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| 1 | /* | ||
| 2 | * Copyright (c) 1998, 2011, 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; | ||
| 27 | |||
| 28 | import java.util.*; | ||
| 29 | |||
| 30 | import java.security.*; | ||
| 31 | import java.security.Provider.Service; | ||
| 32 | import java.security.spec.AlgorithmParameterSpec; | ||
| 33 | |||
| 34 | import java.nio.ByteBuffer; | ||
| 35 | |||
| 36 | import sun.security.util.Debug; | ||
| 37 | import sun.security.jca.*; | ||
| 38 | import sun.security.jca.GetInstance.Instance; | ||
| 39 | |||
| 40 | /** | ||
| 41 | * This class provides the functionality of a "Message Authentication Code" | ||
| 42 | * (MAC) algorithm. | ||
| 43 | * | ||
| 44 | * <p> A MAC provides a way to check | ||
| 45 | * the integrity of information transmitted over or stored in an unreliable | ||
| 46 | * medium, based on a secret key. Typically, message | ||
| 47 | * authentication codes are used between two parties that share a secret | ||
| 48 | * key in order to validate information transmitted between these | ||
| 49 | * parties. | ||
| 50 | * | ||
| 51 | * <p> A MAC mechanism that is based on cryptographic hash functions is | ||
| 52 | * referred to as HMAC. HMAC can be used with any cryptographic hash function, | ||
| 53 | * e.g., MD5 or SHA-1, in combination with a secret shared key. HMAC is | ||
| 54 | * specified in RFC 2104. | ||
| 55 | * | ||
| 56 | * <p> Every implementation of the Java platform is required to support | ||
| 57 | * the following standard <code>Mac</code> algorithms: | ||
| 58 | * <ul> | ||
| 59 | * <li><tt>HmacMD5</tt></li> | ||
| 60 | * <li><tt>HmacSHA1</tt></li> | ||
| 61 | * <li><tt>HmacSHA256</tt></li> | ||
| 62 | * </ul> | ||
| 63 | * These algorithms are described in the | ||
| 64 | * <a href="{@docRoot}/../technotes/guides/security/StandardNames.html#Mac"> | ||
| 65 | * Mac section</a> of the | ||
| 66 | * Java Cryptography Architecture Standard Algorithm Name Documentation. | ||
| 67 | * Consult the release documentation for your implementation to see if any | ||
| 68 | * other algorithms are supported. | ||
| 69 | * | ||
| 70 | * @author Jan Luehe | ||
| 71 | * | ||
| 72 | * @since 1.4 | ||
| 73 | */ | ||
| 74 | |||
| 75 | public class Mac implements Cloneable { | ||
| 76 | |||
| 77 | private static final Debug debug = | ||
| 78 | Debug.getInstance("jca", "Mac"); | ||
| 79 | |||
| 80 | // The provider | ||
| 81 | private Provider provider; | ||
| 82 | |||
| 83 | // The provider implementation (delegate) | ||
| 84 | private MacSpi spi; | ||
| 85 | |||
| 86 | // The name of the MAC algorithm. | ||
| 87 | private final String algorithm; | ||
| 88 | |||
| 89 | // Has this object been initialized? | ||
| 90 | private boolean initialized = false; | ||
| 91 | |||
| 92 | // next service to try in provider selection | ||
| 93 | // null once provider is selected | ||
| 94 | private Service firstService; | ||
| 95 | |||
| 96 | // remaining services to try in provider selection | ||
| 97 | // null once provider is selected | ||
| 98 | private Iterator serviceIterator; | ||
| 99 | |||
| 100 | private final Object lock; | ||
| 101 | |||
| 102 | /** | ||
| 103 | * Creates a MAC object. | ||
| 104 | * | ||
| 105 | * @param macSpi the delegate | ||
| 106 | * @param provider the provider | ||
| 107 | * @param algorithm the algorithm | ||
| 108 | */ | ||
| 109 | protected Mac(MacSpi macSpi, Provider provider, String algorithm) { | ||
| 110 | this.spi = macSpi; | ||
| 111 | this.provider = provider; | ||
| 112 | this.algorithm = algorithm; | ||
| 113 | serviceIterator = null; | ||
| 114 | lock = null; | ||
| 115 | } | ||
| 116 | |||
| 117 | private Mac(Service s, Iterator t, String algorithm) { | ||
| 118 | firstService = s; | ||
| 119 | serviceIterator = t; | ||
| 120 | this.algorithm = algorithm; | ||
| 121 | lock = new Object(); | ||
| 122 | } | ||
| 123 | |||
| 124 | /** | ||
| 125 | * Returns the algorithm name of this <code>Mac</code> object. | ||
| 126 | * | ||
| 127 | * <p>This is the same name that was specified in one of the | ||
| 128 | * <code>getInstance</code> calls that created this | ||
| 129 | * <code>Mac</code> object. | ||
| 130 | * | ||
| 131 | * @return the algorithm name of this <code>Mac</code> object. | ||
| 132 | */ | ||
| 133 | public final String getAlgorithm() { | ||
| 134 | return this.algorithm; | ||
| 135 | } | ||
| 136 | |||
| 137 | /** | ||
| 138 | * Returns a <code>Mac</code> object that implements the | ||
| 139 | * specified MAC algorithm. | ||
| 140 | * | ||
| 141 | * <p> This method traverses the list of registered security Providers, | ||
| 142 | * starting with the most preferred Provider. | ||
| 143 | * A new Mac object encapsulating the | ||
| 144 | * MacSpi implementation from the first | ||
| 145 | * Provider that supports the specified algorithm is returned. | ||
| 146 | * | ||
| 147 | * <p> Note that the list of registered providers may be retrieved via | ||
| 148 | * the {@link Security#getProviders() Security.getProviders()} method. | ||
| 149 | * | ||
| 150 | * @param algorithm the standard name of the requested MAC algorithm. | ||
| 151 | * See the Mac section in the <a href= | ||
| 152 | * "{@docRoot}/../technotes/guides/security/StandardNames.html#Mac"> | ||
| 153 | * Java Cryptography Architecture Standard Algorithm Name Documentation</a> | ||
| 154 | * for information about standard algorithm names. | ||
| 155 | * | ||
| 156 | * @return the new <code>Mac</code> object. | ||
| 157 | * | ||
| 158 | * @exception NoSuchAlgorithmException if no Provider supports a | ||
| 159 | * MacSpi implementation for the | ||
| 160 | * specified algorithm. | ||
| 161 | * | ||
| 162 | * @see java.security.Provider | ||
| 163 | */ | ||
| 164 | public static final Mac getInstance(String algorithm) | ||
| 165 | throws NoSuchAlgorithmException { | ||
| 166 | List services = GetInstance.getServices("Mac", algorithm); | ||
| 167 | // make sure there is at least one service from a signed provider | ||
| 168 | Iterator t = services.iterator(); | ||
| 169 | while (t.hasNext()) { | ||
| 170 | Service s = (Service)t.next(); | ||
| 171 | if (JceSecurity.canUseProvider(s.getProvider()) == false) { | ||
| 172 | continue; | ||
| 173 | } | ||
| 174 | return new Mac(s, t, algorithm); | ||
| 175 | } | ||
| 176 | throw new NoSuchAlgorithmException | ||
| 177 | ("Algorithm " + algorithm + " not available"); | ||
| 178 | } | ||
| 179 | |||
| 180 | /** | ||
| 181 | * Returns a <code>Mac</code> object that implements the | ||
| 182 | * specified MAC algorithm. | ||
| 183 | * | ||
| 184 | * <p> A new Mac object encapsulating the | ||
| 185 | * MacSpi implementation from the specified provider | ||
| 186 | * is returned. The specified provider must be registered | ||
| 187 | * in the security provider list. | ||
| 188 | * | ||
| 189 | * <p> Note that the list of registered providers may be retrieved via | ||
| 190 | * the {@link Security#getProviders() Security.getProviders()} method. | ||
| 191 | * | ||
| 192 | * @param algorithm the standard name of the requested MAC algorithm. | ||
| 193 | * See the Mac section in the <a href= | ||
| 194 | * "{@docRoot}/../technotes/guides/security/StandardNames.html#Mac"> | ||
| 195 | * Java Cryptography Architecture Standard Algorithm Name Documentation</a> | ||
| 196 | * for information about standard algorithm names. | ||
| 197 | * | ||
| 198 | * @param provider the name of the provider. | ||
| 199 | * | ||
| 200 | * @return the new <code>Mac</code> object. | ||
| 201 | * | ||
| 202 | * @exception NoSuchAlgorithmException if a MacSpi | ||
| 203 | * implementation for the specified algorithm is not | ||
| 204 | * available from the specified provider. | ||
| 205 | * | ||
| 206 | * @exception NoSuchProviderException if the specified provider is not | ||
| 207 | * registered in the security provider list. | ||
| 208 | * | ||
| 209 | * @exception IllegalArgumentException if the <code>provider</code> | ||
| 210 | * is null or empty. | ||
| 211 | * | ||
| 212 | * @see java.security.Provider | ||
| 213 | */ | ||
| 214 | public static final Mac getInstance(String algorithm, String provider) | ||
| 215 | throws NoSuchAlgorithmException, NoSuchProviderException { | ||
| 216 | Instance instance = JceSecurity.getInstance | ||
| 217 | ("Mac", MacSpi.class, algorithm, provider); | ||
| 218 | return new Mac((MacSpi)instance.impl, instance.provider, algorithm); | ||
| 219 | } | ||
| 220 | |||
| 221 | /** | ||
| 222 | * Returns a <code>Mac</code> object that implements the | ||
| 223 | * specified MAC algorithm. | ||
| 224 | * | ||
| 225 | * <p> A new Mac object encapsulating the | ||
| 226 | * MacSpi implementation from the specified Provider | ||
| 227 | * object is returned. Note that the specified Provider object | ||
| 228 | * does not have to be registered in the provider list. | ||
| 229 | * | ||
| 230 | * @param algorithm the standard name of the requested MAC algorithm. | ||
| 231 | * See the Mac section in the <a href= | ||
| 232 | * "{@docRoot}/../technotes/guides/security/StandardNames.html#Mac"> | ||
| 233 | * Java Cryptography Architecture Standard Algorithm Name Documentation</a> | ||
| 234 | * for information about standard algorithm names. | ||
| 235 | * | ||
| 236 | * @param provider the provider. | ||
| 237 | * | ||
| 238 | * @return the new <code>Mac</code> object. | ||
| 239 | * | ||
| 240 | * @exception NoSuchAlgorithmException if a MacSpi | ||
| 241 | * implementation for the specified algorithm is not available | ||
| 242 | * from the specified Provider object. | ||
| 243 | * | ||
| 244 | * @exception IllegalArgumentException if the <code>provider</code> | ||
| 245 | * is null. | ||
| 246 | * | ||
| 247 | * @see java.security.Provider | ||
| 248 | */ | ||
| 249 | public static final Mac getInstance(String algorithm, Provider provider) | ||
| 250 | throws NoSuchAlgorithmException { | ||
| 251 | Instance instance = JceSecurity.getInstance | ||
| 252 | ("Mac", MacSpi.class, algorithm, provider); | ||
| 253 | return new Mac((MacSpi)instance.impl, instance.provider, algorithm); | ||
| 254 | } | ||
| 255 | |||
| 256 | // max number of debug warnings to print from chooseFirstProvider() | ||
| 257 | private static int warnCount = 10; | ||
| 258 | |||
| 259 | /** | ||
| 260 | * Choose the Spi from the first provider available. Used if | ||
| 261 | * delayed provider selection is not possible because init() | ||
| 262 | * is not the first method called. | ||
| 263 | */ | ||
| 264 | void chooseFirstProvider() { | ||
| 265 | if ((spi != null) || (serviceIterator == null)) { | ||
| 266 | return; | ||
| 267 | } | ||
| 268 | synchronized (lock) { | ||
| 269 | if (spi != null) { | ||
| 270 | return; | ||
| 271 | } | ||
| 272 | if (debug != null) { | ||
| 273 | int w = --warnCount; | ||
| 274 | if (w >= 0) { | ||
| 275 | debug.println("Mac.init() not first method " | ||
| 276 | + "called, disabling delayed provider selection"); | ||
| 277 | if (w == 0) { | ||
| 278 | debug.println("Further warnings of this type will " | ||
| 279 | + "be suppressed"); | ||
| 280 | } | ||
| 281 | new Exception("Call trace").printStackTrace(); | ||
| 282 | } | ||
| 283 | } | ||
| 284 | Exception lastException = null; | ||
| 285 | while ((firstService != null) || serviceIterator.hasNext()) { | ||
| 286 | Service s; | ||
| 287 | if (firstService != null) { | ||
| 288 | s = firstService; | ||
| 289 | firstService = null; | ||
| 290 | } else { | ||
| 291 | s = (Service)serviceIterator.next(); | ||
| 292 | } | ||
| 293 | if (JceSecurity.canUseProvider(s.getProvider()) == false) { | ||
| 294 | continue; | ||
| 295 | } | ||
| 296 | try { | ||
| 297 | Object obj = s.newInstance(null); | ||
| 298 | if (obj instanceof MacSpi == false) { | ||
| 299 | continue; | ||
| 300 | } | ||
| 301 | spi = (MacSpi)obj; | ||
| 302 | provider = s.getProvider(); | ||
| 303 | // not needed any more | ||
| 304 | firstService = null; | ||
| 305 | serviceIterator = null; | ||
| 306 | return; | ||
| 307 | } catch (NoSuchAlgorithmException e) { | ||
| 308 | lastException = e; | ||
| 309 | } | ||
| 310 | } | ||
| 311 | ProviderException e = new ProviderException | ||
| 312 | ("Could not construct MacSpi instance"); | ||
| 313 | if (lastException != null) { | ||
| 314 | e.initCause(lastException); | ||
| 315 | } | ||
| 316 | throw e; | ||
| 317 | } | ||
| 318 | } | ||
| 319 | |||
| 320 | private void chooseProvider(Key key, AlgorithmParameterSpec params) | ||
| 321 | throws InvalidKeyException, InvalidAlgorithmParameterException { | ||
| 322 | synchronized (lock) { | ||
| 323 | if (spi != null) { | ||
| 324 | spi.engineInit(key, params); | ||
| 325 | return; | ||
| 326 | } | ||
| 327 | Exception lastException = null; | ||
| 328 | while ((firstService != null) || serviceIterator.hasNext()) { | ||
| 329 | Service s; | ||
| 330 | if (firstService != null) { | ||
| 331 | s = firstService; | ||
| 332 | firstService = null; | ||
| 333 | } else { | ||
| 334 | s = (Service)serviceIterator.next(); | ||
| 335 | } | ||
| 336 | // if provider says it does not support this key, ignore it | ||
| 337 | if (s.supportsParameter(key) == false) { | ||
| 338 | continue; | ||
| 339 | } | ||
| 340 | if (JceSecurity.canUseProvider(s.getProvider()) == false) { | ||
| 341 | continue; | ||
| 342 | } | ||
| 343 | try { | ||
| 344 | MacSpi spi = (MacSpi)s.newInstance(null); | ||
| 345 | spi.engineInit(key, params); | ||
| 346 | provider = s.getProvider(); | ||
| 347 | this.spi = spi; | ||
| 348 | firstService = null; | ||
| 349 | serviceIterator = null; | ||
| 350 | return; | ||
| 351 | } catch (Exception e) { | ||
| 352 | // NoSuchAlgorithmException from newInstance() | ||
| 353 | // InvalidKeyException from init() | ||
| 354 | // RuntimeException (ProviderException) from init() | ||
| 355 | if (lastException == null) { | ||
| 356 | lastException = e; | ||
| 357 | } | ||
| 358 | } | ||
| 359 | } | ||
| 360 | // no working provider found, fail | ||
| 361 | if (lastException instanceof InvalidKeyException) { | ||
| 362 | throw (InvalidKeyException)lastException; | ||
| 363 | } | ||
| 364 | if (lastException instanceof InvalidAlgorithmParameterException) { | ||
| 365 | throw (InvalidAlgorithmParameterException)lastException; | ||
| 366 | } | ||
| 367 | if (lastException instanceof RuntimeException) { | ||
| 368 | throw (RuntimeException)lastException; | ||
| 369 | } | ||
| 370 | String kName = (key != null) ? key.getClass().getName() : "(null)"; | ||
| 371 | throw new InvalidKeyException | ||
| 372 | ("No installed provider supports this key: " | ||
| 373 | + kName, lastException); | ||
| 374 | } | ||
| 375 | } | ||
| 376 | |||
| 377 | /** | ||
| 378 | * Returns the provider of this <code>Mac</code> object. | ||
| 379 | * | ||
| 380 | * @return the provider of this <code>Mac</code> object. | ||
| 381 | */ | ||
| 382 | public final Provider getProvider() { | ||
| 383 | chooseFirstProvider(); | ||
| 384 | return this.provider; | ||
| 385 | } | ||
| 386 | |||
| 387 | /** | ||
| 388 | * Returns the length of the MAC in bytes. | ||
| 389 | * | ||
| 390 | * @return the MAC length in bytes. | ||
| 391 | */ | ||
| 392 | public final int getMacLength() { | ||
| 393 | chooseFirstProvider(); | ||
| 394 | return spi.engineGetMacLength(); | ||
| 395 | } | ||
| 396 | |||
| 397 | /** | ||
| 398 | * Initializes this <code>Mac</code> object with the given key. | ||
| 399 | * | ||
| 400 | * @param key the key. | ||
| 401 | * | ||
| 402 | * @exception InvalidKeyException if the given key is inappropriate for | ||
| 403 | * initializing this MAC. | ||
| 404 | */ | ||
| 405 | public final void init(Key key) throws InvalidKeyException { | ||
| 406 | try { | ||
| 407 | if (spi != null) { | ||
| 408 | spi.engineInit(key, null); | ||
| 409 | } else { | ||
| 410 | chooseProvider(key, null); | ||
| 411 | } | ||
| 412 | } catch (InvalidAlgorithmParameterException e) { | ||
| 413 | throw new InvalidKeyException("init() failed", e); | ||
| 414 | } | ||
| 415 | initialized = true; | ||
| 416 | } | ||
| 417 | |||
| 418 | /** | ||
| 419 | * Initializes this <code>Mac</code> object with the given key and | ||
| 420 | * algorithm parameters. | ||
| 421 | * | ||
| 422 | * @param key the key. | ||
| 423 | * @param params the algorithm parameters. | ||
| 424 | * | ||
| 425 | * @exception InvalidKeyException if the given key is inappropriate for | ||
| 426 | * initializing this MAC. | ||
| 427 | * @exception InvalidAlgorithmParameterException if the given algorithm | ||
| 428 | * parameters are inappropriate for this MAC. | ||
| 429 | */ | ||
| 430 | public final void init(Key key, AlgorithmParameterSpec params) | ||
| 431 | throws InvalidKeyException, InvalidAlgorithmParameterException { | ||
| 432 | if (spi != null) { | ||
| 433 | spi.engineInit(key, params); | ||
| 434 | } else { | ||
| 435 | chooseProvider(key, params); | ||
| 436 | } | ||
| 437 | initialized = true; | ||
| 438 | } | ||
| 439 | |||
| 440 | /** | ||
| 441 | * Processes the given byte. | ||
| 442 | * | ||
| 443 | * @param input the input byte to be processed. | ||
| 444 | * | ||
| 445 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 446 | * initialized. | ||
| 447 | */ | ||
| 448 | public final void update(byte input) throws IllegalStateException { | ||
| 449 | chooseFirstProvider(); | ||
| 450 | if (initialized == false) { | ||
| 451 | throw new IllegalStateException("MAC not initialized"); | ||
| 452 | } | ||
| 453 | spi.engineUpdate(input); | ||
| 454 | } | ||
| 455 | |||
| 456 | /** | ||
| 457 | * Processes the given array of bytes. | ||
| 458 | * | ||
| 459 | * @param input the array of bytes to be processed. | ||
| 460 | * | ||
| 461 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 462 | * initialized. | ||
| 463 | */ | ||
| 464 | public final void update(byte[] input) throws IllegalStateException { | ||
| 465 | chooseFirstProvider(); | ||
| 466 | if (initialized == false) { | ||
| 467 | throw new IllegalStateException("MAC not initialized"); | ||
| 468 | } | ||
| 469 | if (input != null) { | ||
| 470 | spi.engineUpdate(input, 0, input.length); | ||
| 471 | } | ||
| 472 | } | ||
| 473 | |||
| 474 | /** | ||
| 475 | * Processes the first <code>len</code> bytes in <code>input</code>, | ||
| 476 | * starting at <code>offset</code> inclusive. | ||
| 477 | * | ||
| 478 | * @param input the input buffer. | ||
| 479 | * @param offset the offset in <code>input</code> where the input starts. | ||
| 480 | * @param len the number of bytes to process. | ||
| 481 | * | ||
| 482 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 483 | * initialized. | ||
| 484 | */ | ||
| 485 | public final void update(byte[] input, int offset, int len) | ||
| 486 | throws IllegalStateException { | ||
| 487 | chooseFirstProvider(); | ||
| 488 | if (initialized == false) { | ||
| 489 | throw new IllegalStateException("MAC not initialized"); | ||
| 490 | } | ||
| 491 | |||
| 492 | if (input != null) { | ||
| 493 | if ((offset < 0) || (len > (input.length - offset)) || (len < 0)) | ||
| 494 | throw new IllegalArgumentException("Bad arguments"); | ||
| 495 | spi.engineUpdate(input, offset, len); | ||
| 496 | } | ||
| 497 | } | ||
| 498 | |||
| 499 | /** | ||
| 500 | * Processes <code>input.remaining()</code> bytes in the ByteBuffer | ||
| 501 | * <code>input</code>, starting at <code>input.position()</code>. | ||
| 502 | * Upon return, the buffer's position will be equal to its limit; | ||
| 503 | * its limit will not have changed. | ||
| 504 | * | ||
| 505 | * @param input the ByteBuffer | ||
| 506 | * | ||
| 507 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 508 | * initialized. | ||
| 509 | * @since 1.5 | ||
| 510 | */ | ||
| 511 | public final void update(ByteBuffer input) { | ||
| 512 | chooseFirstProvider(); | ||
| 513 | if (initialized == false) { | ||
| 514 | throw new IllegalStateException("MAC not initialized"); | ||
| 515 | } | ||
| 516 | if (input == null) { | ||
| 517 | throw new IllegalArgumentException("Buffer must not be null"); | ||
| 518 | } | ||
| 519 | spi.engineUpdate(input); | ||
| 520 | } | ||
| 521 | |||
| 522 | /** | ||
| 523 | * Finishes the MAC operation. | ||
| 524 | * | ||
| 525 | * <p>A call to this method resets this <code>Mac</code> object to the | ||
| 526 | * state it was in when previously initialized via a call to | ||
| 527 | * <code>init(Key)</code> or | ||
| 528 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 529 | * That is, the object is reset and available to generate another MAC from | ||
| 530 | * the same key, if desired, via new calls to <code>update</code> and | ||
| 531 | * <code>doFinal</code>. | ||
| 532 | * (In order to reuse this <code>Mac</code> object with a different key, | ||
| 533 | * it must be reinitialized via a call to <code>init(Key)</code> or | ||
| 534 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 535 | * | ||
| 536 | * @return the MAC result. | ||
| 537 | * | ||
| 538 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 539 | * initialized. | ||
| 540 | */ | ||
| 541 | public final byte[] doFinal() throws IllegalStateException { | ||
| 542 | chooseFirstProvider(); | ||
| 543 | if (initialized == false) { | ||
| 544 | throw new IllegalStateException("MAC not initialized"); | ||
| 545 | } | ||
| 546 | byte[] mac = spi.engineDoFinal(); | ||
| 547 | spi.engineReset(); | ||
| 548 | return mac; | ||
| 549 | } | ||
| 550 | |||
| 551 | /** | ||
| 552 | * Finishes the MAC operation. | ||
| 553 | * | ||
| 554 | * <p>A call to this method resets this <code>Mac</code> object to the | ||
| 555 | * state it was in when previously initialized via a call to | ||
| 556 | * <code>init(Key)</code> or | ||
| 557 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 558 | * That is, the object is reset and available to generate another MAC from | ||
| 559 | * the same key, if desired, via new calls to <code>update</code> and | ||
| 560 | * <code>doFinal</code>. | ||
| 561 | * (In order to reuse this <code>Mac</code> object with a different key, | ||
| 562 | * it must be reinitialized via a call to <code>init(Key)</code> or | ||
| 563 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 564 | * | ||
| 565 | * <p>The MAC result is stored in <code>output</code>, starting at | ||
| 566 | * <code>outOffset</code> inclusive. | ||
| 567 | * | ||
| 568 | * @param output the buffer where the MAC result is stored | ||
| 569 | * @param outOffset the offset in <code>output</code> where the MAC is | ||
| 570 | * stored | ||
| 571 | * | ||
| 572 | * @exception ShortBufferException if the given output buffer is too small | ||
| 573 | * to hold the result | ||
| 574 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 575 | * initialized. | ||
| 576 | */ | ||
| 577 | public final void doFinal(byte[] output, int outOffset) | ||
| 578 | throws ShortBufferException, IllegalStateException | ||
| 579 | { | ||
| 580 | chooseFirstProvider(); | ||
| 581 | if (initialized == false) { | ||
| 582 | throw new IllegalStateException("MAC not initialized"); | ||
| 583 | } | ||
| 584 | int macLen = getMacLength(); | ||
| 585 | if (output == null || output.length-outOffset < macLen) { | ||
| 586 | throw new ShortBufferException | ||
| 587 | ("Cannot store MAC in output buffer"); | ||
| 588 | } | ||
| 589 | byte[] mac = doFinal(); | ||
| 590 | System.arraycopy(mac, 0, output, outOffset, macLen); | ||
| 591 | return; | ||
| 592 | } | ||
| 593 | |||
| 594 | /** | ||
| 595 | * Processes the given array of bytes and finishes the MAC operation. | ||
| 596 | * | ||
| 597 | * <p>A call to this method resets this <code>Mac</code> object to the | ||
| 598 | * state it was in when previously initialized via a call to | ||
| 599 | * <code>init(Key)</code> or | ||
| 600 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 601 | * That is, the object is reset and available to generate another MAC from | ||
| 602 | * the same key, if desired, via new calls to <code>update</code> and | ||
| 603 | * <code>doFinal</code>. | ||
| 604 | * (In order to reuse this <code>Mac</code> object with a different key, | ||
| 605 | * it must be reinitialized via a call to <code>init(Key)</code> or | ||
| 606 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 607 | * | ||
| 608 | * @param input data in bytes | ||
| 609 | * @return the MAC result. | ||
| 610 | * | ||
| 611 | * @exception IllegalStateException if this <code>Mac</code> has not been | ||
| 612 | * initialized. | ||
| 613 | */ | ||
| 614 | public final byte[] doFinal(byte[] input) throws IllegalStateException | ||
| 615 | { | ||
| 616 | chooseFirstProvider(); | ||
| 617 | if (initialized == false) { | ||
| 618 | throw new IllegalStateException("MAC not initialized"); | ||
| 619 | } | ||
| 620 | update(input); | ||
| 621 | return doFinal(); | ||
| 622 | } | ||
| 623 | |||
| 624 | /** | ||
| 625 | * Resets this <code>Mac</code> object. | ||
| 626 | * | ||
| 627 | * <p>A call to this method resets this <code>Mac</code> object to the | ||
| 628 | * state it was in when previously initialized via a call to | ||
| 629 | * <code>init(Key)</code> or | ||
| 630 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 631 | * That is, the object is reset and available to generate another MAC from | ||
| 632 | * the same key, if desired, via new calls to <code>update</code> and | ||
| 633 | * <code>doFinal</code>. | ||
| 634 | * (In order to reuse this <code>Mac</code> object with a different key, | ||
| 635 | * it must be reinitialized via a call to <code>init(Key)</code> or | ||
| 636 | * <code>init(Key, AlgorithmParameterSpec)</code>. | ||
| 637 | */ | ||
| 638 | public final void reset() { | ||
| 639 | chooseFirstProvider(); | ||
| 640 | spi.engineReset(); | ||
| 641 | } | ||
| 642 | |||
| 643 | /** | ||
| 644 | * Returns a clone if the provider implementation is cloneable. | ||
| 645 | * | ||
| 646 | * @return a clone if the provider implementation is cloneable. | ||
| 647 | * | ||
| 648 | * @exception CloneNotSupportedException if this is called on a | ||
| 649 | * delegate that does not support <code>Cloneable</code>. | ||
| 650 | */ | ||
| 651 | public final Object clone() throws CloneNotSupportedException { | ||
| 652 | chooseFirstProvider(); | ||
| 653 | Mac that = (Mac)super.clone(); | ||
| 654 | that.spi = (MacSpi)this.spi.clone(); | ||
| 655 | return that; | ||
| 656 | } | ||
| 657 | } | ||