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 }