Java tutorial
/* * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ 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()); } } }