1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17
18package javax.crypto.spec;
19
20import java.security.spec.AlgorithmParameterSpec;
21import java.security.spec.MGF1ParameterSpec;
22
23/**
24 * The algorithm parameter specification for the <i>OAEP Padding</i> algorithm.
25 * <p>
26 * This padding algorithm is defined in the <a
27 * href="http://www.ietf.org/rfc/rfc3447.txt">PKCS #1</a> standard.
28 */
29public class OAEPParameterSpec implements AlgorithmParameterSpec {
30
31    private final String mdName;
32    private final String mgfName;
33    private final AlgorithmParameterSpec mgfSpec;
34    private final PSource pSrc;
35
36    /**
37     * The algorithm parameter instance with default values.
38     * <p>
39     * It uses the following parameters:
40     * <ul><li>message digest : <code>"SHA-1"</code></li>
41     * <li>mask generation function (<i>mgf</i>) : <code>"MGF1"</code></li>
42     * <li>parameters for the <i>mgf</i> : "SHA-1" {@link MGF1ParameterSpec#SHA1}</li>
43     * <li>the source of the label <code>L</code>: {@link PSource.PSpecified#DEFAULT}</li>
44     * </ul>
45     */
46    public static final OAEPParameterSpec DEFAULT = new OAEPParameterSpec();
47
48    private OAEPParameterSpec() {
49        this.mdName = "SHA-1";
50        this.mgfName = "MGF1";
51        this.mgfSpec = MGF1ParameterSpec.SHA1;
52        this.pSrc = PSource.PSpecified.DEFAULT;
53    }
54
55    /**
56     * Creates a new <code>OAEPParameterSpec</code> instance with the specified
57     * <i>message digest</i> algorithm name, <i>mask generation function</i>
58     * (<i>mgf</i>) algorithm name, <i>parameters</i> for the <i>mgf</i>
59     * algorithm and the <i>source of the label <code>L</code></i>.
60     *
61     * @param mdName
62     *            the message digest algorithm name.
63     * @param mgfName
64     *            the mask generation function algorithm name.
65     * @param mgfSpec
66     *            the algorithm parameter specification for the mask generation
67     *            function algorithm.
68     * @param pSrc
69     *            the source of the label <code>L</code>.
70     * @throws NullPointerException
71     *             if one of <code>mdName</code>, <code>mgfName</code> or
72     *             <code>pSrc</code> is null.
73     */
74    public OAEPParameterSpec(String mdName, String mgfName,
75                                AlgorithmParameterSpec mgfSpec, PSource pSrc) {
76        if (mdName == null) {
77            throw new NullPointerException("mdName == null");
78        } else if (mgfName == null) {
79            throw new NullPointerException("mgfName == null");
80        } else if (pSrc == null) {
81            throw new NullPointerException("pSrc == null");
82        }
83        this.mdName = mdName;
84        this.mgfName = mgfName;
85        this.mgfSpec = mgfSpec;
86        this.pSrc = pSrc;
87    }
88
89    /**
90     * Returns the algorithm name of the <i>message digest</i>.
91     *
92     * @return the algorithm name of the message digest.
93     */
94    public String getDigestAlgorithm() {
95        return mdName;
96    }
97
98    /**
99     * Returns the algorithm name of the <i>mask generation function</i>.
100     *
101     * @return the algorithm name of the mask generation function.
102     */
103    public String getMGFAlgorithm() {
104        return mgfName;
105    }
106
107    /**
108     * Returns the algorithm parameter specification for the mask generation
109     * function algorithm.
110     *
111     * @return the algorithm parameter specification for the mask generation
112     *         function algorithm.
113     */
114    public AlgorithmParameterSpec getMGFParameters() {
115        return mgfSpec;
116    }
117
118    /**
119     * Returns the source of the label <code>L</code>.
120     *
121     * @return the source of the label <code>L</code>.
122     */
123    public PSource getPSource() {
124        return pSrc;
125    }
126}
127
128