1 /* 2 * Copyright (c) 1999, 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 javax.crypto; 27 28 import java.security.Key; 29 import java.security.AlgorithmParameters; 30 import java.security.InvalidKeyException; 31 import java.security.InvalidAlgorithmParameterException; 32 import java.security.spec.AlgorithmParameterSpec; 33 34 /** 35 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) 36 * for the <code>ExemptionMechanism</code> class. 37 * All the abstract methods in this class must be implemented by each 38 * cryptographic service provider who wishes to supply the implementation 39 * of a particular exemption mechanism. 40 * 41 * @author Sharon Liu 42 * 43 * @since 1.4 44 */ 45 46 public abstract class ExemptionMechanismSpi { 47 48 /** 49 * Constructor for subclasses to call. 50 */ ExemptionMechanismSpi()51 public ExemptionMechanismSpi() {} 52 53 /** 54 * Returns the length in bytes that an output buffer would need to be in 55 * order to hold the result of the next 56 * {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob} 57 * operation, given the input length <code>inputLen</code> (in bytes). 58 * 59 * <p>The actual output length of the next 60 * {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob} 61 * call may be smaller than the length returned by this method. 62 * 63 * @param inputLen the input length (in bytes) 64 * 65 * @return the required output buffer size (in bytes) 66 */ engineGetOutputSize(int inputLen)67 protected abstract int engineGetOutputSize(int inputLen); 68 69 /** 70 * Initializes this exemption mechanism with a key. 71 * 72 * <p>If this exemption mechanism requires any algorithm parameters 73 * that cannot be derived from the given <code>key</code>, the underlying 74 * exemption mechanism implementation is supposed to generate the required 75 * parameters itself (using provider-specific default values); in the case 76 * that algorithm parameters must be specified by the caller, an 77 * <code>InvalidKeyException</code> is raised. 78 * 79 * @param key the key for this exemption mechanism 80 * 81 * @exception InvalidKeyException if the given key is inappropriate for 82 * this exemption mechanism. 83 * @exception ExemptionMechanismException if problem(s) encountered in the 84 * process of initializing. 85 */ engineInit(Key key)86 protected abstract void engineInit(Key key) 87 throws InvalidKeyException, ExemptionMechanismException; 88 89 /** 90 * Initializes this exemption mechanism with a key and a set of algorithm 91 * parameters. 92 * 93 * <p>If this exemption mechanism requires any algorithm parameters and 94 * <code>params</code> is null, the underlying exemption mechanism 95 * implementation is supposed to generate the required parameters 96 * itself (using provider-specific default values); in the case that 97 * algorithm parameters must be specified by the caller, an 98 * <code>InvalidAlgorithmParameterException</code> is raised. 99 * 100 * @param key the key for this exemption mechanism 101 * @param params the algorithm parameters 102 * 103 * @exception InvalidKeyException if the given key is inappropriate for 104 * this exemption mechanism. 105 * @exception InvalidAlgorithmParameterException if the given algorithm 106 * parameters are inappropriate for this exemption mechanism. 107 * @exception ExemptionMechanismException if problem(s) encountered in the 108 * process of initializing. 109 */ engineInit(Key key, AlgorithmParameterSpec params)110 protected abstract void engineInit(Key key, AlgorithmParameterSpec params) 111 throws InvalidKeyException, InvalidAlgorithmParameterException, 112 ExemptionMechanismException; 113 114 /** 115 * Initializes this exemption mechanism with a key and a set of algorithm 116 * parameters. 117 * 118 * <p>If this exemption mechanism requires any algorithm parameters 119 * and <code>params</code> is null, the underlying exemption mechanism 120 * implementation is supposed to generate the required parameters 121 * itself (using provider-specific default values); in the case that 122 * algorithm parameters must be specified by the caller, an 123 * <code>InvalidAlgorithmParameterException</code> is raised. 124 * 125 * @param key the key for this exemption mechanism 126 * @param params the algorithm parameters 127 * 128 * @exception InvalidKeyException if the given key is inappropriate for 129 * this exemption mechanism. 130 * @exception InvalidAlgorithmParameterException if the given algorithm 131 * parameters are inappropriate for this exemption mechanism. 132 * @exception ExemptionMechanismException if problem(s) encountered in the 133 * process of initializing. 134 */ engineInit(Key key, AlgorithmParameters params)135 protected abstract void engineInit(Key key, AlgorithmParameters params) 136 throws InvalidKeyException, InvalidAlgorithmParameterException, 137 ExemptionMechanismException; 138 139 /** 140 * Generates the exemption mechanism key blob. 141 * 142 * @return the new buffer with the result key blob. 143 * 144 * @exception ExemptionMechanismException if problem(s) encountered in the 145 * process of generating. 146 */ engineGenExemptionBlob()147 protected abstract byte[] engineGenExemptionBlob() 148 throws ExemptionMechanismException; 149 150 /** 151 * Generates the exemption mechanism key blob, and stores the result in 152 * the <code>output</code> buffer, starting at <code>outputOffset</code> 153 * inclusive. 154 * 155 * <p>If the <code>output</code> buffer is too small to hold the result, 156 * a <code>ShortBufferException</code> is thrown. In this case, repeat this 157 * call with a larger output buffer. Use 158 * {@link #engineGetOutputSize(int) engineGetOutputSize} to determine 159 * how big the output buffer should be. 160 * 161 * @param output the buffer for the result 162 * @param outputOffset the offset in <code>output</code> where the result 163 * is stored 164 * 165 * @return the number of bytes stored in <code>output</code> 166 * 167 * @exception ShortBufferException if the given output buffer is too small 168 * to hold the result. 169 * @exception ExemptionMechanismException if problem(s) encountered in the 170 * process of generating. 171 */ engineGenExemptionBlob(byte[] output, int outputOffset)172 protected abstract int engineGenExemptionBlob 173 (byte[] output, int outputOffset) 174 throws ShortBufferException, ExemptionMechanismException; 175 } 176