Source for gnu.javax.crypto.mode.ECB

   1: /* ECB.java --
   2:    Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc.
   3: 
   4: This file is a 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 of the License, or (at
   9: your option) 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; if not, write to the Free Software
  18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19: 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 gnu.javax.crypto.mode;
  40: 
  41: import gnu.java.security.Registry;
  42: import gnu.javax.crypto.cipher.IBlockCipher;
  43: 
  44: /**
  45:  * The implementation of the Electronic Codebook mode.
  46:  * <p>
  47:  * The Electronic Codebook (ECB) mode is a confidentiality mode that is defined
  48:  * as follows:
  49:  * <ul>
  50:  * <li>ECB Encryption: C<sub>j</sub> = CIPH<sub>K</sub>(P<sub>j</sub>)
  51:  * for j = 1...n</li>
  52:  * <li>ECB Decryption: P<sub>j</sub> = CIPH<sup>-1</sup><sub>K</sub>(C<sub>j</sub>)
  53:  * for j = 1...n</li>
  54:  * </ul>
  55:  * <p>
  56:  * In ECB encryption, the forward cipher function is applied directly, and
  57:  * independently, to each block of the plaintext. The resulting sequence of
  58:  * output blocks is the ciphertext.
  59:  * <p>
  60:  * In ECB decryption, the inverse cipher function is applied directly, and
  61:  * independently, to each block of the ciphertext. The resulting sequence of
  62:  * output blocks is the plaintext.
  63:  * <p>
  64:  * References:
  65:  * <ol>
  66:  * <li><a
  67:  * href="http://csrc.nist.gov/encryption/modes/Recommendation/Modes01.pdf">
  68:  * Recommendation for Block Cipher Modes of Operation Methods and Techniques</a>,
  69:  * Morris Dworkin.</li>
  70:  * </ol>
  71:  */
  72: public class ECB
  73:     extends BaseMode
  74:     implements Cloneable
  75: {
  76:   /**
  77:    * Trivial package-private constructor for use by the Factory class.
  78:    *
  79:    * @param underlyingCipher the underlying cipher implementation.
  80:    * @param cipherBlockSize the underlying cipher block size to use.
  81:    */
  82:   ECB(IBlockCipher underlyingCipher, int cipherBlockSize)
  83:   {
  84:     super(Registry.ECB_MODE, underlyingCipher, cipherBlockSize);
  85:   }
  86: 
  87:   /**
  88:    * Private constructor for cloning purposes.
  89:    *
  90:    * @param that the mode to clone.
  91:    */
  92:   private ECB(ECB that)
  93:   {
  94:     this((IBlockCipher) that.cipher.clone(), that.cipherBlockSize);
  95:   }
  96: 
  97:   public Object clone()
  98:   {
  99:     return new ECB(this);
 100:   }
 101: 
 102:   public void setup()
 103:   {
 104:     if (modeBlockSize != cipherBlockSize)
 105:       throw new IllegalArgumentException(IMode.MODE_BLOCK_SIZE);
 106:   }
 107: 
 108:   public void teardown()
 109:   {
 110:   }
 111: 
 112:   public void encryptBlock(byte[] in, int i, byte[] out, int o)
 113:   {
 114:     cipher.encryptBlock(in, i, out, o);
 115:   }
 116: 
 117:   public void decryptBlock(byte[] in, int i, byte[] out, int o)
 118:   {
 119:     cipher.decryptBlock(in, i, out, o);
 120:   }
 121: }