001 /* CipherSpi.java -- The cipher service provider interface. 002 Copyright (C) 2004, 2006 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package javax.crypto; 040 041 import java.nio.ByteBuffer; 042 043 import java.security.AlgorithmParameters; 044 import java.security.InvalidAlgorithmParameterException; 045 import java.security.InvalidKeyException; 046 import java.security.Key; 047 import java.security.NoSuchAlgorithmException; 048 import java.security.SecureRandom; 049 import java.security.spec.AlgorithmParameterSpec; 050 051 /** 052 * <p>This class represents the <i>Service Provider Interface</i> 053 * (<b>SPI</b>) for cryptographic ciphers.</p> 054 * 055 * <p>Providers of cryptographic ciphers must subclass this for every 056 * cipher they implement, implementing the abstract methods as 057 * appropriate, then provide an entry that points to the subclass in 058 * their implementation of {@link java.security.Provider}.</p> 059 * 060 * <p>CipherSpi objects are instantiated along with {@link Cipher}s when 061 * the {@link Cipher#getInstance(java.lang.String)} methods are invoked. 062 * Particular ciphers are referenced by a <i>transformation</i>, which 063 * is a String consisting of the cipher's name or the ciper's name 064 * followed by a mode and a padding. Transformations all follow the 065 * general form:</p> 066 * 067 * <ul> 068 * <li><i>algorithm</i>, or</li> 069 * <li><i>algorithm</i>/<i>mode</i>/<i>padding</i> 070 * </ul> 071 * 072 * <p>Cipher names in the master {@link java.security.Provider} class 073 * may be:</p> 074 * 075 * <ol> 076 * <li>The algorithm's name, which uses a pluggable mode and padding: 077 * <code>Cipher.<i>algorithm</i></code></li> 078 * <li>The algorithm's name and the mode, which uses pluggable padding: 079 * <code>Cipher.<i>algorithm</i>/<i>mode</i></code></li> 080 * <li>The algorithm's name and the padding, which uses a pluggable 081 * mode: <code>Cipher.<i>algorithm</i>//<i>padding</i></code></li> 082 * <li>The algorihtm's name, the mode, and the padding: 083 * <code>Cipher.<i>algorithm</i>/<i>mode</i>/<i>padding</i></code></li> 084 * </ol> 085 * 086 * <p>When any {@link Cipher#getInstance(java.lang.String)} method is 087 * invoked, the following happens if the transformation is simply 088 * <i>algorithm</i>:</p> 089 * 090 * <ol> 091 * <li>If the provider defines a <code>CipherSpi</code> implementation 092 * for "<i>algorithm</i>", return it. Otherwise throw a {@link 093 * java.security.NoSuchAlgorithmException}.</li> 094 * </ol> 095 * 096 * <p>If the transformation is of the form 097 * <i>algorithm</i>/<i>mode</i>/<i>padding</i>:</p> 098 * 099 * <ol> 100 * <li>If the provider defines a <code>CipherSpi</code> subclass for 101 * "<i>algorithm</i>/<i>mode</i>/<i>padding</i>", return it. Otherwise 102 * go to step 2.</li> 103 * 104 * <li>If the provider defines a <code>CipherSpi</code> subclass for 105 * "<i>algorithm</i>/<i>mode</i>", instatiate it, call {@link 106 * #engineSetPadding(java.lang.String)} for the padding name, and return 107 * it. Otherwise go to step 3.</li> 108 * 109 * <li>If the provider defines a <code>CipherSpi</code> subclass for 110 * "<i>algorithm</i>//<i>padding</i>", instatiate it, call {@link 111 * #engineSetMode(java.lang.String)} for the mode name, and return 112 * it. Otherwise go to step 4.</li> 113 * 114 * <li>If the provider defines a <code>CipherSpi</code> subclass for 115 * "<i>algorithm</i>", instatiate it, call {@link 116 * #engineSetMode(java.lang.String)} for the mode name, call {@link 117 * #engineSetPadding(java.lang.String)} for the padding name, and return 118 * it. Otherwise throw a {@link java.security.NoSuchAlgorithmException}.</li> 119 * </ol> 120 * 121 * @author Casey Marshall (csm@gnu.org) 122 * @since 1.4 123 */ 124 public abstract class CipherSpi 125 { 126 127 // Constructors. 128 // ------------------------------------------------------------------------ 129 130 /** 131 * Create a new CipherSpi. 132 */ 133 public CipherSpi() 134 { 135 } 136 137 // Abstract methods to be implemented by providers. 138 // ------------------------------------------------------------------------ 139 140 /** 141 * Finishes a multi-part transformation or transforms a portion of a 142 * byte array, and returns the transformed bytes. 143 * 144 * @param input The input bytes. 145 * @param inputOffset The index in the input at which to start. 146 * @param inputLength The number of bytes to transform. 147 * @return The transformed bytes in a new array. 148 * @throws javax.crypto.IllegalBlockSizeException If this instance has 149 * no padding and the input size is not a multiple of the 150 * block size. 151 * @throws javax.crypto.BadPaddingException If this instance is being 152 * used for decryption and the padding is not appropriate for 153 * this instance's padding scheme. 154 */ 155 protected abstract byte[] 156 engineDoFinal(byte[] input, int inputOffset, int inputLength) 157 throws IllegalBlockSizeException, BadPaddingException; 158 159 /** 160 * Finishes a multi-part transformation or transforms a portion of a 161 * byte array, and stores the transformed bytes in the supplied array. 162 * 163 * @param input The input bytes. 164 * @param inputOffset The index in the input at which to start. 165 * @param inputLength The number of bytes to transform. 166 * @param output The output byte array. 167 * @param outputOffset The index in the output array at which to start. 168 * @return The number of transformed bytes stored in the output array. 169 * @throws javax.crypto.IllegalBlockSizeException If this instance has 170 * no padding and the input size is not a multiple of the 171 * block size. 172 * @throws javax.crypto.BadPaddingException If this instance is being 173 * used for decryption and the padding is not appropriate for 174 * this instance's padding scheme. 175 * @throws javax.crypto.ShortBufferException If there is not enough 176 * space in the output array for the transformed bytes. 177 */ 178 protected abstract int 179 engineDoFinal(byte[] input, int inputOffset, int inputLength, 180 byte[] output, int outputOffset) 181 throws IllegalBlockSizeException, BadPaddingException, ShortBufferException; 182 183 /** 184 * @since 1.5 185 */ 186 protected int engineDoFinal (ByteBuffer input, ByteBuffer output) 187 throws BadPaddingException, IllegalBlockSizeException, 188 ShortBufferException 189 { 190 int total = 0; 191 byte[] inbuf = new byte[256]; 192 while (input.hasRemaining ()) 193 { 194 int in = Math.min (inbuf.length, input.remaining ()); 195 input.get (inbuf, 0, in); 196 byte[] outbuf = new byte[engineGetOutputSize (in)]; 197 int out = 0; 198 if (input.hasRemaining ()) // i.e., we have more 'update' calls 199 out = engineUpdate (inbuf, 0, in, outbuf, 0); 200 else 201 out = engineDoFinal (inbuf, 0, in, outbuf, 0); 202 output.put (outbuf, 0, out); 203 total += out; 204 } 205 return total; 206 } 207 208 /** 209 * Returns the block size of the underlying cipher. 210 * 211 * @return The block size. 212 */ 213 protected abstract int engineGetBlockSize(); 214 215 /** 216 * Returns the initializaiton vector this cipher was initialized with, 217 * if any. 218 * 219 * @return The IV, or null if this cipher uses no IV or if this 220 * instance has not been initialized yet. 221 */ 222 protected abstract byte[] engineGetIV(); 223 224 /** 225 * <p>Return the length of the given key in bits.</p> 226 * 227 * <p>For compatibility this method is not declared 228 * <code>abstract</code>, and the default implementation will throw an 229 * {@link java.lang.UnsupportedOperationException}. Concrete 230 * subclasses should override this method to return the correct 231 * value.</p> 232 * 233 * @param key The key to get the size for. 234 * @return The size of the key, in bits. 235 * @throws java.security.InvalidKeyException If the key's length 236 * cannot be determined by this implementation. 237 */ 238 protected int engineGetKeySize(Key key) throws InvalidKeyException 239 { 240 throw new UnsupportedOperationException(); 241 } 242 243 /** 244 * <p>Returns the size, in bytes, an output buffer must be for a call 245 * to {@link #engineUpdate(byte[],int,int,byte[],int)} or {@link 246 * #engineDoFinal(byte[],int,int,byte[],int)} to succeed.</p> 247 * 248 * <p>The actual output length may be smaller than the value returned 249 * by this method, as it considers the padding length as well. The 250 * length considered is the argument plus the length of any buffered, 251 * unprocessed bytes.</p> 252 * 253 * @param inputLength The input length, in bytes. 254 * @return The size an output buffer must be. 255 */ 256 protected abstract int engineGetOutputSize(int inputLength); 257 258 /** 259 * Returns the parameters that this cipher is using. This may be the 260 * parameters used to initialize this cipher, or it may be parameters 261 * that have been initialized with random values. 262 * 263 * @return This cipher's parameters, or <code>null</code> if this 264 * cipher does not use parameters. 265 */ 266 protected abstract AlgorithmParameters engineGetParameters(); 267 268 /** 269 * Initializes this cipher with an operation mode, key, and source of 270 * randomness. If this cipher requires any other initializing data, 271 * for example an initialization vector, then it should generate it 272 * from the provided source of randomness. 273 * 274 * @param opmode The operation mode, one of {@link 275 * Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link 276 * Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}. 277 * @param key The key to initialize this cipher with. 278 * @param random The source of random bytes to use. 279 * @throws java.security.InvalidKeyException If the given key is not 280 * acceptable for this implementation. 281 */ 282 protected abstract void engineInit(int opmode, Key key, SecureRandom random) 283 throws InvalidKeyException; 284 285 /** 286 * Initializes this cipher with an operation mode, key, parameters, 287 * and source of randomness. If this cipher requires any other 288 * initializing data, for example an initialization vector, then it should 289 * generate it from the provided source of randomness. 290 * 291 * @param opmode The operation mode, one of {@link 292 * Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link 293 * Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}. 294 * @param key The key to initialize this cipher with. 295 * @param params The algorithm parameters to initialize with. 296 * @param random The source of random bytes to use. 297 * @throws java.security.InvalidAlgorithmParameterException If the 298 * given parameters are not appropriate for this 299 * implementation. 300 * @throws java.security.InvalidKeyException If the given key is not 301 * acceptable for this implementation. 302 */ 303 protected abstract void 304 engineInit(int opmode, Key key, AlgorithmParameters params, 305 SecureRandom random) 306 throws InvalidAlgorithmParameterException, InvalidKeyException; 307 308 /** 309 * Initializes this cipher with an operation mode, key, parameters, 310 * and source of randomness. If this cipher requires any other 311 * initializing data, for example an initialization vector, then it should 312 * generate it from the provided source of randomness. 313 * 314 * @param opmode The operation mode, one of {@link 315 * Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link 316 * Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}. 317 * @param key The key to initialize this cipher with. 318 * @param params The algorithm parameters to initialize with. 319 * @param random The source of random bytes to use. 320 * @throws java.security.InvalidAlgorithmParameterException If the 321 * given parameters are not appropriate for this 322 * implementation. 323 * @throws java.security.InvalidKeyException If the given key is not 324 * acceptable for this implementation. 325 */ 326 protected abstract void 327 engineInit(int opmode, Key key, AlgorithmParameterSpec params, 328 SecureRandom random) 329 throws InvalidAlgorithmParameterException, InvalidKeyException; 330 331 /** 332 * Set the mode in which this cipher is to run. 333 * 334 * @param mode The name of the mode to use. 335 * @throws java.security.NoSuchAlgorithmException If the mode is 336 * not supported by this cipher's provider. 337 */ 338 protected abstract void engineSetMode(String mode) 339 throws NoSuchAlgorithmException; 340 341 /** 342 * Set the method with which the input is to be padded. 343 * 344 * @param padding The name of the padding to use. 345 * @throws javax.crypto.NoSuchPaddingException If the padding is not 346 * supported by this cipher's provider. 347 */ 348 protected abstract void engineSetPadding(String padding) 349 throws NoSuchPaddingException; 350 351 /** 352 * <p>Unwraps a previously-wrapped key.</p> 353 * 354 * <p>For compatibility this method is not declared 355 * <code>abstract</code>, and the default implementation will throw an 356 * {@link java.lang.UnsupportedOperationException}.</p> 357 * 358 * @param wrappedKey The wrapped key. 359 * @param wrappedKeyAlgorithm The name of the algorithm used to wrap 360 * this key. 361 * @param wrappedKeyType The type of wrapped key; one of 362 * {@link Cipher#PRIVATE_KEY}, 363 * {@link Cipher#PUBLIC_KEY}, or 364 * {@link Cipher#SECRET_KEY}. 365 * @return The unwrapped key. 366 * @throws java.security.InvalidKeyException If the key cannot be 367 * unwrapped, or if <code>wrappedKeyType</code> is an 368 * inappropriate type for the unwrapped key. 369 * @throws java.security.NoSuchAlgorithmException If the 370 * <code>wrappedKeyAlgorithm</code> is unknown. 371 */ 372 protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, 373 int wrappedKeyType) 374 throws InvalidKeyException, NoSuchAlgorithmException 375 { 376 throw new UnsupportedOperationException(); 377 } 378 379 /** 380 * Continue with a multi-part transformation, returning a new array of 381 * the transformed bytes. 382 * 383 * @param input The next input bytes. 384 * @param inputOffset The index in the input array from which to start. 385 * @param inputLength The number of bytes to input. 386 * @return The transformed bytes. 387 */ 388 protected abstract byte[] 389 engineUpdate(byte[] input, int inputOffset, int inputLength); 390 391 /** 392 * Continue with a multi-part transformation, storing the transformed 393 * bytes into the specified array. 394 * 395 * @param input The next input bytes. 396 * @param inputOffset The index in the input from which to start. 397 * @param inputLength The number of bytes to input. 398 * @param output The output buffer. 399 * @param outputOffset The index in the output array from which to start. 400 * @return The transformed bytes. 401 * @throws javax.crypto.ShortBufferException If there is not enough 402 * space in the output array to store the transformed bytes. 403 */ 404 protected abstract int 405 engineUpdate(byte[] input, int inputOffset, int inputLength, 406 byte[] output, int outputOffset) 407 throws ShortBufferException; 408 409 /** 410 * @since 1.5 411 */ 412 protected int engineUpdate (ByteBuffer input, ByteBuffer output) 413 throws ShortBufferException 414 { 415 int total = 0; 416 byte[] inbuf = new byte[256]; 417 while (input.hasRemaining ()) 418 { 419 int in = Math.min (inbuf.length, input.remaining ()); 420 input.get (inbuf, 0, in); 421 byte[] outbuf = new byte[engineGetOutputSize (in)]; 422 int out = engineUpdate (inbuf, 0, in, outbuf, 0); 423 output.put (outbuf, 0, out); 424 total += out; 425 } 426 return total; 427 } 428 429 /** 430 * <p>Wrap a key.</p> 431 * 432 * <p>For compatibility this method is not declared 433 * <code>abstract</code>, and the default implementation will throw an 434 * {@link java.lang.UnsupportedOperationException}.</p> 435 * 436 * @param key The key to wrap. 437 * @return The wrapped key. 438 * @throws java.security.InvalidKeyException If the key cannot be 439 * wrapped. 440 */ 441 protected byte[] engineWrap(Key key) throws InvalidKeyException, IllegalBlockSizeException 442 { 443 throw new UnsupportedOperationException(); 444 } 445 }