/* * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.crypto.provider; import java.security.InvalidKeyException; /** * This class represents ciphers in electronic codebook (ECB) mode. * * <p>This mode is implemented independently of a particular cipher. * Ciphers to which this mode should apply (e.g., DES) must be * <i>plugged-in</i> using the constructor. * * <p>NOTE: This class does not deal with buffering or padding. * * @author Gigi Ankeny */ final class ElectronicCodeBook extends FeedbackCipher {     ElectronicCodeBook(SymmetricCipher embeddedCipher) {        super(embeddedCipher);    }     /**     * Gets the name of the feedback mechanism     *     * @return the name of the feedback mechanism     */    String getFeedback() {        return "ECB";    }     /**     * Resets the iv to its original value.     * This is used when doFinal is called in the Cipher class, so that the     * cipher can be reused (with its original iv).     */    void reset() {        // empty    }     /**     * Save the current content of this cipher.     */    void save() {}     /**     * Restores the content of this cipher to the previous saved one.     */    void restore() {}     /**     * Initializes the cipher in the specified mode with the given key     * and iv.     *     * @param decrypting flag indicating encryption or decryption     * @param algorithm the algorithm name     * @param key the key     * @param iv the iv     *     * @exception InvalidKeyException if the given key is inappropriate for     * initializing this cipher     */    void init(boolean decrypting, String algorithm, byte[] key, byte[] iv)            throws InvalidKeyException {        if ((key == null) || (iv != null)) {            throw new InvalidKeyException("Internal error");        }        embeddedCipher.init(decrypting, algorithm, key);    }     /**     * Performs encryption operation.     *     * <p>The input plain text <code>plain</code>, starting at     * <code>plainOffset</code> and ending at     * <code>(plainOffset + len - 1)</code>, is encrypted.     * The result is stored in <code>cipher</code>, starting at     * <code>cipherOffset</code>.     *     * <p>It is the application's responsibility to make sure that     * <code>plainLen</code> is a multiple of the embedded cipher's block size,     * as any excess bytes are ignored.     *     * <p>It is also the application's responsibility to make sure that     * <code>init</code> has been called before this method is called.     * (This check is omitted here, to avoid double checking.)     *     * @param in the buffer with the input data to be encrypted     * @param inOffset the offset in <code>plain</code>     * @param len the length of the input data     * @param out the buffer for the result     * @param outOff the offset in <code>cipher</code>     */    void encrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {        while (len >= blockSize) {            embeddedCipher.encryptBlock(in, inOff, out, outOff);            len -= blockSize;            inOff += blockSize;            outOff += blockSize;        }    }     /**     * Performs decryption operation.     *     * <p>The input cipher text <code>cipher</code>, starting at     * <code>cipherOffset</code> and ending at     * <code>(cipherOffset + len - 1)</code>, is decrypted.     * The result is stored in <code>plain</code>, starting at     * <code>plainOffset</code>.     *     * <p>It is the application's responsibility to make sure that     * <code>cipherLen</code> is a multiple of the embedded cipher's block     * size, as any excess bytes are ignored.     *     * <p>It is also the application's responsibility to make sure that     * <code>init</code> has been called before this method is called.     * (This check is omitted here, to avoid double checking.)     *     * @param in the buffer with the input data to be decrypted     * @param inOff the offset in <code>cipherOffset</code>     * @param len the length of the input data     * @param out the buffer for the result     * @param outOff the offset in <code>plain</code>     */    void decrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {        while (len >= blockSize) {            embeddedCipher.decryptBlock(in, inOff, out, outOff);            len -= blockSize;            inOff += blockSize;            outOff += blockSize;        }    } }