1 /* NullCipherImpl.java -- implementation of NullCipher.
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;
40 
41 import java.security.AlgorithmParameters;
42 import java.security.Key;
43 import java.security.SecureRandom;
44 import java.security.spec.AlgorithmParameterSpec;
45 
46 /**
47  * Implementation of the identity cipher.
48  */
49 final class NullCipherImpl extends CipherSpi
50 {
51 
52   // Constructor.
53   // -------------------------------------------------------------------------
54 
NullCipherImpl()55   NullCipherImpl()
56   {
57     super();
58   }
59 
60   // Instance methods.
61   // -------------------------------------------------------------------------
62 
engineSetMode(String mode)63   protected void engineSetMode(String mode) { }
engineSetPadding(String padding)64   protected void engineSetPadding(String padding) { }
65 
engineGetBlockSize()66   protected int engineGetBlockSize()
67   {
68     return 1;
69   }
70 
engineGetOutputSize(int inputLen)71   protected int engineGetOutputSize(int inputLen)
72   {
73     return inputLen;
74   }
75 
engineGetIV()76   protected byte[] engineGetIV()
77   {
78     return null;
79   }
80 
engineGetParameters()81   protected AlgorithmParameters engineGetParameters()
82   {
83     return null;
84   }
85 
engineInit(int mode, Key key, SecureRandom random)86   protected void engineInit(int mode, Key key, SecureRandom random) { }
engineInit(int mode, Key key, AlgorithmParameterSpec spec, SecureRandom random)87   protected void engineInit(int mode, Key key, AlgorithmParameterSpec spec, SecureRandom random) { }
engineInit(int mode, Key key, AlgorithmParameters params, SecureRandom random)88   protected void engineInit(int mode, Key key, AlgorithmParameters params, SecureRandom random) { }
89 
engineUpdate(byte[] input, int inputOffset, int inputLen)90   protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen)
91   {
92     if (input == null)
93       return new byte[0];
94     if (inputOffset < 0 || inputLen < 0 || inputOffset + inputLen > input.length)
95       throw new ArrayIndexOutOfBoundsException();
96     byte[] output = new byte[inputLen];
97     System.arraycopy(input, inputOffset, output, 0, inputLen);
98     return output;
99   }
100 
engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)101   protected int engineUpdate(byte[] input, int inputOffset, int inputLen,
102                              byte[] output, int outputOffset)
103     throws ShortBufferException
104   {
105     if (input == null)
106       return 0;
107     if (inputOffset < 0 || inputLen < 0 || inputOffset + inputLen > input.length
108         || outputOffset < 0)
109       throw new ArrayIndexOutOfBoundsException();
110     if (output.length - outputOffset < inputLen)
111       throw new ShortBufferException();
112     System.arraycopy(input, inputOffset, output, outputOffset, inputLen);
113     return inputLen;
114   }
115 
engineDoFinal(byte[] input, int inputOffset, int inputLen)116   protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)
117   {
118     return engineUpdate(input, inputOffset, inputLen);
119   }
120 
engineDoFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)121   protected int engineDoFinal(byte[] input, int inputOffset, int inputLen,
122                               byte[] output, int outputOffset)
123     throws ShortBufferException
124   {
125     return engineUpdate(input, inputOffset, inputLen, output, outputOffset);
126   }
127 }
128