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[apple/security.git] / AppleCSP / AppleCSP / BlockCryptor.cpp
1 /*
2 * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
3 *
4 * The contents of this file constitute Original Code as defined in and are
5 * subject to the Apple Public Source License Version 1.2 (the 'License').
6 * You may not use this file except in compliance with the License. Please obtain
7 * a copy of the License at http://www.apple.com/publicsource and read it before
8 * using this file.
9 *
10 * This Original Code and all software distributed under the License are
11 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
12 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
13 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
14 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
15 * specific language governing rights and limitations under the License.
16 */
17
18
19 /*
20 * BlockCryptor.cpp - common context for block-oriented encryption algorithms
21 *
22 * Created March 5 2001 by dmitch
23 */
24
25 #include "BlockCryptor.h"
26 #include "BinaryKey.h"
27 #include "AppleCSPSession.h"
28 #include <Security/cssmalloc.h>
29 #include <Security/utilities.h>
30 #include <Security/cssmerr.h>
31 #include <string.h>
32 #include <Security/debugging.h>
33 #include <Security/cssmdata.h>
34
35 #define BlockCryptDebug(args...) secdebug("blockCrypt", ## args)
36 #define bprintf(args...) secdebug("blockCryptBuf", ## args)
37 #define ioprintf(args...) secdebug("blockCryptIo", ## args)
38
39 BlockCryptor::~BlockCryptor()
40 {
41 if(mInBuf) {
42 memset(mInBuf, 0, mInBlockSize);
43 session().free(mInBuf);
44 mInBuf = NULL;
45 }
46 if(mChainBuf) {
47 memset(mChainBuf, 0, mInBlockSize);
48 session().free(mChainBuf);
49 mChainBuf = NULL;
50 }
51 mInBufSize = 0;
52 }
53
54 /*
55 * Reusable setup functions called from subclass's init.
56 * This is the general purpose one....
57 */
58 void BlockCryptor::setup(
59 size_t blockSizeIn, // block size of input
60 size_t blockSizeOut, // block size of output
61 bool pkcsPad, // this class performs PKCS{5,7} padding
62 bool needsFinal, // needs final update with valid data
63 BC_Mode mode, // ECB, CBC
64 const CssmData *iv) // init vector, required for CBC
65 //Ê must be at least blockSizeIn bytes
66 {
67 if(pkcsPad && needsFinal) {
68 BlockCryptDebug("BlockCryptor::setup pkcsPad && needsFinal");
69 CssmError::throwMe(CSSMERR_CSP_INTERNAL_ERROR);
70 }
71 mPkcsPadding = pkcsPad;
72 mMode = mode;
73 mNeedFinalData = needsFinal;
74
75 /* set up inBuf, all configurations */
76 if(mInBuf != NULL) {
77 /* only reuse if same size */
78 if(mInBlockSize != blockSizeIn) {
79 session().free(mInBuf);
80 mInBuf = NULL;
81 }
82 }
83 if(mInBuf == NULL) {
84 mInBuf = (uint8 *)session().malloc(blockSizeIn);
85 }
86
87 /* set up chain buf, decrypt/CBC only */
88 if((mMode == BCM_CBC) && !encoding()) {
89 if(mChainBuf != NULL) {
90 /* only reuse if same size */
91 if(mInBlockSize != blockSizeIn) {
92 session().free(mChainBuf);
93 mChainBuf = NULL;
94 }
95 }
96 if(mChainBuf == NULL) {
97 mChainBuf = (uint8 *)session().malloc(blockSizeIn);
98 }
99 }
100
101 /* IV iff CBC mode, and ensure IV is big enough */
102 switch(mMode) {
103 case BCM_ECB:
104 if(iv != NULL) {
105 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_INIT_VECTOR);
106 }
107 break;
108 case BCM_CBC:
109 if(iv == NULL) {
110 CssmError::throwMe(CSSMERR_CSP_MISSING_ATTR_INIT_VECTOR);
111 }
112 if(blockSizeIn != blockSizeOut) {
113 /* no can do, must be same block sizes */
114 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_MODE);
115 }
116 if(iv->Length < blockSizeIn) {
117 /* not enough IV */
118 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_INIT_VECTOR);
119 }
120 /* save IV as appropriate */
121 if(encoding()) {
122 memmove(mInBuf, iv->Data, blockSizeIn);
123 }
124 else {
125 assert(mChainBuf != NULL);
126 memmove(mChainBuf, iv->Data, blockSizeIn);
127 }
128 break;
129 }
130
131 mInBlockSize = blockSizeIn;
132 mInBufSize = 0;
133 mOutBlockSize = blockSizeOut;
134 mOpStarted = false;
135 }
136
137 /*
138 * This one is used by simple, well-behaved algorithms which don't do their own
139 * padding and which rely on us to do everything but one-block-at-a-time
140 * encrypt and decrypt.
141 */
142 void BlockCryptor::setup(
143 size_t blockSize, // block size of input and output
144 const Context &context)
145 {
146 bool padEnable = false;
147 bool chainEnable = false;
148 bool ivEnable = false;
149 CssmData *iv = NULL;
150
151 /*
152 * Validate context
153 * IV optional per mode
154 * pad optional per mode
155 * Currently we ignore extraneous attributes (e.g., it's OK to pass in
156 * an IV if the mode doesn't specify it), mainly for simplifying test routines.
157 */
158 CSSM_ENCRYPT_MODE cssmMode = context.getInt(CSSM_ATTRIBUTE_MODE);
159
160 switch (cssmMode) {
161 /* no mode attr --> 0 == CSSM_ALGMODE_NONE, not currently supported */
162 case CSSM_ALGMODE_CBCPadIV8:
163 padEnable = true;
164 ivEnable = true;
165 chainEnable = true;
166 break;
167
168 case CSSM_ALGMODE_CBC_IV8:
169 ivEnable = true;
170 chainEnable = true;
171 break;
172
173 case CSSM_ALGMODE_ECB:
174 break;
175
176 case CSSM_ALGMODE_ECBPad:
177 padEnable = true;
178 break;
179
180 default:
181 errorLog1("DESContext::init: illegal mode (%d)\n", (int)cssmMode);
182 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_MODE);
183 }
184
185 if(padEnable) {
186 /* validate padding type */
187 uint32 padding = context.getInt(CSSM_ATTRIBUTE_PADDING); // 0 ==> PADDING_NONE
188 if(blockSize == 8) {
189 switch(padding) {
190 /* backwards compatibility - used to be PKCS1, should be PKCS5 or 7 */
191 case CSSM_PADDING_PKCS7:
192 case CSSM_PADDING_PKCS5:
193 case CSSM_PADDING_PKCS1: //Êthis goes away soon
194 /* OK */
195 break;
196 default:
197 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_PADDING);
198 }
199 }
200 else {
201 switch(padding) {
202 case CSSM_PADDING_PKCS5: // this goes away soon
203 case CSSM_PADDING_PKCS7:
204 /* OK */
205 break;
206 default:
207 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_PADDING);
208 }
209 }
210 }
211 if(ivEnable) {
212 /* make sure there's an IV in the context of sufficient length */
213 iv = context.get<CssmData>(CSSM_ATTRIBUTE_INIT_VECTOR);
214 if(iv == NULL) {
215 CssmError::throwMe(CSSMERR_CSP_MISSING_ATTR_INIT_VECTOR);
216 }
217 if(iv->Length < blockSize) {
218 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_INIT_VECTOR);
219 }
220 }
221 setup(blockSize,
222 blockSize,
223 padEnable,
224 false, // needsFinal
225 chainEnable ? BCM_CBC : BCM_ECB,
226 iv);
227 }
228
229 /*
230 * Update always leaves some data in mInBuf if:
231 * mNeedsFinalData is true, or
232 * decrypting and mPkcsPadding true.
233 * Also, we always process all of the input (except on error).
234 */
235 void BlockCryptor::update(
236 void *inp,
237 size_t &inSize, // in/out
238 void *outp,
239 size_t &outSize) // in/out
240 {
241 UInt8 *uInp = (UInt8 *)inp;
242 UInt8 *uOutp = (UInt8 *)outp;
243 size_t uInSize = inSize; // input bytes to go
244 size_t uOutSize = 0; // ouput bytes generated
245 size_t uOutLeft = outSize; // bytes remaining in outp
246 size_t toMove;
247 size_t actMoved;
248 unsigned i;
249 bool needLeftOver = mNeedFinalData || (!encoding() && mPkcsPadding);
250
251 assert(mInBuf != NULL);
252 mOpStarted = true;
253
254 if(mInBufSize) {
255 /* attempt to fill mInBuf from inp */
256 toMove = mInBlockSize - mInBufSize;
257 if(toMove > uInSize) {
258 toMove = uInSize;
259 }
260 if(encoding() && (mMode == BCM_CBC)) {
261 /* xor into last cipherblock or IV */
262 for(i=0; i<toMove; i++) {
263 mInBuf[mInBufSize + i] ^= *uInp++;
264 }
265 }
266 else {
267 /* use incoming data as is */
268 memmove(mInBuf+mInBufSize, uInp, toMove);
269 uInp += toMove;
270 }
271 uInSize -= toMove;
272 mInBufSize += toMove;
273
274 /*
275 * Process inBuf if it's full, but skip if no more data in uInp and
276 * inBuf might be needed (by us for unpadding on decrypt, or by
277 * subclass for anything) for a final call
278 */
279 if((mInBufSize == mInBlockSize) && !((uInSize == 0) && needLeftOver)) {
280 actMoved = uOutLeft;
281 if(encoding()) {
282 encryptBlock(mInBuf, mInBlockSize, uOutp, actMoved, false);
283 if(mMode == BCM_CBC) {
284 /* save ciphertext for chaining next block */
285 assert(mInBlockSize == actMoved);
286 memmove(mInBuf, uOutp, mInBlockSize);
287 }
288 }
289 else {
290 decryptBlock(mInBuf, uOutp, actMoved, false);
291 if(mMode == BCM_CBC) {
292 /* xor in last ciphertext */
293 assert(mInBlockSize == actMoved);
294 for(i=0; i<mInBlockSize; i++) {
295 uOutp[i] ^= mChainBuf[i];
296 }
297 /* save this ciphertext for next chain */
298 memmove(mChainBuf, mInBuf, mInBlockSize);
299 }
300 }
301 uOutSize += actMoved;
302 uOutp += actMoved;
303 uOutLeft -= actMoved;
304 mInBufSize = 0;
305 assert(uOutSize <= outSize);
306 }
307 } /* processing mInBuf */
308 if(uInSize == 0) {
309 /* done */
310 outSize = uOutSize;
311 ioprintf("=== BlockCryptor::update encrypt %d inSize 0x%lx outSize 0x%lx",
312 encoding() ? 1 : 0, inSize, outSize);
313 return;
314 }
315
316 /*
317 * en/decrypt even blocks in (remaining) inp.
318 */
319 unsigned leftOver = uInSize % mInBlockSize;
320 if((leftOver == 0) && needLeftOver) {
321 /*
322 * Even blocks coming in, but we really need to leave some data
323 * in the buffer (because the subclass asked for it, or we're decrypting
324 * with PKCS padding). Save one block for mInBuf.
325 */
326 leftOver = mInBlockSize;
327 }
328 toMove = uInSize - leftOver;
329 if(encoding()) {
330 while(toMove) {
331 actMoved = uOutLeft;
332 if(mMode == BCM_ECB) {
333 /* encrypt directly from input to output */
334 encryptBlock(uInp, mInBlockSize, uOutp, actMoved, false);
335 }
336 else {
337 /* xor into last ciphertext, encrypt the result */
338 for(i=0; i<mInBlockSize; i++) {
339 mInBuf[i] ^= uInp[i];
340 }
341 encryptBlock(mInBuf, mInBlockSize, uOutp, actMoved, false);
342
343 /* save new ciphertext for next chain */
344 assert(actMoved == mInBlockSize);
345 memmove(mInBuf, uOutp, mInBlockSize);
346 }
347 uOutSize += actMoved;
348 uOutp += actMoved;
349 uInp += mInBlockSize;
350 uOutLeft -= actMoved;
351 toMove -= mInBlockSize;
352 assert(uOutSize <= outSize);
353 } /* main encrypt loop */
354 }
355 else {
356 /* decrypting */
357 while(toMove) {
358 actMoved = uOutLeft;
359 if(mMode == BCM_CBC) {
360 /* save this ciphertext for chain; don't assume in != out */
361 memmove(mInBuf, uInp, mInBlockSize);
362 decryptBlock(uInp, uOutp, actMoved, false);
363
364 /* chain in previous ciphertext */
365 assert(mInBlockSize == actMoved);
366 for(i=0; i<mInBlockSize; i++) {
367 uOutp[i] ^= mChainBuf[i];
368 }
369
370 /* save current ciphertext for next block */
371 memmove(mChainBuf, mInBuf, mInBlockSize);
372 }
373 else {
374 /* ECB */
375 decryptBlock(uInp, uOutp, actMoved, false);
376 }
377 uOutSize += actMoved;
378 uOutp += actMoved;
379 uInp += mInBlockSize;
380 uOutLeft -= actMoved;
381 toMove -= mInBlockSize;
382 assert(uOutSize <= outSize);
383 } /* main decrypt loop */
384 }
385
386 /* leftover bytes from inp --> mInBuf */
387 if(leftOver) {
388 if(encoding() && (mMode == BCM_CBC)) {
389 /* xor into last cipherblock or IV */
390 for(i=0; i<leftOver; i++) {
391 mInBuf[i] ^= *uInp++;
392 }
393 }
394 else {
395 memmove(mInBuf, uInp, leftOver);
396 }
397 }
398 mInBufSize = leftOver;
399 outSize = uOutSize;
400 ioprintf("=== BlockCryptor::update encrypt %d inSize 0x%lx outSize 0x%lx",
401 encoding() ? 1 : 0, inSize, outSize);
402 }
403
404 void BlockCryptor::final(
405 CssmData &out)
406 {
407 size_t uOutSize = 0; // ouput bytes generated
408 size_t actMoved;
409 size_t uOutLeft = out.Length; // bytes remaining in out
410 unsigned i;
411
412 assert(mInBuf != NULL);
413 mOpStarted = true;
414 if((mInBufSize == 0) && mNeedFinalData) {
415 /* only way this could happen: no update() called (at least not with
416 * non-zero input data sizes) */
417 BlockCryptDebug("BlockCryptor::final with no mInBuf data");
418 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
419 }
420 if(encoding()) {
421 UInt8 *ctext = out.Data;
422
423 if(mPkcsPadding) {
424 /*
425 Ê* PKCS5/7 padding: pad byte = size of padding.
426 * This assertion courtesy of the limitation on the mutual
427 * exclusivity of mPkcsPadding and mNeedFinalData.
428 */
429 assert(mInBufSize < mInBlockSize);
430 size_t padSize = mInBlockSize - mInBufSize;
431 UInt8 *padPtr = mInBuf + mInBufSize;
432 if(mMode == BCM_ECB) {
433 for(i=0; i<padSize; i++) {
434 *padPtr++ = padSize;
435 }
436 }
437 else {
438 for(i=0; i<padSize; i++) {
439 *padPtr++ ^= padSize;
440 }
441 }
442 mInBufSize = mInBlockSize;
443 } /* PKCS padding */
444
445 /*
446 * Encrypt final mInBuf. If it's not full, the BlockCryptObject better know
447 * how to pad....
448 */
449 if(mInBufSize) {
450 actMoved = uOutLeft;
451 encryptBlock(mInBuf, mInBufSize, ctext, actMoved, true);
452 uOutSize += actMoved;
453 mInBufSize = 0;
454 assert(uOutSize <= out.length());
455 }
456 out.length(uOutSize);
457 } /* encrypting */
458
459 else {
460 if(mInBufSize == 0) {
461 if(mPkcsPadding) {
462 BlockCryptDebug("BlockCryptor::final decrypt/pad with no mInBuf data");
463 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
464 }
465 else {
466 /* simple decrypt op complete */
467 ioprintf("=== BlockCryptor::final encrypt 0 outSize 0");
468 out.length(0);
469 return;
470 }
471 }
472
473 /*
474 * Decrypt - must have exactly one block of ciphertext.
475 * We trust CSPContext, and our own outputSize(), to have set up
476 * the current output buffer with enough space to handle the
477 * full size of the decrypt, even though - due to padding - we
478 * might actually pass less than that amount back to caller.
479 */
480 if(mInBufSize != mInBlockSize) {
481 BlockCryptDebug("BlockCryptor::final unaligned ciphertext");
482 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
483 }
484
485 UInt8 *ptext = out.Data;
486 actMoved = uOutLeft;
487 decryptBlock(mInBuf, ptext, actMoved, true);
488 if(mMode == BCM_CBC) {
489 /* chain in previous ciphertext one more time */
490 assert(mInBlockSize == actMoved);
491 for(i=0; i<mInBlockSize; i++) {
492 ptext[i] ^= mChainBuf[i];
493 }
494 }
495 if(mPkcsPadding) {
496 assert(actMoved == mOutBlockSize);
497
498 /* ensure integrity of padding byte(s) */
499 unsigned padSize = ptext[mOutBlockSize - 1];
500 if(padSize > mOutBlockSize) {
501 BlockCryptDebug("BlockCryptor::final malformed ciphertext (1)");
502 CssmError::throwMe(CSSM_ERRCODE_INVALID_DATA);
503 }
504 UInt8 *padPtr = ptext + mOutBlockSize - padSize;
505 for(unsigned i=0; i<padSize; i++) {
506 if(*padPtr++ != padSize) {
507 BlockCryptDebug("BlockCryptor::final malformed ciphertext "
508 "(2)");
509 CssmError::throwMe(CSSM_ERRCODE_INVALID_DATA);
510 }
511 }
512 actMoved -= padSize;
513 }
514 assert(actMoved <= out.length());
515 out.length(actMoved);
516 } /* decrypting */
517 ioprintf("=== BlockCryptor::final encrypt %d outSize 0x%lx",
518 encoding() ? 1 : 0, out.Length);
519 }
520
521 /*
522 * These three are only valid for algorithms for which encrypting one block
523 * of plaintext always yields exactly one block of ciphertext, and vice versa
524 * for decrypt. The block sizes for plaintext and ciphertext do NOT have to be
525 * the same. Subclasses (e.g. FEED) which do not meet this criterion will have
526 * to override.
527 */
528
529 void BlockCryptor::minimumProgress(
530 size_t &inSize,
531 size_t &outSize)
532 {
533 /* each size = one block (including buffered input) */
534 inSize = mInBlockSize - mInBufSize;
535 if(inSize == 0) {
536 /* i.e., we're holding a whole buffer */
537 inSize++;
538 }
539 outSize = mOutBlockSize;
540 bprintf("--- BlockCryptor::minProgres inSize 0x%lx outSize 0x%lx mInBufSize 0x%lx",
541 inSize, outSize, mInBufSize);
542 }
543
544 size_t BlockCryptor::inputSize(
545 size_t outSize) // input for given output size
546 {
547 size_t inSize;
548
549 if(outSize < mOutBlockSize) {
550 /*
551 * Sometimes CSPFullPluginSession calls us like this....in this
552 * case the legal inSize is just the remainder of the input buffer,
553 * less one byte (in other words, the max we we gobble up without
554 * producing any output).
555 */
556 inSize = mInBlockSize - mInBufSize;
557 if(inSize == 0) {
558 /* we have a full input buffer! How can this happen!? */
559 BlockCryptDebug("BlockCryptor::inputSize: HELP! zero inSize and outSize!\n");
560 }
561 }
562 else {
563 /* more-or-less normal case */
564 size_t wholeBlocks = outSize / mOutBlockSize;
565 assert(wholeBlocks >= 1);
566 inSize = (wholeBlocks * mInBlockSize) - mInBufSize;
567 if(inSize == 0) {
568 /* i.e., we're holding a whole buffer */
569 inSize++;
570 }
571 }
572 bprintf("--- BlockCryptor::inputSize inSize 0x%lx outSize 0x%lx mInBufSize 0x%lx",
573 inSize, outSize, mInBufSize);
574 return inSize;
575 }
576
577 size_t BlockCryptor::outputSize(
578 bool final,
579 size_t inSize /*= 0*/) // output for given input size
580 {
581 size_t rawBytes = inSize + mInBufSize;
582 // huh?Êdon't round this up!
583 //size_t rawBlocks = (rawBytes + mInBlockSize - 1) / mInBlockSize;
584 size_t rawBlocks = rawBytes / mInBlockSize;
585
586 /*
587 * encrypting: always get one additional block on final() if we're padding
588 * or (we presume) the subclass is padding. Note that we
589 * truncated when calculating rawBlocks; to finish out on the
590 * final block, we (or our subclass) will either have to pad
591 * out the current partial block, or cook up a full pad block if
592 * mInBufSize is currently zero. Subclasses which pad some other
593 * way need to override this method.
594 *
595 * decrypting: outsize always <= insize
596 */
597 if(encoding() && final && (mPkcsPadding || mNeedFinalData)) {
598 rawBlocks++;
599 }
600
601 /* FIXME - optimize for needFinalData? (can squeak by with smaller outSize) */
602 size_t rtn = rawBlocks * mOutBlockSize;
603 bprintf("--- BlockCryptor::outputSize inSize 0x%lx outSize 0x%lx final %d "
604 "inBufSize 0x%lx", inSize, rtn, final, mInBufSize);
605 return rtn;
606 }
607
608
609
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