/* * 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 javax.crypto.spec; import java.security.InvalidKeyException; /** * This class specifies a DES-EDE ("triple-DES") key. * * @author Jan Luehe * * @since 1.4 */public class DESedeKeySpec implements java.security.spec.KeySpec {     /**     * The constant which defines the length of a DESede key in bytes.     */    public static final int DES_EDE_KEY_LEN = 24;     private byte[] key;     /**     * Creates a DESedeKeySpec object using the first 24 bytes in     * <code>key</code> as the key material for the DES-EDE key.     *     * <p> The bytes that constitute the DES-EDE key are those between     * <code>key[0]</code> and <code>key[23]</code> inclusive     *     * @param key the buffer with the DES-EDE key material. The first     * 24 bytes of the buffer are copied to protect against subsequent     * modification.     *     * @exception NullPointerException if <code>key</code> is null.     * @exception InvalidKeyException if the given key material is shorter     * than 24 bytes.     */    public DESedeKeySpec(byte[] key) throws InvalidKeyException {        this(key, 0);    }     /**     * Creates a DESedeKeySpec object using the first 24 bytes in     * <code>key</code>, beginning at <code>offset</code> inclusive,     * as the key material for the DES-EDE key.     *     * <p> The bytes that constitute the DES-EDE key are those between     * <code>key[offset]</code> and <code>key[offset+23]</code> inclusive.     *     * @param key the buffer with the DES-EDE key material. The first     * 24 bytes of the buffer beginning at <code>offset</code> inclusive     * are copied to protect against subsequent modification.     * @param offset the offset in <code>key</code>, where the DES-EDE key     * material starts.     *     * @exception NullPointerException if <code>key</code> is null.     * @exception InvalidKeyException if the given key material, starting at     * <code>offset</code> inclusive, is shorter than 24 bytes     */    public DESedeKeySpec(byte[] key, int offset) throws InvalidKeyException {        if (key.length - offset < 24) {            throw new InvalidKeyException("Wrong key size");        }        this.key = new byte[24];        System.arraycopy(key, offset, this.key, 0, 24);    }     /**     * Returns the DES-EDE key.     *     * @return the DES-EDE key. Returns a new array     * each time this method is called.     */    public byte[] getKey() {        return (byte[])this.key.clone();    }     /**     * Checks if the given DES-EDE key, starting at <code>offset</code>     * inclusive, is parity-adjusted.     *     * @param key    a byte array which holds the key value     * @param offset the offset into the byte array     * @return true if the given DES-EDE key is parity-adjusted, false     * otherwise     *     * @exception NullPointerException if <code>key</code> is null.     * @exception InvalidKeyException if the given key material, starting at     * <code>offset</code> inclusive, is shorter than 24 bytes     */    public static boolean isParityAdjusted(byte[] key, int offset)        throws InvalidKeyException {            if (key.length - offset < 24) {                throw new InvalidKeyException("Wrong key size");            }            if (DESKeySpec.isParityAdjusted(key, offset) == false                || DESKeySpec.isParityAdjusted(key, offset + 8) == false                || DESKeySpec.isParityAdjusted(key, offset + 16) == false) {                return false;            }            return true;    }}