1 /* 2 * Copyright (c) 1998, 2015, 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 javax.crypto.spec; 27 28 import java.security.MessageDigest; 29 import java.security.spec.KeySpec; 30 import java.util.Locale; 31 import javax.crypto.SecretKey; 32 33 /** 34 * This class specifies a secret key in a provider-independent fashion. 35 * 36 * <p>It can be used to construct a <code>SecretKey</code> from a byte array, 37 * without having to go through a (provider-based) 38 * <code>SecretKeyFactory</code>. 39 * 40 * <p>This class is only useful for raw secret keys that can be represented as 41 * a byte array and have no key parameters associated with them, e.g., DES or 42 * Triple DES keys. 43 * 44 * @author Jan Luehe 45 * 46 * @see javax.crypto.SecretKey 47 * @see javax.crypto.SecretKeyFactory 48 * @since 1.4 49 */ 50 public class SecretKeySpec implements KeySpec, SecretKey { 51 52 private static final long serialVersionUID = 6577238317307289933L; 53 54 /** 55 * The secret key. 56 * 57 * @serial 58 */ 59 private byte[] key; 60 61 /** 62 * The name of the algorithm associated with this key. 63 * 64 * @serial 65 */ 66 private String algorithm; 67 68 /** 69 * Constructs a secret key from the given byte array. 70 * 71 * <p>This constructor does not check if the given bytes indeed specify a 72 * secret key of the specified algorithm. For example, if the algorithm is 73 * DES, this constructor does not check if <code>key</code> is 8 bytes 74 * long, and also does not check for weak or semi-weak keys. 75 * In order for those checks to be performed, an algorithm-specific 76 * <i>key specification</i> class (in this case: 77 * {@link DESKeySpec DESKeySpec}) 78 * should be used. 79 * 80 * @param key the key material of the secret key. The contents of 81 * the array are copied to protect against subsequent modification. 82 * @param algorithm the name of the secret-key algorithm to be associated 83 * with the given key material. 84 * See Appendix A in the <a href= 85 * "{@docRoot}openjdk-redirect.html?v=8&path=/technotes/guides/security/crypto/CryptoSpec.html#AppA"> 86 * Java Cryptography Architecture Reference Guide</a> 87 * for information about standard algorithm names. 88 * @exception IllegalArgumentException if <code>algorithm</code> 89 * is null or <code>key</code> is null or empty. 90 */ 91 public SecretKeySpec(byte[] key, String algorithm) { 92 if (key == null || algorithm == null) { 93 throw new IllegalArgumentException("Missing argument"); 94 } 95 if (key.length == 0) { 96 throw new IllegalArgumentException("Empty key"); 97 } 98 this.key = key.clone(); 99 this.algorithm = algorithm; 100 } 101 102 /** 103 * Constructs a secret key from the given byte array, using the first 104 * <code>len</code> bytes of <code>key</code>, starting at 105 * <code>offset</code> inclusive. 106 * 107 * <p> The bytes that constitute the secret key are 108 * those between <code>key[offset]</code> and 109 * <code>key[offset+len-1]</code> inclusive. 110 * 111 * <p>This constructor does not check if the given bytes indeed specify a 112 * secret key of the specified algorithm. For example, if the algorithm is 113 * DES, this constructor does not check if <code>key</code> is 8 bytes 114 * long, and also does not check for weak or semi-weak keys. 115 * In order for those checks to be performed, an algorithm-specific key 116 * specification class (in this case: 117 * {@link DESKeySpec DESKeySpec}) 118 * must be used. 119 * 120 * @param key the key material of the secret key. The first 121 * <code>len</code> bytes of the array beginning at 122 * <code>offset</code> inclusive are copied to protect 123 * against subsequent modification. 124 * @param offset the offset in <code>key</code> where the key material 125 * starts. 126 * @param len the length of the key material. 127 * @param algorithm the name of the secret-key algorithm to be associated 128 * with the given key material. 129 * See Appendix A in the <a href= 130 * "{@docRoot}openjdk-redirect.html?v=8&path=/technotes/guides/security/crypto/CryptoSpec.html#AppA"> 131 * Java Cryptography Architecture Reference Guide</a> 132 * for information about standard algorithm names. 133 * @exception IllegalArgumentException if <code>algorithm</code> 134 * is null or <code>key</code> is null, empty, or too short, 135 * i.e. {@code key.length-offset<len}. 136 * @exception ArrayIndexOutOfBoundsException is thrown if 137 * <code>offset</code> or <code>len</code> index bytes outside the 138 * <code>key</code>. 139 */ 140 public SecretKeySpec(byte[] key, int offset, int len, String algorithm) { 141 if (key == null || algorithm == null) { 142 throw new IllegalArgumentException("Missing argument"); 143 } 144 if (key.length == 0) { 145 throw new IllegalArgumentException("Empty key"); 146 } 147 if (key.length-offset < len) { 148 throw new IllegalArgumentException 149 ("Invalid offset/length combination"); 150 } 151 if (len < 0) { 152 throw new ArrayIndexOutOfBoundsException("len is negative"); 153 } 154 this.key = new byte[len]; 155 System.arraycopy(key, offset, this.key, 0, len); 156 this.algorithm = algorithm; 157 } 158 159 /** 160 * Returns the name of the algorithm associated with this secret key. 161 * 162 * @return the secret key algorithm. 163 */ 164 public String getAlgorithm() { 165 return this.algorithm; 166 } 167 168 /** 169 * Returns the name of the encoding format for this secret key. 170 * 171 * @return the string "RAW". 172 */ 173 public String getFormat() { 174 return "RAW"; 175 } 176 177 /** 178 * Returns the key material of this secret key. 179 * 180 * @return the key material. Returns a new array 181 * each time this method is called. 182 */ 183 public byte[] getEncoded() { 184 return this.key.clone(); 185 } 186 187 /** 188 * Calculates a hash code value for the object. 189 * Objects that are equal will also have the same hashcode. 190 */ 191 public int hashCode() { 192 int retval = 0; 193 for (int i = 1; i < this.key.length; i++) { 194 retval += this.key[i] * i; 195 } 196 if (this.algorithm.equalsIgnoreCase("TripleDES")) 197 return (retval ^= "desede".hashCode()); 198 else 199 return (retval ^= 200 this.algorithm.toLowerCase(Locale.ENGLISH).hashCode()); 201 } 202 203 /** 204 * Tests for equality between the specified object and this 205 * object. Two SecretKeySpec objects are considered equal if 206 * they are both SecretKey instances which have the 207 * same case-insensitive algorithm name and key encoding. 208 * 209 * @param obj the object to test for equality with this object. 210 * 211 * @return true if the objects are considered equal, false if 212 * <code>obj</code> is null or otherwise. 213 */ 214 public boolean equals(Object obj) { 215 if (this == obj) 216 return true; 217 218 if (!(obj instanceof SecretKey)) 219 return false; 220 221 String thatAlg = ((SecretKey)obj).getAlgorithm(); 222 if (!(thatAlg.equalsIgnoreCase(this.algorithm))) { 223 if ((!(thatAlg.equalsIgnoreCase("DESede")) 224 || !(this.algorithm.equalsIgnoreCase("TripleDES"))) 225 && (!(thatAlg.equalsIgnoreCase("TripleDES")) 226 || !(this.algorithm.equalsIgnoreCase("DESede")))) 227 return false; 228 } 229 230 byte[] thatKey = ((SecretKey)obj).getEncoded(); 231 232 return MessageDigest.isEqual(this.key, thatKey); 233 } 234 } 235
