/* * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. *//* * $Id: Reference.java,v 1.9 2005/05/10 16:03:46 mullan Exp $ */package javax.xml.crypto.dsig; import javax.xml.crypto.Data;import javax.xml.crypto.URIReference;import javax.xml.crypto.XMLStructure;import java.io.InputStream;import java.util.List; /** * A representation of the <code>Reference</code> element as defined in the * <a href="http://www.w3.org/TR/xmldsig-core/"> * W3C Recommendation for XML-Signature Syntax and Processing</a>. * The XML schema is defined as: * <code><pre> * &lt;element name="Reference" type="ds:ReferenceType"/&gt; * &lt;complexType name="ReferenceType"&gt; *   &lt;sequence&gt; *     &lt;element ref="ds:Transforms" minOccurs="0"/&gt; *     &lt;element ref="ds:DigestMethod"/&gt; *     &lt;element ref="ds:DigestValue"/&gt; *   &lt;/sequence&gt; *   &lt;attribute name="Id" type="ID" use="optional"/&gt; *   &lt;attribute name="URI" type="anyURI" use="optional"/&gt; *   &lt;attribute name="Type" type="anyURI" use="optional"/&gt; * &lt;/complexType&gt; * * &lt;element name="DigestValue" type="ds:DigestValueType"/&gt; * &lt;simpleType name="DigestValueType"&gt; *   &lt;restriction base="base64Binary"/&gt; * &lt;/simpleType&gt; * </pre></code> * * <p>A <code>Reference</code> instance may be created by invoking one of the * {@link XMLSignatureFactory#newReference newReference} methods of the * {@link XMLSignatureFactory} class; for example: * * <pre> *   XMLSignatureFactory factory = XMLSignatureFactory.getInstance("DOM"); *   Reference ref = factory.newReference *     ("http://www.ietf.org/rfc/rfc3275.txt", *      factory.newDigestMethod(DigestMethod.SHA1, null)); * </pre> * * @author Sean Mullan * @author Erwin van der Koogh * @author JSR 105 Expert Group * @since 1.6 * @see XMLSignatureFactory#newReference(String, DigestMethod) * @see XMLSignatureFactory#newReference(String, DigestMethod, List, String, String) */public interface Reference extends URIReference, XMLStructure {     /**     * Returns an {@link java.util.Collections#unmodifiableList unmodifiable     * list} of {@link Transform}s that are contained in this     * <code>Reference</code>.     *     * @return an unmodifiable list of <code>Transform</code>s     *    (may be empty but never <code>null</code>)     */    List getTransforms();     /**     * Returns the digest method of this <code>Reference</code>.     *     * @return the digest method     */    DigestMethod getDigestMethod();     /**     * Returns the optional <code>Id</code> attribute of this     * <code>Reference</code>, which permits this reference to be     * referenced from elsewhere.     *     * @return the <code>Id</code> attribute (may be <code>null</code> if not     *    specified)     */    String getId();     /**     * Returns the digest value of this <code>Reference</code>.     *     * @return the raw digest value, or <code>null</code> if this reference has     *    not been digested yet. Each invocation of this method returns a new     *    clone to protect against subsequent modification.     */    byte[] getDigestValue();     /**     * Returns the calculated digest value of this <code>Reference</code>     * after a validation operation. This method is useful for debugging if     * the reference fails to validate.     *     * @return the calculated digest value, or <code>null</code> if this     *    reference has not been validated yet. Each invocation of this method     *    returns a new clone to protect against subsequent modification.     */    byte[] getCalculatedDigestValue();     /**     * Validates this reference. This method verifies the digest of this     * reference.     *     * <p>This method only validates the reference the first time it is     * invoked. On subsequent invocations, it returns a cached result.     *     * @return <code>true</code> if this reference was validated successfully;     *    <code>false</code> otherwise     * @param validateContext the validating context     * @throws NullPointerException if <code>validateContext</code> is     *    <code>null</code>     * @throws XMLSignatureException if an unexpected exception occurs while     *    validating the reference     */    boolean validate(XMLValidateContext validateContext)        throws XMLSignatureException;     /**     * Returns the dereferenced data, if     * <a href="XMLSignContext.html#Supported Properties">reference caching</a>     * is enabled. This is the result of dereferencing the URI of this     * reference during a validation or generation operation.     *     * @return the dereferenced data, or <code>null</code> if reference     *    caching is not enabled or this reference has not been generated or     *    validated     */    Data getDereferencedData();     /**     * Returns the pre-digested input stream, if     * <a href="XMLSignContext.html#Supported Properties">reference caching</a>     * is enabled. This is the input to the digest operation during a     * validation or signing operation.     *     * @return an input stream containing the pre-digested input, or     *    <code>null</code> if reference caching is not enabled or this     *    reference has not been generated or validated     */    InputStream getDigestInputStream();}