EncryptedKey Classe
Définition
Important
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Représente l'élément <EncryptedKey>
utilisé dans le chiffrement XML. Cette classe ne peut pas être héritée.
public ref class EncryptedKey sealed : System::Security::Cryptography::Xml::EncryptedType
public sealed class EncryptedKey : System.Security.Cryptography.Xml.EncryptedType
type EncryptedKey = class
inherit EncryptedType
Public NotInheritable Class EncryptedKey
Inherits EncryptedType
- Héritage
Exemples
L’exemple suivant montre comment chiffrer et déchiffrer un élément XML à l’aide de la EncryptedKey classe . Cet exemple affiche ensuite les valeurs des différentes propriétés de la EncryptedKey classe 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 = RSA.Create();
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 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();
}
static void InspectElement(XmlDocument Doc)
{
// Get the EncryptedKey element from the XMLDocument object.
XmlElement encryptedKey = Doc.GetElementsByTagName("EncryptedKey")[0] as XmlElement;
// Create a new EncryptedKey object.
EncryptedKey k = new EncryptedKey();
// Load the XML from the document to
// initialize the EncryptedKey object.
k.LoadXml(encryptedKey);
// Display the properties.
// Most values are Null by default.
Console.WriteLine("EncryptedKey.KeyInfo: " + k.KeyInfo.GetXml().InnerXml);
Console.WriteLine("EncryptedKey.Id: " + k.Id);
Console.WriteLine("EncryptedKey.CarriedKeyName: " + k.CarriedKeyName);
Console.WriteLine("EncryptedKey.CipherData: " + k.CipherData.GetXml().InnerXml);
Console.WriteLine("EncryptedKey.Encoding: " + k.Encoding);
Console.WriteLine("EncryptedKey.EncryptionMethod: " + k.EncryptionMethod.GetXml().InnerXml);
if (k.EncryptionProperties.Count >= 1)
{
Console.WriteLine("EncryptedKey.EncryptionProperties: " + k.EncryptionProperties[0].GetXml().InnerXml);
}
Console.WriteLine("EncryptedKey.MimeType: " + k.MimeType);
Console.WriteLine("EncryptedKey.Recipient: " + k.Recipient);
if (k.ReferenceList.Count >= 1)
{
Console.WriteLine("EncryptedKey.ReferenceList: " + k.ReferenceList[0].GetXml().InnerXml);
}
}
}
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)
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 As RSA = RSA.Create()
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 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 ElementToEncryptParam 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 ElementToEncryptParam 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 elementToEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncryptParam)(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(elementToEncrypt, 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(elementToEncrypt, 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
Sub InspectElement(ByVal Doc As XmlDocument)
' Get the EncryptedKey element from the XMLDocument object.
Dim encryptedKey As XmlElement = Doc.GetElementsByTagName("EncryptedKey")(0)
' Create a new EncryptedKey object.
Dim k As New EncryptedKey()
' Load the XML from the document to
' initialize the EncryptedKey object.
k.LoadXml(encryptedKey)
' Display the properties.
' Most values are Null by default.
Console.WriteLine("EncryptedKey.KeyInfo: " + k.KeyInfo.GetXml().InnerXml)
Console.WriteLine("EncryptedKey.Id: " + k.Id)
Console.WriteLine("EncryptedKey.CarriedKeyName: " + k.CarriedKeyName)
Console.WriteLine("EncryptedKey.CipherData: " + k.CipherData.GetXml().InnerXml)
Console.WriteLine("EncryptedKey.Encoding: " + k.Encoding)
Console.WriteLine("EncryptedKey.EncryptionMethod: " + k.EncryptionMethod.GetXml().InnerXml)
If k.EncryptionProperties.Count >= 1 Then
Console.WriteLine("EncryptedKey.EncryptionProperties: " + k.EncryptionProperties(0).GetXml().InnerXml)
End If
Console.WriteLine("EncryptedKey.MimeType: " + k.MimeType)
Console.WriteLine("EncryptedKey.Recipient: " + k.Recipient)
If k.ReferenceList.Count >= 1 Then
Console.WriteLine("EncryptedKey.ReferenceList: " + k.ReferenceList(0).GetXml().InnerXml)
End If
End Sub
End Module
Remarques
Cette classe représente l’élément <EncryptedKey>
dans le chiffrement XML. L’élément <EncryptedKey>
est utilisé pour envoyer des clés de chiffrement. Il peut être créé dans un document XML autonome, placé dans un document d’application ou à l’intérieur d’un <EncryptedData>
élément en tant qu’enfant d’un <KeyInfo>
élément. La valeur de clé est toujours chiffrée pour le destinataire. Quand <EncryptedKey>
est déchiffrée, la clé résultante est mise à la disposition de l’algorithme <EncryptionMethod>
sans traitement supplémentaire.
L’élément <EncryptedKey>
est similaire à l’élément <EncryptedData>
de la EncryptedData classe, sauf que les données chiffrées sont toujours une valeur de clé.
Constructeurs
EncryptedKey() |
Initialise une nouvelle instance de la classe EncryptedKey. |
Propriétés
CarriedKeyName |
Obtient ou définit l'élément facultatif |
CipherData |
Obtient ou définit la valeur CipherData d'une instance de la classe EncryptedType. (Hérité de EncryptedType) |
Encoding |
Obtient ou définit l'attribut |
EncryptionMethod |
Obtient ou définit l'élément |
EncryptionProperties |
Obtient ou définit l'élément |
Id |
Obtient ou définit l'attribut |
KeyInfo |
Obtient ou définit l'élément |
MimeType |
Obtient ou définit l'attribut |
Recipient |
Obtient ou définit l'attribut facultatif |
ReferenceList |
Obtient ou définit l'élément |
Type |
Obtient ou définit l'attribut |
Méthodes
AddProperty(EncryptionProperty) |
Ajoute un élément enfant |
AddReference(DataReference) |
Ajoute un élément |
AddReference(KeyReference) |
Ajoute un élément |
Equals(Object) |
Détermine si l'objet spécifié est égal à l'objet actuel. (Hérité de Object) |
GetHashCode() |
Fait office de fonction de hachage par défaut. (Hérité de Object) |
GetType() |
Obtient le Type de l'instance actuelle. (Hérité de Object) |
GetXml() |
Retourne la représentation XML de l'objet EncryptedKey. |
LoadXml(XmlElement) |
Charge les informations XML spécifiées dans l'élément |
MemberwiseClone() |
Crée une copie superficielle du Object actuel. (Hérité de Object) |
ToString() |
Retourne une chaîne qui représente l'objet actuel. (Hérité de Object) |