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EncryptedData, constructeur

Remarque : ce constructeur est nouveau dans le .NET Framework version 2.0.

Initialise une nouvelle instance de la classe EncryptedData.

Espace de noms : System.Security.Cryptography.Xml
Assembly : System.Security (dans system.security.dll)

public EncryptedData ()
public EncryptedData ()
public function EncryptedData ()

Ce constructeur crée une nouvelle instance de la classe EncryptedData. Pour plus d'informations sur les standards de chiffrement XML, consultez le document XML Encryption Syntax and Processing, à l'adresse http://www.w3.org/TR/xmlenc-core/.

L'exemple de code suivant montre comment chiffrer et déchiffrer un élément XML à l'aide de la classe EncryptedData. Cet exemple affiche ensuite diverses propriétés de la classe EncryptedData dans la console.

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);
		}

		// 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");

			// Inspect the EncryptedKey element.
			InspectElement(xmlDoc);

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

		}
		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();

	}

	static void InspectElement(XmlDocument Doc)
	{
		// Get the EncryptedData element from the XMLDocument object.
		XmlElement encryptedData = Doc.GetElementsByTagName("EncryptedData")[0] as XmlElement;

		// Create a new EncryptedData object.
		EncryptedData encData = new EncryptedData();

		// Load the XML from the document to
		// initialize the EncryptedData object.
		encData.LoadXml(encryptedData);

		// Display the properties.
		// Most values are Null by default.


		
		Console.WriteLine("EncryptedData.CipherData: " + encData.CipherData.GetXml().InnerXml);
		Console.WriteLine("EncryptedData.Encoding: " + encData.Encoding);
		Console.WriteLine("EncryptedData.EncryptionMethod: " + encData.EncryptionMethod.GetXml().InnerXml);
		if (encData.EncryptionProperties.Count >= 1)
		{
			Console.WriteLine("EncryptedData.EncryptionProperties: " + encData.EncryptionProperties[0].GetXml().InnerXml);
		}

		Console.WriteLine("EncryptedData.Id: " + encData.Id);
		Console.WriteLine("EncryptedData.KeyInfo: " + encData.KeyInfo.GetXml().InnerXml);
		Console.WriteLine("EncryptedData.MimeType: " + encData.MimeType);
	}

}

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Édition Media Center, Windows XP Professionnel Édition x64, Windows XP SP2, Windows XP Starter Edition

Le .NET Framework ne prend pas en charge toutes les versions de chaque plate-forme. Pour obtenir la liste des versions prises en charge, consultez Configuration requise.

.NET Framework

Prise en charge dans : 2.0
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