/*
* $Id$
*
* Copyright 2006 Paulo Soares
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library 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 Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
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 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;
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 <code>close</code>
* is that it closes the output stream. A closed stream cannot perform
* output operations and cannot be reopened.
* <p>
* The <code>close</code> method of <code>OutputStream</code> 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 <code>flush</code> 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.
* <p>
* The <code>flush</code> method of <code>OutputStream</code> does nothing.
*
* @exception IOException if an I/O error occurs.
*
*/
public void flush() throws IOException {
out.flush();
}
/** Writes <code>b.length</code> bytes from the specified byte array
* to this output stream. The general contract for <code>write(b)</code>
* is that it should have exactly the same effect as the call
* <code>write(b, 0, b.length)</code>.
*
* @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 <code>write</code> is that one byte is written
* to the output stream. The byte to be written is the eight
* low-order bits of the argument <code>b</code>. The 24
* high-order bits of <code>b</code> are ignored.
* <p>
* Subclasses of <code>OutputStream</code> must provide an
* implementation for this method.
*
* @param b the <code>byte</code>.
* @exception IOException if an I/O error occurs. In particular,
* an <code>IOException</code> 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 <code>len</code> bytes from the specified byte array
* starting at offset <code>off</code> to this output stream.
* The general contract for <code>write(b, off, len)</code> is that
* some of the bytes in the array <code>b</code> are written to the
* output stream in order; element <code>b[off]</code> is the first
* byte written and <code>b[off+len-1]</code> is the last byte written
* by this operation.
* <p>
* The <code>write</code> method of <code>OutputStream</code> 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.
* <p>
* If <code>b</code> is <code>null</code>, a
* <code>NullPointerException</code> is thrown.
* <p>
* If <code>off</code> is negative, or <code>len</code> is negative, or
* <code>off+len</code> is greater than the length of the array
* <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> 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 <code>IOException</code> 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);
}
}
}
}