/*
* 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();
}