1/*
2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#ifndef OSSL_INTERNAL_PACKET_H
11# define OSSL_INTERNAL_PACKET_H
12
13# include <string.h>
14# include <openssl/bn.h>
15# include <openssl/buffer.h>
16# include <openssl/crypto.h>
17# include <openssl/e_os2.h>
18
19# include "internal/numbers.h"
20
21typedef struct {
22 /* Pointer to where we are currently reading from */
23 const unsigned char *curr;
24 /* Number of bytes remaining */
25 size_t remaining;
26} PACKET;
27
28/* Internal unchecked shorthand; don't use outside this file. */
29static ossl_inline void packet_forward(PACKET *pkt, size_t len)
30{
31 pkt->curr += len;
32 pkt->remaining -= len;
33}
34
35/*
36 * Returns the number of bytes remaining to be read in the PACKET
37 */
38static ossl_inline size_t PACKET_remaining(const PACKET *pkt)
39{
40 return pkt->remaining;
41}
42
43/*
44 * Returns a pointer to the first byte after the packet data.
45 * Useful for integrating with non-PACKET parsing code.
46 * Specifically, we use PACKET_end() to verify that a d2i_... call
47 * has consumed the entire packet contents.
48 */
49static ossl_inline const unsigned char *PACKET_end(const PACKET *pkt)
50{
51 return pkt->curr + pkt->remaining;
52}
53
54/*
55 * Returns a pointer to the PACKET's current position.
56 * For use in non-PACKETized APIs.
57 */
58static ossl_inline const unsigned char *PACKET_data(const PACKET *pkt)
59{
60 return pkt->curr;
61}
62
63/*
64 * Initialise a PACKET with |len| bytes held in |buf|. This does not make a
65 * copy of the data so |buf| must be present for the whole time that the PACKET
66 * is being used.
67 */
68__owur static ossl_inline int PACKET_buf_init(PACKET *pkt,
69 const unsigned char *buf,
70 size_t len)
71{
72 /* Sanity check for negative values. */
73 if (len > (size_t)(SIZE_MAX / 2))
74 return 0;
75
76 pkt->curr = buf;
77 pkt->remaining = len;
78 return 1;
79}
80
81/* Initialize a PACKET to hold zero bytes. */
82static ossl_inline void PACKET_null_init(PACKET *pkt)
83{
84 pkt->curr = NULL;
85 pkt->remaining = 0;
86}
87
88/*
89 * Returns 1 if the packet has length |num| and its contents equal the |num|
90 * bytes read from |ptr|. Returns 0 otherwise (lengths or contents not equal).
91 * If lengths are equal, performs the comparison in constant time.
92 */
93__owur static ossl_inline int PACKET_equal(const PACKET *pkt, const void *ptr,
94 size_t num)
95{
96 if (PACKET_remaining(pkt) != num)
97 return 0;
98 return CRYPTO_memcmp(pkt->curr, ptr, num) == 0;
99}
100
101/*
102 * Peek ahead and initialize |subpkt| with the next |len| bytes read from |pkt|.
103 * Data is not copied: the |subpkt| packet will share its underlying buffer with
104 * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
105 */
106__owur static ossl_inline int PACKET_peek_sub_packet(const PACKET *pkt,
107 PACKET *subpkt, size_t len)
108{
109 if (PACKET_remaining(pkt) < len)
110 return 0;
111
112 return PACKET_buf_init(subpkt, pkt->curr, len);
113}
114
115/*
116 * Initialize |subpkt| with the next |len| bytes read from |pkt|. Data is not
117 * copied: the |subpkt| packet will share its underlying buffer with the
118 * original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
119 */
120__owur static ossl_inline int PACKET_get_sub_packet(PACKET *pkt,
121 PACKET *subpkt, size_t len)
122{
123 if (!PACKET_peek_sub_packet(pkt, subpkt, len))
124 return 0;
125
126 packet_forward(pkt, len);
127
128 return 1;
129}
130
131/*
132 * Peek ahead at 2 bytes in network order from |pkt| and store the value in
133 * |*data|
134 */
135__owur static ossl_inline int PACKET_peek_net_2(const PACKET *pkt,
136 unsigned int *data)
137{
138 if (PACKET_remaining(pkt) < 2)
139 return 0;
140
141 *data = ((unsigned int)(*pkt->curr)) << 8;
142 *data |= *(pkt->curr + 1);
143
144 return 1;
145}
146
147/* Equivalent of n2s */
148/* Get 2 bytes in network order from |pkt| and store the value in |*data| */
149__owur static ossl_inline int PACKET_get_net_2(PACKET *pkt, unsigned int *data)
150{
151 if (!PACKET_peek_net_2(pkt, data))
152 return 0;
153
154 packet_forward(pkt, 2);
155
156 return 1;
157}
158
159/* Same as PACKET_get_net_2() but for a size_t */
160__owur static ossl_inline int PACKET_get_net_2_len(PACKET *pkt, size_t *data)
161{
162 unsigned int i;
163 int ret = PACKET_get_net_2(pkt, &i);
164
165 if (ret)
166 *data = (size_t)i;
167
168 return ret;
169}
170
171/*
172 * Peek ahead at 3 bytes in network order from |pkt| and store the value in
173 * |*data|
174 */
175__owur static ossl_inline int PACKET_peek_net_3(const PACKET *pkt,
176 unsigned long *data)
177{
178 if (PACKET_remaining(pkt) < 3)
179 return 0;
180
181 *data = ((unsigned long)(*pkt->curr)) << 16;
182 *data |= ((unsigned long)(*(pkt->curr + 1))) << 8;
183 *data |= *(pkt->curr + 2);
184
185 return 1;
186}
187
188/* Equivalent of n2l3 */
189/* Get 3 bytes in network order from |pkt| and store the value in |*data| */
190__owur static ossl_inline int PACKET_get_net_3(PACKET *pkt, unsigned long *data)
191{
192 if (!PACKET_peek_net_3(pkt, data))
193 return 0;
194
195 packet_forward(pkt, 3);
196
197 return 1;
198}
199
200/* Same as PACKET_get_net_3() but for a size_t */
201__owur static ossl_inline int PACKET_get_net_3_len(PACKET *pkt, size_t *data)
202{
203 unsigned long i;
204 int ret = PACKET_get_net_3(pkt, &i);
205
206 if (ret)
207 *data = (size_t)i;
208
209 return ret;
210}
211
212/*
213 * Peek ahead at 4 bytes in network order from |pkt| and store the value in
214 * |*data|
215 */
216__owur static ossl_inline int PACKET_peek_net_4(const PACKET *pkt,
217 unsigned long *data)
218{
219 if (PACKET_remaining(pkt) < 4)
220 return 0;
221
222 *data = ((unsigned long)(*pkt->curr)) << 24;
223 *data |= ((unsigned long)(*(pkt->curr + 1))) << 16;
224 *data |= ((unsigned long)(*(pkt->curr + 2))) << 8;
225 *data |= *(pkt->curr + 3);
226
227 return 1;
228}
229
230/* Equivalent of n2l */
231/* Get 4 bytes in network order from |pkt| and store the value in |*data| */
232__owur static ossl_inline int PACKET_get_net_4(PACKET *pkt, unsigned long *data)
233{
234 if (!PACKET_peek_net_4(pkt, data))
235 return 0;
236
237 packet_forward(pkt, 4);
238
239 return 1;
240}
241
242/* Same as PACKET_get_net_4() but for a size_t */
243__owur static ossl_inline int PACKET_get_net_4_len(PACKET *pkt, size_t *data)
244{
245 unsigned long i;
246 int ret = PACKET_get_net_4(pkt, &i);
247
248 if (ret)
249 *data = (size_t)i;
250
251 return ret;
252}
253
254/* Peek ahead at 1 byte from |pkt| and store the value in |*data| */
255__owur static ossl_inline int PACKET_peek_1(const PACKET *pkt,
256 unsigned int *data)
257{
258 if (!PACKET_remaining(pkt))
259 return 0;
260
261 *data = *pkt->curr;
262
263 return 1;
264}
265
266/* Get 1 byte from |pkt| and store the value in |*data| */
267__owur static ossl_inline int PACKET_get_1(PACKET *pkt, unsigned int *data)
268{
269 if (!PACKET_peek_1(pkt, data))
270 return 0;
271
272 packet_forward(pkt, 1);
273
274 return 1;
275}
276
277/* Same as PACKET_get_1() but for a size_t */
278__owur static ossl_inline int PACKET_get_1_len(PACKET *pkt, size_t *data)
279{
280 unsigned int i;
281 int ret = PACKET_get_1(pkt, &i);
282
283 if (ret)
284 *data = (size_t)i;
285
286 return ret;
287}
288
289/*
290 * Peek ahead at 4 bytes in reverse network order from |pkt| and store the value
291 * in |*data|
292 */
293__owur static ossl_inline int PACKET_peek_4(const PACKET *pkt,
294 unsigned long *data)
295{
296 if (PACKET_remaining(pkt) < 4)
297 return 0;
298
299 *data = *pkt->curr;
300 *data |= ((unsigned long)(*(pkt->curr + 1))) << 8;
301 *data |= ((unsigned long)(*(pkt->curr + 2))) << 16;
302 *data |= ((unsigned long)(*(pkt->curr + 3))) << 24;
303
304 return 1;
305}
306
307/* Equivalent of c2l */
308/*
309 * Get 4 bytes in reverse network order from |pkt| and store the value in
310 * |*data|
311 */
312__owur static ossl_inline int PACKET_get_4(PACKET *pkt, unsigned long *data)
313{
314 if (!PACKET_peek_4(pkt, data))
315 return 0;
316
317 packet_forward(pkt, 4);
318
319 return 1;
320}
321
322/*
323 * Peek ahead at |len| bytes from the |pkt| and store a pointer to them in
324 * |*data|. This just points at the underlying buffer that |pkt| is using. The
325 * caller should not free this data directly (it will be freed when the
326 * underlying buffer gets freed
327 */
328__owur static ossl_inline int PACKET_peek_bytes(const PACKET *pkt,
329 const unsigned char **data,
330 size_t len)
331{
332 if (PACKET_remaining(pkt) < len)
333 return 0;
334
335 *data = pkt->curr;
336
337 return 1;
338}
339
340/*
341 * Read |len| bytes from the |pkt| and store a pointer to them in |*data|. This
342 * just points at the underlying buffer that |pkt| is using. The caller should
343 * not free this data directly (it will be freed when the underlying buffer gets
344 * freed
345 */
346__owur static ossl_inline int PACKET_get_bytes(PACKET *pkt,
347 const unsigned char **data,
348 size_t len)
349{
350 if (!PACKET_peek_bytes(pkt, data, len))
351 return 0;
352
353 packet_forward(pkt, len);
354
355 return 1;
356}
357
358/* Peek ahead at |len| bytes from |pkt| and copy them to |data| */
359__owur static ossl_inline int PACKET_peek_copy_bytes(const PACKET *pkt,
360 unsigned char *data,
361 size_t len)
362{
363 if (PACKET_remaining(pkt) < len)
364 return 0;
365
366 memcpy(data, pkt->curr, len);
367
368 return 1;
369}
370
371/*
372 * Read |len| bytes from |pkt| and copy them to |data|.
373 * The caller is responsible for ensuring that |data| can hold |len| bytes.
374 */
375__owur static ossl_inline int PACKET_copy_bytes(PACKET *pkt,
376 unsigned char *data, size_t len)
377{
378 if (!PACKET_peek_copy_bytes(pkt, data, len))
379 return 0;
380
381 packet_forward(pkt, len);
382
383 return 1;
384}
385
386/*
387 * Copy packet data to |dest|, and set |len| to the number of copied bytes.
388 * If the packet has more than |dest_len| bytes, nothing is copied.
389 * Returns 1 if the packet data fits in |dest_len| bytes, 0 otherwise.
390 * Does not forward PACKET position (because it is typically the last thing
391 * done with a given PACKET).
392 */
393__owur static ossl_inline int PACKET_copy_all(const PACKET *pkt,
394 unsigned char *dest,
395 size_t dest_len, size_t *len)
396{
397 if (PACKET_remaining(pkt) > dest_len) {
398 *len = 0;
399 return 0;
400 }
401 *len = pkt->remaining;
402 memcpy(dest, pkt->curr, pkt->remaining);
403 return 1;
404}
405
406/*
407 * Copy |pkt| bytes to a newly allocated buffer and store a pointer to the
408 * result in |*data|, and the length in |len|.
409 * If |*data| is not NULL, the old data is OPENSSL_free'd.
410 * If the packet is empty, or malloc fails, |*data| will be set to NULL.
411 * Returns 1 if the malloc succeeds and 0 otherwise.
412 * Does not forward PACKET position (because it is typically the last thing
413 * done with a given PACKET).
414 */
415__owur static ossl_inline int PACKET_memdup(const PACKET *pkt,
416 unsigned char **data, size_t *len)
417{
418 size_t length;
419
420 OPENSSL_free(*data);
421 *data = NULL;
422 *len = 0;
423
424 length = PACKET_remaining(pkt);
425
426 if (length == 0)
427 return 1;
428
429 *data = OPENSSL_memdup(pkt->curr, length);
430 if (*data == NULL)
431 return 0;
432
433 *len = length;
434 return 1;
435}
436
437/*
438 * Read a C string from |pkt| and copy to a newly allocated, NUL-terminated
439 * buffer. Store a pointer to the result in |*data|.
440 * If |*data| is not NULL, the old data is OPENSSL_free'd.
441 * If the data in |pkt| does not contain a NUL-byte, the entire data is
442 * copied and NUL-terminated.
443 * Returns 1 if the malloc succeeds and 0 otherwise.
444 * Does not forward PACKET position (because it is typically the last thing done
445 * with a given PACKET).
446 */
447__owur static ossl_inline int PACKET_strndup(const PACKET *pkt, char **data)
448{
449 OPENSSL_free(*data);
450
451 /* This will succeed on an empty packet, unless pkt->curr == NULL. */
452 *data = OPENSSL_strndup((const char *)pkt->curr, PACKET_remaining(pkt));
453 return (*data != NULL);
454}
455
456/* Returns 1 if |pkt| contains at least one 0-byte, 0 otherwise. */
457static ossl_inline int PACKET_contains_zero_byte(const PACKET *pkt)
458{
459 return memchr(pkt->curr, 0, pkt->remaining) != NULL;
460}
461
462/* Move the current reading position forward |len| bytes */
463__owur static ossl_inline int PACKET_forward(PACKET *pkt, size_t len)
464{
465 if (PACKET_remaining(pkt) < len)
466 return 0;
467
468 packet_forward(pkt, len);
469
470 return 1;
471}
472
473/*
474 * Reads a variable-length vector prefixed with a one-byte length, and stores
475 * the contents in |subpkt|. |pkt| can equal |subpkt|.
476 * Data is not copied: the |subpkt| packet will share its underlying buffer with
477 * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
478 * Upon failure, the original |pkt| and |subpkt| are not modified.
479 */
480__owur static ossl_inline int PACKET_get_length_prefixed_1(PACKET *pkt,
481 PACKET *subpkt)
482{
483 unsigned int length;
484 const unsigned char *data;
485 PACKET tmp = *pkt;
486 if (!PACKET_get_1(&tmp, &length) ||
487 !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
488 return 0;
489 }
490
491 *pkt = tmp;
492 subpkt->curr = data;
493 subpkt->remaining = length;
494
495 return 1;
496}
497
498/*
499 * Like PACKET_get_length_prefixed_1, but additionally, fails when there are
500 * leftover bytes in |pkt|.
501 */
502__owur static ossl_inline int PACKET_as_length_prefixed_1(PACKET *pkt,
503 PACKET *subpkt)
504{
505 unsigned int length;
506 const unsigned char *data;
507 PACKET tmp = *pkt;
508 if (!PACKET_get_1(&tmp, &length) ||
509 !PACKET_get_bytes(&tmp, &data, (size_t)length) ||
510 PACKET_remaining(&tmp) != 0) {
511 return 0;
512 }
513
514 *pkt = tmp;
515 subpkt->curr = data;
516 subpkt->remaining = length;
517
518 return 1;
519}
520
521/*
522 * Reads a variable-length vector prefixed with a two-byte length, and stores
523 * the contents in |subpkt|. |pkt| can equal |subpkt|.
524 * Data is not copied: the |subpkt| packet will share its underlying buffer with
525 * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
526 * Upon failure, the original |pkt| and |subpkt| are not modified.
527 */
528__owur static ossl_inline int PACKET_get_length_prefixed_2(PACKET *pkt,
529 PACKET *subpkt)
530{
531 unsigned int length;
532 const unsigned char *data;
533 PACKET tmp = *pkt;
534
535 if (!PACKET_get_net_2(&tmp, &length) ||
536 !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
537 return 0;
538 }
539
540 *pkt = tmp;
541 subpkt->curr = data;
542 subpkt->remaining = length;
543
544 return 1;
545}
546
547/*
548 * Like PACKET_get_length_prefixed_2, but additionally, fails when there are
549 * leftover bytes in |pkt|.
550 */
551__owur static ossl_inline int PACKET_as_length_prefixed_2(PACKET *pkt,
552 PACKET *subpkt)
553{
554 unsigned int length;
555 const unsigned char *data;
556 PACKET tmp = *pkt;
557
558 if (!PACKET_get_net_2(&tmp, &length) ||
559 !PACKET_get_bytes(&tmp, &data, (size_t)length) ||
560 PACKET_remaining(&tmp) != 0) {
561 return 0;
562 }
563
564 *pkt = tmp;
565 subpkt->curr = data;
566 subpkt->remaining = length;
567
568 return 1;
569}
570
571/*
572 * Reads a variable-length vector prefixed with a three-byte length, and stores
573 * the contents in |subpkt|. |pkt| can equal |subpkt|.
574 * Data is not copied: the |subpkt| packet will share its underlying buffer with
575 * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
576 * Upon failure, the original |pkt| and |subpkt| are not modified.
577 */
578__owur static ossl_inline int PACKET_get_length_prefixed_3(PACKET *pkt,
579 PACKET *subpkt)
580{
581 unsigned long length;
582 const unsigned char *data;
583 PACKET tmp = *pkt;
584 if (!PACKET_get_net_3(&tmp, &length) ||
585 !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
586 return 0;
587 }
588
589 *pkt = tmp;
590 subpkt->curr = data;
591 subpkt->remaining = length;
592
593 return 1;
594}
595
596/* Writeable packets */
597
598typedef struct wpacket_sub WPACKET_SUB;
599struct wpacket_sub {
600 /* The parent WPACKET_SUB if we have one or NULL otherwise */
601 WPACKET_SUB *parent;
602
603 /*
604 * Offset into the buffer where the length of this WPACKET goes. We use an
605 * offset in case the buffer grows and gets reallocated.
606 */
607 size_t packet_len;
608
609 /* Number of bytes in the packet_len or 0 if we don't write the length */
610 size_t lenbytes;
611
612 /* Number of bytes written to the buf prior to this packet starting */
613 size_t pwritten;
614
615 /* Flags for this sub-packet */
616 unsigned int flags;
617};
618
619typedef struct wpacket_st WPACKET;
620struct wpacket_st {
621 /* The buffer where we store the output data */
622 BUF_MEM *buf;
623
624 /* Fixed sized buffer which can be used as an alternative to buf */
625 unsigned char *staticbuf;
626
627 /*
628 * Offset into the buffer where we are currently writing. We use an offset
629 * in case the buffer grows and gets reallocated.
630 */
631 size_t curr;
632
633 /* Number of bytes written so far */
634 size_t written;
635
636 /* Maximum number of bytes we will allow to be written to this WPACKET */
637 size_t maxsize;
638
639 /* Our sub-packets (always at least one if not finished) */
640 WPACKET_SUB *subs;
641};
642
643/* Flags */
644
645/* Default */
646#define WPACKET_FLAGS_NONE 0
647
648/* Error on WPACKET_close() if no data written to the WPACKET */
649#define WPACKET_FLAGS_NON_ZERO_LENGTH 1
650
651/*
652 * Abandon all changes on WPACKET_close() if no data written to the WPACKET,
653 * i.e. this does not write out a zero packet length
654 */
655#define WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH 2
656
657
658/*
659 * Initialise a WPACKET with the buffer in |buf|. The buffer must exist
660 * for the whole time that the WPACKET is being used. Additionally |lenbytes| of
661 * data is preallocated at the start of the buffer to store the length of the
662 * WPACKET once we know it.
663 */
664int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes);
665
666/*
667 * Same as WPACKET_init_len except there is no preallocation of the WPACKET
668 * length.
669 */
670int WPACKET_init(WPACKET *pkt, BUF_MEM *buf);
671
672/*
673 * Same as WPACKET_init_len except there is no underlying buffer. No data is
674 * ever actually written. We just keep track of how much data would have been
675 * written if a buffer was there.
676 */
677int WPACKET_init_null(WPACKET *pkt, size_t lenbytes);
678
679/*
680 * Same as WPACKET_init_len except we do not use a growable BUF_MEM structure.
681 * A fixed buffer of memory |buf| of size |len| is used instead. A failure will
682 * occur if you attempt to write beyond the end of the buffer
683 */
684int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
685 size_t lenbytes);
686/*
687 * Set the flags to be applied to the current sub-packet
688 */
689int WPACKET_set_flags(WPACKET *pkt, unsigned int flags);
690
691/*
692 * Closes the most recent sub-packet. It also writes out the length of the
693 * packet to the required location (normally the start of the WPACKET) if
694 * appropriate. The top level WPACKET should be closed using WPACKET_finish()
695 * instead of this function.
696 */
697int WPACKET_close(WPACKET *pkt);
698
699/*
700 * The same as WPACKET_close() but only for the top most WPACKET. Additionally
701 * frees memory resources for this WPACKET.
702 */
703int WPACKET_finish(WPACKET *pkt);
704
705/*
706 * Iterate through all the sub-packets and write out their lengths as if they
707 * were being closed. The lengths will be overwritten with the final lengths
708 * when the sub-packets are eventually closed (which may be different if more
709 * data is added to the WPACKET). This function fails if a sub-packet is of 0
710 * length and WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH is set.
711 */
712int WPACKET_fill_lengths(WPACKET *pkt);
713
714/*
715 * Initialise a new sub-packet. Additionally |lenbytes| of data is preallocated
716 * at the start of the sub-packet to store its length once we know it. Don't
717 * call this directly. Use the convenience macros below instead.
718 */
719int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes);
720
721/*
722 * Convenience macros for calling WPACKET_start_sub_packet_len with different
723 * lengths
724 */
725#define WPACKET_start_sub_packet_u8(pkt) \
726 WPACKET_start_sub_packet_len__((pkt), 1)
727#define WPACKET_start_sub_packet_u16(pkt) \
728 WPACKET_start_sub_packet_len__((pkt), 2)
729#define WPACKET_start_sub_packet_u24(pkt) \
730 WPACKET_start_sub_packet_len__((pkt), 3)
731#define WPACKET_start_sub_packet_u32(pkt) \
732 WPACKET_start_sub_packet_len__((pkt), 4)
733
734/*
735 * Same as WPACKET_start_sub_packet_len__() except no bytes are pre-allocated
736 * for the sub-packet length.
737 */
738int WPACKET_start_sub_packet(WPACKET *pkt);
739
740/*
741 * Allocate bytes in the WPACKET for the output. This reserves the bytes
742 * and counts them as "written", but doesn't actually do the writing. A pointer
743 * to the allocated bytes is stored in |*allocbytes|. |allocbytes| may be NULL.
744 * WARNING: the allocated bytes must be filled in immediately, without further
745 * WPACKET_* calls. If not then the underlying buffer may be realloc'd and
746 * change its location.
747 */
748int WPACKET_allocate_bytes(WPACKET *pkt, size_t len,
749 unsigned char **allocbytes);
750
751/*
752 * The same as WPACKET_allocate_bytes() except additionally a new sub-packet is
753 * started for the allocated bytes, and then closed immediately afterwards. The
754 * number of length bytes for the sub-packet is in |lenbytes|. Don't call this
755 * directly. Use the convenience macros below instead.
756 */
757int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
758 unsigned char **allocbytes, size_t lenbytes);
759
760/*
761 * Convenience macros for calling WPACKET_sub_allocate_bytes with different
762 * lengths
763 */
764#define WPACKET_sub_allocate_bytes_u8(pkt, len, bytes) \
765 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 1)
766#define WPACKET_sub_allocate_bytes_u16(pkt, len, bytes) \
767 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 2)
768#define WPACKET_sub_allocate_bytes_u24(pkt, len, bytes) \
769 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 3)
770#define WPACKET_sub_allocate_bytes_u32(pkt, len, bytes) \
771 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 4)
772
773/*
774 * The same as WPACKET_allocate_bytes() except the reserved bytes are not
775 * actually counted as written. Typically this will be for when we don't know
776 * how big arbitrary data is going to be up front, but we do know what the
777 * maximum size will be. If this function is used, then it should be immediately
778 * followed by a WPACKET_allocate_bytes() call before any other WPACKET
779 * functions are called (unless the write to the allocated bytes is abandoned).
780 *
781 * For example: If we are generating a signature, then the size of that
782 * signature may not be known in advance. We can use WPACKET_reserve_bytes() to
783 * handle this:
784 *
785 * if (!WPACKET_sub_reserve_bytes_u16(&pkt, EVP_PKEY_size(pkey), &sigbytes1)
786 * || EVP_SignFinal(md_ctx, sigbytes1, &siglen, pkey) <= 0
787 * || !WPACKET_sub_allocate_bytes_u16(&pkt, siglen, &sigbytes2)
788 * || sigbytes1 != sigbytes2)
789 * goto err;
790 */
791int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes);
792
793/*
794 * The "reserve_bytes" equivalent of WPACKET_sub_allocate_bytes__()
795 */
796int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
797 unsigned char **allocbytes, size_t lenbytes);
798
799/*
800 * Convenience macros for WPACKET_sub_reserve_bytes with different lengths
801 */
802#define WPACKET_sub_reserve_bytes_u8(pkt, len, bytes) \
803 WPACKET_reserve_bytes__((pkt), (len), (bytes), 1)
804#define WPACKET_sub_reserve_bytes_u16(pkt, len, bytes) \
805 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 2)
806#define WPACKET_sub_reserve_bytes_u24(pkt, len, bytes) \
807 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 3)
808#define WPACKET_sub_reserve_bytes_u32(pkt, len, bytes) \
809 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 4)
810
811/*
812 * Write the value stored in |val| into the WPACKET. The value will consume
813 * |bytes| amount of storage. An error will occur if |val| cannot be
814 * accommodated in |bytes| storage, e.g. attempting to write the value 256 into
815 * 1 byte will fail. Don't call this directly. Use the convenience macros below
816 * instead.
817 */
818int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t bytes);
819
820/*
821 * Convenience macros for calling WPACKET_put_bytes with different
822 * lengths
823 */
824#define WPACKET_put_bytes_u8(pkt, val) \
825 WPACKET_put_bytes__((pkt), (val), 1)
826#define WPACKET_put_bytes_u16(pkt, val) \
827 WPACKET_put_bytes__((pkt), (val), 2)
828#define WPACKET_put_bytes_u24(pkt, val) \
829 WPACKET_put_bytes__((pkt), (val), 3)
830#define WPACKET_put_bytes_u32(pkt, val) \
831 WPACKET_put_bytes__((pkt), (val), 4)
832
833/* Set a maximum size that we will not allow the WPACKET to grow beyond */
834int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize);
835
836/* Copy |len| bytes of data from |*src| into the WPACKET. */
837int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len);
838
839/* Set |len| bytes of data to |ch| into the WPACKET. */
840int WPACKET_memset(WPACKET *pkt, int ch, size_t len);
841
842/*
843 * Copy |len| bytes of data from |*src| into the WPACKET and prefix with its
844 * length (consuming |lenbytes| of data for the length). Don't call this
845 * directly. Use the convenience macros below instead.
846 */
847int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
848 size_t lenbytes);
849
850/* Convenience macros for calling WPACKET_sub_memcpy with different lengths */
851#define WPACKET_sub_memcpy_u8(pkt, src, len) \
852 WPACKET_sub_memcpy__((pkt), (src), (len), 1)
853#define WPACKET_sub_memcpy_u16(pkt, src, len) \
854 WPACKET_sub_memcpy__((pkt), (src), (len), 2)
855#define WPACKET_sub_memcpy_u24(pkt, src, len) \
856 WPACKET_sub_memcpy__((pkt), (src), (len), 3)
857#define WPACKET_sub_memcpy_u32(pkt, src, len) \
858 WPACKET_sub_memcpy__((pkt), (src), (len), 4)
859
860/*
861 * Return the total number of bytes written so far to the underlying buffer
862 * including any storage allocated for length bytes
863 */
864int WPACKET_get_total_written(WPACKET *pkt, size_t *written);
865
866/*
867 * Returns the length of the current sub-packet. This excludes any bytes
868 * allocated for the length itself.
869 */
870int WPACKET_get_length(WPACKET *pkt, size_t *len);
871
872/*
873 * Returns a pointer to the current write location, but does not allocate any
874 * bytes.
875 */
876unsigned char *WPACKET_get_curr(WPACKET *pkt);
877
878/* Returns true if the underlying buffer is actually NULL */
879int WPACKET_is_null_buf(WPACKET *pkt);
880
881/* Release resources in a WPACKET if a failure has occurred. */
882void WPACKET_cleanup(WPACKET *pkt);
883
884#endif /* OSSL_INTERNAL_PACKET_H */
885