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      */
PSource(String pSrcName)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      */
getAlgorithm()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          */
PSpecified(byte[] p)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          */
getValue()104         public byte[] getValue() {
105             return (p.length==0? p: p.clone());
106         }
107     }
108 }
109