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/* * Copyright (c) 1997, 2011, 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 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; } }