EncryptionProperty Classe
Définition
Important
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Représente l'élément <EncryptionProperty>
utilisé dans le chiffrement XML. Cette classe ne peut pas être héritée.
public ref class EncryptionProperty sealed
public sealed class EncryptionProperty
type EncryptionProperty = class
Public NotInheritable Class EncryptionProperty
- Héritage
-
EncryptionProperty
Exemples
L’exemple de code suivant chiffre et déchiffre un document XML. Cet exemple de code crée un EncryptionProperty objet qui contient des informations personnalisées sur l’élément EncryptedKey et ajoute l’objet EncryptionProperty à la EncryptionPropertyCollection collection de la EncryptedXml classe . Enfin, cet exemple de code affiche des informations sur l’objet EncryptionProperty et la EncryptionPropertyCollection collection.
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);
// Save some more information about the key using
// the EncryptionProperty element. In this example,
// we will save the value "LibVersion1". You can save
// anything you want here.
// Create a new "EncryptionProperty" XmlElement object.
XmlElement element = new XmlDocument().CreateElement("EncryptionProperty", EncryptedXml.XmlEncNamespaceUrl);
// Set the value of the EncryptionProperty" XmlElement object.
element.InnerText = "LibVersion1";
// Create the EncryptionProperty object using the XmlElement object.
EncryptionProperty encProp = new EncryptionProperty(element);
// Add the EncryptionProperty object to the EncryptedData object.
edElement.AddProperty(encProp);
// 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);
EncryptionPropertyCollection encPropCollection = encData.EncryptionProperties;
Console.WriteLine("Number of elements in the EncryptionPropertyCollection: " + encPropCollection.Count);
//encPropCollection.
foreach(EncryptionProperty encProp in encPropCollection)
{
Console.WriteLine("EncryptionProperty.ID: " + encProp.Id);
Console.WriteLine("EncryptionProperty.PropertyElement: " + encProp.PropertyElement.InnerXml);
Console.WriteLine("EncryptionProperty.Target: " + encProp.Target);
}
Console.WriteLine("EncryptedData.Id: " + encData.Id);
Console.WriteLine("EncryptedData.KeyInfo: " + encData.KeyInfo.GetXml().InnerXml);
Console.WriteLine("EncryptedData.MimeType: " + encData.MimeType);
}
}
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 ElementToEncryptValue 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 ElementToEncryptValue 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(ElementToEncryptValue)(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)
' Save some more information about the key using
' the EncryptionProperty element. In this example,
' we will save the value "LibVersion1". You can save
' anything you want here.
' Create a new "EncryptionProperty" XmlElement object.
Dim element As XmlElement = New XmlDocument().CreateElement("EncryptionProperty", EncryptedXml.XmlEncNamespaceUrl)
' Set the value of the EncryptionProperty" XmlElement object.
element.InnerText = "LibVersion1"
' Create the EncryptionProperty object using the XmlElement object.
Dim encProp As New EncryptionProperty(element)
' Add the EncryptionProperty object to the EncryptedData object.
edElement.AddProperty(encProp)
' 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 EncryptedData element from the XMLDocument object.
Dim encryptedData As XmlElement = Doc.GetElementsByTagName("EncryptedData")(0)
' Create a new EncryptedData object.
Dim encData As 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)
Dim encPropCollection As EncryptionPropertyCollection = encData.EncryptionProperties
Console.WriteLine("Number of elements in the EncryptionPropertyCollection: " + encPropCollection.Count.ToString())
'encPropCollection.
Dim encProp As EncryptionProperty
For Each encProp In encPropCollection
Console.WriteLine("EncryptionProperty.ID: " + encProp.Id)
Console.WriteLine("EncryptionProperty.PropertyElement: " + encProp.PropertyElement.InnerXml)
Console.WriteLine("EncryptionProperty.Target: " + encProp.Target)
Next encProp
Console.WriteLine("EncryptedData.Id: " + encData.Id)
Console.WriteLine("EncryptedData.KeyInfo: " + encData.KeyInfo.GetXml().InnerXml)
Console.WriteLine("EncryptedData.MimeType: " + encData.MimeType)
End Sub
End Module
Remarques
La EncryptionProperty classe encapsule l’élément <EncryptionProperty>
défini par la spécification de traitement et de syntaxe de chiffrement XML du World Wide Web Consortium.
Utilisez la EncryptionProperty classe pour fournir des informations de chiffrement supplémentaires relatives aux EncryptedData éléments et EncryptedKey . Par exemple, utilisez cette classe pour spécifier un horodatage.
Constructeurs
EncryptionProperty() |
Initialise une nouvelle instance de la classe EncryptionProperty. |
EncryptionProperty(XmlElement) |
Initialise une nouvelle instance de la classe EncryptionProperty avec un objet XmlElement. |
Propriétés
Id |
Obtient l'ID de l'objet EncryptionProperty actuel. |
PropertyElement |
Obtient ou définit un objet XmlElement qui représente un objet EncryptionProperty. |
Target |
Obtient la cible de l'objet EncryptionProperty. |
Méthodes
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 un objet XmlElement qui encapsule une instance de la classe EncryptionProperty. |
LoadXml(XmlElement) |
Analyse le XmlElement en entrée et configure l'état interne de l'objet EncryptionProperty en conséquence. |
MemberwiseClone() |
Crée une copie superficielle du Object actuel. (Hérité de Object) |
ToString() |
Retourne une chaîne qui représente l'objet actuel. (Hérité de Object) |