/* * 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 key. * * @author Jan Luehe * * @since 1.4 */public class DESKeySpec implements java.security.spec.KeySpec {     /**     * The constant which defines the length of a DES key in bytes.     */    public static final int DES_KEY_LEN = 8;     private byte[] key;     /*     * Weak/semi-weak keys copied from FIPS 74.     *     * "...The first 6 keys have duals different than themselves, hence     * each is both a key and a dual giving 12 keys with duals. The last     * four keys equal their duals, and are called self-dual keys..."     *     * 1.   E001E001F101F101    01E001E001F101F1     * 2.   FE1FFE1FFEOEFEOE    1FFE1FFEOEFEOEFE     * 3.   E01FE01FF10EF10E    1FE01FEOOEF10EF1     * 4.   01FE01FE01FE01FE    FE01FE01FE01FE01     * 5.   011F011F010E010E    1F011F010E010E01     * 6.   E0FEE0FEF1FEF1FE    FEE0FEE0FEF1FEF1     * 7.   0101010101010101    0101010101010101     * 8.   FEFEFEFEFEFEFEFE    FEFEFEFEFEFEFEFE     * 9.   E0E0E0E0F1F1F1F1    E0E0E0E0F1F1F1F1     * 10.  1F1F1F1F0E0E0E0E    1F1F1F1F0E0E0E0E     */    private static final byte[][] WEAK_KEYS = {         { (byte)0x01, (byte)0x01, (byte)0x01, (byte)0x01, (byte)0x01,          (byte)0x01, (byte)0x01, (byte)0x01 },         { (byte)0xFE, (byte)0xFE, (byte)0xFE, (byte)0xFE, (byte)0xFE,          (byte)0xFE, (byte)0xFE, (byte)0xFE },         { (byte)0x1F, (byte)0x1F, (byte)0x1F, (byte)0x1F, (byte)0x0E,          (byte)0x0E, (byte)0x0E, (byte)0x0E },         { (byte)0xE0, (byte)0xE0, (byte)0xE0, (byte)0xE0, (byte)0xF1,          (byte)0xF1, (byte)0xF1, (byte)0xF1 },         { (byte)0x01, (byte)0xFE, (byte)0x01, (byte)0xFE, (byte)0x01,          (byte)0xFE, (byte)0x01, (byte)0xFE },         { (byte)0x1F, (byte)0xE0, (byte)0x1F, (byte)0xE0, (byte)0x0E,          (byte)0xF1, (byte)0x0E, (byte)0xF1 },         { (byte)0x01, (byte)0xE0, (byte)0x01, (byte)0xE0, (byte)0x01,          (byte)0xF1, (byte)0x01, (byte)0xF1 },         { (byte)0x1F, (byte)0xFE, (byte)0x1F, (byte)0xFE, (byte)0x0E,          (byte)0xFE, (byte)0x0E, (byte)0xFE },         { (byte)0x01, (byte)0x1F, (byte)0x01, (byte)0x1F, (byte)0x01,          (byte)0x0E, (byte)0x01, (byte)0x0E },         { (byte)0xE0, (byte)0xFE, (byte)0xE0, (byte)0xFE, (byte)0xF1,          (byte)0xFE, (byte)0xF1, (byte)0xFE },         { (byte)0xFE, (byte)0x01, (byte)0xFE, (byte)0x01, (byte)0xFE,          (byte)0x01, (byte)0xFE, (byte)0x01 },         { (byte)0xE0, (byte)0x1F, (byte)0xE0, (byte)0x1F, (byte)0xF1,          (byte)0x0E, (byte)0xF1, (byte)0x0E },         { (byte)0xE0, (byte)0x01, (byte)0xE0, (byte)0x01, (byte)0xF1,          (byte)0x01, (byte)0xF1, (byte)0x01 },         { (byte)0xFE, (byte)0x1F, (byte)0xFE, (byte)0x1F, (byte)0xFE,          (byte)0x0E, (byte)0xFE, (byte)0x0E },         { (byte)0x1F, (byte)0x01, (byte)0x1F, (byte)0x01, (byte)0x0E,          (byte)0x01, (byte)0x0E, (byte)0x01 },         { (byte)0xFE, (byte)0xE0, (byte)0xFE, (byte)0xE0, (byte)0xFE,          (byte)0xF1, (byte)0xFE, (byte)0xF1 }    };     /**     * Creates a DESKeySpec object using the first 8 bytes in     * <code>key</code> as the key material for the DES key.     *     * <p> The bytes that constitute the DES key are those between     * <code>key[0]</code> and <code>key[7]</code> inclusive.     *     * @param key the buffer with the DES key material. The first 8 bytes     * of the buffer are copied to protect against subsequent modification.     *     * @exception NullPointerException if the given key material is     * <code>null</code>     * @exception InvalidKeyException if the given key material is shorter     * than 8 bytes.     */    public DESKeySpec(byte[] key) throws InvalidKeyException {        this(key, 0);    }     /**     * Creates a DESKeySpec object using the first 8 bytes in     * <code>key</code>, beginning at <code>offset</code> inclusive,     * as the key material for the DES key.     *     * <p> The bytes that constitute the DES key are those between     * <code>key[offset]</code> and <code>key[offset+7]</code> inclusive.     *     * @param key the buffer with the DES key material. The first 8 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 key     * material starts.     *     * @exception NullPointerException if the given key material is     * <code>null</code>     * @exception InvalidKeyException if the given key material, starting at     * <code>offset</code> inclusive, is shorter than 8 bytes.     */    public DESKeySpec(byte[] key, int offset) throws InvalidKeyException {        if (key.length - offset < DES_KEY_LEN) {            throw new InvalidKeyException("Wrong key size");        }        this.key = new byte[DES_KEY_LEN];        System.arraycopy(key, offset, this.key, 0, DES_KEY_LEN);    }     /**     * Returns the DES key material.     *     * @return the DES key material. Returns a new array     * each time this method is called.     */    public byte[] getKey() {        return (byte[])this.key.clone();    }     /**     * Checks if the given DES key material, starting at <code>offset</code>     * inclusive, is parity-adjusted.     *     * @param key the buffer with the DES key material.     * @param offset the offset in <code>key</code>, where the DES key     * material starts.     *     * @return true if the given DES key material is parity-adjusted, false     * otherwise.     *     * @exception InvalidKeyException if the given key material is     * <code>null</code>, or starting at <code>offset</code> inclusive, is     * shorter than 8 bytes.     */    public static boolean isParityAdjusted(byte[] key, int offset)        throws InvalidKeyException {            if (key == null) {                throw new InvalidKeyException("null key");            }            if (key.length - offset < DES_KEY_LEN) {                throw new InvalidKeyException("Wrong key size");            }             for (int i = 0; i < DES_KEY_LEN; i++) {                int k = Integer.bitCount(key[offset++] & 0xff);                if ((k & 1) == 0) {                    return false;                }            }             return true;    }     /**     * Checks if the given DES key material is weak or semi-weak.     *     * @param key the buffer with the DES key material.     * @param offset the offset in <code>key</code>, where the DES key     * material starts.     *     * @return true if the given DES key material is weak or semi-weak, false     * otherwise.     *     * @exception InvalidKeyException if the given key material is     * <code>null</code>, or starting at <code>offset</code> inclusive, is     * shorter than 8 bytes.     */    public static boolean isWeak(byte[] key, int offset)        throws InvalidKeyException {        if (key == null) {            throw new InvalidKeyException("null key");        }        if (key.length - offset < DES_KEY_LEN) {            throw new InvalidKeyException("Wrong key size");        }        for (int i = 0; i < WEAK_KEYS.length; i++) {            boolean found = true;            for (int j = 0; j < DES_KEY_LEN && found == true; j++) {                if (WEAK_KEYS[i][j] != key[j+offset]) {                    found = false;                }            }            if (found == true) {                return found;            }        }        return false;    }}