is the main class used for XML encryption in the .NET Framework. XML Encryption is a standards-based, interoperable way to encrypt all or part of an XML document or any arbitrary data. The .NET Framework XML encryption classes implement the World Wide Web Consortium (W3C) specification for XML encryption located at http://www.w3.org/TR/xmlenc-core/.

Use the EncryptedXml class whenever you need to share encrypted XML data between applications or organizations in a standard way. Any data encrypted using this class can be decrypted by any implementation of the W3C specification for XML encryption.

XML encryption replaces any plain text XML element or document with the <EncryptedData> element, which contains an encrypted (or cipher text) representation of plain text XML or any arbitrary data. The <EncryptedData> element can optionally contain information about where to find a key that will decrypt the cipher text, and which cryptographic algorithm was used to encrypt the plain text.

The <EncryptedKey> element is similar to the <EncryptedData> element in style and usage, except that it allows you to encrypt a key that will decrypt the value of the <EncryptedData> element. Note that the <EncryptedKey> element and the <EncryptedData> element will never contain an unencrypted key.

Use one of the following methods to exchange key information:

  • Do not include any key information. If you choose this option, both parties must agree on an algorithm and key before they exchange encrypted data.

  • Include the location of the key in the Uniform Resource Identifier (URI) attribute of the <RetrievalMethod> element. Both parties must agree on the key location ahead of time and this location must be kept secret.

  • Include a string name that maps to a key in the <KeyName> element. Both parties must agree on the key name mapping before they exchange encrypted data and this mapping must be kept secret.

  • Include an encrypted key in the <EncryptedKey> element. Both parties must agree on the key that decrypts the encrypted key before they exchange encrypted data. You can optionally include a name or location of the key that will decrypt the key in the <EncryptedKey> element.

Constructors

EncryptedXml() EncryptedXml() EncryptedXml() EncryptedXml()

Initializes a new instance of the EncryptedXml class.

EncryptedXml(XmlDocument) EncryptedXml(XmlDocument) EncryptedXml(XmlDocument) EncryptedXml(XmlDocument)

Initializes a new instance of the EncryptedXml class using the specified XML document.

EncryptedXml(XmlDocument, Evidence) EncryptedXml(XmlDocument, Evidence) EncryptedXml(XmlDocument, Evidence) EncryptedXml(XmlDocument, Evidence)

Initializes a new instance of the EncryptedXml class using the specified XML document and evidence.

Fields

XmlEncAES128KeyWrapUrl XmlEncAES128KeyWrapUrl XmlEncAES128KeyWrapUrl XmlEncAES128KeyWrapUrl

Represents the namespace Uniform Resource Identifier (URI) for the 128-bit Advanced Encryption Standard (AES) Key Wrap algorithm (also known as the Rijndael Key Wrap algorithm). This field is constant.

XmlEncAES128Url XmlEncAES128Url XmlEncAES128Url XmlEncAES128Url

Represents the namespace Uniform Resource Identifier (URI) for the 128-bit Advanced Encryption Standard (AES) algorithm (also known as the Rijndael algorithm). This field is constant.

XmlEncAES192KeyWrapUrl XmlEncAES192KeyWrapUrl XmlEncAES192KeyWrapUrl XmlEncAES192KeyWrapUrl

Represents the namespace Uniform Resource Identifier (URI) for the 192-bit Advanced Encryption Standard (AES) Key Wrap algorithm (also known as the Rijndael Key Wrap algorithm). This field is constant.

XmlEncAES192Url XmlEncAES192Url XmlEncAES192Url XmlEncAES192Url

Represents the namespace Uniform Resource Identifier (URI) for the 192-bit Advanced Encryption Standard (AES) algorithm (also known as the Rijndael algorithm). This field is constant.

XmlEncAES256KeyWrapUrl XmlEncAES256KeyWrapUrl XmlEncAES256KeyWrapUrl XmlEncAES256KeyWrapUrl

Represents the namespace Uniform Resource Identifier (URI) for the 256-bit Advanced Encryption Standard (AES) Key Wrap algorithm (also known as the Rijndael Key Wrap algorithm). This field is constant.

XmlEncAES256Url XmlEncAES256Url XmlEncAES256Url XmlEncAES256Url

Represents the namespace Uniform Resource Identifier (URI) for the 256-bit Advanced Encryption Standard (AES) algorithm (also known as the Rijndael algorithm). This field is constant.

XmlEncDESUrl XmlEncDESUrl XmlEncDESUrl XmlEncDESUrl

Represents the namespace Uniform Resource Identifier (URI) for the Digital Encryption Standard (DES) algorithm. This field is constant.

XmlEncElementContentUrl XmlEncElementContentUrl XmlEncElementContentUrl XmlEncElementContentUrl

Represents the namespace Uniform Resource Identifier (URI) for XML encryption element content. This field is constant.

XmlEncElementUrl XmlEncElementUrl XmlEncElementUrl XmlEncElementUrl

Represents the namespace Uniform Resource Identifier (URI) for an XML encryption element. This field is constant.

XmlEncEncryptedKeyUrl XmlEncEncryptedKeyUrl XmlEncEncryptedKeyUrl XmlEncEncryptedKeyUrl

Represents the namespace Uniform Resource Identifier (URI) for the XML encryption <EncryptedKey> element. This field is constant.

XmlEncNamespaceUrl XmlEncNamespaceUrl XmlEncNamespaceUrl XmlEncNamespaceUrl

Represents the namespace Uniform Resource Identifier (URI) for XML encryption syntax and processing. This field is constant.

XmlEncRSA15Url XmlEncRSA15Url XmlEncRSA15Url XmlEncRSA15Url

Represents the namespace Uniform Resource Identifier (URI) for the RSA Public Key Cryptography Standard (PKCS) Version 1.5 algorithm. This field is constant.

XmlEncRSAOAEPUrl XmlEncRSAOAEPUrl XmlEncRSAOAEPUrl XmlEncRSAOAEPUrl

Represents the namespace Uniform Resource Identifier (URI) for the RSA Optimal Asymmetric Encryption Padding (OAEP) encryption algorithm. This field is constant.

XmlEncSHA256Url XmlEncSHA256Url XmlEncSHA256Url XmlEncSHA256Url

Represents the namespace Uniform Resource Identifier (URI) for the SHA-256 algorithm. This field is constant.

XmlEncSHA512Url XmlEncSHA512Url XmlEncSHA512Url XmlEncSHA512Url

Represents the namespace Uniform Resource Identifier (URI) for the SHA-512 algorithm. This field is constant.

XmlEncTripleDESKeyWrapUrl XmlEncTripleDESKeyWrapUrl XmlEncTripleDESKeyWrapUrl XmlEncTripleDESKeyWrapUrl

Represents the namespace Uniform Resource Identifier (URI) for the TRIPLEDES key wrap algorithm. This field is constant.

XmlEncTripleDESUrl XmlEncTripleDESUrl XmlEncTripleDESUrl XmlEncTripleDESUrl

Represents the namespace Uniform Resource Identifier (URI) for the Triple DES algorithm. This field is constant.

Properties

DocumentEvidence DocumentEvidence DocumentEvidence DocumentEvidence

Gets or sets the evidence of the XmlDocument object from which the EncryptedXml object is constructed.

Encoding Encoding Encoding Encoding

Gets or sets the encoding used for XML encryption.

Mode Mode Mode Mode

Gets or sets the cipher mode used for XML encryption.

Padding Padding Padding Padding

Gets or sets the padding mode used for XML encryption.

Recipient Recipient Recipient Recipient

Gets or sets the recipient of the encrypted key information.

Resolver Resolver Resolver Resolver

Gets or sets the XmlResolver object used by the Document Object Model (DOM) to resolve external XML references.

XmlDSigSearchDepth XmlDSigSearchDepth XmlDSigSearchDepth XmlDSigSearchDepth

Gets or sets the XML digital signature recursion depth to prevent infinite recursion and stack overflow. This might happen if the digital signature XML contains the URI which then points back to the original XML.

Methods

AddKeyNameMapping(String, Object) AddKeyNameMapping(String, Object) AddKeyNameMapping(String, Object) AddKeyNameMapping(String, Object)

Defines a mapping between a key name and a symmetric key or an asymmetric key.

ClearKeyNameMappings() ClearKeyNameMappings() ClearKeyNameMappings() ClearKeyNameMappings()

Resets all key name mapping.

DecryptData(EncryptedData, SymmetricAlgorithm) DecryptData(EncryptedData, SymmetricAlgorithm) DecryptData(EncryptedData, SymmetricAlgorithm) DecryptData(EncryptedData, SymmetricAlgorithm)

Decrypts an <EncryptedData> element using the specified symmetric algorithm.

DecryptDocument() DecryptDocument() DecryptDocument() DecryptDocument()

Decrypts all <EncryptedData> elements of the XML document that were specified during initialization of the EncryptedXml class.

DecryptEncryptedKey(EncryptedKey) DecryptEncryptedKey(EncryptedKey) DecryptEncryptedKey(EncryptedKey) DecryptEncryptedKey(EncryptedKey)

Determines the key represented by the EncryptedKey element.

DecryptKey(Byte[], RSA, Boolean) DecryptKey(Byte[], RSA, Boolean) DecryptKey(Byte[], RSA, Boolean) DecryptKey(Byte[], RSA, Boolean)

Decrypts an <EncryptedKey> element using an asymmetric algorithm.

DecryptKey(Byte[], SymmetricAlgorithm) DecryptKey(Byte[], SymmetricAlgorithm) DecryptKey(Byte[], SymmetricAlgorithm) DecryptKey(Byte[], SymmetricAlgorithm)

Decrypts an <EncryptedKey> element using a symmetric algorithm.

Encrypt(XmlElement, String) Encrypt(XmlElement, String) Encrypt(XmlElement, String) Encrypt(XmlElement, String)

Encrypts the outer XML of an element using the specified key in the key mapping table.

Encrypt(XmlElement, X509Certificate2) Encrypt(XmlElement, X509Certificate2) Encrypt(XmlElement, X509Certificate2) Encrypt(XmlElement, X509Certificate2)

Encrypts the outer XML of an element using the specified X.509 certificate.

EncryptData(Byte[], SymmetricAlgorithm) EncryptData(Byte[], SymmetricAlgorithm) EncryptData(Byte[], SymmetricAlgorithm) EncryptData(Byte[], SymmetricAlgorithm)

Encrypts data in the specified byte array using the specified symmetric algorithm.

EncryptData(XmlElement, SymmetricAlgorithm, Boolean) EncryptData(XmlElement, SymmetricAlgorithm, Boolean) EncryptData(XmlElement, SymmetricAlgorithm, Boolean) EncryptData(XmlElement, SymmetricAlgorithm, Boolean)

Encrypts the specified element or its contents using the specified symmetric algorithm.

EncryptKey(Byte[], RSA, Boolean) EncryptKey(Byte[], RSA, Boolean) EncryptKey(Byte[], RSA, Boolean) EncryptKey(Byte[], RSA, Boolean)

Encrypts the key that a recipient uses to decrypt an <EncryptedData> element.

EncryptKey(Byte[], SymmetricAlgorithm) EncryptKey(Byte[], SymmetricAlgorithm) EncryptKey(Byte[], SymmetricAlgorithm) EncryptKey(Byte[], SymmetricAlgorithm)

Encrypts a key using a symmetric algorithm that a recipient uses to decrypt an <EncryptedData> element.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetDecryptionIV(EncryptedData, String) GetDecryptionIV(EncryptedData, String) GetDecryptionIV(EncryptedData, String) GetDecryptionIV(EncryptedData, String)

Retrieves the decryption initialization vector (IV) from an EncryptedData object.

GetDecryptionKey(EncryptedData, String) GetDecryptionKey(EncryptedData, String) GetDecryptionKey(EncryptedData, String) GetDecryptionKey(EncryptedData, String)

Retrieves the decryption key from the specified EncryptedData object.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetIdElement(XmlDocument, String) GetIdElement(XmlDocument, String) GetIdElement(XmlDocument, String) GetIdElement(XmlDocument, String)

Determines how to resolve internal Uniform Resource Identifier (URI) references.

GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ReplaceData(XmlElement, Byte[]) ReplaceData(XmlElement, Byte[]) ReplaceData(XmlElement, Byte[]) ReplaceData(XmlElement, Byte[])

Replaces an <EncryptedData> element with a specified decrypted sequence of bytes.

ReplaceElement(XmlElement, EncryptedData, Boolean) ReplaceElement(XmlElement, EncryptedData, Boolean) ReplaceElement(XmlElement, EncryptedData, Boolean) ReplaceElement(XmlElement, EncryptedData, Boolean)

Replaces the specified element with the specified EncryptedData object.

ToString() ToString() ToString() ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to