Source for javax.crypto.spec.SecretKeySpec

   1: /* SecretKeySpec.java -- Wrapper for secret keys.
   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.KeySpec;
  42: 
  43: import javax.crypto.SecretKey;
  44: 
  45: /**
  46:  * This is a simple wrapper around a raw byte array, for ciphers that do
  47:  * not require any key parameters other than the bytes themselves.
  48:  *
  49:  * <p>Since this class implements {@link javax.crypto.SecretKey}, which
  50:  * in turn extends {@link java.security.Key}, so instances of this class
  51:  * may be passed directly to the <code>init()</code> methods of {@link
  52:  * javax.crypto.Cipher}.
  53:  *
  54:  * @see javax.crypto.SecretKey
  55:  * @see javax.crypto.SecretKeyFactory
  56:  */
  57: public class SecretKeySpec implements KeySpec, SecretKey
  58: {
  59: 
  60:   // Constants and fields.
  61:   // ------------------------------------------------------------------------
  62: 
  63:   /** Compatible with JDK1.4. */
  64:   private static final long serialVersionUID = 6577238317307289933L;
  65: 
  66:   /** The key bytes. */
  67:   private byte[] key;
  68: 
  69:   /** The algorithm's name. */
  70:   private String algorithm;
  71: 
  72:   // Constructors.
  73:   // ------------------------------------------------------------------------
  74: 
  75:   /**
  76:    * Create a new secret key spec from an entire byte array.
  77:    *
  78:    * @param key       The key material.
  79:    * @param algorithm The name of the algorithm using this key.
  80:    */
  81:   public SecretKeySpec(byte[] key, String algorithm)
  82:   {
  83:     this(key, 0, key.length, algorithm);
  84:   }
  85: 
  86:   /**
  87:    * Create a new secret key spec from part of a byte array.
  88:    *
  89:    * @param key       The key material.
  90:    * @param off       The offset at which key material begins.
  91:    * @param len       The length of key material.
  92:    * @param algorithm The name of the algorithm using this key.
  93:    */
  94:   public SecretKeySpec(byte[] key, int off, int len, String algorithm)
  95:   {
  96:     this.key = new byte[len];
  97:     this.algorithm = algorithm;
  98:     System.arraycopy(key, off, this.key, 0, len);
  99:   }
 100: 
 101:   // Instance methods.
 102:   // ------------------------------------------------------------------------
 103: 
 104:   /**
 105:    * Return the name of the algorithm associated with this secret key.
 106:    *
 107:    * @return The algorithm's name.
 108:    */
 109:   public String getAlgorithm()
 110:   {
 111:     return algorithm;
 112:   }
 113: 
 114:   /**
 115:    * Return the key as a byte array.
 116:    *
 117:    * @return The key material.
 118:    */
 119:   public byte[] getEncoded()
 120:   {
 121:     return key;
 122:   }
 123: 
 124:   /**
 125:    * This key's format, which is always "RAW".
 126:    *
 127:    * @return "RAW"
 128:    */
 129:   public String getFormat()
 130:   {
 131:     return "RAW";
 132:   }
 133: 
 134:   public boolean equals(Object o)
 135:   {
 136:     if (o instanceof SecretKeySpec)
 137:       {
 138:         byte[] okey = ((SecretKeySpec) o).getEncoded();
 139:         if (key.length != okey.length)
 140:           return false;
 141:         for (int i = 0; i < key.length; i++)
 142:           {
 143:             if (key[i] != okey[i])
 144:               return false;
 145:           }
 146:         return algorithm.equals(((SecretKeySpec) o).getAlgorithm());
 147:       }
 148:     else
 149:       {
 150:         return false;
 151:       }
 152:   }
 153: 
 154:   public int hashCode()
 155:   {
 156:     int code = 0;
 157:     for (int i = 0; i < key.length; i++)
 158:       {
 159:         code ^= (key[i] & 0xff) << (i << 3 & 31);
 160:       }
 161:     return code ^ algorithm.hashCode();
 162:   }
 163: }