/*
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id: X509Data.java,v 1.4 2005/05/10 16:35:35 mullan Exp $
 */
package javax.xml.crypto.dsig.keyinfo;

import javax.xml.crypto.XMLStructure;
import java.security.cert.X509CRL;
import java.util.List;

/**
 * A representation of the XML <code>X509Data</code> element as defined in 
 * the <a href="http://www.w3.org/TR/xmldsig-core/">
 * W3C Recommendation for XML-Signature Syntax and Processing</a>. An
 * <code>X509Data</code> object contains one or more identifers of keys 
 * or X.509 certificates (or certificates' identifiers or a revocation list). 
 * The XML Schema Definition is defined as:
 * 
 * <pre>
 *    <element name="X509Data" type="ds:X509DataType"/>
 *    <complexType name="X509DataType"> 
 *        <sequence maxOccurs="unbounded"> 
 *          <choice> 
 *            <element name="X509IssuerSerial" type="ds:X509IssuerSerialType"/>
 *            <element name="X509SKI" type="base64Binary"/>
 *            <element name="X509SubjectName" type="string"/> 
 *            <element name="X509Certificate" type="base64Binary"/>
 *            <element name="X509CRL" type="base64Binary"/> 
 *            <any namespace="##other" processContents="lax"/>
 *          </choice>  
 *        </sequence>
 *    </complexType>
 *
 *    <complexType name="X509IssuerSerialType"> 
 *      <sequence> 
 *        <element name="X509IssuerName" type="string"/> 
 *        <element name="X509SerialNumber" type="integer"/> 
 *      </sequence>
 *    </complexType>
 * </pre>
 *
 * An <code>X509Data</code> instance may be created by invoking the
 * {@link KeyInfoFactory#newX509Data newX509Data} methods of the
 * {@link KeyInfoFactory} class and passing it a list of one or more 
 * {@link XMLStructure}s representing X.509 content; for example:
 * <pre>
 *   KeyInfoFactory factory = KeyInfoFactory.getInstance("DOM");
 *   X509Data x509Data = factory.newX509Data
 *       (Collections.singletonList("cn=Alice"));
 * </pre>
 *
 * @author Sean Mullan
 * @author JSR 105 Expert Group
 * @since 1.6
 * @see KeyInfoFactory#newX509Data(List)
 */
//@@@ check for illegal combinations of data violating MUSTs in W3c spec
public interface X509Data extends XMLStructure {

    /**
     * URI identifying the X509Data KeyInfo type:
     * http://www.w3.org/2000/09/xmldsig#X509Data. This can be specified as
     * the value of the <code>type</code> parameter of the
     * {@link RetrievalMethod} class to describe a remote
     * <code>X509Data</code> structure.
     */
    final static String TYPE = "http://www.w3.org/2000/09/xmldsig#X509Data";

    /**
     * URI identifying the binary (ASN.1 DER) X.509 Certificate KeyInfo type:
     * http://www.w3.org/2000/09/xmldsig#rawX509Certificate. This can be 
     * specified as the value of the <code>type</code> parameter of the
     * {@link RetrievalMethod} class to describe a remote X509 Certificate.
     */
    final static String RAW_X509_CERTIFICATE_TYPE =
        "http://www.w3.org/2000/09/xmldsig#rawX509Certificate";

    /**
     * Returns an {@link java.util.Collections#unmodifiableList unmodifiable 
     * list} of the content in this <code>X509Data</code>. Valid types are 
     * {@link String} (subject names), <code>byte[]</code> (subject key ids), 
     * {@link java.security.cert.X509Certificate}, {@link X509CRL}, 
     * or {@link XMLStructure} ({@link X509IssuerSerial}
     * objects or elements from an external namespace). 
     *
     * @return an unmodifiable list of the content in this <code>X509Data</code>
     *    (never <code>null</code> or empty)
     */
    List getContent();
}