XmlDsigBase64Transform Class
Assembly: System.Security (in system.security.dll)
Use the XmlDsigBase64Transform object when you need to sign the raw data associated with the encoded content of an element.
The Uniform Resource Identifier (URI) that describes the XmlDsigBase64Transform object is defined by the XmlDsigBase64TransformUrl field.
For more information about the Base64 decoding transform, see Section 6.6.2 of the XMLDSIG specification, which is available from the W3C at www.w3.org/TR/xmldsig-core/.
The following code example demonstrates how to use members of the XmlDsigBase64Transform class.
Imports System Imports System.IO Imports System.Xml Imports System.Security.Cryptography Imports System.Security.Cryptography.Xml Public Class Form1 Inherits System.Windows.Forms.Form ' Event handler for Run button. Private Sub Button1_Click( _ ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click tbxOutput.Cursor = Cursors.WaitCursor tbxOutput.Text = "" ' Encrypt an XML message EncryptXML(LoadXMLDoc()) ' Using XmlDsigBase64Transform resolving a Uri. Dim baseUri As New Uri("http://www.microsoft.com") Dim relativeUri As String = "msdn" Dim absoluteUri As Uri = ResolveUris(baseUri, relativeUri) ' Reset the cursor and conclude application. WriteLine(vbCrLf + "This sample completed successfully;" + _ " press Exit to continue.") tbxOutput.Cursor = Cursors.Default End Sub ' Encrypt the text in the specified XmlDocument. Private Sub EncryptXML(ByVal xmlDoc As XmlDocument) Dim xmlTransform As New XmlDsigBase64Transform ' Ensure the transform is using the proper algorithm. xmlTransform.Algorithm = SignedXml.XmlDsigBase64TransformUrl ' Retrieve the XML representation of the current transform. Dim xmlInTransform As XmlElement = xmlTransform.GetXml() WriteLine("Xml representation of the current transform: ") WriteLine(xmlInTransform.OuterXml) ' Retrieve the valid input types for the current transform. Dim validInTypes() As Type = xmlTransform.InputTypes ' Verify the xmlTransform can accept the XMLDocument as an ' input type. For i As Int16 = 0 To validInTypes.Length Step 1 If (validInTypes(i).Equals(xmlDoc.GetType())) Then ' Demonstrate loading the entire Xml Document. xmlTransform.LoadInput(xmlDoc) ' This transform is created for demonstration purposes. Dim secondTransform As New XmlDsigBase64Transform Dim classDescription As String = secondTransform.ToString() ' This call does not perform as expected. ' LoadInnerXml is overridden by the XmlDsigBase64Transform ' class, but is stubbed out. secondTransform.LoadInnerXml(xmlDoc.SelectNodes("//.")) Exit For End If Next Dim validOutTypes() As Type = xmlTransform.OutputTypes For i As Int16 = 0 To validOutTypes.Length Step 1 If (validOutTypes(i).equals(GetType(System.IO.Stream))) Then Try Dim streamType As Type = GetType(System.IO.Stream) Dim outputStream As CryptoStream outputStream = CType( _ xmlTransform.GetOutput(streamType), _ CryptoStream) ' Read the CryptoStream into a stream reader. Dim streamReader As New StreamReader(outputStream) ' Read the stream into a string. Dim outputMessage As String = streamReader.ReadToEnd() ' Close the streams. outputStream.Close() streamReader.Close() ' Display to the console the Xml before and after ' encryption. WriteLine("Encoding the following message: " + _ xmlDoc.InnerText) WriteLine("Message encoded: " + outputMessage) Catch ex As Exception WriteLine("Unexpected exception caught: " + _ ex.ToString()) End Try ' Stop cycling through types, exit operation. Exit For Else Dim outputObject As Object = xmlTransform.GetOutput() End If Next End Sub ' Create an XML document with Element and Text nodes. Private Function LoadXMLDoc() As XmlDocument Dim xmlDoc As New XmlDocument Dim mainNode As XmlNode = xmlDoc.CreateNode( _ XmlNodeType.Element, _ "ContosoMessages", _ "http://www.contoso.com") Dim textNode As XmlNode textNode = xmlDoc.CreateTextNode("Some text to encode.") mainNode.AppendChild(textNode) xmlDoc.AppendChild(mainNode) WriteLine("Created the following XML Document for " + _ "transformation: ") WriteLine(xmlDoc.InnerXml) Return xmlDoc End Function ' Resolve the specified base and relative Uri's . Private Function ResolveUris( _ ByVal baseUri As Uri, _ ByVal relativeUri As String) As Uri Dim xmlResolver As New XmlUrlResolver xmlResolver.Credentials = _ System.Net.CredentialCache.DefaultCredentials Dim xmlTransform As New XmlDsigBase64Transform xmlTransform.Resolver = xmlResolver Dim absoluteUri As Uri = _ xmlResolver.ResolveUri(baseUri, relativeUri) If Not absoluteUri Is Nothing Then WriteLine( _ "Resolved the base Uri and relative Uri to the following:") WriteLine(absoluteUri.ToString()) Else WriteLine("Unable to resolve the base Uri and relative Uri") End If Return absoluteUri End Function ' Write message and carriage return to the output textbox. Private Sub WriteLine(ByVal message As String) tbxOutput.AppendText(message + vbCrLf) End Sub ' Event handler for Exit button. Private Sub Button2_Click( _ ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button2.Click Application.Exit() End Sub #Region " Windows Form Designer generated code " Public Sub New() MyBase.New() 'This call is required by the Windows Form Designer. InitializeComponent() 'Add any initialization after the InitializeComponent() call End Sub 'Form overrides dispose to clean up the component list. Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) If disposing Then If Not (components Is Nothing) Then components.Dispose() End If End If MyBase.Dispose(disposing) End Sub 'Required by the Windows Form Designer Private components As System.ComponentModel.IContainer 'NOTE: The following procedure is required by the Windows Form Designer 'It can be modified using the Windows Form Designer. 'Do not modify it using the code editor. Friend WithEvents Panel2 As System.Windows.Forms.Panel Friend WithEvents Panel1 As System.Windows.Forms.Panel Friend WithEvents Button1 As System.Windows.Forms.Button Friend WithEvents Button2 As System.Windows.Forms.Button Friend WithEvents tbxOutput As System.Windows.Forms.RichTextBox <System.Diagnostics.DebuggerStepThrough()> _ Private Sub InitializeComponent() Me.Panel2 = New System.Windows.Forms.Panel Me.Button1 = New System.Windows.Forms.Button Me.Button2 = New System.Windows.Forms.Button Me.Panel1 = New System.Windows.Forms.Panel Me.tbxOutput = New System.Windows.Forms.RichTextBox Me.Panel2.SuspendLayout() Me.Panel1.SuspendLayout() Me.SuspendLayout() ' 'Panel2 ' Me.Panel2.Controls.Add(Me.Button1) Me.Panel2.Controls.Add(Me.Button2) Me.Panel2.Dock = System.Windows.Forms.DockStyle.Bottom Me.Panel2.DockPadding.All = 20 Me.Panel2.Location = New System.Drawing.Point(0, 320) Me.Panel2.Name = "Panel2" Me.Panel2.Size = New System.Drawing.Size(616, 64) Me.Panel2.TabIndex = 1 ' 'Button1 ' Me.Button1.Dock = System.Windows.Forms.DockStyle.Right Me.Button1.Font = New System.Drawing.Font( _ "Microsoft Sans Serif", _ 9.0!, _ System.Drawing.FontStyle.Regular, _ System.Drawing.GraphicsUnit.Point, _ CType(0, Byte)) Me.Button1.Location = New System.Drawing.Point(446, 20) Me.Button1.Name = "Button1" Me.Button1.Size = New System.Drawing.Size(75, 24) Me.Button1.TabIndex = 2 Me.Button1.Text = "&Run" ' 'Button2 ' Me.Button2.Dock = System.Windows.Forms.DockStyle.Right Me.Button2.Font = New System.Drawing.Font( _ "Microsoft Sans Serif", _ 9.0!, _ System.Drawing.FontStyle.Regular, _ System.Drawing.GraphicsUnit.Point, _ CType(0, Byte)) Me.Button2.Location = New System.Drawing.Point(521, 20) Me.Button2.Name = "Button2" Me.Button2.Size = New System.Drawing.Size(75, 24) Me.Button2.TabIndex = 3 Me.Button2.Text = "E&xit" ' 'Panel1 ' Me.Panel1.Controls.Add(Me.tbxOutput) Me.Panel1.Dock = System.Windows.Forms.DockStyle.Fill Me.Panel1.DockPadding.All = 20 Me.Panel1.Location = New System.Drawing.Point(0, 0) Me.Panel1.Name = "Panel1" Me.Panel1.Size = New System.Drawing.Size(616, 320) Me.Panel1.TabIndex = 2 ' 'tbxOutput ' Me.tbxOutput.AccessibleDescription = _ "Displays output from application." Me.tbxOutput.AccessibleName = "Output textbox." Me.tbxOutput.Dock = System.Windows.Forms.DockStyle.Fill Me.tbxOutput.Location = New System.Drawing.Point(20, 20) Me.tbxOutput.Name = "tbxOutput" Me.tbxOutput.Size = New System.Drawing.Size(576, 280) Me.tbxOutput.TabIndex = 1 Me.tbxOutput.Text = "Click the Run button to run the application." ' 'Form1 ' Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15) Me.ClientSize = New System.Drawing.Size(616, 384) Me.Controls.Add(Me.Panel1) Me.Controls.Add(Me.Panel2) Me.Name = "Form1" Me.Text = "XmlDsigBase64Transform" Me.Panel2.ResumeLayout(False) Me.Panel1.ResumeLayout(False) Me.ResumeLayout(False) End Sub #End Region End Class ' ' This sample produces the following output: ' ' Created the following XML Document for transformation: ' <ContosoMessages xmlns="http://www.contoso.com">Some text to encode. ' </ContosoMessages> ' Xml representation of the current transform: ' <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#base64" xmlns= ' "http://www.w3.org/2000/09/xmldsig#" /> ' Encoding the following message: Some text to encode. ' Message encoded: Jmr^ ' Resolved the base Uri and relative Uri to the following: ' http://www.microsoft.com/msdn ' ' This sample completed successfully; press Exit to continue.
import System.*;
import System.IO.*;
import System.Xml.*;
import System.Security.Cryptography.*;
import System.Security.Cryptography.Xml.*;
class Class1
{
/** @attribute STAThread()
*/
public static void main(String[] args)
{
// Encrypt an XML message
EncryptXML(LoadXMLDoc());
// Using XmlDsigBase64Transform resolving a Uri.
Uri baseUri = new Uri("http://www.microsoft.com");
String relativeUri = "msdn";
Uri absoluteUri = ResolveUris(baseUri, relativeUri);
Console.WriteLine("This sample completed successfully; "
+ "press Enter to exit.");
Console.ReadLine();
} //main
// Encrypt the text in the specified XmlDocument.
private static void EncryptXML(XmlDocument xmlDoc)
{
XmlDsigBase64Transform xmlTransform = new XmlDsigBase64Transform();
// Ensure the transform is using the proper algorithm.
xmlTransform.set_Algorithm(SignedXml.XmlDsigBase64TransformUrl);
// Retrieve the XML representation of the current transform.
XmlElement xmlInTransform = xmlTransform.GetXml();
Console.WriteLine("Xml representation of the current transform: ");
Console.WriteLine(xmlInTransform.get_OuterXml());
// Retrieve the valid input types for the current transform.
Type validInTypes[] = xmlTransform.get_InputTypes();
// Verify the xmlTransform can accept the XMLDocument as an
// input type.
for (int i = 0; i < validInTypes.get_Length(); i++) {
if (validInTypes.get_Item(i).Equals(xmlDoc.GetType())) {
// Demonstrate loading the entire Xml Document.
xmlTransform.LoadInput(xmlDoc);
// This transform is created for demonstration purposes.
XmlDsigBase64Transform secondTransform
= new XmlDsigBase64Transform();
String classDescription = secondTransform.ToString();
// This call does not perform as expected.
// LoadInnerXml is overridden by the XmlDsigBase64Transform
// class, but is stubbed out.
secondTransform.LoadInnerXml(xmlDoc.SelectNodes("//."));
break;
}
}
Type validOutTypes[] = xmlTransform.get_OutputTypes();
for (int i = 0; i < validOutTypes.get_Length(); i++) {
if (validOutTypes.get_Item(i).Equals(
System.IO.Stream.class.ToType())) {
try {
Type streamType = System.IO.Stream.class.ToType();
CryptoStream outputStream = (CryptoStream)xmlTransform.
GetOutput(streamType);
// Read the CryptoStream into a stream reader.
StreamReader streamReader = new StreamReader(outputStream);
// Read the stream into a string.
String outputMessage = streamReader.ReadToEnd();
// Close the streams.
outputStream.Close();
streamReader.Close();
// Display to the console the Xml before and after
// encryption.
Console.WriteLine("Encoding the following message: "
+ xmlDoc.get_InnerText());
Console.WriteLine("Message encoded: " + outputMessage);
}
catch (System.Exception ex) {
Console.WriteLine("Unexpected exception caught: "
+ ex.ToString());
}
break;
}
else {
Object outputObject = xmlTransform.GetOutput();
}
}
} //EncryptXML
// Create an XML document with Element and Text nodes.
private static XmlDocument LoadXMLDoc()
{
XmlDocument xmlDoc = new XmlDocument();
XmlNode mainNode = xmlDoc.CreateNode(XmlNodeType.Element,
"ContosoMessages", "http://www.contoso.com");
XmlNode textNode = xmlDoc.CreateTextNode("Some text to encode.");
mainNode.AppendChild(textNode);
xmlDoc.AppendChild(mainNode);
Console.WriteLine("Created the following XML Document for "
+ "transformation: ");
Console.WriteLine(xmlDoc.get_InnerXml());
return xmlDoc;
} //LoadXMLDoc
// Resolve the specified base and relative Uri's .
private static Uri ResolveUris(Uri baseUri, String relativeUri)
{
XmlUrlResolver xmlResolver = new XmlUrlResolver();
xmlResolver.set_Credentials(System.Net.CredentialCache.
get_DefaultCredentials());
XmlDsigBase64Transform xmlTransform = new XmlDsigBase64Transform();
xmlTransform.set_Resolver(xmlResolver);
Uri absoluteUri = xmlResolver.ResolveUri(baseUri, relativeUri);
if (absoluteUri != null) {
Console.WriteLine("Resolved the base Uri and relative "
+ "Uri to the following:");
Console.WriteLine(absoluteUri.ToString());
}
else {
Console.WriteLine("Unable to resolve the base "
+ "Uri and relative Uri");
}
return absoluteUri;
} //ResolveUris
} //Class1
//
// This sample produces the following output:
//
// Created the following XML Document for transformation:
// <ContosoMessages xmlns="http://www.contoso.com">Some text to encode.
// </ContosoMessages>
// Xml representation of the current transform:
// <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#base64" xmlns=
// "http://www.w3.org/2000/09/xmldsig#" />
// Encoding the following message: Some text to encode.
// Message encoded: Jmr^
// Resolved the base Uri and relative Uri to the following:
// http://www.microsoft.com/msdn
// This sample completed successfully; press Enter to exit.
System.Security.Cryptography.Xml.Transform
System.Security.Cryptography.Xml.XmlDsigBase64Transform
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
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.