DataObject Class

Definition

Namespace:

System.Security.Cryptography.Xml

Assembly:

System.Security.Cryptography.Xml.dll

Represents the object element of an XML signature that holds data to be signed.

public ref class DataObject

public class DataObject

type DataObject = class

Public Class DataObject

Inheritance

Object

DataObject

Examples

The following code example demonstrates how to generate an enveloping XML signature.

#using <System.dll>
#using <System.Xml.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::IO;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
using namespace System::Xml;
int main()
{
   
   // Create example data to sign.
   XmlDocument^ document = gcnew XmlDocument;
   XmlNode^ node = document->CreateNode( XmlNodeType::Element, "", "MyElement", "samples" );
   node->InnerText = "This is some text";
   document->AppendChild( node );
   Console::Error->WriteLine( "Data to sign:\n{0}\n", document->OuterXml );
   
   // Create the SignedXml message.
   SignedXml^ signedXml = gcnew SignedXml;
   RSA^ key = RSA::Create();
   signedXml->SigningKey = key;
   
   // Create a data object to hold the data to sign.
   DataObject^ dataObject = gcnew DataObject;
   dataObject->Data = document->ChildNodes;
   dataObject->Id = "MyObjectId";
   
   // Add the data object to the signature.
   signedXml->AddObject( dataObject );
   
   // Create a reference to be able to package everything into the
   // message.
   Reference^ reference = gcnew Reference;
   reference->Uri = "#MyObjectId";
   
   // Add it to the message.
   signedXml->AddReference( reference );
   
   // Add a KeyInfo.
   KeyInfo^ keyInfo = gcnew KeyInfo;
   keyInfo->AddClause( gcnew RSAKeyValue( key ) );
   signedXml->KeyInfo = keyInfo;
   
   // Compute the signature.
   signedXml->ComputeSignature();
   
   // Get the XML representation of the signature.
   XmlElement^ xmlSignature = signedXml->GetXml();
   Console::WriteLine( xmlSignature->OuterXml );
}

using System;
using System.IO;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Xml;

public class XMLdsigsample1 {

static void Main(String[] args)
{
     // Create example data to sign.
     XmlDocument document = new XmlDocument();
     XmlNode  node = document.CreateNode(XmlNodeType.Element, "", "MyElement", "samples");
     node.InnerText = "This is some text";
     document.AppendChild(node);
     Console.Error.WriteLine("Data to sign:\n" + document.OuterXml + "\n");

     // Create the SignedXml message.
     SignedXml signedXml = new SignedXml();
     RSA key = RSA.Create();
     signedXml.SigningKey = key;

     // Create a data object to hold the data to sign.
     DataObject dataObject = new DataObject();
     dataObject.Data = document.ChildNodes;
     dataObject.Id = "MyObjectId";

     // Add the data object to the signature.
     signedXml.AddObject(dataObject);

     // Create a reference to be able to package everything into the
     // message.
     Reference reference = new Reference();
     reference.Uri = "#MyObjectId";

     // Add it to the message.
     signedXml.AddReference(reference);

     // Add a KeyInfo.
     KeyInfo keyInfo = new KeyInfo();
     keyInfo.AddClause(new RSAKeyValue(key));
     signedXml.KeyInfo = keyInfo;

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

     // Get the XML representation of the signature.
     XmlElement xmlSignature = signedXml.GetXml();
     Console.WriteLine(xmlSignature.OuterXml);
}
}

Imports System.IO
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.Xml

 _


Public Class XMLdsigsample1

   Shared Sub Main(args() As [String])
      ' Create example data to sign.
      Dim document As New XmlDocument()
      Dim node As XmlNode = document.CreateNode(XmlNodeType.Element, "", "MyElement", "samples")
      node.InnerText = "This is some text"
      document.AppendChild(node)
      Console.Error.WriteLine("Data to sign:")
      Console.Error.WriteLine()
      Console.Error.WriteLine(document.OuterXml)
      Console.Error.WriteLine()
      
      ' Create the SignedXml message.
      Dim signedXml As New SignedXml()
      Dim key As RSA = RSA.Create()
      signedXml.SigningKey = key
      
      ' Create a data object to hold the data to sign.
      Dim dataObject As New DataObject()
      dataObject.Data = document.ChildNodes
      dataObject.Id = "MyObjectId"
      
      ' Add the data object to the signature.
      signedXml.AddObject(dataObject)
      
      ' Create a reference to be able to package everything into the
      ' message.
      Dim reference As New Reference()
      reference.Uri = "#MyObjectId"
      
      ' Add it to the message.
      signedXml.AddReference(reference)
      
      ' Add a KeyInfo.
      Dim keyInfo As New KeyInfo()
      keyInfo.AddClause(New RSAKeyValue(key))
      signedXml.KeyInfo = keyInfo
      
      ' Compute the signature.
      signedXml.ComputeSignature()
      
      ' Get the XML representation of the signature.
      Dim xmlSignature As XmlElement = signedXml.GetXml()
      Console.WriteLine(xmlSignature.OuterXml)
   End Sub
End Class

The following code example demonstrates how to check an XML signature.

#using <System.dll>
#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::IO;
using namespace System::Xml;
int main()
{
   array<String^>^args = System::Environment::GetCommandLineArgs();
   Console::WriteLine( "Verifying {0}...", args[ 1 ] );

   // Create a SignedXml.
   SignedXml^ signedXml = gcnew SignedXml;

   // Load the XML.
   XmlDocument^ xmlDocument = gcnew XmlDocument;
   xmlDocument->PreserveWhitespace = true;
   xmlDocument->Load( gcnew XmlTextReader( args[ 1 ] ) );
   XmlNodeList^ nodeList = xmlDocument->GetElementsByTagName( "Signature" );
   signedXml->LoadXml( safe_cast<XmlElement^>(nodeList[ 0 ]) );
   if ( signedXml->CheckSignature() )
   {
      Console::WriteLine( "Signature check OK" );
   }
   else
   {
      Console::WriteLine( "Signature check FAILED" );
   }
}

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.IO;
using System.Xml;

public class Verify {

    public static void Main(String[] args)
    {

        Console.WriteLine("Verifying " + args[0] + "...");

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

        // Load the XML.
        XmlDocument xmlDocument = new XmlDocument();
        xmlDocument.PreserveWhitespace = true;
        xmlDocument.Load(new XmlTextReader(args[0]));

        XmlNodeList nodeList = xmlDocument.GetElementsByTagName("Signature");
        signedXml.LoadXml((XmlElement)nodeList[0]);

        if (signedXml.CheckSignature()) {
            Console.WriteLine("Signature check OK");
        } else {
            Console.WriteLine("Signature check FAILED");
        }
    }
}

Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.IO
Imports System.Xml

 _

Public Class Verify
   
   Public Shared Sub Main(args() As [String])
      
      Console.WriteLine(("Verifying " + args(0) + "..."))
      
      ' Create a SignedXml.
      Dim signedXml As New SignedXml()
      
      ' Load the XML.
      Dim xmlDocument As New XmlDocument()
      xmlDocument.PreserveWhitespace = True
      xmlDocument.Load(New XmlTextReader(args(0)))
      
      Dim nodeList As XmlNodeList = xmlDocument.GetElementsByTagName("Signature")
      signedXml.LoadXml(CType(nodeList(0), XmlElement))
      
      If signedXml.CheckSignature() Then
         Console.WriteLine("Signature check OK")
      Else
         Console.WriteLine("Signature check FAILED")
      End If
   End Sub
End Class

Remarks

Use the DataObject class to store information or metadata directly in an XML signature. For example, you can store the signature generation date or the signer's identity. The DataObject class may or may not be covered by the XML signature.

The class corresponds to the <Object> element in the World Wide Web Consortium (W3C) specification for XML Signatures. For more information about the W3C specification, see https://www.w3.org/TR/xmldsig-core/.

Constructors

DataObject()	Initializes a new instance of the DataObject class.
DataObject(String, String, String, XmlElement)	Initializes a new instance of the DataObject class with the specified identification, MIME type, encoding, and data.

Properties

Data	Gets or sets the data value of the current DataObject object.
Encoding	Gets or sets the encoding of the current DataObject object.
Id	Gets or sets the identification of the current DataObject object.
MimeType	Gets or sets the MIME type of the current DataObject object.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
GetXml()	Returns the XML representation of the DataObject object.
LoadXml(XmlElement)	Loads a DataObject state from an XML element.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)