DataObject Class

Definition

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

C#
public class DataObject
Inheritance
DataObject

Examples

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

C#
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);
}
}

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

C#
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");
        }
    }
}

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)

Applies to

Product Versions
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9