001/*
002 * $Id: AESCipher.java 4784 2011-03-15 08:33:00Z blowagie $
003 *
004 * This file is part of the iText (R) project.
005 * Copyright (c) 1998-2011 1T3XT BVBA
006 * Authors: Bruno Lowagie, Paulo Soares, et al.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU Affero General Public License version 3
010 * as published by the Free Software Foundation with the addition of the
011 * following permission added to Section 15 as permitted in Section 7(a):
012 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
013 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
014 *
015 * This program is distributed in the hope that it will be useful, but
016 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
017 * or FITNESS FOR A PARTICULAR PURPOSE.
018 * See the GNU Affero General Public License for more details.
019 * You should have received a copy of the GNU Affero General Public License
020 * along with this program; if not, see http://www.gnu.org/licenses or write to
021 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
022 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
023 * http://itextpdf.com/terms-of-use/
024 *
025 * The interactive user interfaces in modified source and object code versions
026 * of this program must display Appropriate Legal Notices, as required under
027 * Section 5 of the GNU Affero General Public License.
028 *
029 * In accordance with Section 7(b) of the GNU Affero General Public License,
030 * a covered work must retain the producer line in every PDF that is created
031 * or manipulated using iText.
032 *
033 * You can be released from the requirements of the license by purchasing
034 * a commercial license. Buying such a license is mandatory as soon as you
035 * develop commercial activities involving the iText software without
036 * disclosing the source code of your own applications.
037 * These activities include: offering paid services to customers as an ASP,
038 * serving PDFs on the fly in a web application, shipping iText with a closed
039 * source product.
040 *
041 * For more information, please contact iText Software Corp. at this
042 * address: sales@itextpdf.com
043 */
044package com.itextpdf.text.pdf.crypto;
045
046import org.bouncycastle.crypto.BlockCipher;
047import org.bouncycastle.crypto.engines.AESFastEngine;
048import org.bouncycastle.crypto.modes.CBCBlockCipher;
049import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
050import org.bouncycastle.crypto.params.KeyParameter;
051import org.bouncycastle.crypto.params.ParametersWithIV;
052
053/**
054 * Creates an AES Cipher with CBC and padding PKCS5/7.
055 * @author Paulo Soares
056 */
057public class AESCipher {
058    private PaddedBufferedBlockCipher bp;
059    
060    /** Creates a new instance of AESCipher */
061    public AESCipher(boolean forEncryption, byte[] key, byte[] iv) {
062        BlockCipher aes = new AESFastEngine();
063        BlockCipher cbc = new CBCBlockCipher(aes);
064        bp = new PaddedBufferedBlockCipher(cbc);
065        KeyParameter kp = new KeyParameter(key);
066        ParametersWithIV piv = new ParametersWithIV(kp, iv);
067        bp.init(forEncryption, piv);
068    }
069    
070    public byte[] update(byte[] inp, int inpOff, int inpLen) {
071        int neededLen = bp.getUpdateOutputSize(inpLen);
072        byte[] outp = null;
073        if (neededLen > 0)
074            outp = new byte[neededLen];
075        else
076            neededLen = 0;
077        bp.processBytes(inp, inpOff, inpLen, outp, 0);
078        return outp;
079    }
080    
081    public byte[] doFinal() {
082        int neededLen = bp.getOutputSize(0);
083        byte[] outp = new byte[neededLen];
084        int n = 0;
085        try {
086            n = bp.doFinal(outp, 0);
087        } catch (Exception ex) {
088            return outp;
089        }
090        if (n != outp.length) {
091            byte[] outp2 = new byte[n];
092            System.arraycopy(outp, 0, outp2, 0, n);
093            return outp2;
094        }
095        else
096            return outp;
097    }
098    
099}