1 /* 2 * Copyright (c) 1997, 2017, 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; 27 28 import java.security.*; 29 import java.security.spec.*; 30 31 /** 32 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) 33 * for the <code>KeyGenerator</code> class. 34 * All the abstract methods in this class must be implemented by each 35 * cryptographic service provider who wishes to supply the implementation 36 * of a key generator for a particular algorithm. 37 * 38 * <p>In case the client does not explicitly initialize the KeyGenerator 39 * (via a call to an {@code init} method), each provider must 40 * supply (and document) a default initialization. 41 * See the Keysize Restriction sections of the 42 * {@extLink security_guide_jdk_providers JDK Providers} 43 * document for information on the KeyGenerator defaults used by 44 * JDK providers. 45 * However, note that defaults may vary across different providers. 46 * Additionally, the default value for a provider may change in a future 47 * version. Therefore, it is recommended to explicitly initialize the 48 * KeyGenerator instead of relying on provider-specific defaults. 49 * 50 * @author Jan Luehe 51 * 52 * @see SecretKey 53 * @since 1.4 54 */ 55 56 public abstract class KeyGeneratorSpi { 57 58 /** 59 * Initializes the key generator. 60 * 61 * @param random the source of randomness for this generator 62 */ engineInit(SecureRandom random)63 protected abstract void engineInit(SecureRandom random); 64 65 /** 66 * Initializes the key generator with the specified parameter 67 * set and a user-provided source of randomness. 68 * 69 * @param params the key generation parameters 70 * @param random the source of randomness for this key generator 71 * 72 * @exception InvalidAlgorithmParameterException if <code>params</code> is 73 * inappropriate for this key generator 74 */ engineInit(AlgorithmParameterSpec params, SecureRandom random)75 protected abstract void engineInit(AlgorithmParameterSpec params, 76 SecureRandom random) 77 throws InvalidAlgorithmParameterException; 78 79 /** 80 * Initializes this key generator for a certain keysize, using the given 81 * source of randomness. 82 * 83 * @param keysize the keysize. This is an algorithm-specific metric, 84 * specified in number of bits. 85 * @param random the source of randomness for this key generator 86 * 87 * @exception InvalidParameterException if the keysize is wrong or not 88 * supported. 89 */ engineInit(int keysize, SecureRandom random)90 protected abstract void engineInit(int keysize, SecureRandom random); 91 92 /** 93 * Generates a secret key. 94 * 95 * @return the new key 96 */ engineGenerateKey()97 protected abstract SecretKey engineGenerateKey(); 98 } 99