1 /* 2 * Copyright (c) 2004, 2009, 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 sun.security.krb5.internal.crypto.dk; 27 28 import javax.crypto.Cipher; 29 import javax.crypto.Mac; 30 import javax.crypto.SecretKeyFactory; 31 import javax.crypto.SecretKey; 32 import javax.crypto.spec.SecretKeySpec; 33 import javax.crypto.spec.DESKeySpec; 34 import javax.crypto.spec.DESedeKeySpec; 35 import javax.crypto.spec.IvParameterSpec; 36 import java.security.spec.KeySpec; 37 import java.security.GeneralSecurityException; 38 import java.security.InvalidKeyException; 39 import java.util.Arrays; 40 41 public class Des3DkCrypto extends DkCrypto { 42 43 private static final byte[] ZERO_IV = new byte[] {0, 0, 0, 0, 0, 0, 0, 0}; 44 Des3DkCrypto()45 public Des3DkCrypto() { 46 } 47 getKeySeedLength()48 protected int getKeySeedLength() { 49 return 168; // bits; 3DES key material has 21 bytes 50 } 51 stringToKey(char[] salt)52 public byte[] stringToKey(char[] salt) throws GeneralSecurityException { 53 byte[] saltUtf8 = null; 54 try { 55 saltUtf8 = charToUtf8(salt); 56 return stringToKey(saltUtf8, null); 57 } finally { 58 if (saltUtf8 != null) { 59 Arrays.fill(saltUtf8, (byte)0); 60 } 61 // Caller responsible for clearing its own salt 62 } 63 } 64 stringToKey(byte[] secretAndSalt, byte[] opaque)65 private byte[] stringToKey(byte[] secretAndSalt, byte[] opaque) 66 throws GeneralSecurityException { 67 68 if (opaque != null && opaque.length > 0) { 69 throw new RuntimeException("Invalid parameter to stringToKey"); 70 } 71 72 byte[] tmpKey = randomToKey(nfold(secretAndSalt, getKeySeedLength())); 73 return dk(tmpKey, KERBEROS_CONSTANT); 74 } 75 parityFix(byte[] value)76 public byte[] parityFix(byte[] value) 77 throws GeneralSecurityException { 78 // fix key parity 79 setParityBit(value); 80 return value; 81 } 82 83 /* 84 * From RFC 3961. 85 * 86 * The 168 bits of random key data are converted to a protocol key value 87 * as follows. First, the 168 bits are divided into three groups of 56 88 * bits, which are expanded individually into 64 bits as in des3Expand(). 89 * Result is a 24 byte (192-bit) key. 90 */ randomToKey(byte[] in)91 protected byte[] randomToKey(byte[] in) { 92 if (in.length != 21) { 93 throw new IllegalArgumentException("input must be 168 bits"); 94 } 95 96 byte[] one = keyCorrection(des3Expand(in, 0, 7)); 97 byte[] two = keyCorrection(des3Expand(in, 7, 14)); 98 byte[] three = keyCorrection(des3Expand(in, 14, 21)); 99 100 byte[] key = new byte[24]; 101 System.arraycopy(one, 0, key, 0, 8); 102 System.arraycopy(two, 0, key, 8, 8); 103 System.arraycopy(three, 0, key, 16, 8); 104 105 return key; 106 } 107 keyCorrection(byte[] key)108 private static byte[] keyCorrection(byte[] key) { 109 // check for weak key 110 try { 111 if (DESKeySpec.isWeak(key, 0)) { 112 key[7] = (byte)(key[7] ^ 0xF0); 113 } 114 } catch (InvalidKeyException ex) { 115 // swallow, since it should never happen 116 } 117 return key; 118 } 119 120 /** 121 * From RFC 3961. 122 * 123 * Expands a 7-byte array into an 8-byte array that contains parity bits. 124 * The 56 bits are expanded into 64 bits as follows: 125 * 1 2 3 4 5 6 7 p 126 * 9 10 11 12 13 14 15 p 127 * 17 18 19 20 21 22 23 p 128 * 25 26 27 28 29 30 31 p 129 * 33 34 35 36 37 38 39 p 130 * 41 42 43 44 45 46 47 p 131 * 49 50 51 52 53 54 55 p 132 * 56 48 40 32 24 16 8 p 133 * 134 * (PI,P2,...,P8) are reserved for parity bits computed on the preceding 135 * seven independent bits and set so that the parity of the octet is odd, 136 * i.e., there is an odd number of "1" bits in the octet. 137 * 138 * @param start index of starting byte (inclusive) 139 * @param end index of ending byte (exclusive) 140 */ des3Expand(byte[] input, int start, int end)141 private static byte[] des3Expand(byte[] input, int start, int end) { 142 if ((end - start) != 7) 143 throw new IllegalArgumentException( 144 "Invalid length of DES Key Value:" + start + "," + end); 145 146 byte[] result = new byte[8]; 147 byte last = 0; 148 System.arraycopy(input, start, result, 0, 7); 149 byte posn = 0; 150 151 // Fill in last row 152 for (int i = start; i < end; i++) { 153 byte bit = (byte) (input[i]&0x01); 154 if (debug) { 155 System.out.println(i + ": " + Integer.toHexString(input[i]) + 156 " bit= " + Integer.toHexString(bit)); 157 } 158 ++posn; 159 if (bit != 0) { 160 last |= (bit<<posn); 161 } 162 } 163 164 if (debug) { 165 System.out.println("last: " + Integer.toHexString(last)); 166 } 167 result[7] = last; 168 setParityBit(result); 169 return result; 170 } 171 172 /** 173 * Sets the parity bit (0th bit) in each byte so that each byte 174 * contains an odd number of 1's. 175 */ setParityBit(byte[] key)176 private static void setParityBit(byte[] key) { 177 for (int i = 0; i < key.length; i++) { 178 int b = key[i] & 0xfe; 179 b |= (Integer.bitCount(b) & 1) ^ 1; 180 key[i] = (byte) b; 181 } 182 } 183 getCipher(byte[] key, byte[] ivec, int mode)184 protected Cipher getCipher(byte[] key, byte[] ivec, int mode) 185 throws GeneralSecurityException { 186 // NoSuchAlgorithException 187 SecretKeyFactory factory = SecretKeyFactory.getInstance("desede"); 188 189 // InvalidKeyException 190 KeySpec spec = new DESedeKeySpec(key, 0); 191 192 // InvalidKeySpecException 193 SecretKey secretKey = factory.generateSecret(spec); 194 195 // IV 196 if (ivec == null) { 197 ivec = ZERO_IV; 198 } 199 200 // NoSuchAlgorithmException, NoSuchPaddingException 201 // NoSuchProviderException 202 Cipher cipher = Cipher.getInstance("DESede/CBC/NoPadding"); 203 IvParameterSpec encIv = new IvParameterSpec(ivec, 0, ivec.length); 204 205 // InvalidKeyException, InvalidAlgorithParameterException 206 cipher.init(mode, secretKey, encIv); 207 208 return cipher; 209 } 210 getChecksumLength()211 public int getChecksumLength() { 212 return 20; // bytes 213 } 214 getHmac(byte[] key, byte[] msg)215 protected byte[] getHmac(byte[] key, byte[] msg) 216 throws GeneralSecurityException { 217 218 SecretKey keyKi = new SecretKeySpec(key, "HmacSHA1"); 219 Mac m = Mac.getInstance("HmacSHA1"); 220 m.init(keyKi); 221 return m.doFinal(msg); 222 } 223 } 224