1 /* 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.crypto.provider; 27 28 import javax.crypto.KeyGeneratorSpi; 29 import javax.crypto.SecretKey; 30 import javax.crypto.spec.DESedeKeySpec; 31 import java.security.SecureRandom; 32 import java.security.InvalidParameterException; 33 import java.security.InvalidAlgorithmParameterException; 34 import java.security.InvalidKeyException; 35 import java.security.spec.AlgorithmParameterSpec; 36 37 /** 38 * This class generates a Triple DES key. 39 * 40 * @author Jan Luehe 41 * 42 */ 43 44 public final class DESedeKeyGenerator extends KeyGeneratorSpi { 45 46 private SecureRandom random = null; 47 private int keysize = 168; 48 49 /** 50 * Empty constructor 51 */ DESedeKeyGenerator()52 public DESedeKeyGenerator() { 53 } 54 55 /** 56 * Initializes this key generator. 57 * 58 * @param random the source of randomness for this generator 59 */ engineInit(SecureRandom random)60 protected void engineInit(SecureRandom random) { 61 this.random = random; 62 } 63 64 /** 65 * Initializes this key generator with the specified parameter 66 * set and a user-provided source of randomness. 67 * 68 * @param params the key generation parameters 69 * @param random the source of randomness for this key generator 70 * 71 * @exception InvalidAlgorithmParameterException if <code>params</code> is 72 * inappropriate for this key generator 73 */ engineInit(AlgorithmParameterSpec params, SecureRandom random)74 protected void engineInit(AlgorithmParameterSpec params, 75 SecureRandom random) 76 throws InvalidAlgorithmParameterException { 77 throw new InvalidAlgorithmParameterException 78 ("Triple DES key generation does not take any parameters"); 79 } 80 81 /** 82 * Initializes this key generator for a certain keysize, using the given 83 * source of randomness. 84 * 85 * @param keysize the keysize. This is an algorithm-specific 86 * metric specified in number of bits. A keysize with 112 bits of entropy 87 * corresponds to a Triple DES key with 2 intermediate keys, and a keysize 88 * with 168 bits of entropy corresponds to a Triple DES key with 3 89 * intermediate keys. 90 * @param random the source of randomness for this key generator 91 */ engineInit(int keysize, SecureRandom random)92 protected void engineInit(int keysize, SecureRandom random) { 93 if ((keysize != 112) && (keysize != 168)) { 94 throw new InvalidParameterException("Wrong keysize: must be " 95 + "equal to 112 or 168"); 96 } 97 this.keysize = keysize; 98 this.engineInit(random); 99 } 100 101 /** 102 * Generates the Triple DES key. 103 * 104 * @return the new Triple DES key 105 */ engineGenerateKey()106 protected SecretKey engineGenerateKey() { 107 if (this.random == null) { 108 this.random = SunJCE.getRandom(); 109 } 110 111 byte[] rawkey = new byte[DESedeKeySpec.DES_EDE_KEY_LEN]; 112 113 if (keysize == 168) { 114 // 3 intermediate keys 115 this.random.nextBytes(rawkey); 116 117 // Do parity adjustment for each intermediate key 118 DESKeyGenerator.setParityBit(rawkey, 0); 119 DESKeyGenerator.setParityBit(rawkey, 8); 120 DESKeyGenerator.setParityBit(rawkey, 16); 121 } else { 122 // 2 intermediate keys 123 byte[] tmpkey = new byte[16]; 124 this.random.nextBytes(tmpkey); 125 DESKeyGenerator.setParityBit(tmpkey, 0); 126 DESKeyGenerator.setParityBit(tmpkey, 8); 127 System.arraycopy(tmpkey, 0, rawkey, 0, tmpkey.length); 128 // Copy the first 8 bytes into the last 129 System.arraycopy(tmpkey, 0, rawkey, 16, 8); 130 java.util.Arrays.fill(tmpkey, (byte)0x00); 131 } 132 133 DESedeKey desEdeKey = null; 134 try { 135 desEdeKey = new DESedeKey(rawkey); 136 } catch (InvalidKeyException ike) { 137 // this never happens 138 throw new RuntimeException(ike.getMessage()); 139 } 140 141 java.util.Arrays.fill(rawkey, (byte)0x00); 142 143 return desEdeKey; 144 } 145 } 146