EncryptionProperty Klasse

Definition

Namespace:

System.Security.Cryptography.Xml

Assembly:

System.Security.Cryptography.Xml.dll

Assembly:

System.Security.dll

Stellt das bei der XML-Verschlüsselung verwendete <EncryptionProperty>-Element dar. Diese Klasse kann nicht vererbt werden.

public ref class EncryptionProperty sealed

public sealed class EncryptionProperty

type EncryptionProperty = class

Public NotInheritable Class EncryptionProperty

Vererbung

Object

EncryptionProperty

Beispiele

Im folgenden Codebeispiel wird ein XML-Dokument verschlüsselt und entschlüsselt. In diesem Codebeispiel wird ein EncryptionProperty Objekt erstellt, das benutzerdefinierte Informationen zum EncryptedKey Element enthält, und fügt das EncryptionProperty Objekt der EncryptionPropertyCollection Auflistung der EncryptedXml Klasse hinzu. Schließlich zeigt dieses Codebeispiel Informationen über das EncryptionProperty Objekt und die EncryptionPropertyCollection Auflistung an.

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

Hinweise

Die EncryptionProperty Klasse kapselt das Element, das durch die <EncryptionProperty> XML-Verschlüsselungssyntax und Die Verarbeitungsspezifikation des World Wide Web Consortium definiert ist.

Verwenden Sie die EncryptionProperty Klasse, um zusätzliche Verschlüsselungsinformationen im Zusammenhang mit den EncryptedData Elementen EncryptedKey bereitzustellen. Verwenden Sie beispielsweise diese Klasse, um einen Zeitstempel anzugeben.

Konstruktoren

EncryptionProperty()	Initialisiert eine neue Instanz der EncryptionProperty-Klasse.
EncryptionProperty(XmlElement)	Initialisiert eine neue Instanz der EncryptionProperty-Klasse mit einem XmlElement-Objekt.

Eigenschaften

Id	Ruft die ID des aktuellen EncryptionProperty-Objekts ab.
PropertyElement	Ruft ein XmlElement-Objekt ab, das ein EncryptionProperty-Objekt darstellt, oder legt dieses fest.
Target	Ruft das Ziel des EncryptionProperty-Objekts ab.

Methoden

Equals(Object)	Bestimmt, ob das angegebene Objekt gleich dem aktuellen Objekt ist. (Geerbt von Object)
GetHashCode()	Fungiert als Standardhashfunktion. (Geerbt von Object)
GetType()	Ruft den Type der aktuellen Instanz ab. (Geerbt von Object)
GetXml()	Gibt ein XmlElement-Objekt zurück, das eine Instanz der EncryptionProperty-Klasse kapselt.
LoadXml(XmlElement)	Analysiert das Eingabe-XmlElement und konfiguriert den internen Zustand des EncryptionProperty-Objekts für eine Übereinstimmung.
MemberwiseClone()	Erstellt eine flache Kopie des aktuellen Object. (Geerbt von Object)
ToString()	Gibt eine Zeichenfolge zurück, die das aktuelle Objekt darstellt. (Geerbt von Object)