/*

 * Copyright (c) 2003, 2018, 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

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 */

package javax.crypto.spec;

/**

 * This class specifies the source for encoding input P in OAEP Padding,

 * as defined in the

 * <a href="https://tools.ietf.org/rfc/rfc8017.txt">PKCS#1 v2.2</a> standard.

 * <pre>

 * PSourceAlgorithm ::= AlgorithmIdentifier {

 *   {PKCS1PSourceAlgorithms}

 * }

 * </pre>

 * where

 * <pre>

 * PKCS1PSourceAlgorithms    ALGORITHM-IDENTIFIER ::= {

 *   { OID id-pSpecified PARAMETERS EncodingParameters },

 *   ...  -- Allows for future expansion --

 * }

 * EncodingParameters ::= OCTET STRING(SIZE(0..MAX))

 * </pre>

 * @author Valerie Peng

 *

 * @since 1.5

 */

public class PSource {

    private String pSrcName;

    /**

     * Constructs a source of the encoding input P for OAEP

     * padding as defined in the PKCS #1 standard using the

     * specified PSource algorithm.

     * @param pSrcName the algorithm for the source of the

     * encoding input P.

     * @exception NullPointerException if <code>pSrcName</code>

     * is null.

     */

    protected PSource(String pSrcName) {

        if (pSrcName == null) {

            throw new NullPointerException("pSource algorithm is null");

        }

        this.pSrcName = pSrcName;

    }

    /**

     * Returns the PSource algorithm name.

     *

     * @return the PSource algorithm name.

     */

    public String getAlgorithm() {

        return pSrcName;

    }

    /**

     * This class is used to explicitly specify the value for

     * encoding input P in OAEP Padding.

     *

     * @since 1.5

     */

    public static final class PSpecified extends PSource {

        private byte[] p = new byte[0];

        /**

         * The encoding input P whose value equals byte[0].

         */

        public static final PSpecified DEFAULT = new PSpecified(new byte[0]);

        /**

         * Constructs the source explicitly with the specified

         * value <code>p</code> as the encoding input P.

         * Note:

         * @param p the value of the encoding input. The contents

         * of the array are copied to protect against subsequent

         * modification.

         * @exception NullPointerException if <code>p</code> is null.

         */

        public PSpecified(byte[] p) {

            super("PSpecified");

            this.p = p.clone();

        }

        /**

         * Returns the value of encoding input P.

         * @return the value of encoding input P. A new array is

         * returned each time this method is called.

         */

        public byte[] getValue() {

            return (p.length==0? p: p.clone());

        }

    }

}