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EncryptedXml.EncryptKey Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Security.Cryptography.Xml
Assembly:
System.Security.Cryptography.Xml.dll
Assembly:
System.Security.dll
Pacchetto:
System.Security.Cryptography.Xml v8.0.2
Pacchetto:
System.Security.Cryptography.Xml v9.0.0-rc.2.24473.5

Crittografa la chiave usata dal destinatario per decrittografare l'elemento <EncryptedData>.

Overload

EncryptKey(Byte[], SymmetricAlgorithm)

Crittografa una chiave usando l'algoritmo simmetrico che il destinatario userà per decrittografare l'elemento <EncryptedData>.
EncryptKey(Byte[], RSA, Boolean)

Crittografa la chiave usata dal destinatario per decrittografare l'elemento <EncryptedData>.

Esempio

Nell'esempio di codice seguente viene illustrato come crittografare un documento XML usando una chiave asimmetrica. In questo esempio viene creata una chiave di sessione simmetrica per crittografare il documento e quindi viene utilizzata la chiave asimmetrica per incorporare una versione crittografata della chiave di sessione nel documento XML.

#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 Aes key.
   Aes^ sessionKey = Aes::Create();
   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 = RSA::Create();
   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 = RSA.Create();

        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 Aes key.
        Aes sessionKey = Aes.Create();
        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.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 = RSA = RSA.Create()


        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 Aes key.
        Dim sessionKey As Aes = Aes.Create()
        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

Commenti

Usare il EncryptKey metodo per crittografare la chiave usata da un destinatario per decrittografare un <EncryptedData> elemento. Questo metodo inserisce la chiave crittografata all'interno di un <EncryptedKey> elemento .

EncryptKey(Byte[], SymmetricAlgorithm)

Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs

Crittografa una chiave usando l'algoritmo simmetrico che il destinatario userà per decrittografare l'elemento <EncryptedData>.

public:
 static cli::array <System::Byte> ^ EncryptKey(cli::array <System::Byte> ^ keyData, System::Security::Cryptography::SymmetricAlgorithm ^ symmetricAlgorithm);
public static byte[] EncryptKey (byte[] keyData, System.Security.Cryptography.SymmetricAlgorithm symmetricAlgorithm);
static member EncryptKey : byte[] * System.Security.Cryptography.SymmetricAlgorithm -> byte[]
Public Shared Function EncryptKey (keyData As Byte(), symmetricAlgorithm As SymmetricAlgorithm) As Byte()

Parametri

keyData
Byte[]

Chiave da crittografare.

symmetricAlgorithm
SymmetricAlgorithm

Chiave simmetrica usata per crittografare keyData.

Restituisce

Byte[]

Matrice di byte che rappresenta il valore crittografato del parametro keyData.

Eccezioni

ArgumentNullException

Il valore del parametro keyData è null.

-oppure-

Il valore del parametro symmetricAlgorithm è null.

CryptographicException

Il valore del parametro symmetricAlgorithm non è rappresentato dall'algoritmo di wrapping della chiave Triple DES o AES (Advanced Encryption Standard), noto anche come Rijndael.

Commenti

Usare il EncryptKey metodo per crittografare la chiave usata da un destinatario per decrittografare un <EncryptedData> elemento. Questo metodo accetta un valore per il symmetricAlgorithm parametro che rappresenta l'algoritmo Triple DES o l'algoritmo di wrapping della chiave AES (detto anche Rijndael).

Si noti che questo metodo non inserisce automaticamente la chiave crittografata all'interno di un <EncryptedKey> elemento. È necessario creare manualmente l'elemento <EncryptedKey> all'interno del documento.

Si applica a

EncryptKey(Byte[], RSA, Boolean)

Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs
Origine:
EncryptedXml.cs

Crittografa la chiave usata dal destinatario per decrittografare l'elemento <EncryptedData>.

public:
 static cli::array <System::Byte> ^ EncryptKey(cli::array <System::Byte> ^ keyData, System::Security::Cryptography::RSA ^ rsa, bool useOAEP);
public static byte[] EncryptKey (byte[] keyData, System.Security.Cryptography.RSA rsa, bool useOAEP);
static member EncryptKey : byte[] * System.Security.Cryptography.RSA * bool -> byte[]
Public Shared Function EncryptKey (keyData As Byte(), rsa As RSA, useOAEP As Boolean) As Byte()

Parametri

keyData
Byte[]

Chiave da crittografare.

rsa
RSA

Chiave asimmetrica usata per crittografare keyData.

useOAEP
Boolean

Valore che specifica se usare la spaziatura interna OAEP (Optimal Asymmetric Encryption Padding).

Restituisce

Byte[]

Matrice di byte che rappresenta il valore crittografato del parametro keyData.

Eccezioni

ArgumentNullException

Il valore del parametro keyData è null.

-oppure-

Il valore del parametro rsa è null.

Esempio

Nell'esempio di codice seguente viene illustrato come crittografare un documento XML usando una chiave asimmetrica. In questo esempio viene creata una chiave di sessione simmetrica per crittografare il documento e quindi viene utilizzata la chiave asimmetrica per incorporare una versione crittografata della chiave di sessione nel documento XML.

#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 Aes key.
   Aes^ sessionKey = Aes::Create();
   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 = RSA::Create();
   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 = RSA.Create();

        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 Aes key.
        Aes sessionKey = Aes.Create();
        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.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 = RSA = RSA.Create()


        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 Aes key.
        Dim sessionKey As Aes = Aes.Create()
        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

Commenti

Usare il EncryptKey metodo per crittografare la chiave usata da un destinatario per decrittografare un <EncryptedData> elemento. Questo metodo accetta un valore per rsa che rappresenta l'algoritmo RSA PKCS#1 v1.5 o l'algoritmo RSA PKCS#1 di tipo 2 (detto anche OAEP).

Si noti che questo metodo non inserisce automaticamente la chiave crittografata all'interno di un <EncryptedKey> elemento. È necessario creare manualmente l'elemento <EncryptedKey> all'interno del documento.

Si applica a