001/* RC5ParameterSpec.java -- parameters for RC5. 002 Copyright (C) 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package javax.crypto.spec; 040 041import 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 */ 051public 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}