/* * $Id: OutputStreamEncryption.java 5075 2012-02-27 16:36:18Z blowagie $ * * This file is part of the iText (R) project. * Copyright (c) 1998-2012 1T3XT BVBA * Authors: Bruno Lowagie, Paulo Soares, et al. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License version 3 * as published by the Free Software Foundation with the addition of the * following permission added to Section 15 as permitted in Section 7(a): * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT, * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Affero General Public License for more details. * You should have received a copy of the GNU Affero General Public License * along with this program; if not, see http://www.gnu.org/licenses or write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA, 02110-1301 USA, or download the license from the following URL: * http://itextpdf.com/terms-of-use/ * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License. * * In accordance with Section 7(b) of the GNU Affero General Public License, * a covered work must retain the producer line in every PDF that is created * or manipulated using iText. * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial activities involving the iText software without * disclosing the source code of your own applications. * These activities include: offering paid services to customers as an ASP, * serving PDFs on the fly in a web application, shipping iText with a closed * source product. * * For more information, please contact iText Software Corp. at this * address: sales@itextpdf.com */ package com.lowagie.text.pdf; import com.lowagie.text.ExceptionConverter; import com.lowagie.text.pdf.crypto.AESCipher; import com.lowagie.text.pdf.crypto.IVGenerator; import com.lowagie.text.pdf.crypto.ARCFOUREncryption; import java.io.IOException; import java.io.OutputStream; public class OutputStreamEncryption extends OutputStream { protected OutputStream out; protected ARCFOUREncryption arcfour; protected AESCipher cipher; private byte[] sb = new byte[1]; private static final int AES_128 = 4; private static final int AES_256 = 5; private boolean aes; private boolean finished; /** Creates a new instance of OutputStreamCounter */ public OutputStreamEncryption(OutputStream out, byte key[], int off, int len, int revision) { try { this.out = out; aes = (revision == AES_128 || revision == AES_256); if (aes) { byte[] iv = IVGenerator.getIV(); byte[] nkey = new byte[len]; System.arraycopy(key, off, nkey, 0, len); cipher = new AESCipher(true, nkey, iv); write(iv); } else { arcfour = new ARCFOUREncryption(); arcfour.prepareARCFOURKey(key, off, len); } } catch (Exception ex) { throw new ExceptionConverter(ex); } } public OutputStreamEncryption(OutputStream out, byte key[], int revision) { this(out, key, 0, key.length, revision); } /** Closes this output stream and releases any system resources * associated with this stream. The general contract of close * is that it closes the output stream. A closed stream cannot perform * output operations and cannot be reopened. *

* The close method of OutputStream does nothing. * * @exception IOException if an I/O error occurs. * */ public void close() throws IOException { finish(); out.close(); } /** Flushes this output stream and forces any buffered output bytes * to be written out. The general contract of flush is * that calling it is an indication that, if any bytes previously * written have been buffered by the implementation of the output * stream, such bytes should immediately be written to their * intended destination. *

* The flush method of OutputStream does nothing. * * @exception IOException if an I/O error occurs. * */ public void flush() throws IOException { out.flush(); } /** Writes b.length bytes from the specified byte array * to this output stream. The general contract for write(b) * is that it should have exactly the same effect as the call * write(b, 0, b.length). * * @param b the data. * @exception IOException if an I/O error occurs. * @see java.io.OutputStream#write(byte[], int, int) * */ public void write(byte[] b) throws IOException { write(b, 0, b.length); } /** Writes the specified byte to this output stream. The general * contract for write is that one byte is written * to the output stream. The byte to be written is the eight * low-order bits of the argument b. The 24 * high-order bits of b are ignored. *

* Subclasses of OutputStream must provide an * implementation for this method. * * @param b the byte. * @exception IOException if an I/O error occurs. In particular, * an IOException may be thrown if the * output stream has been closed. * */ public void write(int b) throws IOException { sb[0] = (byte)b; write(sb, 0, 1); } /** Writes len bytes from the specified byte array * starting at offset off to this output stream. * The general contract for write(b, off, len) is that * some of the bytes in the array b are written to the * output stream in order; element b[off] is the first * byte written and b[off+len-1] is the last byte written * by this operation. *

* The write method of OutputStream calls * the write method of one argument on each of the bytes to be * written out. Subclasses are encouraged to override this method and * provide a more efficient implementation. *

* If b is null, a * NullPointerException is thrown. *

* If off is negative, or len is negative, or * off+len is greater than the length of the array * b, then an IndexOutOfBoundsException is thrown. * * @param b the data. * @param off the start offset in the data. * @param len the number of bytes to write. * @exception IOException if an I/O error occurs. In particular, * an IOException is thrown if the output * stream is closed. * */ public void write(byte[] b, int off, int len) throws IOException { if (aes) { byte[] b2 = cipher.update(b, off, len); if (b2 == null || b2.length == 0) return; out.write(b2, 0, b2.length); } else { byte[] b2 = new byte[Math.min(len, 4192)]; while (len > 0) { int sz = Math.min(len, b2.length); arcfour.encryptARCFOUR(b, off, sz, b2, 0); out.write(b2, 0, sz); len -= sz; off += sz; } } } public void finish() throws IOException { if (!finished) { finished = true; if (aes) { byte[] b; try { b = cipher.doFinal(); } catch (Exception ex) { throw new ExceptionConverter(ex); } out.write(b, 0, b.length); } } } }