EncryptedKey 類別

定義

命名空間:

System.Security.Cryptography.Xml

組件:

System.Security.Cryptography.Xml.dll

表示 XML 加密中的 <EncryptedKey> 項目。 此類別無法獲得繼承。

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

繼承

Object

EncryptedType

EncryptedKey

範例

下列範例說明如何使用 類別來加密和解密 XML 專案 EncryptedKey 。 此範例接著會將 類別的各種屬性值 EncryptedKey 顯示至主控台。

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

備註

這個類別代表 <EncryptedKey> XML 加密中的 專案。 元素 <EncryptedKey> 是用來傳送加密金鑰。 它可以在獨立 XML 檔中建立、放在應用程式檔內，或位於 <EncryptedData> 元素內 <KeyInfo> 做為專案的子系。 金鑰值一律會加密給收件者。 解密時 <EncryptedKey> ，產生的密鑰會提供給演算法， <EncryptionMethod> 而不會進行任何額外的處理。

元素 <EncryptedKey> 類似於 <EncryptedData> 類別的 EncryptedData 元素，不同之處在於加密的數據一律是密鑰值。

建構函式

EncryptedKey()

初始化 EncryptedKey 類別的新執行個體。

屬性

CarriedKeyName	取得或設定 XML 加密中選擇性的 <CarriedKeyName> 項目。
CipherData	取得或設定 CipherData 類別執行個體的 EncryptedType 值。 (繼承來源 EncryptedType)
Encoding	取得或設定 XML 加密中 EncryptedType 執行個體的 Encoding 屬性。 (繼承來源 EncryptedType)
EncryptionMethod	取得或設定 XML 加密中的 <EncryptionMethod> 項目。 (繼承來源 EncryptedType)
EncryptionProperties	取得或設定 XML 加密中的 <EncryptionProperties> 項目。 (繼承來源 EncryptedType)
Id	取得或設定 XML 加密中 EncryptedType 執行個體的 Id 屬性。 (繼承來源 EncryptedType)
KeyInfo	取得或設定 XML 加密中的 <KeyInfo> 項目。 (繼承來源 EncryptedType)
MimeType	取得或設定 XML 加密中 EncryptedType 執行個體的 MimeType 屬性。 (繼承來源 EncryptedType)
Recipient	取得或設定 XML 加密中的選擇性 Recipient 屬性。
ReferenceList	取得或設定 XML 加密中的 <ReferenceList> 項目。
Type	取得或設定 XML 加密中 EncryptedType 執行個體的 Type 屬性。 (繼承來源 EncryptedType)

方法

AddProperty(EncryptionProperty)	在 XML 加密的目前 EncryptedType 物件中，將 <EncryptionProperty> 子項目新增至 <EncryptedProperties> 項目。 (繼承來源 EncryptedType)
AddReference(DataReference)	將 <DataReference> 項目新增至 <ReferenceList> 項目。
AddReference(KeyReference)	將 <KeyReference> 項目新增至 <ReferenceList> 項目。
Equals(Object)	判斷指定的物件是否等於目前的物件。 (繼承來源 Object)
GetHashCode()	做為預設雜湊函式。 (繼承來源 Object)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
GetXml()	傳回 EncryptedKey 物件的 XML 表示。
LoadXml(XmlElement)	將指定的 XML 資訊載入 XML 加密的 <EncryptedKey> 項目中。
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)