CipherData.CipherReference Property

Definition

Namespace:

System.Security.Cryptography.Xml

Assembly:

System.Security.Cryptography.Xml.dll

Source:

CipherData.cs

Gets or sets the <CipherReference> element.

C#

public System.Security.Cryptography.Xml.CipherReference? CipherReference { get; set; }

Property Value

CipherReference

A CipherReference object.

Exceptions

ArgumentNullException

The CipherReference property was set to null.

CryptographicException

The CipherReference property was set more than once.

Examples

The following code example shows how to create a new instance of the CipherData class using CipherReference information.

C#

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

/// This sample used the EncryptedData class to create an encrypted data element
/// and write it to an XML file. It demonstrates the use of CipherReference.
namespace EncryptedDataSample
{
    class Example
    {
        [STAThread]
        static void Main(string[] args)
        {
            //Create a URI string.
            String uri = "http://www.woodgrovebank.com/document.xml";
            // Create a Base64 transform. The input content retrieved from the
            // URI should be Base64-decoded before other processing.
            Transform base64 = new XmlDsigBase64Transform();
            //Create a transform chain and add the transform to it.
            TransformChain tc = new TransformChain();
            tc.Add(base64);
            //Create <CipherReference> information.
            CipherReference reference = new CipherReference(uri, tc);

            // Create a new CipherData object using the CipherReference information.
            // Note that you cannot assign both a CipherReference and a CipherValue
            // to a CipherData object.
            CipherData cd = new CipherData(reference);

            // Create a new EncryptedData object.
            EncryptedData ed = new EncryptedData();

            //Add an encryption method to the object.
            ed.Id = "ED";
            ed.EncryptionMethod = new EncryptionMethod("http://www.w3.org/2001/04/xmlenc#aes128-cbc");
            ed.CipherData = cd;

            //Add key information to the object.
            KeyInfo ki = new KeyInfo();
            ki.AddClause(new KeyInfoRetrievalMethod("#EK", "http://www.w3.org/2001/04/xmlenc#EncryptedKey"));
            ed.KeyInfo = ki;

            // Create new XML document and put encrypted data into it.
            XmlDocument doc = new XmlDocument();
            XmlElement encryptionPropertyElement = (XmlElement)doc.CreateElement("EncryptionProperty", EncryptedXml.XmlEncNamespaceUrl);
            EncryptionProperty ep = new EncryptionProperty(encryptionPropertyElement);
            ed.AddProperty(ep);

            // Output the resulting XML information into a file.
            try
            {
                string path = @"c:\test\MyTest.xml";

                File.WriteAllText(path, ed.GetXml().OuterXml);
            }
            catch (IOException e)
            {
                Console.WriteLine("File IO error. {0}", e);
            }
        }
    }
}

Remarks

The <CipherReference> element identifies a source which, when processed, yields the encrypted data. For more information about this element, see CipherReference.

Note

A CipherData object can have either a CipherReference property or a CipherValue property, but not both. A CryptographicException is thrown if both are assigned to a CipherData object.

Applies to