1 /* 2 * Copyright (c) 1997, 2020, 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 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 * 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 61 public abstract class AlgorithmParameterGeneratorSpi { 62 63 /** 64 * Constructor for subclasses to call. 65 */ AlgorithmParameterGeneratorSpi()66 public AlgorithmParameterGeneratorSpi() {} 67 68 /** 69 * Initializes this parameter generator for a certain size 70 * and source of randomness. 71 * 72 * @param size the size (number of bits). 73 * @param random the source of randomness. 74 */ engineInit(int size, SecureRandom random)75 protected abstract void engineInit(int size, SecureRandom random); 76 77 /** 78 * Initializes this parameter generator with a set of 79 * algorithm-specific parameter generation values. 80 * 81 * @param genParamSpec the set of algorithm-specific parameter generation values. 82 * @param random the source of randomness. 83 * 84 * @throws InvalidAlgorithmParameterException if the given parameter 85 * generation values are inappropriate for this parameter generator. 86 */ engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random)87 protected abstract void engineInit(AlgorithmParameterSpec genParamSpec, 88 SecureRandom random) 89 throws InvalidAlgorithmParameterException; 90 91 /** 92 * Generates the parameters. 93 * 94 * @return the new AlgorithmParameters object. 95 */ engineGenerateParameters()96 protected abstract AlgorithmParameters engineGenerateParameters(); 97 } 98