1 /*
2 * Copyright (c) 2002, 2016, 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 com.sun.crypto.provider;
27
28 import java.util.Arrays;
29 import java.util.Locale;
30
31 import java.security.*;
32 import java.security.spec.*;
33 import javax.crypto.*;
34 import javax.crypto.spec.*;
35 import javax.crypto.BadPaddingException;
36
37 /**
38 * This class represents the symmetric algorithms in its various modes
39 * (<code>ECB</code>, <code>CFB</code>, <code>OFB</code>, <code>CBC</code>,
40 * <code>PCBC</code>, <code>CTR</code>, and <code>CTS</code>) and
41 * padding schemes (<code>PKCS5Padding</code>, <code>NoPadding</code>,
42 * <code>ISO10126Padding</code>).
43 *
44 * @author Gigi Ankeny
45 * @author Jan Luehe
46 * @see ElectronicCodeBook
47 * @see CipherFeedback
48 * @see OutputFeedback
49 * @see CipherBlockChaining
50 * @see PCBC
51 * @see CounterMode
52 * @see CipherTextStealing
53 */
54
55 final class CipherCore {
56
57 /*
58 * internal buffer
59 */
60 private byte[] buffer = null;
61
62 /*
63 * block size of cipher in bytes
64 */
65 private int blockSize = 0;
66
67 /*
68 * unit size (number of input bytes that can be processed at a time)
69 */
70 private int unitBytes = 0;
71
72 /*
73 * index of the content size left in the buffer
74 */
75 private int buffered = 0;
76
77 /*
78 * minimum number of bytes in the buffer required for
79 * FeedbackCipher.encryptFinal()/decryptFinal() call.
80 * update() must buffer this many bytes before starting
81 * to encrypt/decrypt data.
82 * currently, only the following cases have non-zero values:
83 * 1) CTS mode - due to its special handling on the last two blocks
84 * (the last one may be incomplete).
85 * 2) GCM mode + decryption - due to its trailing tag bytes
86 */
87 private int minBytes = 0;
88
89 /*
90 * number of bytes needed to make the total input length a multiple
91 * of the blocksize (this is used in feedback mode, when the number of
92 * input bytes that are processed at a time is different from the block
93 * size)
94 */
95 private int diffBlocksize = 0;
96
97 /*
98 * padding class
99 */
100 private Padding padding = null;
101
102 /*
103 * internal cipher engine
104 */
105 private FeedbackCipher cipher = null;
106
107 /*
108 * the cipher mode
109 */
110 private int cipherMode = ECB_MODE;
111
112 /*
113 * are we encrypting or decrypting?
114 */
115 private boolean decrypting = false;
116
117 /*
118 * Block Mode constants
119 */
120 private static final int ECB_MODE = 0;
121 private static final int CBC_MODE = 1;
122 private static final int CFB_MODE = 2;
123 private static final int OFB_MODE = 3;
124 private static final int PCBC_MODE = 4;
125 private static final int CTR_MODE = 5;
126 private static final int CTS_MODE = 6;
127 static final int GCM_MODE = 7;
128
129 /*
130 * variables used for performing the GCM (key+iv) uniqueness check.
131 * To use GCM mode safely, the cipher object must be re-initialized
132 * with a different combination of key + iv values for each
133 * encryption operation. However, checking all past key + iv values
134 * isn't feasible. Thus, we only do a per-instance check of the
135 * key + iv values used in previous encryption.
136 * For decryption operations, no checking is necessary.
137 * NOTE: this key+iv check have to be done inside CipherCore class
138 * since CipherCore class buffers potential tag bytes in GCM mode
139 * and may not call GaloisCounterMode when there isn't sufficient
140 * input to process.
141 */
142 private boolean requireReinit = false;
143 private byte[] lastEncKey = null;
144 private byte[] lastEncIv = null;
145
146 /**
147 * Creates an instance of CipherCore with default ECB mode and
148 * PKCS5Padding.
149 */
150 CipherCore(SymmetricCipher impl, int blkSize) {
151 blockSize = blkSize;
152 unitBytes = blkSize;
153 diffBlocksize = blkSize;
154
155 /*
156 * The buffer should be usable for all cipher mode and padding
157 * schemes. Thus, it has to be at least (blockSize+1) for CTS.
158 * In decryption mode, it also hold the possible padding block.
159 */
160 buffer = new byte[blockSize*2];
161
162 // set mode and padding
163 cipher = new ElectronicCodeBook(impl);
164 padding = new PKCS5Padding(blockSize);
165 }
166
167 /**
168 * Sets the mode of this cipher.
169 *
170 * @param mode the cipher mode
171 *
172 * @exception NoSuchAlgorithmException if the requested cipher mode does
173 * not exist for this cipher
174 */
175 void setMode(String mode) throws NoSuchAlgorithmException {
176 if (mode == null)
177 throw new NoSuchAlgorithmException("null mode");
178
179 String modeUpperCase = mode.toUpperCase(Locale.ENGLISH);
180
181 if (modeUpperCase.equals("ECB")) {
182 return;
183 }
184
185 SymmetricCipher rawImpl = cipher.getEmbeddedCipher();
186 if (modeUpperCase.equals("CBC")) {
187 cipherMode = CBC_MODE;
188 cipher = new CipherBlockChaining(rawImpl);
189 } else if (modeUpperCase.equals("CTS")) {
190 cipherMode = CTS_MODE;
191 cipher = new CipherTextStealing(rawImpl);
192 minBytes = blockSize+1;
193 padding = null;
194 } else if (modeUpperCase.equals("CTR")) {
195 cipherMode = CTR_MODE;
196 cipher = new CounterMode(rawImpl);
197 unitBytes = 1;
198 padding = null;
199 } else if (modeUpperCase.equals("GCM")) {
200 // can only be used for block ciphers w/ 128-bit block size
201 if (blockSize != 16) {
202 throw new NoSuchAlgorithmException
203 ("GCM mode can only be used for AES cipher");
204 }
205 cipherMode = GCM_MODE;
206 cipher = new GaloisCounterMode(rawImpl);
207 padding = null;
208 } else if (modeUpperCase.startsWith("CFB")) {
209 cipherMode = CFB_MODE;
210 unitBytes = getNumOfUnit(mode, "CFB".length(), blockSize);
211 cipher = new CipherFeedback(rawImpl, unitBytes);
212 } else if (modeUpperCase.startsWith("OFB")) {
213 cipherMode = OFB_MODE;
214 unitBytes = getNumOfUnit(mode, "OFB".length(), blockSize);
215 cipher = new OutputFeedback(rawImpl, unitBytes);
216 } else if (modeUpperCase.equals("PCBC")) {
217 cipherMode = PCBC_MODE;
218 cipher = new PCBC(rawImpl);
219 }
220 else {
221 throw new NoSuchAlgorithmException("Cipher mode: " + mode
222 + " not found");
223 }
224 }
225
226 /**
227 * Returns the mode of this cipher.
228 *
229 * @return the parsed cipher mode
230 */
231 int getMode() {
232 return cipherMode;
233 }
234
235 private static int getNumOfUnit(String mode, int offset, int blockSize)
236 throws NoSuchAlgorithmException {
237 int result = blockSize; // use blockSize as default value
238 if (mode.length() > offset) {
239 int numInt;
240 try {
241 Integer num = Integer.valueOf(mode.substring(offset));
242 numInt = num.intValue();
243 result = numInt >> 3;
244 } catch (NumberFormatException e) {
245 throw new NoSuchAlgorithmException
246 ("Algorithm mode: " + mode + " not implemented");
247 }
248 if ((numInt % 8 != 0) || (result > blockSize)) {
249 throw new NoSuchAlgorithmException
250 ("Invalid algorithm mode: " + mode);
251 }
252 }
253 return result;
254 }
255
256
257 /**
258 * Sets the padding mechanism of this cipher.
259 *
260 * @param padding the padding mechanism
261 *
262 * @exception NoSuchPaddingException if the requested padding mechanism
263 * does not exist
264 */
265 void setPadding(String paddingScheme)
266 throws NoSuchPaddingException
267 {
268 if (paddingScheme == null) {
269 throw new NoSuchPaddingException("null padding");
270 }
271 if (paddingScheme.equalsIgnoreCase("NoPadding")) {
272 padding = null;
273 } else if (paddingScheme.equalsIgnoreCase("ISO10126Padding")) {
274 padding = new ISO10126Padding(blockSize);
275 } else if (!paddingScheme.equalsIgnoreCase("PKCS5Padding")) {
276 throw new NoSuchPaddingException("Padding: " + paddingScheme
277 + " not implemented");
278 }
279 if ((padding != null) &&
280 ((cipherMode == CTR_MODE) || (cipherMode == CTS_MODE)
281 || (cipherMode == GCM_MODE))) {
282 padding = null;
283 String modeStr = null;
284 switch (cipherMode) {
285 case CTR_MODE:
286 modeStr = "CTR";
287 break;
288 case GCM_MODE:
289 modeStr = "GCM";
290 break;
291 case CTS_MODE:
292 modeStr = "CTS";
293 break;
294 default:
295 // should never happen
296 }
297 if (modeStr != null) {
298 throw new NoSuchPaddingException
299 (modeStr + " mode must be used with NoPadding");
300 }
301 }
302 }
303
304 /**
305 * Returns the length in bytes that an output buffer would need to be in
306 * order to hold the result of the next <code>update</code> or
307 * <code>doFinal</code> operation, given the input length
308 * <code>inputLen</code> (in bytes).
309 *
310 * <p>This call takes into account any unprocessed (buffered) data from a
311 * previous <code>update</code> call, padding, and AEAD tagging.
312 *
313 * <p>The actual output length of the next <code>update</code> or
314 * <code>doFinal</code> call may be smaller than the length returned by
315 * this method.
316 *
317 * @param inputLen the input length (in bytes)
318 *
319 * @return the required output buffer size (in bytes)
320 */
321 int getOutputSize(int inputLen) {
322 // estimate based on the maximum
323 return getOutputSizeByOperation(inputLen, true);
324 }
325
326 private int getOutputSizeByOperation(int inputLen, boolean isDoFinal) {
327 int totalLen = buffered + inputLen + cipher.getBufferedLength();
328 switch (cipherMode) {
329 case GCM_MODE:
330 if (isDoFinal) {
331 int tagLen = ((GaloisCounterMode) cipher).getTagLen();
332 if (!decrypting) {
333 totalLen += tagLen;
334 } else {
335 totalLen -= tagLen;
336 }
337 }
338 if (totalLen < 0) {
339 totalLen = 0;
340 }
341 break;
342 default:
343 if (padding != null && !decrypting) {
344 if (unitBytes != blockSize) {
345 if (totalLen < diffBlocksize) {
346 totalLen = diffBlocksize;
347 } else {
348 int residue = (totalLen - diffBlocksize) % blockSize;
349 totalLen += (blockSize - residue);
350 }
351 } else {
352 totalLen += padding.padLength(totalLen);
353 }
354 }
355 break;
356 }
357 return totalLen;
358 }
359
360 /**
361 * Returns the initialization vector (IV) in a new buffer.
362 *
363 * <p>This is useful in the case where a random IV has been created
364 * (see <a href = "#init">init</a>),
365 * or in the context of password-based encryption or
366 * decryption, where the IV is derived from a user-provided password.
367 *
368 * @return the initialization vector in a new buffer, or null if the
369 * underlying algorithm does not use an IV, or if the IV has not yet
370 * been set.
371 */
372 byte[] getIV() {
373 byte[] iv = cipher.getIV();
374 return (iv == null) ? null : iv.clone();
375 }
376
377 /**
378 * Returns the parameters used with this cipher.
379 *
380 * <p>The returned parameters may be the same that were used to initialize
381 * this cipher, or may contain the default set of parameters or a set of
382 * randomly generated parameters used by the underlying cipher
383 * implementation (provided that the underlying cipher implementation
384 * uses a default set of parameters or creates new parameters if it needs
385 * parameters but was not initialized with any).
386 *
387 * @return the parameters used with this cipher, or null if this cipher
388 * does not use any parameters.
389 */
390 AlgorithmParameters getParameters(String algName) {
391 if (cipherMode == ECB_MODE) {
392 return null;
393 }
394 AlgorithmParameters params = null;
395 AlgorithmParameterSpec spec;
396 byte[] iv = getIV();
397 if (iv == null) {
398 // generate spec using default value
399 if (cipherMode == GCM_MODE) {
400 iv = new byte[GaloisCounterMode.DEFAULT_IV_LEN];
401 } else {
402 iv = new byte[blockSize];
403 }
404 SunJCE.getRandom().nextBytes(iv);
405 }
406 if (cipherMode == GCM_MODE) {
407 algName = "GCM";
408 spec = new GCMParameterSpec
409 (((GaloisCounterMode) cipher).getTagLen()*8, iv);
410 } else {
411 if (algName.equals("RC2")) {
412 RC2Crypt rawImpl = (RC2Crypt) cipher.getEmbeddedCipher();
413 spec = new RC2ParameterSpec
414 (rawImpl.getEffectiveKeyBits(), iv);
415 } else {
416 spec = new IvParameterSpec(iv);
417 }
418 }
419 try {
420 params = AlgorithmParameters.getInstance(algName,
421 SunJCE.getInstance());
422 params.init(spec);
423 } catch (NoSuchAlgorithmException nsae) {
424 // should never happen
425 throw new RuntimeException("Cannot find " + algName +
426 " AlgorithmParameters implementation in SunJCE provider");
427 } catch (InvalidParameterSpecException ipse) {
428 // should never happen
429 throw new RuntimeException(spec.getClass() + " not supported");
430 }
431 return params;
432 }
433
434 /**
435 * Initializes this cipher with a key and a source of randomness.
436 *
437 * <p>The cipher is initialized for one of the following four operations:
438 * encryption, decryption, key wrapping or key unwrapping, depending on
439 * the value of <code>opmode</code>.
440 *
441 * <p>If this cipher requires an initialization vector (IV), it will get
442 * it from <code>random</code>.
443 * This behaviour should only be used in encryption or key wrapping
444 * mode, however.
445 * When initializing a cipher that requires an IV for decryption or
446 * key unwrapping, the IV
447 * (same IV that was used for encryption or key wrapping) must be provided
448 * explicitly as a
449 * parameter, in order to get the correct result.
450 *
451 * <p>This method also cleans existing buffer and other related state
452 * information.
453 *
454 * @param opmode the operation mode of this cipher (this is one of
455 * the following:
456 * <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
457 * <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
458 * @param key the secret key
459 * @param random the source of randomness
460 *
461 * @exception InvalidKeyException if the given key is inappropriate for
462 * initializing this cipher
463 */
464 void init(int opmode, Key key, SecureRandom random)
465 throws InvalidKeyException {
466 try {
467 init(opmode, key, (AlgorithmParameterSpec)null, random);
468 } catch (InvalidAlgorithmParameterException e) {
469 throw new InvalidKeyException(e.getMessage());
470 }
471 }
472
473 /**
474 * Initializes this cipher with a key, a set of
475 * algorithm parameters, and a source of randomness.
476 *
477 * <p>The cipher is initialized for one of the following four operations:
478 * encryption, decryption, key wrapping or key unwrapping, depending on
479 * the value of <code>opmode</code>.
480 *
481 * <p>If this cipher (including its underlying feedback or padding scheme)
482 * requires any random bytes, it will get them from <code>random</code>.
483 *
484 * @param opmode the operation mode of this cipher (this is one of
485 * the following:
486 * <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
487 * <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
488 * @param key the encryption key
489 * @param params the algorithm parameters
490 * @param random the source of randomness
491 *
492 * @exception InvalidKeyException if the given key is inappropriate for
493 * initializing this cipher
494 * @exception InvalidAlgorithmParameterException if the given algorithm
495 * parameters are inappropriate for this cipher
496 */
497 void init(int opmode, Key key, AlgorithmParameterSpec params,
498 SecureRandom random)
499 throws InvalidKeyException, InvalidAlgorithmParameterException {
500 decrypting = (opmode == Cipher.DECRYPT_MODE)
501 || (opmode == Cipher.UNWRAP_MODE);
502
503 byte[] keyBytes = getKeyBytes(key);
504 int tagLen = -1;
505 byte[] ivBytes = null;
506 if (params != null) {
507 if (cipherMode == GCM_MODE) {
508 if (params instanceof GCMParameterSpec) {
509 tagLen = ((GCMParameterSpec)params).getTLen();
510 if (tagLen < 96 || tagLen > 128 || ((tagLen & 0x07) != 0)) {
511 throw new InvalidAlgorithmParameterException
512 ("Unsupported TLen value; must be one of " +
513 "{128, 120, 112, 104, 96}");
514 }
515 tagLen = tagLen >> 3;
516 ivBytes = ((GCMParameterSpec)params).getIV();
517 } else {
518 throw new InvalidAlgorithmParameterException
519 ("Unsupported parameter: " + params);
520 }
521 } else {
522 if (params instanceof IvParameterSpec) {
523 ivBytes = ((IvParameterSpec)params).getIV();
524 if ((ivBytes == null) || (ivBytes.length != blockSize)) {
525 throw new InvalidAlgorithmParameterException
526 ("Wrong IV length: must be " + blockSize +
527 " bytes long");
528 }
529 } else if (params instanceof RC2ParameterSpec) {
530 ivBytes = ((RC2ParameterSpec)params).getIV();
531 if ((ivBytes != null) && (ivBytes.length != blockSize)) {
532 throw new InvalidAlgorithmParameterException
533 ("Wrong IV length: must be " + blockSize +
534 " bytes long");
535 }
536 } else {
537 throw new InvalidAlgorithmParameterException
538 ("Unsupported parameter: " + params);
539 }
540 }
541 }
542 if (cipherMode == ECB_MODE) {
543 if (ivBytes != null) {
544 throw new InvalidAlgorithmParameterException
545 ("ECB mode cannot use IV");
546 }
547 } else if (ivBytes == null) {
548 if (decrypting) {
549 throw new InvalidAlgorithmParameterException("Parameters "
550 + "missing");
551 }
552
553 if (random == null) {
554 random = SunJCE.getRandom();
555 }
556 if (cipherMode == GCM_MODE) {
557 ivBytes = new byte[GaloisCounterMode.DEFAULT_IV_LEN];
558 } else {
559 ivBytes = new byte[blockSize];
560 }
561 random.nextBytes(ivBytes);
562 }
563
564 buffered = 0;
565 diffBlocksize = blockSize;
566
567 String algorithm = key.getAlgorithm();
568
569 // GCM mode needs additional handling
570 if (cipherMode == GCM_MODE) {
571 if(tagLen == -1) {
572 tagLen = GaloisCounterMode.DEFAULT_TAG_LEN;
573 }
574 if (decrypting) {
575 minBytes = tagLen;
576 } else {
577 // check key+iv for encryption in GCM mode
578 requireReinit =
579 Arrays.equals(ivBytes, lastEncIv) &&
580 MessageDigest.isEqual(keyBytes, lastEncKey);
581 if (requireReinit) {
582 throw new InvalidAlgorithmParameterException
583 ("Cannot reuse iv for GCM encryption");
584 }
585 lastEncIv = ivBytes;
586 lastEncKey = keyBytes;
587 }
588 ((GaloisCounterMode) cipher).init
589 (decrypting, algorithm, keyBytes, ivBytes, tagLen);
590 } else {
591 cipher.init(decrypting, algorithm, keyBytes, ivBytes);
592 }
593 // skip checking key+iv from now on until after doFinal()
594 requireReinit = false;
595 }
596
597 void init(int opmode, Key key, AlgorithmParameters params,
598 SecureRandom random)
599 throws InvalidKeyException, InvalidAlgorithmParameterException {
600 AlgorithmParameterSpec spec = null;
601 String paramType = null;
602 if (params != null) {
603 try {
604 if (cipherMode == GCM_MODE) {
605 paramType = "GCM";
606 spec = params.getParameterSpec(GCMParameterSpec.class);
607 } else {
608 // NOTE: RC2 parameters are always handled through
609 // init(..., AlgorithmParameterSpec,...) method, so
610 // we can assume IvParameterSpec type here.
611 paramType = "IV";
612 spec = params.getParameterSpec(IvParameterSpec.class);
613 }
614 } catch (InvalidParameterSpecException ipse) {
615 throw new InvalidAlgorithmParameterException
616 ("Wrong parameter type: " + paramType + " expected");
617 }
618 }
619 init(opmode, key, spec, random);
620 }
621
622 /**
623 * Return the key bytes of the specified key. Throw an InvalidKeyException
624 * if the key is not usable.
625 */
626 static byte[] getKeyBytes(Key key) throws InvalidKeyException {
627 if (key == null) {
628 throw new InvalidKeyException("No key given");
629 }
630 // note: key.getFormat() may return null
631 if (!"RAW".equalsIgnoreCase(key.getFormat())) {
632 throw new InvalidKeyException("Wrong format: RAW bytes needed");
633 }
634 byte[] keyBytes = key.getEncoded();
635 if (keyBytes == null) {
636 throw new InvalidKeyException("RAW key bytes missing");
637 }
638 return keyBytes;
639 }
640
641
642 /**
643 * Continues a multiple-part encryption or decryption operation
644 * (depending on how this cipher was initialized), processing another data
645 * part.
646 *
647 * <p>The first <code>inputLen</code> bytes in the <code>input</code>
648 * buffer, starting at <code>inputOffset</code>, are processed, and the
649 * result is stored in a new buffer.
650 *
651 * @param input the input buffer
652 * @param inputOffset the offset in <code>input</code> where the input
653 * starts
654 * @param inputLen the input length
655 *
656 * @return the new buffer with the result
657 *
658 * @exception IllegalStateException if this cipher is in a wrong state
659 * (e.g., has not been initialized)
660 */
661 byte[] update(byte[] input, int inputOffset, int inputLen) {
662 if (requireReinit) {
663 throw new IllegalStateException
664 ("Must use either different key or iv for GCM encryption");
665 }
666
667 byte[] output = null;
668 try {
669 output = new byte[getOutputSizeByOperation(inputLen, false)];
670 int len = update(input, inputOffset, inputLen, output,
671 0);
672 if (len == output.length) {
673 return output;
674 } else {
675 return Arrays.copyOf(output, len);
676 }
677 } catch (ShortBufferException e) {
678 // should never happen
679 throw new ProviderException("Unexpected exception", e);
680 }
681 }
682
683 /**
684 * Continues a multiple-part encryption or decryption operation
685 * (depending on how this cipher was initialized), processing another data
686 * part.
687 *
688 * <p>The first <code>inputLen</code> bytes in the <code>input</code>
689 * buffer, starting at <code>inputOffset</code>, are processed, and the
690 * result is stored in the <code>output</code> buffer, starting at
691 * <code>outputOffset</code>.
692 *
693 * @param input the input buffer
694 * @param inputOffset the offset in <code>input</code> where the input
695 * starts
696 * @param inputLen the input length
697 * @param output the buffer for the result
698 * @param outputOffset the offset in <code>output</code> where the result
699 * is stored
700 *
701 * @return the number of bytes stored in <code>output</code>
702 *
703 * @exception ShortBufferException if the given output buffer is too small
704 * to hold the result
705 */
706 int update(byte[] input, int inputOffset, int inputLen, byte[] output,
707 int outputOffset) throws ShortBufferException {
708 if (requireReinit) {
709 throw new IllegalStateException
710 ("Must use either different key or iv for GCM encryption");
711 }
712
713 // figure out how much can be sent to crypto function
714 int len = buffered + inputLen - minBytes;
715 if (padding != null && decrypting) {
716 // do not include the padding bytes when decrypting
717 len -= blockSize;
718 }
719 // do not count the trailing bytes which do not make up a unit
720 len = (len > 0 ? (len - (len % unitBytes)) : 0);
721
722 // check output buffer capacity
723 if ((output == null) ||
724 ((output.length - outputOffset) < len)) {
725 throw new ShortBufferException("Output buffer must be "
726 + "(at least) " + len
727 + " bytes long");
728 }
729
730 int outLen = 0;
731 if (len != 0) { // there is some work to do
732 if ((input == output)
733 && (outputOffset < (inputOffset + inputLen))
734 && (inputOffset < (outputOffset + buffer.length))) {
735 // copy 'input' out to avoid its content being
736 // overwritten prematurely.
737 input = Arrays.copyOfRange(input, inputOffset,
738 inputOffset + inputLen);
739 inputOffset = 0;
740 }
741 if (len <= buffered) {
742 // all to-be-processed data are from 'buffer'
743 if (decrypting) {
744 outLen = cipher.decrypt(buffer, 0, len, output, outputOffset);
745 } else {
746 outLen = cipher.encrypt(buffer, 0, len, output, outputOffset);
747 }
748 buffered -= len;
749 if (buffered != 0) {
750 System.arraycopy(buffer, len, buffer, 0, buffered);
751 }
752 } else { // len > buffered
753 int inputConsumed = len - buffered;
754 int temp;
755 if (buffered > 0) {
756 int bufferCapacity = buffer.length - buffered;
757 if (bufferCapacity != 0) {
758 temp = Math.min(bufferCapacity, inputConsumed);
759 if (unitBytes != blockSize) {
760 temp -= ((buffered + temp) % unitBytes);
761 }
762 System.arraycopy(input, inputOffset, buffer, buffered, temp);
763 inputOffset += temp;
764 inputConsumed -= temp;
765 inputLen -= temp;
766 buffered += temp;
767 }
768 // process 'buffer'
769 if (decrypting) {
770 outLen = cipher.decrypt(buffer, 0, buffered, output, outputOffset);
771 } else {
772 outLen = cipher.encrypt(buffer, 0, buffered, output, outputOffset);
773 }
774 outputOffset += outLen;
775 buffered = 0;
776 }
777 if (inputConsumed > 0) { // still has input to process
778 if (decrypting) {
779 outLen += cipher.decrypt(input, inputOffset, inputConsumed,
780 output, outputOffset);
781 } else {
782 outLen += cipher.encrypt(input, inputOffset, inputConsumed,
783 output, outputOffset);
784 }
785 inputOffset += inputConsumed;
786 inputLen -= inputConsumed;
787 }
788 }
789 // Let's keep track of how many bytes are needed to make
790 // the total input length a multiple of blocksize when
791 // padding is applied
792 if (unitBytes != blockSize) {
793 if (len < diffBlocksize) {
794 diffBlocksize -= len;
795 } else {
796 diffBlocksize = blockSize -
797 ((len - diffBlocksize) % blockSize);
798 }
799 }
800 }
801 // Store remaining input into 'buffer' again
802 if (inputLen > 0) {
803 System.arraycopy(input, inputOffset, buffer, buffered,
804 inputLen);
805 buffered += inputLen;
806 }
807 return outLen;
808 }
809
810 /**
811 * Encrypts or decrypts data in a single-part operation,
812 * or finishes a multiple-part operation.
813 * The data is encrypted or decrypted, depending on how this cipher was
814 * initialized.
815 *
816 * <p>The first <code>inputLen</code> bytes in the <code>input</code>
817 * buffer, starting at <code>inputOffset</code>, and any input bytes that
818 * may have been buffered during a previous <code>update</code> operation,
819 * are processed, with padding (if requested) being applied.
820 * The result is stored in a new buffer.
821 *
822 * <p>The cipher is reset to its initial state (uninitialized) after this
823 * call.
824 *
825 * @param input the input buffer
826 * @param inputOffset the offset in <code>input</code> where the input
827 * starts
828 * @param inputLen the input length
829 *
830 * @return the new buffer with the result
831 *
832 * @exception IllegalBlockSizeException if this cipher is a block cipher,
833 * no padding has been requested (only in encryption mode), and the total
834 * input length of the data processed by this cipher is not a multiple of
835 * block size
836 * @exception BadPaddingException if this cipher is in decryption mode,
837 * and (un)padding has been requested, but the decrypted data is not
838 * bounded by the appropriate padding bytes
839 */
840 byte[] doFinal(byte[] input, int inputOffset, int inputLen)
841 throws IllegalBlockSizeException, BadPaddingException {
842 byte[] output = null;
843 try {
844 output = new byte[getOutputSizeByOperation(inputLen, true)];
845 int len = doFinal(input, inputOffset, inputLen, output, 0);
846 if (len < output.length) {
847 return Arrays.copyOf(output, len);
848 } else {
849 return output;
850 }
851 } catch (ShortBufferException e) {
852 // never thrown
853 throw new ProviderException("Unexpected exception", e);
854 }
855 }
856
857 /**
858 * Encrypts or decrypts data in a single-part operation,
859 * or finishes a multiple-part operation.
860 * The data is encrypted or decrypted, depending on how this cipher was
861 * initialized.
862 *
863 * <p>The first <code>inputLen</code> bytes in the <code>input</code>
864 * buffer, starting at <code>inputOffset</code>, and any input bytes that
865 * may have been buffered during a previous <code>update</code> operation,
866 * are processed, with padding (if requested) being applied.
867 * The result is stored in the <code>output</code> buffer, starting at
868 * <code>outputOffset</code>.
869 *
870 * <p>The cipher is reset to its initial state (uninitialized) after this
871 * call.
872 *
873 * @param input the input buffer
874 * @param inputOffset the offset in <code>input</code> where the input
875 * starts
876 * @param inputLen the input length
877 * @param output the buffer for the result
878 * @param outputOffset the offset in <code>output</code> where the result
879 * is stored
880 *
881 * @return the number of bytes stored in <code>output</code>
882 *
883 * @exception IllegalBlockSizeException if this cipher is a block cipher,
884 * no padding has been requested (only in encryption mode), and the total
885 * input length of the data processed by this cipher is not a multiple of
886 * block size
887 * @exception ShortBufferException if the given output buffer is too small
888 * to hold the result
889 * @exception BadPaddingException if this cipher is in decryption mode,
890 * and (un)padding has been requested, but the decrypted data is not
891 * bounded by the appropriate padding bytes
892 */
893 int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output,
894 int outputOffset)
895 throws IllegalBlockSizeException, ShortBufferException,
896 BadPaddingException {
897 if (requireReinit) {
898 throw new IllegalStateException
899 ("Must use either different key or iv for GCM encryption");
900 }
901
902 int estOutSize = getOutputSizeByOperation(inputLen, true);
903 // check output buffer capacity.
904 // if we are decrypting with padding applied, we can perform this
905 // check only after we have determined how many padding bytes there
906 // are.
907 int outputCapacity = output.length - outputOffset;
908 int minOutSize = (decrypting? (estOutSize - blockSize):estOutSize);
909 if ((output == null) || (outputCapacity < minOutSize)) {
910 throw new ShortBufferException("Output buffer must be "
911 + "(at least) " + minOutSize + " bytes long");
912 }
913
914 // calculate total input length
915 int len = buffered + inputLen;
916
917 // calculate padding length
918 int totalLen = len + cipher.getBufferedLength();
919 int paddingLen = 0;
920 // will the total input length be a multiple of blockSize?
921 if (unitBytes != blockSize) {
922 if (totalLen < diffBlocksize) {
923 paddingLen = diffBlocksize - totalLen;
924 } else {
925 paddingLen = blockSize -
926 ((totalLen - diffBlocksize) % blockSize);
927 }
928 } else if (padding != null) {
929 paddingLen = padding.padLength(totalLen);
930 }
931
932 if (decrypting && (padding != null) &&
933 (paddingLen > 0) && (paddingLen != blockSize)) {
934 throw new IllegalBlockSizeException
935 ("Input length must be multiple of " + blockSize +
936 " when decrypting with padded cipher");
937 }
938
939 /*
940 * prepare the final input, assemble a new buffer if any
941 * of the following is true:
942 * - 'input' and 'output' are the same buffer
943 * - there are internally buffered bytes
944 * - doing encryption and padding is needed
945 */
946 byte[] finalBuf = input;
947 int finalOffset = inputOffset;
948 int finalBufLen = inputLen;
949 if ((buffered != 0) || (!decrypting && padding != null) ||
950 ((input == output)
951 && (outputOffset < (inputOffset + inputLen))
952 && (inputOffset < (outputOffset + buffer.length)))) {
953 if (decrypting || padding == null) {
954 paddingLen = 0;
955 }
956 finalBuf = new byte[len + paddingLen];
957 finalOffset = 0;
958 if (buffered != 0) {
959 System.arraycopy(buffer, 0, finalBuf, 0, buffered);
960 }
961 if (inputLen != 0) {
962 System.arraycopy(input, inputOffset, finalBuf,
963 buffered, inputLen);
964 }
965 if (paddingLen != 0) {
966 padding.padWithLen(finalBuf, (buffered+inputLen), paddingLen);
967 }
968 finalBufLen = finalBuf.length;
969 }
970 int outLen = 0;
971 if (decrypting) {
972 // if the size of specified output buffer is less than
973 // the length of the cipher text, then the current
974 // content of cipher has to be preserved in order for
975 // users to retry the call with a larger buffer in the
976 // case of ShortBufferException.
977 if (outputCapacity < estOutSize) {
978 cipher.save();
979 }
980 // create temporary output buffer so that only "real"
981 // data bytes are passed to user's output buffer.
982 byte[] outWithPadding = new byte[estOutSize];
983 outLen = finalNoPadding(finalBuf, finalOffset, outWithPadding,
984 0, finalBufLen);
985
986 if (padding != null) {
987 int padStart = padding.unpad(outWithPadding, 0, outLen);
988 if (padStart < 0) {
989 throw new BadPaddingException("Given final block not "
990 + "properly padded");
991 }
992 outLen = padStart;
993 }
994
995 if (outputCapacity < outLen) {
996 // restore so users can retry with a larger buffer
997 cipher.restore();
998 throw new ShortBufferException("Output buffer too short: "
999 + (outputCapacity)
1000 + " bytes given, " + outLen
1001 + " bytes needed");
1002 }
1003 // copy the result into user-supplied output buffer
1004 System.arraycopy(outWithPadding, 0, output, outputOffset, outLen);
1005 } else { // encrypting
1006 try {
1007 outLen = finalNoPadding(finalBuf, finalOffset, output,
1008 outputOffset, finalBufLen);
1009 } finally {
1010 // reset after doFinal() for GCM encryption
1011 requireReinit = (cipherMode == GCM_MODE);
1012 }
1013 }
1014
1015 buffered = 0;
1016 diffBlocksize = blockSize;
1017 if (cipherMode != ECB_MODE) {
1018 cipher.reset();
1019 }
1020 return outLen;
1021 }
1022
1023 private int finalNoPadding(byte[] in, int inOfs, byte[] out, int outOfs,
1024 int len)
1025 throws IllegalBlockSizeException, AEADBadTagException,
1026 ShortBufferException {
1027
1028 if ((cipherMode != GCM_MODE) && (in == null || len == 0)) {
1029 return 0;
1030 }
1031 if ((cipherMode != CFB_MODE) && (cipherMode != OFB_MODE) &&
1032 (cipherMode != GCM_MODE) &&
1033 ((len % unitBytes) != 0) && (cipherMode != CTS_MODE)) {
1034 if (padding != null) {
1035 throw new IllegalBlockSizeException
1036 ("Input length (with padding) not multiple of " +
1037 unitBytes + " bytes");
1038 } else {
1039 throw new IllegalBlockSizeException
1040 ("Input length not multiple of " + unitBytes
1041 + " bytes");
1042 }
1043 }
1044 int outLen = 0;
1045 if (decrypting) {
1046 outLen = cipher.decryptFinal(in, inOfs, len, out, outOfs);
1047 } else {
1048 outLen = cipher.encryptFinal(in, inOfs, len, out, outOfs);
1049 }
1050 return outLen;
1051 }
1052
1053 // Note: Wrap() and Unwrap() are the same in
1054 // each of SunJCE CipherSpi implementation classes.
1055 // They are duplicated due to export control requirements:
1056 // All CipherSpi implementation must be final.
1057 /**
1058 * Wrap a key.
1059 *
1060 * @param key the key to be wrapped.
1061 *
1062 * @return the wrapped key.
1063 *
1064 * @exception IllegalBlockSizeException if this cipher is a block
1065 * cipher, no padding has been requested, and the length of the
1066 * encoding of the key to be wrapped is not a
1067 * multiple of the block size.
1068 *
1069 * @exception InvalidKeyException if it is impossible or unsafe to
1070 * wrap the key with this cipher (e.g., a hardware protected key is
1071 * being passed to a software only cipher).
1072 */
1073 byte[] wrap(Key key)
1074 throws IllegalBlockSizeException, InvalidKeyException {
1075 byte[] result = null;
1076
1077 try {
1078 byte[] encodedKey = key.getEncoded();
1079 if ((encodedKey == null) || (encodedKey.length == 0)) {
1080 throw new InvalidKeyException("Cannot get an encoding of " +
1081 "the key to be wrapped");
1082 }
1083 result = doFinal(encodedKey, 0, encodedKey.length);
1084 } catch (BadPaddingException e) {
1085 // Should never happen
1086 }
1087 return result;
1088 }
1089
1090 /**
1091 * Unwrap a previously wrapped key.
1092 *
1093 * @param wrappedKey the key to be unwrapped.
1094 *
1095 * @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
1096 *
1097 * @param wrappedKeyType the type of the wrapped key.
1098 * This is one of <code>Cipher.SECRET_KEY</code>,
1099 * <code>Cipher.PRIVATE_KEY</code>, or <code>Cipher.PUBLIC_KEY</code>.
1100 *
1101 * @return the unwrapped key.
1102 *
1103 * @exception NoSuchAlgorithmException if no installed providers
1104 * can create keys of type <code>wrappedKeyType</code> for the
1105 * <code>wrappedKeyAlgorithm</code>.
1106 *
1107 * @exception InvalidKeyException if <code>wrappedKey</code> does not
1108 * represent a wrapped key of type <code>wrappedKeyType</code> for
1109 * the <code>wrappedKeyAlgorithm</code>.
1110 */
1111 Key unwrap(byte[] wrappedKey, String wrappedKeyAlgorithm,
1112 int wrappedKeyType)
1113 throws InvalidKeyException, NoSuchAlgorithmException {
1114 byte[] encodedKey;
1115 try {
1116 encodedKey = doFinal(wrappedKey, 0, wrappedKey.length);
1117 } catch (BadPaddingException ePadding) {
1118 throw new InvalidKeyException("The wrapped key is not padded " +
1119 "correctly");
1120 } catch (IllegalBlockSizeException eBlockSize) {
1121 throw new InvalidKeyException("The wrapped key does not have " +
1122 "the correct length");
1123 }
1124 return ConstructKeys.constructKey(encodedKey, wrappedKeyAlgorithm,
1125 wrappedKeyType);
1126 }
1127
1128 /**
1129 * Continues a multi-part update of the Additional Authentication
1130 * Data (AAD), using a subset of the provided buffer.
1131 * <p>
1132 * Calls to this method provide AAD to the cipher when operating in
1133 * modes such as AEAD (GCM/CCM). If this cipher is operating in
1134 * either GCM or CCM mode, all AAD must be supplied before beginning
1135 * operations on the ciphertext (via the {@code update} and {@code
1136 * doFinal} methods).
1137 *
1138 * @param src the buffer containing the AAD
1139 * @param offset the offset in {@code src} where the AAD input starts
1140 * @param len the number of AAD bytes
1141 *
1142 * @throws IllegalStateException if this cipher is in a wrong state
1143 * (e.g., has not been initialized), does not accept AAD, or if
1144 * operating in either GCM or CCM mode and one of the {@code update}
1145 * methods has already been called for the active
1146 * encryption/decryption operation
1147 * @throws UnsupportedOperationException if this method
1148 * has not been overridden by an implementation
1149 *
1150 * @since 1.8
1151 */
1152 void updateAAD(byte[] src, int offset, int len) {
1153 if (requireReinit) {
1154 throw new IllegalStateException
1155 ("Must use either different key or iv for GCM encryption");
1156 }
1157 cipher.updateAAD(src, offset, len);
1158 }
1159 }