1 /*
   2  * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.crypto.spec;
  27 
  28 /**
  29  * This class specifies the source for encoding input P in OAEP Padding,
  30  * as defined in the
  31  * <a href="http://www.ietf.org/rfc/rfc3447.txt">PKCS #1</a>
  32  * standard.
  33  * <pre>
  34  * PKCS1PSourceAlgorithms    ALGORITHM-IDENTIFIER ::= {
  35  *   { OID id-pSpecified PARAMETERS OCTET STRING },
  36  *   ...  -- Allows for future expansion --
  37  * }
  38  * </pre>
  39  * @author Valerie Peng
  40  *
  41  * @since 1.5
  42  */
  43 public class PSource {
  44 
  45     private String pSrcName;
  46 
  47     /**
  48      * Constructs a source of the encoding input P for OAEP
  49      * padding as defined in the PKCS #1 standard using the
  50      * specified PSource algorithm.
  51      * @param pSrcName the algorithm for the source of the
  52      * encoding input P.
  53      * @exception NullPointerException if <code>pSrcName</code>
  54      * is null.
  55      */
  56     protected PSource(String pSrcName) {
  57         if (pSrcName == null) {
  58             throw new NullPointerException("pSource algorithm is null");
  59         }
  60         this.pSrcName = pSrcName;
  61     }
  62     /**
  63      * Returns the PSource algorithm name.
  64      *
  65      * @return the PSource algorithm name.
  66      */
  67     public String getAlgorithm() {
  68         return pSrcName;
  69     }
  70 
  71     /**
  72      * This class is used to explicitly specify the value for
  73      * encoding input P in OAEP Padding.
  74      *
  75      * @since 1.5
  76      */
  77     public static final class PSpecified extends PSource {
  78 
  79         private byte[] p = new byte[0];
  80 
  81         /**
  82          * The encoding input P whose value equals byte[0].
  83          */
  84         public static final PSpecified DEFAULT = new PSpecified(new byte[0]);
  85 
  86         /**
  87          * Constructs the source explicitly with the specified
  88          * value <code>p</code> as the encoding input P.
  89          * Note:
  90          * @param p the value of the encoding input. The contents
  91          * of the array are copied to protect against subsequent
  92          * modification.
  93          * @exception NullPointerException if <code>p</code> is null.
  94          */
  95         public PSpecified(byte[] p) {
  96             super("PSpecified");
  97             this.p = p.clone();
  98         }
  99         /**
 100          * Returns the value of encoding input P.
 101          * @return the value of encoding input P. A new array is
 102          * returned each time this method is called.
 103          */
 104         public byte[] getValue() {
 105             return (p.length==0? p: p.clone());
 106         }
 107     }
 108 }