EncryptedXml.EncryptData Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee worden XML-gegevens versleuteld met behulp van een symmetrisch algoritme.
Overloads
| Name | Description |
|---|---|
| EncryptData(Byte[], SymmetricAlgorithm) |
Hiermee worden gegevens in de opgegeven bytematrix versleuteld met behulp van het opgegeven symmetrische algoritme. |
| EncryptData(XmlElement, SymmetricAlgorithm, Boolean) |
Hiermee versleutelt u het opgegeven element of de inhoud ervan met behulp van het opgegeven symmetrische algoritme. |
Voorbeelden
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een symmetrische sleutel. Dit voorbeeld bevat geen belangrijke informatie in het versleutelde XML-document.
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);
return;
}
// 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, SymmetricAlgorithm Alg)
{
// 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
// 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.
string encryptionMethod = null;
if (Alg is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Alg is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
else if (Alg is Aes)
{
switch (Alg.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// 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)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullException("Doc");
if (Alg == null)
throw new ArgumentNullException("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);
}
}
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)
Return
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 ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm)
' Check the arguments.
If Doc Is Nothing Then
Throw New ArgumentNullException("Doc")
End If
If ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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.
Dim encryptionMethod As String = Nothing
If TypeOf Alg Is TripleDES Then
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
ElseIf TypeOf Alg Is DES Then
encryptionMethod = EncryptedXml.XmlEncDESUrl
ElseIf TypeOf Alg Is Aes Then
Select Case Alg.KeySize
Case 128
encryptionMethod = EncryptedXml.XmlEncAES128Url
Case 192
encryptionMethod = EncryptedXml.XmlEncAES192Url
Case 256
encryptionMethod = EncryptedXml.XmlEncAES256Url
End Select
Else
' Throw an exception if the transform is not in the previous categories
Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
End If
edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)
' 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(elementEncrypt, edElement, False)
End Sub
Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm)
' 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
' 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
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een symmetrische sleutel. In dit voorbeeld wordt een sleutelnaam ingesloten in het versleutelde XML-document dat door de ontsleutelingsmethode wordt gebruikt om de juiste ontsleutelingssleutel te vinden.
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);
return;
}
// Create a new TripleDES key.
TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();
try
{
// Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", tDESkey, "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, "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, SymmetricAlgorithm 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
// 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.
string encryptionMethod = null;
if (Alg is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Alg is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
else if (Alg is Aes)
{
switch (Alg.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// Set the KeyInfo element to specify the
// name of a 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.
edElement.KeyInfo.AddClause(kin);
// 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, 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();
}
}
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)
Return
End Try
' Create a new TripleDES key.
Dim tDESkey As New TripleDESCryptoServiceProvider()
Try
' Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", tDESkey, "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, "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 ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm, ByVal KeyName As String)
' Check the arguments.
If Doc Is Nothing Then
Throw New ArgumentNullException("Doc")
End If
If ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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.
Dim encryptionMethod As String = Nothing
If TypeOf Alg Is TripleDES Then
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
ElseIf TypeOf Alg Is DES Then
encryptionMethod = EncryptedXml.XmlEncDESUrl
ElseIf TypeOf Alg Is Aes Then
Select Case Alg.KeySize
Case 128
encryptionMethod = EncryptedXml.XmlEncAES128Url
Case 192
encryptionMethod = EncryptedXml.XmlEncAES192Url
Case 256
encryptionMethod = EncryptedXml.XmlEncAES256Url
End Select
Else
' Throw an exception if the transform is not in the previous categories
Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
End If
edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)
' Set the KeyInfo element to specify the
' name of a 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.
edElement.KeyInfo.AddClause(kin)
' 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(elementEncrypt, edElement, False)
End Sub
Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm, 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
End Module
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een asymmetrische sleutel. In dit voorbeeld wordt een symmetrische sessiesleutel gemaakt om het document te versleutelen en wordt vervolgens de asymmetrische sleutel gebruikt om een versleutelde versie van de sessiesleutel in te sluiten in het XML-document.
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);
return;
}
// 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");
// Display the encrypted XML to the console.
Console.WriteLine("Encrypted XML:");
Console.WriteLine();
Console.WriteLine(xmlDoc.OuterXml);
xmlDoc.Save("test.xml");
// Decrypt the "creditcard" element.
Decrypt(xmlDoc, rsaKey, "rsaKey");
xmlDoc.Save("test.xml");
// 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 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();
}
}
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)
Return
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 = RSA = RSA.Create()
Try
' Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", rsaKey, "rsaKey")
' Display the encrypted XML to the console.
Console.WriteLine("Encrypted XML:")
Console.WriteLine()
Console.WriteLine(xmlDoc.OuterXml)
xmlDoc.Save("test.xml")
' Decrypt the "creditcard" element.
Decrypt(xmlDoc, rsaKey, "rsaKey")
' Display the encrypted XML to the console.
Console.WriteLine()
Console.WriteLine("Decrypted XML:")
Console.WriteLine()
Console.WriteLine(xmlDoc.OuterXml)
xmlDoc.Save("test.xml")
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 ElementToEncrypt 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 ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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(elementEncrypt, 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
End Module
EncryptData(Byte[], SymmetricAlgorithm)
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
Hiermee worden gegevens in de opgegeven bytematrix versleuteld met behulp van het opgegeven symmetrische algoritme.
public:
cli::array <System::Byte> ^ EncryptData(cli::array <System::Byte> ^ plaintext, System::Security::Cryptography::SymmetricAlgorithm ^ symmetricAlgorithm);
public byte[] EncryptData(byte[] plaintext, System.Security.Cryptography.SymmetricAlgorithm symmetricAlgorithm);
member this.EncryptData : byte[] * System.Security.Cryptography.SymmetricAlgorithm -> byte[]
Public Function EncryptData (plaintext As Byte(), symmetricAlgorithm As SymmetricAlgorithm) As Byte()
Parameters
- plaintext
- Byte[]
De gegevens die moeten worden versleuteld.
- symmetricAlgorithm
- SymmetricAlgorithm
Het symmetrische algoritme dat moet worden gebruikt voor versleuteling.
Retouren
Een bytematrix met versleutelde gegevens.
Uitzonderingen
De waarde van de plaintext parameter is null.
– of –
De waarde van de symmetricAlgorithm parameter is null.
De gegevens kunnen niet worden versleuteld met behulp van de opgegeven parameters.
Voorbeelden
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een symmetrische sleutel. Dit voorbeeld bevat geen belangrijke informatie in het versleutelde XML-document.
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);
return;
}
// 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, SymmetricAlgorithm Alg)
{
// 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
// 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.
string encryptionMethod = null;
if (Alg is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Alg is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
else if (Alg is Aes)
{
switch (Alg.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// 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)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullException("Doc");
if (Alg == null)
throw new ArgumentNullException("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);
}
}
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)
Return
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 ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm)
' Check the arguments.
If Doc Is Nothing Then
Throw New ArgumentNullException("Doc")
End If
If ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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.
Dim encryptionMethod As String = Nothing
If TypeOf Alg Is TripleDES Then
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
ElseIf TypeOf Alg Is DES Then
encryptionMethod = EncryptedXml.XmlEncDESUrl
ElseIf TypeOf Alg Is Aes Then
Select Case Alg.KeySize
Case 128
encryptionMethod = EncryptedXml.XmlEncAES128Url
Case 192
encryptionMethod = EncryptedXml.XmlEncAES192Url
Case 256
encryptionMethod = EncryptedXml.XmlEncAES256Url
End Select
Else
' Throw an exception if the transform is not in the previous categories
Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
End If
edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)
' 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(elementEncrypt, edElement, False)
End Sub
Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm)
' 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
' 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
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een symmetrische sleutel. In dit voorbeeld wordt een sleutelnaam ingesloten in het versleutelde XML-document dat door de ontsleutelingsmethode wordt gebruikt om de juiste ontsleutelingssleutel te vinden.
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);
return;
}
// Create a new TripleDES key.
TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();
try
{
// Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", tDESkey, "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, "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, SymmetricAlgorithm 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
// 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.
string encryptionMethod = null;
if (Alg is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Alg is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
else if (Alg is Aes)
{
switch (Alg.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// Set the KeyInfo element to specify the
// name of a 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.
edElement.KeyInfo.AddClause(kin);
// 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, 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();
}
}
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)
Return
End Try
' Create a new TripleDES key.
Dim tDESkey As New TripleDESCryptoServiceProvider()
Try
' Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", tDESkey, "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, "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 ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm, ByVal KeyName As String)
' Check the arguments.
If Doc Is Nothing Then
Throw New ArgumentNullException("Doc")
End If
If ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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.
Dim encryptionMethod As String = Nothing
If TypeOf Alg Is TripleDES Then
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
ElseIf TypeOf Alg Is DES Then
encryptionMethod = EncryptedXml.XmlEncDESUrl
ElseIf TypeOf Alg Is Aes Then
Select Case Alg.KeySize
Case 128
encryptionMethod = EncryptedXml.XmlEncAES128Url
Case 192
encryptionMethod = EncryptedXml.XmlEncAES192Url
Case 256
encryptionMethod = EncryptedXml.XmlEncAES256Url
End Select
Else
' Throw an exception if the transform is not in the previous categories
Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
End If
edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)
' Set the KeyInfo element to specify the
' name of a 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.
edElement.KeyInfo.AddClause(kin)
' 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(elementEncrypt, edElement, False)
End Sub
Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm, 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
End Module
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een asymmetrische sleutel. In dit voorbeeld wordt een symmetrische sessiesleutel gemaakt om het document te versleutelen en wordt vervolgens de asymmetrische sleutel gebruikt om een versleutelde versie van de sessiesleutel in te sluiten in het XML-document.
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);
return;
}
// 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");
// Display the encrypted XML to the console.
Console.WriteLine("Encrypted XML:");
Console.WriteLine();
Console.WriteLine(xmlDoc.OuterXml);
xmlDoc.Save("test.xml");
// Decrypt the "creditcard" element.
Decrypt(xmlDoc, rsaKey, "rsaKey");
xmlDoc.Save("test.xml");
// 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 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();
}
}
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)
Return
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 = RSA = RSA.Create()
Try
' Encrypt the "creditcard" element.
Encrypt(xmlDoc, "creditcard", rsaKey, "rsaKey")
' Display the encrypted XML to the console.
Console.WriteLine("Encrypted XML:")
Console.WriteLine()
Console.WriteLine(xmlDoc.OuterXml)
xmlDoc.Save("test.xml")
' Decrypt the "creditcard" element.
Decrypt(xmlDoc, rsaKey, "rsaKey")
' Display the encrypted XML to the console.
Console.WriteLine()
Console.WriteLine("Decrypted XML:")
Console.WriteLine()
Console.WriteLine(xmlDoc.OuterXml)
xmlDoc.Save("test.xml")
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 ElementToEncrypt 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 ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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(elementEncrypt, 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
End Module
Opmerkingen
De geretourneerde bytematrix kan in een <CipherValue> element worden geplaatst. Bij deze methode wordt ervan uitgegaan dat de gegevens die zijn opgegeven in de plaintext parameter een bytematrix zijn die XML-gegevens bevat.
Van toepassing op
EncryptData(XmlElement, SymmetricAlgorithm, Boolean)
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
- Bron:
- EncryptedXml.cs
Hiermee versleutelt u het opgegeven element of de inhoud ervan met behulp van het opgegeven symmetrische algoritme.
public:
cli::array <System::Byte> ^ EncryptData(System::Xml::XmlElement ^ inputElement, System::Security::Cryptography::SymmetricAlgorithm ^ symmetricAlgorithm, bool content);
public byte[] EncryptData(System.Xml.XmlElement inputElement, System.Security.Cryptography.SymmetricAlgorithm symmetricAlgorithm, bool content);
member this.EncryptData : System.Xml.XmlElement * System.Security.Cryptography.SymmetricAlgorithm * bool -> byte[]
Public Function EncryptData (inputElement As XmlElement, symmetricAlgorithm As SymmetricAlgorithm, content As Boolean) As Byte()
Parameters
- inputElement
- XmlElement
Het element of de inhoud ervan die moeten worden versleuteld.
- symmetricAlgorithm
- SymmetricAlgorithm
Het symmetrische algoritme dat moet worden gebruikt voor versleuteling.
- content
- Boolean
true alleen de inhoud van het element te versleutelen; false om het hele element te versleutelen.
Retouren
Een bytematrix die de versleutelde gegevens bevat.
Uitzonderingen
De waarde van de inputElement parameter is null.
– of –
De waarde van de symmetricAlgorithm parameter is null.
Voorbeelden
In het volgende codevoorbeeld ziet u hoe u een XML-document versleutelt met behulp van een symmetrische sleutel. Dit voorbeeld bevat geen belangrijke informatie in het versleutelde XML-document.
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);
return;
}
// 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, SymmetricAlgorithm Alg)
{
// 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
// 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.
string encryptionMethod = null;
if (Alg is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Alg is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
else if (Alg is Aes)
{
switch (Alg.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// 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)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullException("Doc");
if (Alg == null)
throw new ArgumentNullException("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);
}
}
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)
Return
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 ElementToEncrypt As String, ByVal Alg As SymmetricAlgorithm)
' Check the arguments.
If Doc Is Nothing Then
Throw New ArgumentNullException("Doc")
End If
If ElementToEncrypt 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 elementEncrypt As XmlElement = Doc.GetElementsByTagName(ElementToEncrypt)(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(elementEncrypt, 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.
Dim encryptionMethod As String = Nothing
If TypeOf Alg Is TripleDES Then
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl
ElseIf TypeOf Alg Is DES Then
encryptionMethod = EncryptedXml.XmlEncDESUrl
ElseIf TypeOf Alg Is Aes Then
Select Case Alg.KeySize
Case 128
encryptionMethod = EncryptedXml.XmlEncAES128Url
Case 192
encryptionMethod = EncryptedXml.XmlEncAES192Url
Case 256
encryptionMethod = EncryptedXml.XmlEncAES256Url
End Select
Else
' Throw an exception if the transform is not in the previous categories
Throw New CryptographicException("The specified algorithm is not supported for XML Encryption.")
End If
edElement.EncryptionMethod = New EncryptionMethod(encryptionMethod)
' 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(elementEncrypt, edElement, False)
End Sub
Sub Decrypt(ByVal Doc As XmlDocument, ByVal Alg As SymmetricAlgorithm)
' 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
' 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
Opmerkingen
De geretourneerde bytematrixgegevens zijn de waarde van het <CipherValue> element.