1 /* 2 * Copyright (c) 1999, 2007, 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 * Returns the length in bytes that an output buffer would need to be in 50 * order to hold the result of the next 51 * {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob} 52 * operation, given the input length <code>inputLen</code> (in bytes). 53 * 54 * <p>The actual output length of the next 55 * {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob} 56 * call may be smaller than the length returned by this method. 57 * 58 * @param inputLen the input length (in bytes) 59 * 60 * @return the required output buffer size (in bytes) 61 */ 62 protected abstract int engineGetOutputSize(int inputLen); 63 64 /** 65 * Initializes this exemption mechanism with a key. 66 * 67 * <p>If this exemption mechanism requires any algorithm parameters 68 * that cannot be derived from the given <code>key</code>, the underlying 69 * exemption mechanism implementation is supposed to generate the required 70 * parameters itself (using provider-specific default values); in the case 71 * that algorithm parameters must be specified by the caller, an 72 * <code>InvalidKeyException</code> is raised. 73 * 74 * @param key the key for this exemption mechanism 75 * 76 * @exception InvalidKeyException if the given key is inappropriate for 77 * this exemption mechanism. 78 * @exception ExemptionMechanismException if problem(s) encountered in the 79 * process of initializing. 80 */ 81 protected abstract void engineInit(Key key) 82 throws InvalidKeyException, ExemptionMechanismException; 83 84 /** 85 * Initializes this exemption mechanism with a key and a set of algorithm 86 * parameters. 87 * 88 * <p>If this exemption mechanism requires any algorithm parameters and 89 * <code>params</code> is null, the underlying exemption mechanism 90 * implementation is supposed to generate the required parameters 91 * itself (using provider-specific default values); in the case that 92 * algorithm parameters must be specified by the caller, an 93 * <code>InvalidAlgorithmParameterException</code> is raised. 94 * 95 * @param key the key for this exemption mechanism 96 * @param params the algorithm parameters 97 * 98 * @exception InvalidKeyException if the given key is inappropriate for 99 * this exemption mechanism. 100 * @exception InvalidAlgorithmParameterException if the given algorithm 101 * parameters are inappropriate for this exemption mechanism. 102 * @exception ExemptionMechanismException if problem(s) encountered in the 103 * process of initializing. 104 */ 105 protected abstract void engineInit(Key key, AlgorithmParameterSpec params) 106 throws InvalidKeyException, InvalidAlgorithmParameterException, 107 ExemptionMechanismException; 108 109 /** 110 * Initializes this exemption mechanism with a key and a set of algorithm 111 * parameters. 112 * 113 * <p>If this exemption mechanism requires any algorithm parameters 114 * and <code>params</code> is null, the underlying exemption mechanism 115 * implementation is supposed to generate the required parameters 116 * itself (using provider-specific default values); in the case that 117 * algorithm parameters must be specified by the caller, an 118 * <code>InvalidAlgorithmParameterException</code> is raised. 119 * 120 * @param key the key for this exemption mechanism 121 * @param params the algorithm parameters 122 * 123 * @exception InvalidKeyException if the given key is inappropriate for 124 * this exemption mechanism. 125 * @exception InvalidAlgorithmParameterException if the given algorithm 126 * parameters are inappropriate for this exemption mechanism. 127 * @exception ExemptionMechanismException if problem(s) encountered in the 128 * process of initializing. 129 */ 130 protected abstract void engineInit(Key key, AlgorithmParameters params) 131 throws InvalidKeyException, InvalidAlgorithmParameterException, 132 ExemptionMechanismException; 133 134 /** 135 * Generates the exemption mechanism key blob. 136 * 137 * @return the new buffer with the result key blob. 138 * 139 * @exception ExemptionMechanismException if problem(s) encountered in the 140 * process of generating. 141 */ 142 protected abstract byte[] engineGenExemptionBlob() 143 throws ExemptionMechanismException; 144 145 /** 146 * Generates the exemption mechanism key blob, and stores the result in 147 * the <code>output</code> buffer, starting at <code>outputOffset</code> 148 * inclusive. 149 * 150 * <p>If the <code>output</code> buffer is too small to hold the result, 151 * a <code>ShortBufferException</code> is thrown. In this case, repeat this 152 * call with a larger output buffer. Use 153 * {@link #engineGetOutputSize(int) engineGetOutputSize} to determine 154 * how big the output buffer should be. 155 * 156 * @param output the buffer for the result 157 * @param outputOffset the offset in <code>output</code> where the result 158 * is stored 159 * 160 * @return the number of bytes stored in <code>output</code> 161 * 162 * @exception ShortBufferException if the given output buffer is too small 163 * to hold the result. 164 * @exception ExemptionMechanismException if problem(s) encountered in the 165 * process of generating. 166 */ 167 protected abstract int engineGenExemptionBlob 168 (byte[] output, int outputOffset) 169 throws ShortBufferException, ExemptionMechanismException; 170 } 171
