2362N/A * Copyright (c) 2004, 2007, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * This class represents ciphers in cipher text stealing (CTS) mode. 0N/A * <br>CTS provides a way to allow block ciphers to operate on partial 0N/A * blocks without padding, and all bits of the message go through 0N/A * the encryption algorithm, rather than simply being XOR'd. 0N/A * <br>More details can be found in RFC 2040 section 8 "Description 0N/A * <p>This mode is implemented independently of a particular cipher. 0N/A * Ciphers to which this mode should apply (e.g., DES) must be 0N/A * <i>plugged-in</i> using the constructor. 0N/A * <p>NOTE#1: CTS requires the input data to be at least one block 0N/A * long. Thus, callers of this class has to buffer the input data 0N/A * to make sure the input data passed to encryptFinal()/decryptFinal() 0N/A * is not shorter than a block. 0N/A * <p>NOTE#2: This class does not deal with buffering or padding 0N/A * just like all other cipher mode implementations. 0N/A * @author Valerie Peng 0N/A * Gets the name of this feedback mode. 0N/A * @return the string <code>CBC</code> 0N/A * Performs the last encryption operation. 0N/A * <p>The input plain text <code>plain</code>, starting at 0N/A * <code>plainOffset</code> and ending at 0N/A * <code>(plainOffset + len - 1)</code>, is encrypted. 0N/A * The result is stored in <code>cipher</code>, starting at 0N/A * <code>cipherOffset</code>. 0N/A * <p>It is the application's responsibility to make sure that 0N/A * <code>plainLen</code> is a multiple of the embedded cipher's block size, 0N/A * as any excess bytes are ignored. 0N/A * @param plain the buffer with the input data to be encrypted 0N/A * @param plainOffset the offset in <code>plain</code> 0N/A * @param plainLen the length of the input data 0N/A * @param cipher the buffer for the result 0N/A * @param cipherOffset the offset in <code>cipher</code> 0N/A // number of bytes in the last block 0N/A // swap the last two blocks after encryption 0N/A // Do final CTS step for last two blocks (the second of which 0N/A // may or may not be incomplete). 0N/A // now encrypt the next-to-last block 0N/A // encrypt the last block 0N/A * Performs decryption operation. 0N/A * <p>The input cipher text <code>cipher</code>, starting at 0N/A * <code>cipherOffset</code> and ending at 0N/A * <code>(cipherOffset + len - 1)</code>, is decrypted. 0N/A * The result is stored in <code>plain</code>, starting at 0N/A * <code>plainOffset</code>. 0N/A * <p>It is the application's responsibility to make sure that 0N/A * <code>cipherLen</code> is a multiple of the embedded cipher's block 0N/A * size, as any excess bytes are ignored. 0N/A * <p>It is also the application's responsibility to make sure that 0N/A * <code>init</code> has been called before this method is called. 0N/A * (This check is omitted here, to avoid double checking.) 0N/A * @param cipher the buffer with the input data to be decrypted 0N/A * @param cipherOffset the offset in <code>cipherOffset</code> 0N/A * @param cipherLen the length of the input data 0N/A * @param plain the buffer for the result 0N/A * @param plainOffset the offset in <code>plain</code> 0N/A // number of bytes in the last block 0N/A // swap the last two blocks before decryption 0N/A // Do final CTS step for last two blocks (the second of which 0N/A // may or may not be incomplete). 0N/A // now decrypt the next-to-last block 0N/A // decrypt the last block 0N/A //System.arraycopy(r, 0, tmp, 0, r.length);