001 /* RC5ParameterSpec.java -- parameters for RC5.
002 Copyright (C) 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.crypto.spec;
040
041 import java.security.spec.AlgorithmParameterSpec;
042
043 /**
044 * A wrapper for parameters to the <a
045 * href="http://www.rsasecurity.com/rsalabs/faq/3-6-4.html">RC5</a>
046 * block cipher.
047 *
048 * @author Casey Marshall (csm@gnu.org)
049 * @since 1.4
050 */
051 public class RC5ParameterSpec implements AlgorithmParameterSpec
052 {
053
054 // Fields.
055 // ------------------------------------------------------------------------
056
057 /** The IV. */
058 private byte[] iv;
059
060 /** The number of rounds. */
061 private int rounds;
062
063 /** The version number. */
064 private int version;
065
066 /** The word size, in bits. */
067 private int wordSize;
068
069 // Constructors.
070 // ------------------------------------------------------------------------
071
072 /**
073 * Create RC5 parameters without an IV.
074 *
075 * @param version The version number.
076 * @param rounds The number of rounds.
077 * @param wordSize The size of a word, in bits.
078 */
079 public RC5ParameterSpec(int version, int rounds, int wordSize)
080 {
081 this.version = version;
082 this.rounds = rounds;
083 this.wordSize = wordSize;
084 }
085
086 /**
087 * Create RC5 parameters with an IV. The bytes in <code>iv</code> in
088 * the range <code>[0, 2*(wordSize/8)-1]</code> are used.
089 *
090 * @param version The version number.
091 * @param rounds The number of rounds.
092 * @param wordSize The size of a word, in bits.
093 * @param iv The IV data.
094 */
095 public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv)
096 {
097 this(version, rounds, wordSize, iv, 0);
098 }
099
100 /**
101 * Create RC5 parameters with an IV. The bytes in <code>iv</code> in
102 * the range <code>[off, off+2*(wordSize/8)-1]</code> are used.
103 *
104 * @param version The version number.
105 * @param rounds The number of rounds.
106 * @param wordSize The size of a word, in bits.
107 * @param iv The IV data.
108 * @param off From where in the array the IV starts.
109 */
110 public
111 RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv, int off)
112 {
113 this(version, rounds, wordSize);
114 int ivLength = 2 * (wordSize / 8);
115 if (off < 0)
116 throw new IllegalArgumentException();
117 if (iv.length - off < ivLength)
118 {
119 throw new IllegalArgumentException("IV too short");
120 }
121 this.iv = new byte[ivLength];
122 System.arraycopy(iv, off, this.iv, 0, ivLength);
123 }
124
125 // Instance methods.
126 // ------------------------------------------------------------------------
127
128 /**
129 * Return the initializaiton vector, or <code>null</code> if none was
130 * specified.
131 *
132 * @return The IV, or null.
133 */
134 public byte[] getIV()
135 {
136 return iv;
137 }
138
139 /**
140 * Get the number of rounds.
141 *
142 * @return The number of rounds.
143 */
144 public int getRounds()
145 {
146 return rounds;
147 }
148
149 /**
150 * Get the version number.
151 *
152 * @return The version number.
153 */
154 public int getVersion()
155 {
156 return version;
157 }
158
159 /**
160 * Get the word size, in bits.
161 *
162 * @return The word size, in bits.
163 */
164 public int getWordSize()
165 {
166 return wordSize;
167 }
168
169 public boolean equals(Object o)
170 {
171 if (this == o) return true;
172 byte[] oiv = ((RC5ParameterSpec) o).getIV();
173 if (iv != oiv)
174 {
175 if (iv == null || oiv == null) return false;
176 if (iv.length != oiv.length) return false;
177 for (int i = 0; i < iv.length; i++)
178 {
179 if (iv[i] != oiv[i])
180 {
181 return false;
182 }
183 }
184 }
185 return rounds == ((RC5ParameterSpec) o).getRounds()
186 && version == ((RC5ParameterSpec) o).getVersion()
187 && wordSize == ((RC5ParameterSpec) o).getWordSize();
188 }
189
190 public int hashCode()
191 {
192 int code = rounds + version + wordSize;
193 if (iv != null)
194 {
195 for (int i = 0; i < iv.length; i++)
196 {
197 code += iv[i];
198 }
199 }
200 return code;
201 }
202 }