From 6025b6016517c6d898d8957d1d7e03ba71431912 Mon Sep 17 00:00:00 2001 From: tknall Date: Fri, 1 Dec 2006 12:20:24 +0000 Subject: Initial import of release 2.2. git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@4 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c --- src/main/java/org/pdfbox/encryption/ARCFour.java | 182 +++++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 src/main/java/org/pdfbox/encryption/ARCFour.java (limited to 'src/main/java/org/pdfbox/encryption/ARCFour.java') diff --git a/src/main/java/org/pdfbox/encryption/ARCFour.java b/src/main/java/org/pdfbox/encryption/ARCFour.java new file mode 100644 index 0000000..6eeeb95 --- /dev/null +++ b/src/main/java/org/pdfbox/encryption/ARCFour.java @@ -0,0 +1,182 @@ +/** + * Copyright (c) 2003, www.pdfbox.org + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. Neither the name of pdfbox; nor the names of its + * contributors may be used to endorse or promote products derived from this + * software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * http://www.pdfbox.org + * + */ +package org.pdfbox.encryption; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; + +/** + * This class is an implementation of the alleged RC4 algorithm. + * + * @author Ben Litchfield + * @version $Revision: 1.7 $ + */ +public class ARCFour +{ + private int[] salt; + private int b; + private int c; + + /** + * Constructor. + * + */ + public ARCFour() + { + salt = new int[256]; + } + + /** + * This will reset the key to be used. + * + * @param key The RC4 key used during encryption. + */ + public void setKey( byte[] key ) + { + b = 0; + c = 0; + + if(key.length < 1 || key.length > 32) + { + throw new IllegalArgumentException("number of bytes must be between 1 and 32"); + } + for(int i = 0; i < salt.length; i++) + { + salt[i] = i; + } + + int keyIndex = 0; + int saltIndex = 0; + for( int i = 0; i < salt.length; i++) + { + saltIndex = (fixByte(key[keyIndex]) + salt[i] + saltIndex) % 256; + swap( salt, i, saltIndex ); + keyIndex = (keyIndex + 1) % key.length; + } + + } + + /** + * Thie will ensure that the value for a byte >=0. + * + * @param aByte The byte to test against. + * + * @return A value >=0 and < 256 + */ + private static final int fixByte( byte aByte ) + { + return aByte < 0 ? 256 + aByte : aByte; + } + + /** + * This will swap two values in an array. + * + * @param data The array to swap from. + * @param firstIndex The index of the first element to swap. + * @param secondIndex The index of the second element to swap. + */ + private static final void swap( int[] data, int firstIndex, int secondIndex ) + { + int tmp = data[ firstIndex ]; + data[ firstIndex ] = data[ secondIndex ]; + data[ secondIndex ] = tmp; + } + + /** + * This will encrypt and write the next byte. + * + * @param aByte The byte to encrypt. + * @param output The stream to write to. + * + * @throws IOException If there is an error writing to the output stream. + */ + public void write( byte aByte, OutputStream output ) throws IOException + { + b = (b + 1) % 256; + c = (salt[b] + c) % 256; + swap( salt, b, c ); + int saltIndex = (salt[b] + salt[c]) % 256; + output.write(aByte ^ (byte)salt[saltIndex]); + } + + /** + * This will encrypt and write the data. + * + * @param data The data to encrypt. + * @param output The stream to write to. + * + * @throws IOException If there is an error writing to the output stream. + */ + public void write( byte[] data, OutputStream output ) throws IOException + { + for( int i = 0; i < data.length; i++ ) + { + write( data[i], output ); + } + } + + /** + * This will encrypt and write the data. + * + * @param data The data to encrypt. + * @param output The stream to write to. + * + * @throws IOException If there is an error writing to the output stream. + */ + public void write( InputStream data, OutputStream output ) throws IOException + { + byte[] buffer = new byte[1024]; + int amountRead = 0; + while( (amountRead = data.read( buffer )) != -1 ) + { + write( buffer, 0, amountRead, output ); + } + } + + /** + * This will encrypt and write the data. + * + * @param data The data to encrypt. + * @param offset The offset into the array to start reading data from. + * @param len The number of bytes to attempt to read. + * @param output The stream to write to. + * + * @throws IOException If there is an error writing to the output stream. + */ + public void write( byte[] data, int offset, int len, OutputStream output) throws IOException + { + for( int i = offset; i < offset + len; i++ ) + { + write( data[i], output ); + } + } +} \ No newline at end of file -- cgit v1.2.3