J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.crypto.spec; |
| 27 | |
| 28 | import java.security.InvalidKeyException; |
| 29 | |
| 30 | /** |
| 31 | * This class specifies a DES-EDE ("triple-DES") key. |
| 32 | * |
| 33 | * @author Jan Luehe |
| 34 | * |
| 35 | * @since 1.4 |
| 36 | */ |
| 37 | public class DESedeKeySpec implements java.security.spec.KeySpec { |
| 38 | |
| 39 | /** |
| 40 | * The constant which defines the length of a DESede key in bytes. |
| 41 | */ |
| 42 | public static final int DES_EDE_KEY_LEN = 24; |
| 43 | |
| 44 | private byte[] key; |
| 45 | |
| 46 | /** |
| 47 | * Creates a DESedeKeySpec object using the first 24 bytes in |
| 48 | * <code>key</code> as the key material for the DES-EDE key. |
| 49 | * |
| 50 | * <p> The bytes that constitute the DES-EDE key are those between |
| 51 | * <code>key[0]</code> and <code>key[23]</code> inclusive |
| 52 | * |
| 53 | * @param key the buffer with the DES-EDE key material. The first |
| 54 | * 24 bytes of the buffer are copied to protect against subsequent |
| 55 | * modification. |
| 56 | * |
| 57 | * @exception NullPointerException if <code>key</code> is null. |
| 58 | * @exception InvalidKeyException if the given key material is shorter |
| 59 | * than 24 bytes. |
| 60 | */ |
| 61 | public DESedeKeySpec(byte[] key) throws InvalidKeyException { |
| 62 | this(key, 0); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Creates a DESedeKeySpec object using the first 24 bytes in |
| 67 | * <code>key</code>, beginning at <code>offset</code> inclusive, |
| 68 | * as the key material for the DES-EDE key. |
| 69 | * |
| 70 | * <p> The bytes that constitute the DES-EDE key are those between |
| 71 | * <code>key[offset]</code> and <code>key[offset+23]</code> inclusive. |
| 72 | * |
| 73 | * @param key the buffer with the DES-EDE key material. The first |
| 74 | * 24 bytes of the buffer beginning at <code>offset</code> inclusive |
| 75 | * are copied to protect against subsequent modification. |
| 76 | * @param offset the offset in <code>key</code>, where the DES-EDE key |
| 77 | * material starts. |
| 78 | * |
| 79 | * @exception NullPointerException if <code>key</code> is null. |
| 80 | * @exception InvalidKeyException if the given key material, starting at |
| 81 | * <code>offset</code> inclusive, is shorter than 24 bytes |
| 82 | */ |
| 83 | public DESedeKeySpec(byte[] key, int offset) throws InvalidKeyException { |
| 84 | if (key.length - offset < 24) { |
| 85 | throw new InvalidKeyException("Wrong key size"); |
| 86 | } |
| 87 | this.key = new byte[24]; |
| 88 | System.arraycopy(key, offset, this.key, 0, 24); |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Returns the DES-EDE key. |
| 93 | * |
| 94 | * @return the DES-EDE key. Returns a new array |
| 95 | * each time this method is called. |
| 96 | */ |
| 97 | public byte[] getKey() { |
| 98 | return (byte[])this.key.clone(); |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Checks if the given DES-EDE key, starting at <code>offset</code> |
| 103 | * inclusive, is parity-adjusted. |
| 104 | * |
| 105 | * @param key a byte array which holds the key value |
| 106 | * @param offset the offset into the byte array |
| 107 | * @return true if the given DES-EDE key is parity-adjusted, false |
| 108 | * otherwise |
| 109 | * |
| 110 | * @exception NullPointerException if <code>key</code> is null. |
| 111 | * @exception InvalidKeyException if the given key material, starting at |
| 112 | * <code>offset</code> inclusive, is shorter than 24 bytes |
| 113 | */ |
| 114 | public static boolean isParityAdjusted(byte[] key, int offset) |
| 115 | throws InvalidKeyException { |
| 116 | if (key.length - offset < 24) { |
| 117 | throw new InvalidKeyException("Wrong key size"); |
| 118 | } |
| 119 | if (DESKeySpec.isParityAdjusted(key, offset) == false |
| 120 | || DESKeySpec.isParityAdjusted(key, offset + 8) == false |
| 121 | || DESKeySpec.isParityAdjusted(key, offset + 16) == false) { |
| 122 | return false; |
| 123 | } |
| 124 | return true; |
| 125 | } |
| 126 | } |