XmlDsigC14NTransform Class

Definition

Represents the C14N XML canonicalization transform for a digital signature as defined by the World Wide Web Consortium (W3C), without comments.

public ref class XmlDsigC14NTransform : System::Security::Cryptography::Xml::Transform
public class XmlDsigC14NTransform : System.Security.Cryptography.Xml.Transform
type XmlDsigC14NTransform = class
    inherit Transform
Public Class XmlDsigC14NTransform
Inherits Transform
Inheritance
XmlDsigC14NTransform
Derived

Examples

This section contains two code examples. The first example demonstrates how to sign non-XML data using a detached signature. Example #1 creates a signature of www.microsoft.com in an XML file and then verifies the file. The second example demonstrates how to call members of the XmlDsigC14NTransform class.

Example #1

//
// This example signs a file specified by a URI 
// using a detached signature. It then verifies  
// the signed XML.
//
#using <System.Security.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
using namespace System::Text;
using namespace System::Xml;

// Sign an XML file and save the signature in a new file.
void SignDetachedResource( String^ URIString, String^ XmlSigFileName, RSA^ Key )
{
   
   // Create a SignedXml object.
   SignedXml^ signedXml = gcnew SignedXml;
   
   // Assign the key to the SignedXml object.
   signedXml->SigningKey = Key;
   
   // Create a reference to be signed.
   Reference^ reference = gcnew Reference;
   
   // Add the passed URI to the reference object.
   reference->Uri = URIString;

   // Add the reference to the SignedXml object.
   signedXml->AddReference( reference );
   
   // Add an RSAKeyValue KeyInfo (optional; helps recipient find key to validate).
   KeyInfo^ keyInfo = gcnew KeyInfo;
   keyInfo->AddClause( gcnew RSAKeyValue( safe_cast<RSA^>(Key) ) );
   signedXml->KeyInfo = keyInfo;
   
   // Compute the signature.
   signedXml->ComputeSignature();
   
   // Get the XML representation of the signature and save
   // it to an XmlElement object.
   XmlElement^ xmlDigitalSignature = signedXml->GetXml();
   
   // Save the signed XML document to a file specified
   // using the passed string.
   XmlTextWriter^ xmltw = gcnew XmlTextWriter( XmlSigFileName,gcnew UTF8Encoding( false ) );
   xmlDigitalSignature->WriteTo( xmltw );
   xmltw->Close();
}


// Verify the signature of an XML file and return the result.
Boolean VerifyDetachedSignature( String^ XmlSigFileName )
{
   
   // Create a new XML document.
   XmlDocument^ xmlDocument = gcnew XmlDocument;
   
   // Load the passed XML file into the document.
   xmlDocument->Load( XmlSigFileName );
   
   // Create a new SignedXMl object.
   SignedXml^ signedXml = gcnew SignedXml;
   
   // Find the "Signature" node and create a new
   // XmlNodeList object.
   XmlNodeList^ nodeList = xmlDocument->GetElementsByTagName( "Signature" );
   
   // Load the signature node.
   signedXml->LoadXml( safe_cast<XmlElement^>(nodeList->Item( 0 )) );
   
   // Check the signature and return the result.
   return signedXml->CheckSignature();
}



[STAThread]
int main()
{
   array<String^>^args = Environment::GetCommandLineArgs();
   
   // The URI to sign.
   String^ resourceToSign = "http://www.microsoft.com";
   
   // The name of the file to which to save the XML signature.
   String^ XmlFileName = "xmldsig.xml";
   try
   {
      
      // Generate a signing key.
      RSA^ Key = RSA::Create();
      Console::WriteLine( "Signing: {0}", resourceToSign );
      
      // Sign the detached resourceand save the signature in an XML file.
      SignDetachedResource( resourceToSign, XmlFileName, Key );
      Console::WriteLine( "XML signature was successfully computed and saved to {0}.", XmlFileName );
      
      // Verify the signature of the signed XML.
      Console::WriteLine( "Verifying signature..." );
      
      //Verify the XML signature in the XML file.
      bool result = VerifyDetachedSignature( XmlFileName );
      
      // Display the results of the signature verification to 
      // the console.
      if ( result )
      {
         Console::WriteLine( "The XML signature is valid." );
      }
      else
      {
         Console::WriteLine( "The XML signature is not valid." );
      }
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}
//
// This example signs a file specified by a URI 
// using a detached signature. It then verifies  
// the signed XML.
//

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Text;
using System.Xml;

class XMLDSIGDetached
{
    
    [STAThread]
    static void Main(string[] args)
    {
    // The URI to sign.
        string resourceToSign = "http://www.microsoft.com";
        
        // The name of the file to which to save the XML signature.
        string XmlFileName = "xmldsig.xml";

        try
        {

            // Generate a signing key.
            RSA Key = RSA.Create();

            Console.WriteLine("Signing: {0}", resourceToSign);

            // Sign the detached resourceand save the signature in an XML file.
            SignDetachedResource(resourceToSign, XmlFileName, Key);

            Console.WriteLine("XML signature was successfully computed and saved to {0}.", XmlFileName);

            // Verify the signature of the signed XML.
            Console.WriteLine("Verifying signature...");

            //Verify the XML signature in the XML file.
            bool result = VerifyDetachedSignature(XmlFileName);

            // Display the results of the signature verification to 
            // the console.
            if(result)
            {
                Console.WriteLine("The XML signature is valid.");
            }
            else
            {
                Console.WriteLine("The XML signature is not valid.");
            }
        }
        catch(CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }

    // Sign an XML file and save the signature in a new file.
    public static void SignDetachedResource(string URIString, string XmlSigFileName, RSA Key)
    {
        // Create a SignedXml object.
        SignedXml signedXml = new SignedXml();

        // Assign the key to the SignedXml object.
        signedXml.SigningKey = Key;

        // Create a reference to be signed.
        Reference reference = new Reference();

        // Add the passed URI to the reference object.
        reference.Uri = URIString;
        
        // Add the reference to the SignedXml object.
        signedXml.AddReference(reference);

        // Add an RSAKeyValue KeyInfo (optional; helps recipient find key to validate).
        KeyInfo keyInfo = new KeyInfo();
        keyInfo.AddClause(new RSAKeyValue((RSA)Key));	
        signedXml.KeyInfo = keyInfo;

        // Compute the signature.
        signedXml.ComputeSignature();

        // Get the XML representation of the signature and save
        // it to an XmlElement object.
        XmlElement xmlDigitalSignature = signedXml.GetXml();

        // Save the signed XML document to a file specified
        // using the passed string.
        XmlTextWriter xmltw = new XmlTextWriter(XmlSigFileName, new UTF8Encoding(false));
        xmlDigitalSignature.WriteTo(xmltw);
        xmltw.Close();
    }
    // Verify the signature of an XML file and return the result.
    public static Boolean VerifyDetachedSignature(string XmlSigFileName)
    {	
        // Create a new XML document.
        XmlDocument xmlDocument = new XmlDocument();

        // Load the passed XML file into the document.
        xmlDocument.Load(XmlSigFileName);
    
        // Create a new SignedXMl object.
        SignedXml signedXml = new SignedXml();

        // Find the "Signature" node and create a new
        // XmlNodeList object.
        XmlNodeList nodeList = xmlDocument.GetElementsByTagName("Signature");

        // Load the signature node.
        signedXml.LoadXml((XmlElement)nodeList[0]);

        // Check the signature and return the result.
        return signedXml.CheckSignature();
    }
}
'
' This example signs a file specified by a URI 
' using a detached signature. It then verifies  
' the signed XML.
'
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.Text
Imports System.Xml


Class XMLDSIGDetached

   
   <STAThread()>  _
   Overloads Shared Sub Main(args() As String)
      ' The URI to sign.
      Dim resourceToSign As String = "http://www.microsoft.com"
      
      ' The name of the file to which to save the XML signature.
      Dim XmlFileName As String = "xmldsig.xml"
      
      Try
         
         ' Generate a signing key.
         Dim Key As RSA = RSA.Create()
         
         Console.WriteLine("Signing: {0}", resourceToSign)
         
         ' Sign the detached resourceand save the signature in an XML file.
         SignDetachedResource(resourceToSign, XmlFileName, Key)
         
         Console.WriteLine("XML signature was successfully computed and saved to {0}.", XmlFileName)
         
         ' Verify the signature of the signed XML.
         Console.WriteLine("Verifying signature...")
         
         'Verify the XML signature in the XML file.
         Dim result As Boolean = VerifyDetachedSignature(XmlFileName)
         
         ' Display the results of the signature verification to 
         ' the console.
         If result Then
            Console.WriteLine("The XML signature is valid.")
         Else
            Console.WriteLine("The XML signature is not valid.")
         End If
      Catch e As CryptographicException
         Console.WriteLine(e.Message)
      End Try 
   End Sub 
   
   
   ' Sign an XML file and save the signature in a new file.
   Public Shared Sub SignDetachedResource(URIString As String, XmlSigFileName As String, Key As RSA)
      ' Create a SignedXml object.
      Dim signedXml As New SignedXml()
      
      ' Assign the key to the SignedXml object.
      signedXml.SigningKey = Key
      
      ' Create a reference to be signed.
      Dim reference As New Reference()
      
      ' Add the passed URI to the reference object.
      reference.Uri = URIString
      
      ' Add the reference to the SignedXml object.
      signedXml.AddReference(reference)
      
      ' Add an RSAKeyValue KeyInfo (optional; helps recipient find key to validate).
      Dim keyInfo As New KeyInfo()
      keyInfo.AddClause(New RSAKeyValue(CType(Key, RSA)))
      signedXml.KeyInfo = keyInfo
      
      ' Compute the signature.
      signedXml.ComputeSignature()
      
      ' Get the XML representation of the signature and save
      ' it to an XmlElement object.
      Dim xmlDigitalSignature As XmlElement = signedXml.GetXml()
      
      ' Save the signed XML document to a file specified
      ' using the passed string.
      Dim xmltw As New XmlTextWriter(XmlSigFileName, New UTF8Encoding(False))
      xmlDigitalSignature.WriteTo(xmltw)
      xmltw.Close()
   End Sub 
 
   ' Verify the signature of an XML file and return the result.
   Public Shared Function VerifyDetachedSignature(XmlSigFileName As String) As [Boolean]
      ' Create a new XML document.
      Dim xmlDocument As New XmlDocument()
      
      ' Load the passed XML file into the document.
      xmlDocument.Load(XmlSigFileName)
      
      ' Create a new SignedXMl object.
      Dim signedXml As New SignedXml()
      
      ' Find the "Signature" node and create a new
      ' XmlNodeList object.
      Dim nodeList As XmlNodeList = xmlDocument.GetElementsByTagName("Signature")
      
      ' Load the signature node.
      signedXml.LoadXml(CType(nodeList(0), XmlElement))
      
      ' Check the signature and return the result.
      Return signedXml.CheckSignature()
   End Function
End Class

Example #2

#using <System.dll>
#using <System.Xml.dll>
#using <System.Security.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
using namespace System::Security::Cryptography::X509Certificates;

ref class Class1
{
private:
   static String^ Certificate = L"..\\..\\my509.cer";

public:
   [STAThread]
   static void Main()
   {
      // Encrypt an XML message
      XmlDocument^ productsXml = LoadProducts();
      ShowTransformProperties( productsXml );
      SignDocument( productsXml );
      ShowTransformProperties( productsXml );
      
      // Use XmlDsigC14NTransform to resolve a Uri.
      Uri^ baseUri = gcnew Uri( L"http://www.contoso.com" );
      String^ relativeUri = L"xml";
      Uri^ absoluteUri = ResolveUris( baseUri, relativeUri );
      Console::WriteLine( L"This sample completed successfully; "
         L"press Enter to exit." );
      Console::ReadLine();
   }


private:
   // Encrypt the text in the specified XmlDocument.
   static void ShowTransformProperties( XmlDocument^ xmlDoc )
   {
      XmlDsigC14NTransform^ xmlTransform =
         gcnew XmlDsigC14NTransform( true );

      // Ensure the transform is using the appropriate algorithm.
      xmlTransform->Algorithm =
         SignedXml::XmlDsigExcC14NTransformUrl;

      // Retrieve the XML representation of the current transform.
      XmlElement^ xmlInTransform = xmlTransform->GetXml();

      Console::WriteLine( L"\nXml representation of the current transform: " );
      Console::WriteLine( xmlInTransform->OuterXml );
      
      // Retrieve the valid input types for the current transform.
      array<Type^>^validInTypes = xmlTransform->InputTypes;

      // Verify the xmlTransform can accept the XMLDocument as an
      // input type.
      for ( int i = 0; i < validInTypes->Length; i++ )
      {
         if ( validInTypes[ i ] == xmlDoc->GetType() )
         {
            // Load the document into the transfrom.
            xmlTransform->LoadInput( xmlDoc );

            XmlDsigC14NTransform^ secondTransform = gcnew XmlDsigC14NTransform;

            String^ classDescription = secondTransform->ToString();

            // This call does not perform as expected.
            // This transform does not contain inner XML elements
            secondTransform->LoadInnerXml( xmlDoc->SelectNodes( L"//." ) );

            break;
         }
      }
      
      array<Type^>^validOutTypes = xmlTransform->OutputTypes;

      for ( int i = 0; i < validOutTypes->Length; i++ )
      {
         if ( validOutTypes[ i ] == System::IO::Stream::typeid )
         {
            try
            {
               
               Type^ streamType = System::IO::Stream::typeid;
               MemoryStream^ outputStream = static_cast<MemoryStream^>(
                  xmlTransform->GetOutput( streamType ));

               // Read the CryptoStream into a stream reader.
               StreamReader^ streamReader =
                  gcnew 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( L"Encoding the following xml: {0}",
                  xmlDoc->OuterXml );
               Console::WriteLine( L"Message encoded: {0}", outputMessage );
            }
            catch ( Exception^ ex ) 
            {
               Console::WriteLine( L"Unexpected exception caught: {0}", ex );
            }

            break;
         }
         else
         {
            Object^ outputObject = xmlTransform->GetOutput();
         }
      }
   }

   // Create an XML document describing various products.
   static XmlDocument^ LoadProducts()
   {
      XmlDocument^ xmlDoc = gcnew XmlDocument;
      String^ contosoProducts = L"<PRODUCTS>";
      contosoProducts = String::Concat( contosoProducts,
         L"<PRODUCT><ID>123</ID>");
      contosoProducts = String::Concat( contosoProducts,
         L"<DESCRIPTION>Router</DESCRIPTION></PRODUCT>");
      contosoProducts = String::Concat( contosoProducts,
         L"<PRODUCT><ID>456</ID>");
       contosoProducts = String::Concat( contosoProducts,
        L"<DESCRIPTION>Keyboard</DESCRIPTION></PRODUCT>");
      
      // Include a comment to test the comments feature of the transform.
      contosoProducts = String::Concat( contosoProducts,
         L"<!--Comments are included in the transform-->" );
      
      // Include the CDATA tag to test the transform results.
      contosoProducts = String::Concat( contosoProducts,
         L"<PARTNER_URL><![CDATA['http:\\\\www.contoso.com" );
      contosoProducts = String::Concat( contosoProducts,
         L"\\partner.asp?h1=en&h2=cr']]></PARTNER_URL>" );
      contosoProducts = String::Concat( contosoProducts,
         L"</PRODUCTS>" );

      xmlDoc->LoadXml( contosoProducts );
      return xmlDoc;
   }

   // Create a signature and add it to the specified document.
   static void SignDocument( XmlDocument^ xmlDoc )
   {
      // Generate a signing key.
      RSA^ Key = RSA::Create();
      
      // Create a SignedXml object.
      SignedXml^ signedXml = gcnew SignedXml( xmlDoc );
      
      // Add the key to the SignedXml document.
      signedXml->SigningKey = Key;
      
      // Create a reference to be signed.
      Reference^ reference = gcnew Reference;
      reference->Uri = L"";
      
      // Add an enveloped transformation to the reference.
      reference->AddTransform( gcnew XmlDsigC14NTransform );
      
      // Add the reference to the SignedXml object.
      signedXml->AddReference( reference );
      try
      {
         // Create a new KeyInfo object.
         KeyInfo^ keyInfo = gcnew KeyInfo;
         
         // Load the X509 certificate.
         X509Certificate^ MSCert =
            X509Certificate::CreateFromCertFile( Certificate );
         
         // Load the certificate into a KeyInfoX509Data object
         // and add it to the KeyInfo object.
         keyInfo->AddClause( gcnew KeyInfoX509Data( MSCert ) );
         
         // Add the KeyInfo object to the SignedXml object.
         signedXml->KeyInfo = keyInfo;
      }
      catch ( FileNotFoundException^ ) 
      {
         Console::WriteLine( L"Unable to locate the following file: {0}",
            Certificate );
      }
      catch ( CryptographicException^ ex ) 
      {
         Console::WriteLine( L"Unexpected exception caught while creating "
         L"the certificate:{0}", ex );
      }
      
      // Compute the signature.
      signedXml->ComputeSignature();
      
      // Add the signature branch to the original tree so it is enveloped.
      xmlDoc->DocumentElement->AppendChild( signedXml->GetXml() );
   }

   // Resolve the specified base and relative Uri's .
   static Uri^ ResolveUris( Uri^ baseUri, String^ relativeUri )
   {
      XmlUrlResolver^ xmlResolver = gcnew XmlUrlResolver;
      xmlResolver->Credentials =
         System::Net::CredentialCache::DefaultCredentials;
      XmlDsigC14NTransform^ xmlTransform = gcnew XmlDsigC14NTransform;
      xmlTransform->Resolver = xmlResolver;

      Uri^ absoluteUri = xmlResolver->ResolveUri( baseUri, relativeUri );
      if ( absoluteUri != nullptr )
      {
         Console::WriteLine(
            L"\nResolved the base Uri and relative Uri to the following:" );
         Console::WriteLine( absoluteUri );
      }
      else
      {
         Console::WriteLine( L"Unable to resolve the base Uri and relative Uri" );
      }

      return absoluteUri;
   }
};

int main()
{
   Class1::Main();
}

//
// This sample produces the following output:
//
// Xml representation of the current transform:
// <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmln
// s="http://www.w3.org/2000/09/xmldsig#" />
// Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// ><![CDATA['http:\\www.contoso.com\partner.asp?h1=en&h2=cr']]></PARTNER_URL>
// </PRODUCTS>Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// >'http:\\www.contoso.com\partner.asp?h1=en&h2=cr'</PARTNER_URL></PRODUC
// TS>
// Xml representation of the current transform:
// <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmln
// s="http://www.w3.org/2000/09/xmldsig#" />
// Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// ><![CDATA['http:\\www.contoso.com\partner.asp?h1=en&h2=cr']]></PARTNER_URL>
// <Signature xmlns="http://www.w3.org/2000/09/xmldsig#"><SignedInfo><Canonica
// lizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"
// /><SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" /
// ><Reference URI=""><Transforms><Transform Algorithm="http://www.w3.org/TR/2
// 001/REC-xml-c14n-20010315" /></Transforms><DigestMethod Algorithm="http://w
// ww.w3.org/2000/09/xmldsig#sha1" /><DigestValue>BFN2s0/NA2NGgb/R0mvfnNM0Ito=
// </DigestValue></Reference></SignedInfo><SignatureValue>vSfZUG5xHuNxzOSEbQjN
// dtEt1D+O7I1LTJ13RrwLaJSfQPrdT/s8IeaA+idw2f2WGuGrdqMJUddpE4GxfK61HmPQ6S7lBG+
// +ND+YaUYf2AtTRs3SnToXQQrARa/pHVjsKxYHR/9tjy6maHBwxjgjFQABvYZu0gZHYRuXvvfxv0
// 8=</SignatureValue><KeyInfo><X509Data xmlns="http://www.w3.org/2000/09/xmld
// sig#"><X509Certificate>MIICCzCCAXSgAwIBAgIQ5eVQY8pRZ5xBF2WLkYPjijANBgkqhkiG
// 9w0BAQQFADAbMRkwFwYDVQQDExBHcmVnc0NlcnRpZmljYXRlMB4XDTAzMDkxNzIzMzU0N1oXDTM
// 5MTIzMTIzNTk1OVowGzEZMBcGA1UEAxMQR3JlZ3NDZXJ0aWZpY2F0ZTCBnzANBgkqhkiG9w0BAQ
// EFAAOBjQAwgYkCgYEAmFJ4v7rS3BYTXgVW9PgBFfTYAcB/m9mOFCmUrrChcBpoEtu/tSESlNfEH
// pECIdqg9vUrCNSkY08HRn3ueNeBSnSpssWd8/XoOboWLh1nd+79Y5uZd1WOJI4s0XM0MegZgCoJ
// cEEhpxCd/HOPIQvEsbpN/DuFiovZLo+Ek3hHoxMCAwEAAaNQME4wTAYDVR0BBEUwQ4AQaCb19dl
// yf/zSxPVYQZY9AKEdMBsxGTAXBgNVBAMTEEdyZWdzQ2VydGlmaWNhdGWCEOXlUGPKUWecQRdli5
// GD44owDQYJKoZIhvcNAQEEBQADgYEAZuZaFDGDJogh7FuT0hfaMAVlRONv6wWVBJVV++eUo38Xu
// RfJ5nNJ0UnhiV2sEtLobYBPEIrNhuk8skdU0AHgx4ILiA4rR96ifWwxtrFQF+h+DL2ZB7xhwcOJ
// +Pa7IC4wIaEp/oBmmX+JHSzfQt6/If4ohwikfxfljKMyIcMlwl4=</X509Certificate></X50
// 9Data></KeyInfo></Signature></PRODUCTS>
//
// Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Router</DESCRI
// PTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRIPTION></P
// RODUCT><!--Comments are included in the transform--><PARTNER_URL>'http:\\ww
// w.contoso.com\partner.asp?h1=en&h2=cr'</PARTNER_URL><Signature><SignedI
// nfo><CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c1
// 4n-20010315"></CanonicalizationMethod><SignatureMethod Algorithm="http://ww
// w.w3.org/2000/09/xmldsig#rsa-sha1"></SignatureMethod><Reference URI=""><Tra
// nsforms><Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-200103
// 15"></Transform></Transforms><DigestMethod Algorithm="http://www.w3.org/200
// 0/09/xmldsig#sha1"></DigestMethod><DigestValue>BFN2s0/NA2NGgb/R0mvfnNM0Ito=
// </DigestValue></Reference></SignedInfo><SignatureValue>vSfZUG5xHuNxzOSEbQjN
// dtEt1D+O7I1LTJ13RrwLaJSfQPrdT/s8IeaA+idw2f2WGuGrdqMJUddpE4GxfK61HmPQ6S7lBG+
// +ND+YaUYf2AtTRs3SnToXQQrARa/pHVjsKxYHR/9tjy6maHBwxjgjFQABvYZu0gZHYRuXvvfxv0
// 8=</SignatureValue><KeyInfo><X509Data xmlns="http://www.w3.org/2000/09/xmld
// sig#"><X509Certificate>MIICCzCCAXSgAwIBAgIQ5eVQY8pRZ5xBF2WLkYPjijANBgkqhkiG
// 9w0BAQQFADAbMRkwFwYDVQQDExBHcmVnc0NlcnRpZmljYXRlMB4XDTAzMDkxNzIzMzU0N1oXDTM
// 5MTIzMTIzNTk1OVowGzEZMBcGA1UEAxMQR3JlZ3NDZXJ0aWZpY2F0ZTCBnzANBgkqhkiG9w0BAQ
// EFAAOBjQAwgYkCgYEAmFJ4v7rS3BYTXgVW9PgBFfTYAcB/m9mOFCmUrrChcBpoEtu/tSESlNfEH
// pECIdqg9vUrCNSkY08HRn3ueNeBSnSpssWd8/XoOboWLh1nd+79Y5uZd1WOJI4s0XM0MegZgCoJ
// cEEhpxCd/HOPIQvEsbpN/DuFiovZLo+Ek3hHoxMCAwEAAaNQME4wTAYDVR0BBEUwQ4AQaCb19dl
// yf/zSxPVYQZY9AKEdMBsxGTAXBgNVBAMTEEdyZWdzQ2VydGlmaWNhdGWCEOXlUGPKUWecQRdli5
// GD44owDQYJKoZIhvcNAQEEBQADgYEAZuZaFDGDJogh7FuT0hfaMAVlRONv6wWVBJVV++eUo38Xu
// RfJ5nNJ0UnhiV2sEtLobYBPEIrNhuk8skdU0AHgx4ILiA4rR96ifWwxtrFQF+h+DL2ZB7xhwcOJ
// +Pa7IC4wIaEp/oBmmX+JHSzfQt6/If4ohwikfxfljKMyIcMlwl4=</X509Certificate></X50
// 9Data></KeyInfo></Signature></PRODUCTS>
//
// Resolved the base Uri and relative Uri to the following:
// http://www.contoso.com/xml
// This sample completed successfully; press Enter to exit.
using System;
using System.IO;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Security.Cryptography.X509Certificates;

class Class1
{
    private static string Certificate =  "..\\..\\my509.cer";

    [STAThread]
    static void Main(string[] args)
    {
        // Encrypt an XML message
        XmlDocument productsXml = LoadProducts();
        ShowTransformProperties(productsXml);

        SignDocument(ref productsXml);
        ShowTransformProperties(productsXml);

        // Use XmlDsigC14NTransform to resolve a Uri.
        Uri baseUri = new Uri("http://www.contoso.com");
        string relativeUri = "xml";
        Uri absoluteUri = ResolveUris(baseUri, relativeUri);

        Console.WriteLine("This sample completed successfully; " +
            "press Enter to exit.");
        Console.ReadLine();
    }

    // Encrypt the text in the specified XmlDocument.
    private static void ShowTransformProperties(XmlDocument xmlDoc)
    {
        XmlDsigC14NTransform xmlTransform = 
            new XmlDsigC14NTransform(true);

        // Ensure the transform is using the appropriate algorithm.
        xmlTransform.Algorithm =
            SignedXml.XmlDsigExcC14NTransformUrl;

        // Retrieve the XML representation of the current transform.
        XmlElement xmlInTransform = xmlTransform.GetXml();

        Console.WriteLine("\nXml representation of the current transform: ");
        Console.WriteLine(xmlInTransform.OuterXml);

        // Retrieve the valid input types for the current transform.
        Type[] validInTypes = xmlTransform.InputTypes;

        // Verify the xmlTransform can accept the XMLDocument as an
        // input type.
        for (int i=0; i<validInTypes.Length; i++)
        {
            if (validInTypes[i] == xmlDoc.GetType())
            {
                // Load the document into the transfrom.
                xmlTransform.LoadInput(xmlDoc);

                XmlDsigC14NTransform secondTransform = 
                    new XmlDsigC14NTransform();

                string classDescription = secondTransform.ToString();

                // This call does not perform as expected.
                // This transform does not contain inner XML elements
                secondTransform.LoadInnerXml(xmlDoc.SelectNodes("//."));

                break;
            }
        }

        Type[] validOutTypes = xmlTransform.OutputTypes;

        for (int i=0; i<validOutTypes.Length;i++)
        {
            if (validOutTypes[i] == typeof(System.IO.Stream))
            {
                try 
                {
                    Type streamType = typeof(System.IO.Stream);
                    MemoryStream outputStream = (MemoryStream) 
                        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 xml: " +
                        xmlDoc.OuterXml);
                    Console.WriteLine("Message encoded: " + outputMessage);
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Unexpected exception caught: " +
                        ex.ToString());
                }

                break;
            }
            else
            {
                object outputObject = xmlTransform.GetOutput();
            }
        }
    }

    // Create an XML document describing various products.
    private static XmlDocument LoadProducts()
    {
        XmlDocument xmlDoc = new XmlDocument();

        string contosoProducts = "<PRODUCTS>";
        contosoProducts += "<PRODUCT><ID>123</ID>";
        contosoProducts += "<DESCRIPTION>Router</DESCRIPTION></PRODUCT>";
        contosoProducts += "<PRODUCT><ID>456</ID>";
        contosoProducts += "<DESCRIPTION>Keyboard</DESCRIPTION></PRODUCT>";

        // Include a comment to test the comments feature of the transform.
        contosoProducts += "<!--Comments are included in the transform-->";

        // Include the CDATA tag to test the transform results.
        contosoProducts += "<PARTNER_URL><![CDATA['http:\\\\www.contoso.com";
        contosoProducts += "\\partner.asp?h1=en&h2=cr']]></PARTNER_URL>";
        contosoProducts += "</PRODUCTS>";

        xmlDoc.LoadXml(contosoProducts);
        return xmlDoc;
    }

    // Create a signature and add it to the specified document.
    private static void SignDocument(ref XmlDocument xmlDoc)
    {
        // Generate a signing key.
        RSA Key = RSA.Create();

        // Create a SignedXml object.
        SignedXml signedXml = new SignedXml(xmlDoc);

        // Add the key to the SignedXml document. 
        signedXml.SigningKey = Key;

        // Create a reference to be signed.
        Reference reference = new Reference();
        reference.Uri = "";

        // Add an enveloped transformation to the reference.
        reference.AddTransform(new XmlDsigC14NTransform());

        // Add the reference to the SignedXml object.
        signedXml.AddReference(reference);

        try 
        {
            // Create a new KeyInfo object.
            KeyInfo keyInfo = new KeyInfo();

            // Load the X509 certificate.
            X509Certificate MSCert =
                X509Certificate.CreateFromCertFile(Certificate);

            // Load the certificate into a KeyInfoX509Data object
            // and add it to the KeyInfo object.
            keyInfo.AddClause(new KeyInfoX509Data(MSCert));

            // Add the KeyInfo object to the SignedXml object.
            signedXml.KeyInfo = keyInfo;
        }
        catch (FileNotFoundException)
        {
            Console.WriteLine("Unable to locate the following file: " + 
                Certificate);
        }
        catch (CryptographicException ex)
        {
            Console.WriteLine("Unexpected exception caught whild creating " +
                "the certificate:" + ex.ToString());
        }

        // Compute the signature.
        signedXml.ComputeSignature();

        // Add the signature branch to the original tree so it is enveloped.
        xmlDoc.DocumentElement.AppendChild(signedXml.GetXml());
    }

    // Resolve the specified base and relative Uri's .
    private static Uri ResolveUris(Uri baseUri, string relativeUri)
    {
        XmlUrlResolver xmlResolver = new XmlUrlResolver();
        xmlResolver.Credentials = 
            System.Net.CredentialCache.DefaultCredentials;

        XmlDsigC14NTransform xmlTransform =
            new XmlDsigC14NTransform();
        xmlTransform.Resolver = xmlResolver;

        Uri absoluteUri = xmlResolver.ResolveUri(baseUri, relativeUri);

        if (absoluteUri != null)
        {
            Console.WriteLine(
                "\nResolved 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;
    }
}
//
// This sample produces the following output:
//
// Xml representation of the current transform:
// <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmln
// s="http://www.w3.org/2000/09/xmldsig#" />
// Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// ><![CDATA['http:\\www.contoso.com\partner.asp?h1=en&h2=cr']]></PARTNER_URL>
// </PRODUCTS>Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// >'http:\\www.contoso.com\partner.asp?h1=en&h2=cr'</PARTNER_URL></PRODUC
// TS>

// Xml representation of the current transform:
// <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmln
// s="http://www.w3.org/2000/09/xmldsig#" />
// Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rou
// ter</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESC
// RIPTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL
// ><![CDATA['http:\\www.contoso.com\partner.asp?h1=en&h2=cr']]></PARTNER_URL>
// <Signature xmlns="http://www.w3.org/2000/09/xmldsig#"><SignedInfo><Canonica
// lizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" 
// /><SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" /
// ><Reference URI=""><Transforms><Transform Algorithm="http://www.w3.org/TR/2
// 001/REC-xml-c14n-20010315" /></Transforms><DigestMethod Algorithm="http://w
// ww.w3.org/2000/09/xmldsig#sha1" /><DigestValue>BFN2s0/NA2NGgb/R0mvfnNM0Ito=
// </DigestValue></Reference></SignedInfo><SignatureValue>vSfZUG5xHuNxzOSEbQjN
// dtEt1D+O7I1LTJ13RrwLaJSfQPrdT/s8IeaA+idw2f2WGuGrdqMJUddpE4GxfK61HmPQ6S7lBG+
// +ND+YaUYf2AtTRs3SnToXQQrARa/pHVjsKxYHR/9tjy6maHBwxjgjFQABvYZu0gZHYRuXvvfxv0
// 8=</SignatureValue><KeyInfo><X509Data xmlns="http://www.w3.org/2000/09/xmld
// sig#"><X509Certificate>MIICCzCCAXSgAwIBAgIQ5eVQY8pRZ5xBF2WLkYPjijANBgkqhkiG
// 9w0BAQQFADAbMRkwFwYDVQQDExBHcmVnc0NlcnRpZmljYXRlMB4XDTAzMDkxNzIzMzU0N1oXDTM
// 5MTIzMTIzNTk1OVowGzEZMBcGA1UEAxMQR3JlZ3NDZXJ0aWZpY2F0ZTCBnzANBgkqhkiG9w0BAQ
// EFAAOBjQAwgYkCgYEAmFJ4v7rS3BYTXgVW9PgBFfTYAcB/m9mOFCmUrrChcBpoEtu/tSESlNfEH
// pECIdqg9vUrCNSkY08HRn3ueNeBSnSpssWd8/XoOboWLh1nd+79Y5uZd1WOJI4s0XM0MegZgCoJ
// cEEhpxCd/HOPIQvEsbpN/DuFiovZLo+Ek3hHoxMCAwEAAaNQME4wTAYDVR0BBEUwQ4AQaCb19dl
// yf/zSxPVYQZY9AKEdMBsxGTAXBgNVBAMTEEdyZWdzQ2VydGlmaWNhdGWCEOXlUGPKUWecQRdli5
// GD44owDQYJKoZIhvcNAQEEBQADgYEAZuZaFDGDJogh7FuT0hfaMAVlRONv6wWVBJVV++eUo38Xu
// RfJ5nNJ0UnhiV2sEtLobYBPEIrNhuk8skdU0AHgx4ILiA4rR96ifWwxtrFQF+h+DL2ZB7xhwcOJ
// +Pa7IC4wIaEp/oBmmX+JHSzfQt6/If4ohwikfxfljKMyIcMlwl4=</X509Certificate></X50
// 9Data></KeyInfo></Signature></PRODUCTS>
//
// Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Router</DESCRI
// PTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRIPTION></P
// RODUCT><!--Comments are included in the transform--><PARTNER_URL>'http:\\ww
// w.contoso.com\partner.asp?h1=en&h2=cr'</PARTNER_URL><Signature><SignedI
// nfo><CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c1
// 4n-20010315"></CanonicalizationMethod><SignatureMethod Algorithm="http://ww
// w.w3.org/2000/09/xmldsig#rsa-sha1"></SignatureMethod><Reference URI=""><Tra
// nsforms><Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-200103
// 15"></Transform></Transforms><DigestMethod Algorithm="http://www.w3.org/200
// 0/09/xmldsig#sha1"></DigestMethod><DigestValue>BFN2s0/NA2NGgb/R0mvfnNM0Ito=
// </DigestValue></Reference></SignedInfo><SignatureValue>vSfZUG5xHuNxzOSEbQjN
// dtEt1D+O7I1LTJ13RrwLaJSfQPrdT/s8IeaA+idw2f2WGuGrdqMJUddpE4GxfK61HmPQ6S7lBG+
// +ND+YaUYf2AtTRs3SnToXQQrARa/pHVjsKxYHR/9tjy6maHBwxjgjFQABvYZu0gZHYRuXvvfxv0
// 8=</SignatureValue><KeyInfo><X509Data xmlns="http://www.w3.org/2000/09/xmld
// sig#"><X509Certificate>MIICCzCCAXSgAwIBAgIQ5eVQY8pRZ5xBF2WLkYPjijANBgkqhkiG
// 9w0BAQQFADAbMRkwFwYDVQQDExBHcmVnc0NlcnRpZmljYXRlMB4XDTAzMDkxNzIzMzU0N1oXDTM
// 5MTIzMTIzNTk1OVowGzEZMBcGA1UEAxMQR3JlZ3NDZXJ0aWZpY2F0ZTCBnzANBgkqhkiG9w0BAQ
// EFAAOBjQAwgYkCgYEAmFJ4v7rS3BYTXgVW9PgBFfTYAcB/m9mOFCmUrrChcBpoEtu/tSESlNfEH
// pECIdqg9vUrCNSkY08HRn3ueNeBSnSpssWd8/XoOboWLh1nd+79Y5uZd1WOJI4s0XM0MegZgCoJ
// cEEhpxCd/HOPIQvEsbpN/DuFiovZLo+Ek3hHoxMCAwEAAaNQME4wTAYDVR0BBEUwQ4AQaCb19dl
// yf/zSxPVYQZY9AKEdMBsxGTAXBgNVBAMTEEdyZWdzQ2VydGlmaWNhdGWCEOXlUGPKUWecQRdli5
// GD44owDQYJKoZIhvcNAQEEBQADgYEAZuZaFDGDJogh7FuT0hfaMAVlRONv6wWVBJVV++eUo38Xu
// RfJ5nNJ0UnhiV2sEtLobYBPEIrNhuk8skdU0AHgx4ILiA4rR96ifWwxtrFQF+h+DL2ZB7xhwcOJ
// +Pa7IC4wIaEp/oBmmX+JHSzfQt6/If4ohwikfxfljKMyIcMlwl4=</X509Certificate></X50
// 9Data></KeyInfo></Signature></PRODUCTS>
//
// Resolved the base Uri and relative Uri to the following:
// http://www.contoso.com/xml
// This sample completed successfully; press Enter to exit.
Imports System.IO
Imports System.Xml
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.Security.Cryptography.X509Certificates

Public Class Form1
    Inherits System.Windows.Forms.Form

    Private certificateFilePath As String = "..\\my509.cer"

    ' 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
        Dim productsXml As XmlDocument = LoadProducts()
        ShowTransformProperties(productsXml)

        SignDocument(productsXml)
        ShowTransformProperties(productsXml)

        ' Use XmlDsigC14NTransform to resolve a Uri.
        Dim baseUri As New Uri("http://www.contoso.com")
        Dim relativeUri As String = "xml"
        Dim absoluteUri As Uri = ResolveUris(baseUri, relativeUri)

        ' Align interface and conclude application.
        WriteLine(vbCrLf + "This sample completed successfully;" + _
            " press Exit to continue.")

        ' Reset the cursor.
        tbxOutput.Cursor = Cursors.Default
    End Sub

    ' Encrypt the text in the specified XmlDocument.
    Private Sub ShowTransformProperties(ByVal xmlDoc As XmlDocument)
        Dim xmlTransform As New XmlDsigC14NTransform(True)

        ' Ensure the transform is using the appropriate algorithm.
        xmlTransform.Algorithm = _
            SignedXml.XmlDsigExcC14NTransformUrl

        ' Retrieve the XML representation of the current transform.
        Dim xmlInTransform As XmlElement = xmlTransform.GetXml()

        WriteLine(vbCrLf + "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
                ' Load the document into the transfrom.
                xmlTransform.LoadInput(xmlDoc)

                Dim secondTransform As New XmlDsigC14NTransform

                Dim classDescription As String = secondTransform.ToString()

                ' This call does not perform as expected.
                ' This transform does not contain inner XML elements
                secondTransform.LoadInnerXml(xmlDoc.SelectNodes("//."))
                Exit For
            End If
        Next

        Dim validOutTypes() As Type = xmlTransform.OutputTypes
        For i As Int16 = 0 To validOutTypes.Length - 1 Step 1
            If (validOutTypes(i).Equals(GetType(System.IO.Stream))) Then
                Try
                    Dim streamType As Type = GetType(System.IO.Stream)
                    Dim outputStream As MemoryStream
                    outputStream = CType( _
                        xmlTransform.GetOutput(streamType), _
                        MemoryStream)

                    ' 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 xml: " + _
                        xmlDoc.OuterXml)
                    WriteLine("Message encoded: " + outputMessage)

                Catch ex As Exception
                    WriteLine("Unexpected exception caught: " + ex.ToString())

                End Try
            Else
                Dim outputObject As Object = xmlTransform.GetOutput()

            End If
        Next
    End Sub

    ' Create an XML document describing various products.
    Private Function LoadProducts() As XmlDocument
        Dim xmlDoc As New XmlDocument

        Dim contosoProducts As String = "<PRODUCTS>"
        contosoProducts += "<PRODUCT><ID>123</ID>"
        contosoProducts += "<DESCRIPTION>Router</DESCRIPTION></PRODUCT>"
        contosoProducts += "<PRODUCT><ID>456</ID>"
        contosoProducts += "<DESCRIPTION>Keyboard</DESCRIPTION></PRODUCT>"

        ' Include a comment to test the comments feature of the transform.
        contosoProducts += "<!--Comments are included in the transform-->"

        ' Include the CDATA tag to test the transform results.
        contosoProducts += "<PARTNER_URL><![CDATA['http:\\\\www.contoso.com"
        contosoProducts += "\\partner.asp?h1=en&h2=cr']]></PARTNER_URL>"
        contosoProducts += "</PRODUCTS>"

        xmlDoc.LoadXml(contosoProducts)
        Return xmlDoc
    End Function

    ' Create a signature and add it to the specified document.
    Private Sub SignDocument(ByRef xmlDoc As XmlDocument)
        ' Generate a signing key.
        Dim Key As RSA = RSA.Create()

        ' Create a SignedXml object.
        Dim signedXml As New SignedXml(xmlDoc)

        ' Add the key to the SignedXml document. 
        signedXml.SigningKey = Key

        ' Create a reference to be signed.
        Dim reference As New Reference
        reference.Uri = ""

        ' Add an enveloped transformation to the reference.
        reference.AddTransform(New XmlDsigC14NTransform)

        ' Add the reference to the SignedXml object.
        signedXml.AddReference(reference)

        Try
            ' Create a new KeyInfo object.
            Dim keyInfo As New KeyInfo

            ' Load the X509 certificate.
            Dim certificate As X509Certificate
            certificate = X509Certificate.CreateFromCertFile( _
                certificateFilePath)

            ' Load the certificate into a KeyInfoX509Data object
            ' and add it to the KeyInfo object.
            keyInfo.AddClause(New KeyInfoX509Data(certificate))

            ' Add the KeyInfo object to the SignedXml object.
            signedXml.KeyInfo = keyInfo
        Catch ex As FileNotFoundException
            WriteLine("Unable to locate the following file: " + _
                certificateFilePath)
        Catch ex As CryptographicException
            WriteLine("Unexpected exception caught whild creating " + _
                "the certificate:" + ex.ToString())
        End Try

        ' Compute the signature.
        signedXml.ComputeSignature()

        ' Add the signature branch to the original tree so it is enveloped.
        xmlDoc.DocumentElement.AppendChild(signedXml.GetXml())
    End Sub

    ' 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 XmlDsigC14NTransform
        xmlTransform.Resolver = xmlResolver

        Dim absoluteUri As Uri = xmlResolver.ResolveUri(baseUri, relativeUri)

        If Not absoluteUri Is Nothing Then
            WriteLine(vbCrLf + _
                "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 specified 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 = "XmlDsigC14NTransform"
        Me.Panel2.ResumeLayout(False)
        Me.Panel1.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

#End Region
End Class
'
' This sample produces the following output:
'
' Xml representation of the current transform: 
' <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmlns
' ="http://www.w3.org/2000/09/xmldsig#" />
' Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rout
' er</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRI
' PTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL><!
' [CDATA['http:\\\\www.contoso.com\\partner.asp?h1=en&h2=cr']]></PARTNER_URL><
' /PRODUCTS>
' Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Router</DESCRIP
' TION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRIPTION></PRO
' DUCT><!--Comments are included in the transform--><PARTNER_URL>'http:\\\\www
' .contoso.com\\partner.asp?h1=en&h2=cr'</PARTNER_URL></PRODUCTS>
' Unable to locate the following file: ..\\my509.cer
' 
' Xml representation of the current transform: 
' <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" xmlns
' ="http://www.w3.org/2000/09/xmldsig#" />
' Encoding the following xml: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Rout
' er</DESCRIPTION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRI
' PTION></PRODUCT><!--Comments are included in the transform--><PARTNER_URL><!
' [CDATA['http:\\\\www.contoso.com\\partner.asp?h1=en&h2=cr']]></PARTNER_URL><
' Signature xmlns="http://www.w3.org/2000/09/xmldsig#"><SignedInfo><Canonicali
' zationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" /><
' SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" /><Re
' ference URI=""><Transforms><Transform Algorithm="http://www.w3.org/TR/2001/R
' EC-xml-c14n-20010315" /></Transforms><DigestMethod Algorithm="http://www.w3.
' org/2000/09/xmldsig#sha1" /><DigestValue>reODk69AR9ytcttnNovo4tHNr7s=</Diges
' tValue></Reference></SignedInfo><SignatureValue>shFIRZqXidkxzQtZwGa7xqWoS0yF
' GDot63A8v17KZzmfDWTaluGk25fvKJ4Bv4Z1ENxevyQY/wCGzsto9FJUvTXsJ9/jTOwIvRQt1204
' gJ8SgTex8epH/2xnfvdEqZR8HWJq3X/NixGhMUCpmEFwZMn3V/8qryg8mhYp72jPTFI=</Signat
' ureValue></Signature></PRODUCTS>
' Message encoded: <PRODUCTS><PRODUCT><ID>123</ID><DESCRIPTION>Router</DESCRIP
' TION></PRODUCT><PRODUCT><ID>456</ID><DESCRIPTION>Keyboard</DESCRIPTION></PRO
' DUCT><!--Comments are included in the transform--><PARTNER_URL>'http:\\\\www
' .contoso.com\\partner.asp?h1=en&h2=cr'</PARTNER_URL><Signature><SignedIn
' fo><CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n
' -20010315"></CanonicalizationMethod><SignatureMethod Algorithm="http://www.w
' 3.org/2000/09/xmldsig#rsa-sha1"></SignatureMethod><Reference URI=""><Transfo
' rms><Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"><
' /Transform></Transforms><DigestMethod Algorithm="http://www.w3.org/2000/09/x
' mldsig#sha1"></DigestMethod><DigestValue>reODk69AR9ytcttnNovo4tHNr7s=</Diges
' tValue></Reference></SignedInfo><SignatureValue>shFIRZqXidkxzQtZwGa7xqWoS0yF
' GDot63A8v17KZzmfDWTaluGk25fvKJ4Bv4Z1ENxevyQY/wCGzsto9FJUvTXsJ9/jTOwIvRQt1204
' gJ8SgTex8epH/2xnfvdEqZR8HWJq3X/NixGhMUCpmEFwZMn3V/8qryg8mhYp72jPTFI=</Signat
' ureValue></Signature></PRODUCTS>
' 
' Resolved the base Uri and relative Uri to the following:
' http://www.contoso.com/xml
' 
' This sample completed successfully; press Exit to continue.

Remarks

The XmlDsigC14NTransform class represents the C14N XML canonicalization transform that describes the canonical form of an XML document. This transform allows a signer to create a digest (used to create a digital signature) using the canonical form of an XML document. A recipient can then verify the XML digital signature using the same canonical form of the XML document with the same transform.

Use the XmlDsigC14NTransform class when you need to sign an XML document that does not contain comments.

In most cases, a new instance of a canonicalization transform class is not required. To specify a canonicalization transform, pass the Uniform Resource Identifier (URI) that describes the transform to the CanonicalizationMethod property, which is accessible from the SignedInfo property. To acquire a reference to the canonicalization transform, use the CanonicalizationMethodObject property, which is accessible from the SignedInfo property.

The URI that describes the XmlDsigC14NTransform class is defined by the XmlDsigC14NTransformUrl field and the XmlDsigCanonicalizationUrl field.

You would only need to create a new instance of a canonicalization transform class for manually hashing an XML document or for using your own canonicalization algorithm.

For more information about the C14N transform, see Sections 6.5 and 6.6.1 of the W3C XMLDSIG specification. The canonicalization algorithm is defined in the W3C Canonical XML specification.

Constructors

XmlDsigC14NTransform()

Initializes a new instance of the XmlDsigC14NTransform class.

XmlDsigC14NTransform(Boolean)

Initializes a new instance of the XmlDsigC14NTransform class with comments, if specified.

Properties

Algorithm

Gets or sets the Uniform Resource Identifier (URI) that identifies the algorithm performed by the current transform.

(Inherited from Transform)
Context

Gets or sets an XmlElement object that represents the document context under which the current Transform object is running.

(Inherited from Transform)
InputTypes

Gets an array of types that are valid inputs to the LoadInput(Object) method of the current XmlDsigC14NTransform object.

OutputTypes

Gets an array of types that are possible outputs from the GetOutput() methods of the current XmlDsigC14NTransform object.

PropagatedNamespaces

Gets or sets a Hashtable object that contains the namespaces that are propagated into the signature.

(Inherited from Transform)
Resolver

Sets the current XmlResolver object.

(Inherited from Transform)

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetDigestedOutput(HashAlgorithm)

Returns the digest associated with an XmlDsigC14NTransform object.

GetDigestedOutput(HashAlgorithm)

When overridden in a derived class, returns the digest associated with a Transform object.

(Inherited from Transform)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetInnerXml()

Returns an XML representation of the parameters of an XmlDsigC14NTransform object that are suitable to be included as subelements of an XMLDSIG <Transform> element.

GetOutput()

Returns the output of the current XmlDsigC14NTransform object.

GetOutput(Type)

Returns the output of the current XmlDsigC14NTransform object of type Stream.

GetType()

Gets the Type of the current instance.

(Inherited from Object)
GetXml()

Returns the XML representation of the current Transform object.

(Inherited from Transform)
LoadInnerXml(XmlNodeList)

Parses the specified XmlNodeList object as transform-specific content of a <Transform> element; this method is not supported because this element has no inner XML elements.

LoadInput(Object)

Loads the specified input into the current XmlDsigC14NTransform object.

MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to