1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.  Oracle designates this
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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).
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24 */
25
26package java.security;
27
28import java.security.spec.AlgorithmParameterSpec;
29
30/**
31 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
32 * for the {@code AlgorithmParameterGenerator} class, which
33 * is used to generate a set of parameters to be used with a certain algorithm.
34 *
35 * <p> All the abstract methods in this class must be implemented by each
36 * cryptographic service provider who wishes to supply the implementation
37 * of a parameter generator for a particular algorithm.
38 *
39 * <p> In case the client does not explicitly initialize the
40 * AlgorithmParameterGenerator (via a call to an {@code engineInit}
41 * method), each provider must supply (and document) a default initialization.
42 * See the Keysize Restriction sections of the
43 * {@extLink security_guide_jdk_providers JDK Providers}
44 * document for information on the AlgorithmParameterGenerator defaults
45 * used by JDK providers.
46 * However, note that defaults may vary across different providers.
47 * Additionally, the default value for a provider may change in a future
48 * version. Therefore, it is recommended to explicitly initialize the
49 * AlgorithmParameterGenerator instead of relying on provider-specific defaults.
50 *
51 * @author Jan Luehe
52 *
53 *
54 * @see AlgorithmParameterGenerator
55 * @see AlgorithmParameters
56 * @see java.security.spec.AlgorithmParameterSpec
57 *
58 * @since 1.2
59 */
60
61public abstract class AlgorithmParameterGeneratorSpi {
62
63    /**
64     * Initializes this parameter generator for a certain size
65     * and source of randomness.
66     *
67     * @param size the size (number of bits).
68     * @param random the source of randomness.
69     */
70    protected abstract void engineInit(int size, SecureRandom random);
71
72    /**
73     * Initializes this parameter generator with a set of
74     * algorithm-specific parameter generation values.
75     *
76     * @param genParamSpec the set of algorithm-specific parameter generation values.
77     * @param random the source of randomness.
78     *
79     * @exception InvalidAlgorithmParameterException if the given parameter
80     * generation values are inappropriate for this parameter generator.
81     */
82    protected abstract void engineInit(AlgorithmParameterSpec genParamSpec,
83                                       SecureRandom random)
84        throws InvalidAlgorithmParameterException;
85
86    /**
87     * Generates the parameters.
88     *
89     * @return the new AlgorithmParameters object.
90     */
91    protected abstract AlgorithmParameters engineGenerateParameters();
92}
93