001/* RC2ParameterSpec.java -- Wrapper for RC2 parameters. 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 for the <a 045 * href="http://www.rsasecurity.com/rsalabs/faq/3-6-2.html">RC2</a> 046 * block cipher ("RC" means either "Rivest Cipher" or "Ron's Code", 047 * depending upon who you ask and when). 048 * 049 * @author Casey Marshall (csm@gnu.org) 050 * @since 1.4 051 */ 052public class RC2ParameterSpec implements AlgorithmParameterSpec 053{ 054 055 // Constants and fields. 056 // ------------------------------------------------------------------------ 057 058 /** The length of an RC2 IV, in bytes. */ 059 private static final int RC2_IV_LENGTH = 8; 060 061 /** The effective key length, in bits. */ 062 private int effectiveKeyBits; 063 064 /** The initialization vector. */ 065 private byte[] iv; 066 067 // Constructors. 068 // ------------------------------------------------------------------------ 069 070 /** 071 * Create RC2 parameters without an IV. 072 * 073 * @param effectiveKeyBits The number of effective key bits. 074 */ 075 public RC2ParameterSpec(int effectiveKeyBits) 076 { 077 this.effectiveKeyBits = effectiveKeyBits; 078 } 079 080 /** 081 * Create RC2 parameters with an IV. 082 * 083 * @param effectiveKeyBits The number of effective key bits. 084 * @param iv The IV; the first eight bytes of this array 085 * are used. 086 */ 087 public RC2ParameterSpec(int effectiveKeyBits, byte[] iv) 088 { 089 this(effectiveKeyBits, iv, 0); 090 } 091 092 /** 093 * Create RC2 parameters with an IV. 094 * 095 * @param effectiveKeyBits The number of effective key bits. 096 * @param iv The IV; the first eight bytes of this array 097 * after <code>offset</code> are used. 098 * @param offset From whence to start in the array. 099 */ 100 public RC2ParameterSpec(int effectiveKeyBits, byte[] iv, int offset) 101 { 102 if (iv.length - offset < RC2_IV_LENGTH) 103 { 104 throw new IllegalArgumentException("IV too short"); 105 } 106 this.effectiveKeyBits = effectiveKeyBits; 107 this.iv = new byte[RC2_IV_LENGTH]; 108 System.arraycopy(iv, offset, this.iv, 0, RC2_IV_LENGTH); 109 } 110 111 // Instance methods. 112 // ------------------------------------------------------------------------ 113 114 /** 115 * Get the number of effective key bits. 116 * 117 * @return The numer of effective key bits. 118 */ 119 public int getEffectiveKeyBits() 120 { 121 return effectiveKeyBits; 122 } 123 124 /** 125 * Return the initialization vector, or <code>null</code> if none was 126 * specified. 127 * 128 * @return The IV, or null. 129 */ 130 public byte[] getIV() 131 { 132 return iv; 133 } 134 135 public boolean equals(Object o) 136 { 137 if (this == o) return true; 138 byte[] oiv = ((RC2ParameterSpec) o).getIV(); 139 if (iv != oiv) 140 { 141 if (iv == null || oiv == null) return false; 142 if (iv.length != oiv.length) return false; 143 for (int i = 0; i < iv.length; i++) 144 { 145 if (iv[i] != oiv[i]) 146 { 147 return false; 148 } 149 } 150 } 151 return effectiveKeyBits == ((RC2ParameterSpec) o).getEffectiveKeyBits(); 152 } 153 154 public int hashCode() 155 { 156 int code = effectiveKeyBits; 157 if (iv != null) 158 { 159 for (int i = 0; i < RC2_IV_LENGTH; i++) 160 { 161 code += iv[i]; 162 } 163 } 164 return code; 165 } 166}