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 * Licensed to the Apache Software Foundation (ASF) under one

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 * regarding copyright ownership. The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License. You may obtain a copy of the License at

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 * http://www.apache.org/licenses/LICENSE-2.0

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 * Unless required by applicable law or agreed to in writing,

 * software distributed under the License is distributed on an

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package com.sun.org.apache.xml.internal.security.encryption;

import org.w3c.dom.Attr;

/**

 * {@code CipherReference} identifies a source which, when processed,

 * yields the encrypted octet sequence.

 * <p>

 * The actual value is obtained as follows. The {@code CipherReference URI}

 * contains an identifier that is dereferenced. Should the

 * Transforms, the data resulting from dereferencing the {@code URI} is

 * transformed as specified so as to yield the intended cipher value. For

 * example, if the value is base64 encoded within an XML document; the

 * transforms could specify an XPath expression followed by a base64 decoding so

 * as to extract the octets.

 * <p>

 * The syntax of the {@code URI} and Transforms is similar to that of

 * [XML-DSIG]. However, there is a difference between signature and encryption

 * processing. In [XML-DSIG] both generation and validation processing start

 * with the same source data and perform that transform in the same order. In

 * encryption, the decryptor has only the cipher data and the specified

 * transforms are enumerated for the decryptor, in the order necessary to obtain

 * the octets. Consequently, because it has different semantics Transforms is in

 * the &xenc; namespace.

 * <p>

 * The schema definition is as follows:

 * <pre>{@code

 * <element name='CipherReference' type='xenc:CipherReferenceType'/>

 * <complexType name='CipherReferenceType'>

 *     <sequence>

 *         <element name='Transforms' type='xenc:TransformsType' minOccurs='0'/>

 *     </sequence>

 *     <attribute name='URI' type='anyURI' use='required'/>

 * </complexType>

 * }</pre>

 *

 * @author Axl Mattheus

 */

public interface CipherReference {

    /**

     * Returns an {@code URI} that contains an identifier that should be

     * dereferenced.

     * @return an {@code URI} that contains an identifier that should be

     * dereferenced.

     */

    String getURI();

    /**

     * Gets the URI as an Attribute node.  Used to meld the CipherReference

     * with the XMLSignature ResourceResolvers

     * @return the URI as an Attribute node

     */

    Attr getURIAsAttr();

    /**

     * Returns the {@code Transforms} that specifies how to transform the

     * {@code URI} to yield the appropriate cipher value.

     *

     * @return the transform that specifies how to transform the reference to

     *   yield the intended cipher value.

     */

    Transforms getTransforms();

    /**

     * Sets the {@code Transforms} that specifies how to transform the

     * {@code URI} to yield the appropriate cipher value.

     *

     * @param transforms the set of {@code Transforms} that specifies how

     *   to transform the reference to yield the intended cipher value.

     */

    void setTransforms(Transforms transforms);

}