001 /* RC2ParameterSpec.java -- Wrapper for RC2 parameters.
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 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 */
052 public 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 }