SignedXml.AddObject(DataObject) Method

Definition

Adds a DataObject object to the list of objects to be signed.

public void AddObject (System.Security.Cryptography.Xml.DataObject dataObject);

Parameters

dataObject
DataObject

The DataObject object to add to the list of objects to be signed.

Examples

The following code example computes and XML signature.

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)
    {
        try
        {
            // 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.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 the reference 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();

            Console.WriteLine("The data was signed.");
        }
        catch(CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

Remarks

The AddObject method adds an <Object> element that represents an object to be signed to the <Signature> element of an XML digital signature.

The AddObject method internally calls the AddObject method of the Signature object encapsulated by the SignedXml object. You can also add a DataObject object by directly calling the AddObject method from the Signature property.

For more information about XML digital signatures, see the XMLDSIG specification.

Applies to

Product Versions
.NET 6 (package-provided), 7 (package-provided), 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