J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2002-2007 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 | |
| 27 | package sun.security.ssl; |
| 28 | |
| 29 | import java.security.*; |
| 30 | |
| 31 | /** |
| 32 | * Abstraction for the SSL/TLS hash of all handshake messages that is |
| 33 | * maintained to verify the integrity of the negotiation. Internally, |
| 34 | * it consists of an MD5 and an SHA1 digest. They are used in the client |
| 35 | * and server finished messages and in certificate verify messages (if sent). |
| 36 | * |
| 37 | * This class transparently deals with cloneable and non-cloneable digests. |
| 38 | * |
| 39 | */ |
| 40 | final class HandshakeHash { |
| 41 | |
| 42 | private final MessageDigest md5, sha; |
| 43 | |
| 44 | /** |
| 45 | * Create a new HandshakeHash. needCertificateVerify indicates whether |
| 46 | * a hash for the certificate verify message is required. |
| 47 | */ |
| 48 | HandshakeHash(boolean needCertificateVerify) { |
| 49 | int n = needCertificateVerify ? 3 : 2; |
| 50 | try { |
| 51 | md5 = CloneableDigest.getDigest("MD5", n); |
| 52 | sha = CloneableDigest.getDigest("SHA", n); |
| 53 | } catch (NoSuchAlgorithmException e) { |
| 54 | throw new RuntimeException |
| 55 | ("Algorithm MD5 or SHA not available", e); |
| 56 | |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | void update(byte b) { |
| 61 | md5.update(b); |
| 62 | sha.update(b); |
| 63 | } |
| 64 | |
| 65 | void update(byte[] b, int offset, int len) { |
| 66 | md5.update(b, offset, len); |
| 67 | sha.update(b, offset, len); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Reset the remaining digests. Note this does *not* reset the numbe of |
| 72 | * digest clones that can be obtained. Digests that have already been |
| 73 | * cloned and are gone remain gone. |
| 74 | */ |
| 75 | void reset() { |
| 76 | md5.reset(); |
| 77 | sha.reset(); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Return a new MD5 digest updated with all data hashed so far. |
| 82 | */ |
| 83 | MessageDigest getMD5Clone() { |
| 84 | return cloneDigest(md5); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Return a new SHA digest updated with all data hashed so far. |
| 89 | */ |
| 90 | MessageDigest getSHAClone() { |
| 91 | return cloneDigest(sha); |
| 92 | } |
| 93 | |
| 94 | private static MessageDigest cloneDigest(MessageDigest digest) { |
| 95 | try { |
| 96 | return (MessageDigest)digest.clone(); |
| 97 | } catch (CloneNotSupportedException e) { |
| 98 | // cannot occur for digests generated via CloneableDigest |
| 99 | throw new RuntimeException("Could not clone digest", e); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * A wrapper for MessageDigests that simulates cloning of non-cloneable |
| 107 | * digests. It uses the standard MessageDigest API and therefore can be used |
| 108 | * transparently in place of a regular digest. |
| 109 | * |
| 110 | * Note that we extend the MessageDigest class directly rather than |
| 111 | * MessageDigestSpi. This works because MessageDigest was originally designed |
| 112 | * this way in the JDK 1.1 days which allows us to avoid creating an internal |
| 113 | * provider. |
| 114 | * |
| 115 | * It can be "cloned" a limited number of times, which is specified at |
| 116 | * construction time. This is achieved by internally maintaining n digests |
| 117 | * in parallel. Consequently, it is only 1/n-th times as fast as the original |
| 118 | * digest. |
| 119 | * |
| 120 | * Example: |
| 121 | * MessageDigest md = CloneableDigest.getDigest("SHA", 2); |
| 122 | * md.update(data1); |
| 123 | * MessageDigest md2 = (MessageDigest)md.clone(); |
| 124 | * md2.update(data2); |
| 125 | * byte[] d1 = md2.digest(); // digest of data1 || data2 |
| 126 | * md.update(data3); |
| 127 | * byte[] d2 = md.digest(); // digest of data1 || data3 |
| 128 | * |
| 129 | * This class is not thread safe. |
| 130 | * |
| 131 | */ |
| 132 | final class CloneableDigest extends MessageDigest implements Cloneable { |
| 133 | |
| 134 | /** |
| 135 | * The individual MessageDigests. Initially, all elements are non-null. |
| 136 | * When clone() is called, the non-null element with the maximum index is |
| 137 | * returned and the array element set to null. |
| 138 | * |
| 139 | * All non-null element are always in the same state. |
| 140 | */ |
| 141 | private final MessageDigest[] digests; |
| 142 | |
| 143 | private CloneableDigest(MessageDigest digest, int n, String algorithm) |
| 144 | throws NoSuchAlgorithmException { |
| 145 | super(algorithm); |
| 146 | digests = new MessageDigest[n]; |
| 147 | digests[0] = digest; |
| 148 | for (int i = 1; i < n; i++) { |
| 149 | digests[i] = JsseJce.getMessageDigest(algorithm); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Return a MessageDigest for the given algorithm that can be cloned the |
| 155 | * specified number of times. If the default implementation supports |
| 156 | * cloning, it is returned. Otherwise, an instance of this class is |
| 157 | * returned. |
| 158 | */ |
| 159 | static MessageDigest getDigest(String algorithm, int n) |
| 160 | throws NoSuchAlgorithmException { |
| 161 | MessageDigest digest = JsseJce.getMessageDigest(algorithm); |
| 162 | try { |
| 163 | digest.clone(); |
| 164 | // already cloneable, use it |
| 165 | return digest; |
| 166 | } catch (CloneNotSupportedException e) { |
| 167 | return new CloneableDigest(digest, n, algorithm); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Check if this object is still usable. If it has already been cloned the |
| 173 | * maximum number of times, there are no digests left and this object can no |
| 174 | * longer be used. |
| 175 | */ |
| 176 | private void checkState() { |
| 177 | // XXX handshaking currently doesn't stop updating hashes... |
| 178 | // if (digests[0] == null) { |
| 179 | // throw new IllegalStateException("no digests left"); |
| 180 | // } |
| 181 | } |
| 182 | |
| 183 | protected int engineGetDigestLength() { |
| 184 | checkState(); |
| 185 | return digests[0].getDigestLength(); |
| 186 | } |
| 187 | |
| 188 | protected void engineUpdate(byte b) { |
| 189 | checkState(); |
| 190 | for (int i = 0; (i < digests.length) && (digests[i] != null); i++) { |
| 191 | digests[i].update(b); |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | protected void engineUpdate(byte[] b, int offset, int len) { |
| 196 | checkState(); |
| 197 | for (int i = 0; (i < digests.length) && (digests[i] != null); i++) { |
| 198 | digests[i].update(b, offset, len); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | protected byte[] engineDigest() { |
| 203 | checkState(); |
| 204 | byte[] digest = digests[0].digest(); |
| 205 | digestReset(); |
| 206 | return digest; |
| 207 | } |
| 208 | |
| 209 | protected int engineDigest(byte[] buf, int offset, int len) |
| 210 | throws DigestException { |
| 211 | checkState(); |
| 212 | int n = digests[0].digest(buf, offset, len); |
| 213 | digestReset(); |
| 214 | return n; |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Reset all digests after a digest() call. digests[0] has already been |
| 219 | * implicitly reset by the digest() call and does not need to be reset |
| 220 | * again. |
| 221 | */ |
| 222 | private void digestReset() { |
| 223 | for (int i = 1; (i < digests.length) && (digests[i] != null); i++) { |
| 224 | digests[i].reset(); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | protected void engineReset() { |
| 229 | checkState(); |
| 230 | for (int i = 0; (i < digests.length) && (digests[i] != null); i++) { |
| 231 | digests[i].reset(); |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | public Object clone() { |
| 236 | checkState(); |
| 237 | for (int i = digests.length - 1; i >= 0; i--) { |
| 238 | if (digests[i] != null) { |
| 239 | MessageDigest digest = digests[i]; |
| 240 | digests[i] = null; |
| 241 | return digest; |
| 242 | } |
| 243 | } |
| 244 | // cannot occur |
| 245 | throw new InternalError(); |
| 246 | } |
| 247 | |
| 248 | } |