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comparison: security/nss/lib/smime/cmscipher.c

security/nss/lib/smime/cmscipher.c

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1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5 /*
6 * Encryption/decryption routines for CMS implementation, none of which are exported.
7 */
8
9 #include "cmslocal.h"
10
11 #include "secoid.h"
12 #include "secitem.h"
13 #include "pk11func.h"
14 #include "secerr.h"
15 #include "secpkcs5.h"
16
17 /*
18 * -------------------------------------------------------------------
19 * Cipher stuff.
20 */
21
22 typedef SECStatus (*nss_cms_cipher_function) (void *, unsigned char *, unsigned int *,
23 unsigned int, const unsigned char *, unsigned int);
24 typedef SECStatus (*nss_cms_cipher_destroy) (void *, PRBool);
25
26 #define BLOCK_SIZE 4096
27
28 struct NSSCMSCipherContextStr {
29 void * cx; /* PK11 cipher context */
30 nss_cms_cipher_function doit;
31 nss_cms_cipher_destroy destroy;
32 PRBool encrypt; /* encrypt / decrypt switch */
33 int block_size; /* block & pad sizes for cipher */
34 int pad_size;
35 int pending_count; /* pending data (not yet en/decrypted */
36 unsigned char pending_buf[BLOCK_SIZE];/* because of blocking */
37 };
38
39 /*
40 * NSS_CMSCipherContext_StartDecrypt - create a cipher context to do decryption
41 * based on the given bulk encryption key and algorithm identifier (which
42 * may include an iv).
43 *
44 * XXX Once both are working, it might be nice to combine this and the
45 * function below (for starting up encryption) into one routine, and just
46 * have two simple cover functions which call it.
47 */
48 NSSCMSCipherContext *
49 NSS_CMSCipherContext_StartDecrypt(PK11SymKey *key, SECAlgorithmID *algid)
50 {
51 NSSCMSCipherContext *cc;
52 void *ciphercx;
53 CK_MECHANISM_TYPE cryptoMechType;
54 PK11SlotInfo *slot;
55 SECOidTag algtag;
56 SECItem *param = NULL;
57
58 algtag = SECOID_GetAlgorithmTag(algid);
59
60 /* set param and mechanism */
61 if (SEC_PKCS5IsAlgorithmPBEAlg(algid)) {
62 SECItem *pwitem;
63
64 pwitem = PK11_GetSymKeyUserData(key);
65 if (!pwitem)
66 return NULL;
67
68 cryptoMechType = PK11_GetPBECryptoMechanism(algid, &param, pwitem);
69 if (cryptoMechType == CKM_INVALID_MECHANISM) {
70 SECITEM_FreeItem(param,PR_TRUE);
71 return NULL;
72 }
73
74 } else {
75 cryptoMechType = PK11_AlgtagToMechanism(algtag);
76 if ((param = PK11_ParamFromAlgid(algid)) == NULL)
77 return NULL;
78 }
79
80 cc = (NSSCMSCipherContext *)PORT_ZAlloc(sizeof(NSSCMSCipherContext));
81 if (cc == NULL) {
82 SECITEM_FreeItem(param,PR_TRUE);
83 return NULL;
84 }
85
86 /* figure out pad and block sizes */
87 cc->pad_size = PK11_GetBlockSize(cryptoMechType, param);
88 slot = PK11_GetSlotFromKey(key);
89 cc->block_size = PK11_IsHW(slot) ? BLOCK_SIZE : cc->pad_size;
90 PK11_FreeSlot(slot);
91
92 /* create PK11 cipher context */
93 ciphercx = PK11_CreateContextBySymKey(cryptoMechType, CKA_DECRYPT,
94 key, param);
95 SECITEM_FreeItem(param, PR_TRUE);
96 if (ciphercx == NULL) {
97 PORT_Free (cc);
98 return NULL;
99 }
100
101 cc->cx = ciphercx;
102 cc->doit = (nss_cms_cipher_function) PK11_CipherOp;
103 cc->destroy = (nss_cms_cipher_destroy) PK11_DestroyContext;
104 cc->encrypt = PR_FALSE;
105 cc->pending_count = 0;
106
107 return cc;
108 }
109
110 /*
111 * NSS_CMSCipherContext_StartEncrypt - create a cipher object to do encryption,
112 * based on the given bulk encryption key and algorithm tag. Fill in the
113 * algorithm identifier (which may include an iv) appropriately.
114 *
115 * XXX Once both are working, it might be nice to combine this and the
116 * function above (for starting up decryption) into one routine, and just
117 * have two simple cover functions which call it.
118 */
119 NSSCMSCipherContext *
120 NSS_CMSCipherContext_StartEncrypt(PLArenaPool *poolp, PK11SymKey *key, SECAlgorithmID *algid)
121 {
122 NSSCMSCipherContext *cc;
123 void *ciphercx;
124 SECStatus rv;
125 CK_MECHANISM_TYPE cryptoMechType;
126 PK11SlotInfo *slot;
127 SECItem *param = NULL;
128 PRBool needToEncodeAlgid = PR_FALSE;
129 SECOidTag algtag = SECOID_GetAlgorithmTag(algid);
130
131 /* set param and mechanism */
132 if (SEC_PKCS5IsAlgorithmPBEAlg(algid)) {
133 SECItem *pwitem;
134
135 pwitem = PK11_GetSymKeyUserData(key);
136 if (!pwitem)
137 return NULL;
138
139 cryptoMechType = PK11_GetPBECryptoMechanism(algid, &param, pwitem);
140 if (cryptoMechType == CKM_INVALID_MECHANISM) {
141 SECITEM_FreeItem(param,PR_TRUE);
142 return NULL;
143 }
144 } else {
145 cryptoMechType = PK11_AlgtagToMechanism(algtag);
146 if ((param = PK11_GenerateNewParam(cryptoMechType, key)) == NULL)
147 return NULL;
148 needToEncodeAlgid = PR_TRUE;
149 }
150
151 cc = (NSSCMSCipherContext *)PORT_ZAlloc(sizeof(NSSCMSCipherContext));
152 if (cc == NULL) {
153 goto loser;
154 }
155
156 /* now find pad and block sizes for our mechanism */
157 cc->pad_size = PK11_GetBlockSize(cryptoMechType, param);
158 slot = PK11_GetSlotFromKey(key);
159 cc->block_size = PK11_IsHW(slot) ? BLOCK_SIZE : cc->pad_size;
160 PK11_FreeSlot(slot);
161
162 /* and here we go, creating a PK11 cipher context */
163 ciphercx = PK11_CreateContextBySymKey(cryptoMechType, CKA_ENCRYPT,
164 key, param);
165 if (ciphercx == NULL) {
166 PORT_Free(cc);
167 cc = NULL;
168 goto loser;
169 }
170
171 /*
172 * These are placed after the CreateContextBySymKey() because some
173 * mechanisms have to generate their IVs from their card (i.e. FORTEZZA).
174 * Don't move it from here.
175 * XXX is that right? the purpose of this is to get the correct algid
176 * containing the IVs etc. for encoding. this means we need to set this up
177 * BEFORE encoding the algid in the contentInfo, right?
178 */
179 if (needToEncodeAlgid) {
180 rv = PK11_ParamToAlgid(algtag, param, poolp, algid);
181 if(rv != SECSuccess) {
182 PORT_Free(cc);
183 cc = NULL;
184 goto loser;
185 }
186 }
187
188 cc->cx = ciphercx;
189 cc->doit = (nss_cms_cipher_function)PK11_CipherOp;
190 cc->destroy = (nss_cms_cipher_destroy)PK11_DestroyContext;
191 cc->encrypt = PR_TRUE;
192 cc->pending_count = 0;
193
194 loser:
195 SECITEM_FreeItem(param, PR_TRUE);
196
197 return cc;
198 }
199
200 void
201 NSS_CMSCipherContext_Destroy(NSSCMSCipherContext *cc)
202 {
203 PORT_Assert(cc != NULL);
204 if (cc == NULL)
205 return;
206 (*cc->destroy)(cc->cx, PR_TRUE);
207 PORT_Free(cc);
208 }
209
210 /*
211 * NSS_CMSCipherContext_DecryptLength - find the output length of the next call to decrypt.
212 *
213 * cc - the cipher context
214 * input_len - number of bytes used as input
215 * final - true if this is the final chunk of data
216 *
217 * Result can be used to perform memory allocations. Note that the amount
218 * is exactly accurate only when not doing a block cipher or when final
219 * is false, otherwise it is an upper bound on the amount because until
220 * we see the data we do not know how many padding bytes there are
221 * (always between 1 and bsize).
222 *
223 * Note that this can return zero, which does not mean that the decrypt
224 * operation can be skipped! (It simply means that there are not enough
225 * bytes to make up an entire block; the bytes will be reserved until
226 * there are enough to encrypt/decrypt at least one block.) However,
227 * if zero is returned it *does* mean that no output buffer need be
228 * passed in to the subsequent decrypt operation, as no output bytes
229 * will be stored.
230 */
231 unsigned int
232 NSS_CMSCipherContext_DecryptLength(NSSCMSCipherContext *cc, unsigned int input_len, PRBool final)
233 {
234 int blocks, block_size;
235
236 PORT_Assert (! cc->encrypt);
237
238 block_size = cc->block_size;
239
240 /*
241 * If this is not a block cipher, then we always have the same
242 * number of output bytes as we had input bytes.
243 */
244 if (block_size == 0)
245 return input_len;
246
247 /*
248 * On the final call, we will always use up all of the pending
249 * bytes plus all of the input bytes, *but*, there will be padding
250 * at the end and we cannot predict how many bytes of padding we
251 * will end up removing. The amount given here is actually known
252 * to be at least 1 byte too long (because we know we will have
253 * at least 1 byte of padding), but seemed clearer/better to me.
254 */
255 if (final)
256 return cc->pending_count + input_len;
257
258 /*
259 * Okay, this amount is exactly what we will output on the
260 * next cipher operation. We will always hang onto the last
261 * 1 - block_size bytes for non-final operations. That is,
262 * we will do as many complete blocks as we can *except* the
263 * last block (complete or partial). (This is because until
264 * we know we are at the end, we cannot know when to interpret
265 * and removing the padding byte(s), which are guaranteed to
266 * be there.)
267 */
268 blocks = (cc->pending_count + input_len - 1) / block_size;
269 return blocks * block_size;
270 }
271
272 /*
273 * NSS_CMSCipherContext_EncryptLength - find the output length of the next call to encrypt.
274 *
275 * cc - the cipher context
276 * input_len - number of bytes used as input
277 * final - true if this is the final chunk of data
278 *
279 * Result can be used to perform memory allocations.
280 *
281 * Note that this can return zero, which does not mean that the encrypt
282 * operation can be skipped! (It simply means that there are not enough
283 * bytes to make up an entire block; the bytes will be reserved until
284 * there are enough to encrypt/decrypt at least one block.) However,
285 * if zero is returned it *does* mean that no output buffer need be
286 * passed in to the subsequent encrypt operation, as no output bytes
287 * will be stored.
288 */
289 unsigned int
290 NSS_CMSCipherContext_EncryptLength(NSSCMSCipherContext *cc, unsigned int input_len, PRBool final)
291 {
292 int blocks, block_size;
293 int pad_size;
294
295 PORT_Assert (cc->encrypt);
296
297 block_size = cc->block_size;
298 pad_size = cc->pad_size;
299
300 /*
301 * If this is not a block cipher, then we always have the same
302 * number of output bytes as we had input bytes.
303 */
304 if (block_size == 0)
305 return input_len;
306
307 /*
308 * On the final call, we only send out what we need for
309 * remaining bytes plus the padding. (There is always padding,
310 * so even if we have an exact number of blocks as input, we
311 * will add another full block that is just padding.)
312 */
313 if (final) {
314 if (pad_size == 0) {
315 return cc->pending_count + input_len;
316 } else {
317 blocks = (cc->pending_count + input_len) / pad_size;
318 blocks++;
319 return blocks*pad_size;
320 }
321 }
322
323 /*
324 * Now, count the number of complete blocks of data we have.
325 */
326 blocks = (cc->pending_count + input_len) / block_size;
327
328
329 return blocks * block_size;
330 }
331
332
333 /*
334 * NSS_CMSCipherContext_Decrypt - do the decryption
335 *
336 * cc - the cipher context
337 * output - buffer for decrypted result bytes
338 * output_len_p - number of bytes in output
339 * max_output_len - upper bound on bytes to put into output
340 * input - pointer to input bytes
341 * input_len - number of input bytes
342 * final - true if this is the final chunk of data
343 *
344 * Decrypts a given length of input buffer (starting at "input" and
345 * containing "input_len" bytes), placing the decrypted bytes in
346 * "output" and storing the output length in "*output_len_p".
347 * "cc" is the return value from NSS_CMSCipher_StartDecrypt.
348 * When "final" is true, this is the last of the data to be decrypted.
349 *
350 * This is much more complicated than it sounds when the cipher is
351 * a block-type, meaning that the decryption function will only
352 * operate on whole blocks. But our caller is operating stream-wise,
353 * and can pass in any number of bytes. So we need to keep track
354 * of block boundaries. We save excess bytes between calls in "cc".
355 * We also need to determine which bytes are padding, and remove
356 * them from the output. We can only do this step when we know we
357 * have the final block of data. PKCS #7 specifies that the padding
358 * used for a block cipher is a string of bytes, each of whose value is
359 * the same as the length of the padding, and that all data is padded.
360 * (Even data that starts out with an exact multiple of blocks gets
361 * added to it another block, all of which is padding.)
362 */
363 SECStatus
364 NSS_CMSCipherContext_Decrypt(NSSCMSCipherContext *cc, unsigned char *output,
365 unsigned int *output_len_p, unsigned int max_output_len,
366 const unsigned char *input, unsigned int input_len,
367 PRBool final)
368 {
369 int blocks, bsize, pcount, padsize;
370 unsigned int max_needed, ifraglen, ofraglen, output_len;
371 unsigned char *pbuf;
372 SECStatus rv;
373
374 PORT_Assert (! cc->encrypt);
375
376 /*
377 * Check that we have enough room for the output. Our caller should
378 * already handle this; failure is really an internal error (i.e. bug).
379 */
380 max_needed = NSS_CMSCipherContext_DecryptLength(cc, input_len, final);
381 PORT_Assert (max_output_len >= max_needed);
382 if (max_output_len < max_needed) {
383 /* PORT_SetError (XXX); */
384 return SECFailure;
385 }
386
387 /*
388 * hardware encryption does not like small decryption sizes here, so we
389 * allow both blocking and padding.
390 */
391 bsize = cc->block_size;
392 padsize = cc->pad_size;
393
394 /*
395 * When no blocking or padding work to do, we can simply call the
396 * cipher function and we are done.
397 */
398 if (bsize == 0) {
399 return (* cc->doit) (cc->cx, output, output_len_p, max_output_len,
400 input, input_len);
401 }
402
403 pcount = cc->pending_count;
404 pbuf = cc->pending_buf;
405
406 output_len = 0;
407
408 if (pcount) {
409 /*
410 * Try to fill in an entire block, starting with the bytes
411 * we already have saved away.
412 */
413 while (input_len && pcount < bsize) {
414 pbuf[pcount++] = *input++;
415 input_len--;
416 }
417 /*
418 * If we have at most a whole block and this is not our last call,
419 * then we are done for now. (We do not try to decrypt a lone
420 * single block because we cannot interpret the padding bytes
421 * until we know we are handling the very last block of all input.)
422 */
423 if (input_len == 0 && !final) {
424 cc->pending_count = pcount;
425 if (output_len_p)
426 *output_len_p = 0;
427 return SECSuccess;
428 }
429 /*
430 * Given the logic above, we expect to have a full block by now.
431 * If we do not, there is something wrong, either with our own
432 * logic or with (length of) the data given to us.
433 */
434 if ((padsize != 0) && (pcount % padsize) != 0) {
435 PORT_Assert (final);
436 PORT_SetError (SEC_ERROR_BAD_DATA);
437 return SECFailure;
438 }
439 /*
440 * Decrypt the block.
441 */
442 rv = (*cc->doit)(cc->cx, output, &ofraglen, max_output_len,
443 pbuf, pcount);
444 if (rv != SECSuccess)
445 return rv;
446
447 /*
448 * For now anyway, all of our ciphers have the same number of
449 * bytes of output as they do input. If this ever becomes untrue,
450 * then NSS_CMSCipherContext_DecryptLength needs to be made smarter!
451 */
452 PORT_Assert(ofraglen == pcount);
453
454 /*
455 * Account for the bytes now in output.
456 */
457 max_output_len -= ofraglen;
458 output_len += ofraglen;
459 output += ofraglen;
460 }
461
462 /*
463 * If this is our last call, we expect to have an exact number of
464 * blocks left to be decrypted; we will decrypt them all.
465 *
466 * If not our last call, we always save between 1 and bsize bytes
467 * until next time. (We must do this because we cannot be sure
468 * that none of the decrypted bytes are padding bytes until we
469 * have at least another whole block of data. You cannot tell by
470 * looking -- the data could be anything -- you can only tell by
471 * context, knowing you are looking at the last block.) We could
472 * decrypt a whole block now but it is easier if we just treat it
473 * the same way we treat partial block bytes.
474 */
475 if (final) {
476 if (padsize) {
477 blocks = input_len / padsize;
478 ifraglen = blocks * padsize;
479 } else ifraglen = input_len;
480 PORT_Assert (ifraglen == input_len);
481
482 if (ifraglen != input_len) {
483 PORT_SetError(SEC_ERROR_BAD_DATA);
484 return SECFailure;
485 }
486 } else {
487 blocks = (input_len - 1) / bsize;
488 ifraglen = blocks * bsize;
489 PORT_Assert (ifraglen < input_len);
490
491 pcount = input_len - ifraglen;
492 PORT_Memcpy (pbuf, input + ifraglen, pcount);
493 cc->pending_count = pcount;
494 }
495
496 if (ifraglen) {
497 rv = (* cc->doit)(cc->cx, output, &ofraglen, max_output_len,
498 input, ifraglen);
499 if (rv != SECSuccess)
500 return rv;
501
502 /*
503 * For now anyway, all of our ciphers have the same number of
504 * bytes of output as they do input. If this ever becomes untrue,
505 * then sec_PKCS7DecryptLength needs to be made smarter!
506 */
507 PORT_Assert (ifraglen == ofraglen);
508 if (ifraglen != ofraglen) {
509 PORT_SetError(SEC_ERROR_BAD_DATA);
510 return SECFailure;
511 }
512
513 output_len += ofraglen;
514 } else {
515 ofraglen = 0;
516 }
517
518 /*
519 * If we just did our very last block, "remove" the padding by
520 * adjusting the output length.
521 */
522 if (final && (padsize != 0)) {
523 unsigned int padlen = *(output + ofraglen - 1);
524
525 if (padlen == 0 || padlen > padsize) {
526 PORT_SetError(SEC_ERROR_BAD_DATA);
527 return SECFailure;
528 }
529 output_len -= padlen;
530 }
531
532 PORT_Assert (output_len_p != NULL || output_len == 0);
533 if (output_len_p != NULL)
534 *output_len_p = output_len;
535
536 return SECSuccess;
537 }
538
539 /*
540 * NSS_CMSCipherContext_Encrypt - do the encryption
541 *
542 * cc - the cipher context
543 * output - buffer for decrypted result bytes
544 * output_len_p - number of bytes in output
545 * max_output_len - upper bound on bytes to put into output
546 * input - pointer to input bytes
547 * input_len - number of input bytes
548 * final - true if this is the final chunk of data
549 *
550 * Encrypts a given length of input buffer (starting at "input" and
551 * containing "input_len" bytes), placing the encrypted bytes in
552 * "output" and storing the output length in "*output_len_p".
553 * "cc" is the return value from NSS_CMSCipher_StartEncrypt.
554 * When "final" is true, this is the last of the data to be encrypted.
555 *
556 * This is much more complicated than it sounds when the cipher is
557 * a block-type, meaning that the encryption function will only
558 * operate on whole blocks. But our caller is operating stream-wise,
559 * and can pass in any number of bytes. So we need to keep track
560 * of block boundaries. We save excess bytes between calls in "cc".
561 * We also need to add padding bytes at the end. PKCS #7 specifies
562 * that the padding used for a block cipher is a string of bytes,
563 * each of whose value is the same as the length of the padding,
564 * and that all data is padded. (Even data that starts out with
565 * an exact multiple of blocks gets added to it another block,
566 * all of which is padding.)
567 *
568 * XXX I would kind of like to combine this with the function above
569 * which does decryption, since they have a lot in common. But the
570 * tricky parts about padding and filling blocks would be much
571 * harder to read that way, so I left them separate. At least for
572 * now until it is clear that they are right.
573 */
574 SECStatus
575 NSS_CMSCipherContext_Encrypt(NSSCMSCipherContext *cc, unsigned char *output,
576 unsigned int *output_len_p, unsigned int max_output_len,
577 const unsigned char *input, unsigned int input_len,
578 PRBool final)
579 {
580 int blocks, bsize, padlen, pcount, padsize;
581 unsigned int max_needed, ifraglen, ofraglen, output_len;
582 unsigned char *pbuf;
583 SECStatus rv;
584
585 PORT_Assert (cc->encrypt);
586
587 /*
588 * Check that we have enough room for the output. Our caller should
589 * already handle this; failure is really an internal error (i.e. bug).
590 */
591 max_needed = NSS_CMSCipherContext_EncryptLength (cc, input_len, final);
592 PORT_Assert (max_output_len >= max_needed);
593 if (max_output_len < max_needed) {
594 /* PORT_SetError (XXX); */
595 return SECFailure;
596 }
597
598 bsize = cc->block_size;
599 padsize = cc->pad_size;
600
601 /*
602 * When no blocking and padding work to do, we can simply call the
603 * cipher function and we are done.
604 */
605 if (bsize == 0) {
606 return (*cc->doit)(cc->cx, output, output_len_p, max_output_len,
607 input, input_len);
608 }
609
610 pcount = cc->pending_count;
611 pbuf = cc->pending_buf;
612
613 output_len = 0;
614
615 if (pcount) {
616 /*
617 * Try to fill in an entire block, starting with the bytes
618 * we already have saved away.
619 */
620 while (input_len && pcount < bsize) {
621 pbuf[pcount++] = *input++;
622 input_len--;
623 }
624 /*
625 * If we do not have a full block and we know we will be
626 * called again, then we are done for now.
627 */
628 if (pcount < bsize && !final) {
629 cc->pending_count = pcount;
630 if (output_len_p != NULL)
631 *output_len_p = 0;
632 return SECSuccess;
633 }
634 /*
635 * If we have a whole block available, encrypt it.
636 */
637 if ((padsize == 0) || (pcount % padsize) == 0) {
638 rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len,
639 pbuf, pcount);
640 if (rv != SECSuccess)
641 return rv;
642
643 /*
644 * For now anyway, all of our ciphers have the same number of
645 * bytes of output as they do input. If this ever becomes untrue,
646 * then sec_PKCS7EncryptLength needs to be made smarter!
647 */
648 PORT_Assert (ofraglen == pcount);
649
650 /*
651 * Account for the bytes now in output.
652 */
653 max_output_len -= ofraglen;
654 output_len += ofraglen;
655 output += ofraglen;
656
657 pcount = 0;
658 }
659 }
660
661 if (input_len) {
662 PORT_Assert (pcount == 0);
663
664 blocks = input_len / bsize;
665 ifraglen = blocks * bsize;
666
667 if (ifraglen) {
668 rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len,
669 input, ifraglen);
670 if (rv != SECSuccess)
671 return rv;
672
673 /*
674 * For now anyway, all of our ciphers have the same number of
675 * bytes of output as they do input. If this ever becomes untrue,
676 * then sec_PKCS7EncryptLength needs to be made smarter!
677 */
678 PORT_Assert (ifraglen == ofraglen);
679
680 max_output_len -= ofraglen;
681 output_len += ofraglen;
682 output += ofraglen;
683 }
684
685 pcount = input_len - ifraglen;
686 PORT_Assert (pcount < bsize);
687 if (pcount)
688 PORT_Memcpy (pbuf, input + ifraglen, pcount);
689 }
690
691 if (final) {
692 padlen = padsize - (pcount % padsize);
693 PORT_Memset (pbuf + pcount, padlen, padlen);
694 rv = (* cc->doit) (cc->cx, output, &ofraglen, max_output_len,
695 pbuf, pcount+padlen);
696 if (rv != SECSuccess)
697 return rv;
698
699 /*
700 * For now anyway, all of our ciphers have the same number of
701 * bytes of output as they do input. If this ever becomes untrue,
702 * then sec_PKCS7EncryptLength needs to be made smarter!
703 */
704 PORT_Assert (ofraglen == (pcount+padlen));
705 output_len += ofraglen;
706 } else {
707 cc->pending_count = pcount;
708 }
709
710 PORT_Assert (output_len_p != NULL || output_len == 0);
711 if (output_len_p != NULL)
712 *output_len_p = output_len;
713
714 return SECSuccess;
715 }

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