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Java > Open Source Codes > com > lowagie > text > pdf > crypto > AESCipher


1 /*
2  * $Id: AESCipher.java 2718 2007-04-25 21:12:47Z xlv $
3  *
4  * Copyright 2006 Paulo Soares
5  *
6  * The contents of this file are subject to the Mozilla Public License Version 1.1
7  * (the "License"); you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at http://www.mozilla.org/MPL/
9  *
10  * Software distributed under the License is distributed on an "AS IS" basis,
11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12  * for the specific language governing rights and limitations under the License.
13  *
14  * The Original Code is 'iText, a free JAVA-PDF library'.
15  *
16  * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
17  * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
18  * All Rights Reserved.
19  * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
20  * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
21  *
22  * Contributor(s): all the names of the contributors are added in the source code
23  * where applicable.
24  *
25  * Alternatively, the contents of this file may be used under the terms of the
26  * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
27  * provisions of LGPL are applicable instead of those above. If you wish to
28  * allow use of your version of this file only under the terms of the LGPL
29  * License and not to allow others to use your version of this file under
30  * the MPL, indicate your decision by deleting the provisions above and
31  * replace them with the notice and other provisions required by the LGPL.
32  * If you do not delete the provisions above, a recipient may use your version
33  * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
34  *
35  * This library is free software; you can redistribute it and/or modify it
36  * under the terms of the MPL as stated above or under the terms of the GNU
37  * Library General Public License as published by the Free Software Foundation;
38  * either version 2 of the License, or any later version.
39  *
40  * This library is distributed in the hope that it will be useful, but WITHOUT
41  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
42  * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
43  * details.
44  *
45  * If you didn't download this code from the following link, you should check if
46  * you aren't using an obsolete version:
47  * http://www.lowagie.com/iText/
48  */
49 package com.lowagie.text.pdf.crypto;
50
51 import org.bouncycastle.crypto.BlockCipher;
52 import org.bouncycastle.crypto.engines.AESFastEngine;
53 import org.bouncycastle.crypto.modes.CBCBlockCipher;
54 import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
55 import org.bouncycastle.crypto.params.KeyParameter;
56 import org.bouncycastle.crypto.params.ParametersWithIV;
57
58 /**
59  * Creates an AES Cipher with CBC and padding PKCS5/7.
60  * @author Paulo Soares (psoares@consiste.pt)
61  */
62 public class AESCipher {
63     private PaddedBufferedBlockCipher bp;
64     
65     /** Creates a new instance of AESCipher */
66     public AESCipher(boolean forEncryption, byte[] key, byte[] iv) {
67         BlockCipher aes = new AESFastEngine();
68         BlockCipher cbc = new CBCBlockCipher(aes);
69         bp = new PaddedBufferedBlockCipher(cbc);
70         KeyParameter kp = new KeyParameter(key);
71         ParametersWithIV piv = new ParametersWithIV(kp, iv);
72         bp.init(forEncryption, piv);
73     }
74     
75     public byte[] update(byte[] inp, int inpOff, int inpLen) {
76         int neededLen = bp.getUpdateOutputSize(inpLen);
77         byte[] outp = null;
78         if (neededLen > 0)
79             outp = new byte[neededLen];
80         else
81             neededLen = 0;
82         bp.processBytes(inp, inpOff, inpLen, outp, 0);
83         return outp;
84     }
85     
86     public byte[] doFinal() {
87         int neededLen = bp.getOutputSize(0);
88         byte[] outp = new byte[neededLen];
89         int n = 0;
90         try {
91             n = bp.doFinal(outp, 0);
92         } catch (Exception JavaDoc ex) {
93             return outp;
94         }
95         if (n != outp.length) {
96             byte[] outp2 = new byte[n];
97             System.arraycopy(outp, 0, outp2, 0, n);
98             return outp2;
99         }
100         else
101             return outp;
102     }
103     
104 }
105
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