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25 
26 package java.security;
27 
28 import 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  * For example, the Sun provider uses a default modulus prime size of 1024
43  * bits for the generation of DSA parameters.
44  *
45  * @author Jan Luehe
46  *
47  *
48  * @see AlgorithmParameterGenerator
49  * @see AlgorithmParameters
50  * @see java.security.spec.AlgorithmParameterSpec
51  *
52  * @since 1.2
53  */
54 
55 public abstract class AlgorithmParameterGeneratorSpi {
56 
57     /**
58      * Initializes this parameter generator for a certain size
59      * and source of randomness.
60      *
61      * @param size the size (number of bits).
62      * @param random the source of randomness.
63      */
engineInit(int size, SecureRandom random)64     protected abstract void engineInit(int size, SecureRandom random);
65 
66     /**
67      * Initializes this parameter generator with a set of
68      * algorithm-specific parameter generation values.
69      *
70      * @param genParamSpec the set of algorithm-specific parameter generation values.
71      * @param random the source of randomness.
72      *
73      * @exception InvalidAlgorithmParameterException if the given parameter
74      * generation values are inappropriate for this parameter generator.
75      */
engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random)76     protected abstract void engineInit(AlgorithmParameterSpec genParamSpec,
77                                        SecureRandom random)
78         throws InvalidAlgorithmParameterException;
79 
80     /**
81      * Generates the parameters.
82      *
83      * @return the new AlgorithmParameters object.
84      */
engineGenerateParameters()85     protected abstract AlgorithmParameters engineGenerateParameters();
86 }
87