Source code: javax/crypto/spec/SecretKeySpec.java
1 /* SecretKeySpec.java -- Wrapper for secret keys.
2 Copyright (C) 2004 Free Software Foundation, Inc.
3
4 This file is part of GNU Classpath.
5
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
37
38
39 package javax.crypto.spec;
40
41 import java.security.spec.KeySpec;
42
43 import javax.crypto.SecretKey;
44
45 /**
46 * This is a simple wrapper around a raw byte array, for ciphers that do
47 * not require any key parameters other than the bytes themselves.
48 *
49 * <p>Since this class implements {@link javax.crypto.SecretKey}, which
50 * in turn extends {@link java.security.Key}, so instances of this class
51 * may be passed directly to the <code>init()</code> methods of {@link
52 * javax.crypto.Cipher}.
53 *
54 * @see javax.crypto.SecretKey
55 * @see javax.crypto.SecretKeyFactory
56 */
57 public class SecretKeySpec implements KeySpec, SecretKey
58 {
59
60 // Constants and fields.
61 // ------------------------------------------------------------------------
62
63 /** Compatible with JDK1.4. */
64 private static final long serialVersionUID = 6577238317307289933L;
65
66 /** The key bytes. */
67 private byte[] key;
68
69 /** The algorithm's name. */
70 private String algorithm;
71
72 // Constructors.
73 // ------------------------------------------------------------------------
74
75 /**
76 * Create a new secret key spec from an entire byte array.
77 *
78 * @param key The key material.
79 * @param algorithm The name of the algorithm using this key.
80 */
81 public SecretKeySpec(byte[] key, String algorithm)
82 {
83 this(key, 0, key.length, algorithm);
84 }
85
86 /**
87 * Create a new secret key spec from part of a byte array.
88 *
89 * @param key The key material.
90 * @param off The offset at which key material begins.
91 * @param len The length of key material.
92 * @param algorithm The name of the algorithm using this key.
93 */
94 public SecretKeySpec(byte[] key, int off, int len, String algorithm)
95 {
96 this.key = new byte[len];
97 this.algorithm = algorithm;
98 System.arraycopy(key, off, this.key, 0, len);
99 }
100
101 // Instance methods.
102 // ------------------------------------------------------------------------
103
104 /**
105 * Return the name of the algorithm associated with this secret key.
106 *
107 * @return The algorithm's name.
108 */
109 public String getAlgorithm()
110 {
111 return algorithm;
112 }
113
114 /**
115 * Return the key as a byte array.
116 *
117 * @return The key material.
118 */
119 public byte[] getEncoded()
120 {
121 return key;
122 }
123
124 /**
125 * This key's format, which is always "RAW".
126 *
127 * @return "RAW"
128 */
129 public String getFormat()
130 {
131 return "RAW";
132 }
133
134 public boolean equals(Object o)
135 {
136 byte[] okey = ((SecretKeySpec) o).getEncoded();
137 if (key.length != okey.length) return false;
138 for (int i = 0; i < key.length; i++)
139 {
140 if (key[i] != okey[i])
141 return false;
142 }
143 return algorithm.equals(((SecretKeySpec) o).getAlgorithm());
144 }
145
146 public int hashCode()
147 {
148 int code = 0;
149 for (int i = 0; i < key.length; i++)
150 {
151 code ^= (key[i] & 0xff) << (i << 3 & 31);
152 }
153 return code ^ algorithm.hashCode();
154 }
155 }