EncryptedType.LoadXml メソッド

.NET Framework クラス ライブラリ リファレンス

EncryptedType.LoadXml メソッド

メモ : このメソッドは、.NET Framework version 2.0 で新しく追加されたものです。

XML 情報を XML 暗号化の <EncryptedType> 要素に読み込みます。

名前空間: System.Security.Cryptography.Xml
アセンブリ: System.Security (system.security.dll 内)
構文

Visual Basic (宣言)

Public MustOverride Sub
 LoadXml ( _
    value As XmlElement _
)

Visual Basic (使用法)

Dim instance As EncryptedType
Dim value As XmlElement

instance.LoadXml(value)

C#

public abstract void LoadXml (
    XmlElement value
)

C++

public:
virtual void LoadXml (
    XmlElement^ value
) abstract

J#

public abstract void LoadXml (
    XmlElement value
)

JScript

public abstract function LoadXml (
    value : XmlElement
)

パラメータ

value

<EncryptedType> 要素で使用する、XML 要素を表す XmlElement オブジェクト。

例外

例外の種類	条件
ArgumentNullException	提供された value が null 参照 (Visual Basic では Nothing) です。

解説

このメソッドは、既存の XML 要素を EncryptedType オブジェクトに読み込むために使用します。

使用例

EncryptedType クラスから派生した EncryptedData クラスを使用して、XML 要素を暗号化および復号化する方法を次のコード例に示します。

Visual Basic

Imports System
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 TripleDES key. 
        Dim tDESkey As New
 TripleDESCryptoServiceProvider()


        Try
            ' Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey)

            ' Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)

            ' Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey)

            ' Display the encrypted XML to the console.
            Console.WriteLine()
            Console.WriteLine("Decrypted XML:")
            Console.WriteLine()
            Console.WriteLine(xmlDoc.OuterXml)
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the TripleDES key.
            tDESkey.Clear()
        End Try

    End Sub


    Sub Encrypt(ByVal Doc As
 XmlDocument, ByVal ElementToEncryptString As
 String, ByVal Alg As TripleDESCryptoServiceProvider)

        ''''''''''''''''''''''''''''''''''''''''''''''''''
        ' Find the specified element in the XmlDocument
        ' object and create a new XmlElemnt object.
        ''''''''''''''''''''''''''''''''''''''''''''''''''

        Dim elementToEncrypt As XmlElement
 = Doc.GetElementsByTagName(ElementToEncryptString)(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 
        ' symmetric key.
        ''''''''''''''''''''''''''''''''''''''''''''''''''

        Dim eXml As New
 EncryptedXml()

        Dim encryptedElement As Byte()
 = eXml.EncryptData(elementToEncrypt, Alg, 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.
        ' Determine what kind of algorithm is being used and
        ' supply the appropriate URL to the EncryptionMethod element.
        edElement.EncryptionMethod = New EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl)

        ' 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 SymmetricAlgorithm)

        ' Find the EncryptedData element in the XmlDocument.
        Dim encryptedElement As XmlElement
 = Doc.GetElementsByTagName("EncryptedData")(0) 
   

        ' If the EncryptedData element was not found, throw an exception.
        If encryptedElement Is Nothing
 Then
            Throw New XmlException("The
 EncryptedData element was not found.")
        End If

        ' Create an EncryptedData object and populate it.
        Dim edElement As New
 EncryptedData()
        edElement.LoadXml(encryptedElement)

        ' Create a new EncryptedXml object.
        Dim exml As New
 EncryptedXml()

        ' Decrypt the element using the symmetric key.
        Dim rgbOutput As Byte()
 = exml.DecryptData(edElement, Alg)

        ' Replace the encryptedData element with the plaintext XML element.
        exml.ReplaceData(encryptedElement, rgbOutput)

    End Sub
End Module

C#

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 TripleDES key. 
        TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();


        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey);

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);

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

            // 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 TripleDES key.
            tDESkey.Clear();
        }

    }

    public static void Encrypt(XmlDocument
 Doc, string ElementToEncrypt, TripleDESCryptoServiceProvider
 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 
        // symmetric key.
        //////////////////////////////////////////////////

        EncryptedXml eXml = new EncryptedXml();

        byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, Alg, 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.
        // Determine what kind of algorithm is being used and
        // supply the appropriate URL to the EncryptionMethod element.

        edElement.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl);

        // 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, SymmetricAlgorithm Alg)
    {

        // Find the EncryptedData element in the XmlDocument.
        XmlElement encryptedElement = Doc.GetElementsByTagName("EncryptedData")[0]
 as XmlElement;

        // If the EncryptedData element was not found, throw an exception.
        if (encryptedElement == null)
        {
            throw new XmlException("The EncryptedData element
 was not found.");
        }

        // Create an EncryptedData object and populate it.
        EncryptedData edElement = new EncryptedData();
        edElement.LoadXml(encryptedElement);

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml();

        // Decrypt the element using the symmetric key.
        byte[] rgbOutput = exml.DecryptData(edElement, Alg);

        // Replace the encryptedData element with the plaintext XML
 element.
        exml.ReplaceData(encryptedElement, rgbOutput);

    }


}

プラットフォーム

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

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0

参照

関連項目
EncryptedType クラス
EncryptedType メンバ
System.Security.Cryptography.Xml 名前空間