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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
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7  * published by the Free Software Foundation.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle in the LICENSE file that accompanied this code.
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11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
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17  * You should have received a copy of the GNU General Public License version
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24  */
25 
26 package javax.crypto;
27 
28 import java.security.*;
29 import java.security.spec.*;
30 
31 /**
32  * This class provides a delegate for the identity cipher - one that does not
33  * tranform the plaintext.
34  *
35  * @author  Li Gong
36  * @see Nullcipher
37  *
38  * @since 1.4
39  */
40 
41 final class NullCipherSpi extends CipherSpi {
42 
43     /*
44      * Do not let anybody instantiate this directly (protected).
45      */
NullCipherSpi()46     protected NullCipherSpi() {}
47 
engineSetMode(String mode)48     public void engineSetMode(String mode) {}
49 
engineSetPadding(String padding)50     public void engineSetPadding(String padding) {}
51 
engineGetBlockSize()52     protected int engineGetBlockSize() {
53         return 1;
54     }
55 
engineGetOutputSize(int inputLen)56     protected int engineGetOutputSize(int inputLen) {
57         return inputLen;
58     }
59 
engineGetIV()60     protected byte[] engineGetIV() {
61         byte[] x = new byte[8];
62         return x;
63     }
64 
engineGetParameters()65     protected AlgorithmParameters engineGetParameters() {
66         return null;
67     }
68 
engineInit(int mode, Key key, SecureRandom random)69     protected void engineInit(int mode, Key key, SecureRandom random) {}
70 
engineInit(int mode, Key key, AlgorithmParameterSpec params, SecureRandom random)71     protected void engineInit(int mode, Key key,
72                               AlgorithmParameterSpec params,
73                               SecureRandom random) {}
74 
engineInit(int mode, Key key, AlgorithmParameters params, SecureRandom random)75     protected void engineInit(int mode, Key key,
76                               AlgorithmParameters params,
77                               SecureRandom random) {}
78 
engineUpdate(byte[] input, int inputOffset, int inputLen)79     protected byte[] engineUpdate(byte[] input, int inputOffset,
80                                   int inputLen) {
81         if (input == null) return null;
82         byte[] x = new byte[inputLen];
83         System.arraycopy(input, inputOffset, x, 0, inputLen);
84         return x;
85     }
86 
engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)87     protected int engineUpdate(byte[] input, int inputOffset,
88                                int inputLen, byte[] output,
89                                int outputOffset) {
90         if (input == null) return 0;
91         System.arraycopy(input, inputOffset, output, outputOffset, inputLen);
92         return inputLen;
93     }
94 
engineDoFinal(byte[] input, int inputOffset, int inputLen)95     protected byte[] engineDoFinal(byte[] input, int inputOffset,
96                                    int inputLen)
97     {
98         return engineUpdate(input, inputOffset, inputLen);
99     }
100 
engineDoFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)101     protected int engineDoFinal(byte[] input, int inputOffset,
102                                 int inputLen, byte[] output,
103                                 int outputOffset)
104     {
105         return engineUpdate(input, inputOffset, inputLen,
106                             output, outputOffset);
107     }
108 
engineGetKeySize(Key key)109     protected int engineGetKeySize(Key key)
110     {
111         return 0;
112     }
113 }
114