| /* | |
| * Copyright (c) 1997, 2022, 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 | |
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| * 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 | |
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| */ | |
| 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 final 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; j++) { | |
| if (WEAK_KEYS[i][j] != key[j + offset]) { | |
| found = false; | |
| break; | |
| } | |
| } | |
| if (found) { | |
| return true; | |
| } | |
| } | |
| return false; | |
| } | |
| } |