/*
* $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.itextpdf.text.pdf;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.pdf.crypto.AESCipher;
import com.itextpdf.text.pdf.crypto.IVGenerator;
import com.itextpdf.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 <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);
}
}
}
}