Source for javax.crypto.spec.RC5ParameterSpec

   1: /* RC5ParameterSpec.java -- parameters for RC5.
   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.AlgorithmParameterSpec;
  42: 
  43: /**
  44:  * A wrapper for parameters to the <a
  45:  * href="http://www.rsasecurity.com/rsalabs/faq/3-6-4.html">RC5</a>
  46:  * block cipher.
  47:  *
  48:  * @author Casey Marshall (csm@gnu.org)
  49:  * @since 1.4
  50:  */
  51: public class RC5ParameterSpec implements AlgorithmParameterSpec
  52: {
  53: 
  54:   // Fields.
  55:   // ------------------------------------------------------------------------
  56: 
  57:   /** The IV. */
  58:   private byte[] iv;
  59: 
  60:   /** The number of rounds. */
  61:   private int rounds;
  62: 
  63:   /** The version number. */
  64:   private int version;
  65: 
  66:   /** The word size, in bits. */
  67:   private int wordSize;
  68: 
  69:   // Constructors.
  70:   // ------------------------------------------------------------------------
  71: 
  72:   /**
  73:    * Create RC5 parameters without an IV.
  74:    *
  75:    * @param version  The version number.
  76:    * @param rounds   The number of rounds.
  77:    * @param wordSize The size of a word, in bits.
  78:    */
  79:   public RC5ParameterSpec(int version, int rounds, int wordSize)
  80:   {
  81:     this.version = version;
  82:     this.rounds = rounds;
  83:     this.wordSize = wordSize;
  84:   }
  85: 
  86:   /**
  87:    * Create RC5 parameters with an IV. The bytes in <code>iv</code> in
  88:    * the range <code>[0, 2*(wordSize/8)-1]</code> are used.
  89:    *
  90:    * @param version  The version number.
  91:    * @param rounds   The number of rounds.
  92:    * @param wordSize The size of a word, in bits.
  93:    * @param iv       The IV data.
  94:    */
  95:   public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv)
  96:   {
  97:     this(version, rounds, wordSize, iv, 0);
  98:   }
  99: 
 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: }