1 /*
2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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_SSL_PACKET_LOCAL_H
11 # define OSSL_SSL_PACKET_LOCAL_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
21 typedef 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. */
packet_forward(PACKET * pkt,size_t len)29 static 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 */
PACKET_remaining(const PACKET * pkt)38 static 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 */
PACKET_end(const PACKET * pkt)49 static 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 */
PACKET_data(const PACKET * pkt)58 static 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 */
PACKET_buf_init(PACKET * pkt,const unsigned char * buf,size_t len)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. */
PACKET_null_init(PACKET * pkt)82 static 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 */
PACKET_equal(const PACKET * pkt,const void * ptr,size_t num)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 */
PACKET_peek_sub_packet(const PACKET * pkt,PACKET * subpkt,size_t len)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 */
PACKET_get_sub_packet(PACKET * pkt,PACKET * subpkt,size_t len)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 */
PACKET_peek_net_2(const PACKET * pkt,unsigned int * data)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| */
PACKET_get_net_2(PACKET * pkt,unsigned int * 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 */
PACKET_get_net_2_len(PACKET * pkt,size_t * data)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 */
PACKET_peek_net_3(const PACKET * pkt,unsigned long * data)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| */
PACKET_get_net_3(PACKET * pkt,unsigned long * 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 */
PACKET_get_net_3_len(PACKET * pkt,size_t * data)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 */
PACKET_peek_net_4(const PACKET * pkt,unsigned long * data)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| */
PACKET_get_net_4(PACKET * pkt,unsigned long * 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 */
PACKET_get_net_4_len(PACKET * pkt,size_t * data)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| */
PACKET_peek_1(const PACKET * pkt,unsigned int * 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| */
PACKET_get_1(PACKET * pkt,unsigned int * 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 */
PACKET_get_1_len(PACKET * pkt,size_t * data)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 */
PACKET_peek_4(const PACKET * pkt,unsigned long * data)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 */
PACKET_get_4(PACKET * pkt,unsigned long * data)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 */
PACKET_peek_bytes(const PACKET * pkt,const unsigned char ** data,size_t len)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 */
PACKET_get_bytes(PACKET * pkt,const unsigned char ** data,size_t len)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| */
PACKET_peek_copy_bytes(const PACKET * pkt,unsigned char * data,size_t len)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 */
PACKET_copy_bytes(PACKET * pkt,unsigned char * data,size_t len)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 */
PACKET_copy_all(const PACKET * pkt,unsigned char * dest,size_t dest_len,size_t * len)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 */
PACKET_memdup(const PACKET * pkt,unsigned char ** data,size_t * len)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 */
PACKET_strndup(const PACKET * pkt,char ** data)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. */
PACKET_contains_zero_byte(const PACKET * pkt)457 static 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 */
PACKET_forward(PACKET * pkt,size_t len)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 */
PACKET_get_length_prefixed_1(PACKET * pkt,PACKET * subpkt)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 */
PACKET_as_length_prefixed_1(PACKET * pkt,PACKET * subpkt)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 */
PACKET_get_length_prefixed_2(PACKET * pkt,PACKET * subpkt)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 */
PACKET_as_length_prefixed_2(PACKET * pkt,PACKET * subpkt)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 */
PACKET_get_length_prefixed_3(PACKET * pkt,PACKET * subpkt)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
598 typedef struct wpacket_sub WPACKET_SUB;
599 struct 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
619 typedef struct wpacket_st WPACKET;
620 struct 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 */
664 int 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 */
670 int WPACKET_init(WPACKET *pkt, BUF_MEM *buf);
671
672 /*
673 * Same as WPACKET_init_len except we do not use a growable BUF_MEM structure.
674 * A fixed buffer of memory |buf| of size |len| is used instead. A failure will
675 * occur if you attempt to write beyond the end of the buffer
676 */
677 int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
678 size_t lenbytes);
679 /*
680 * Set the flags to be applied to the current sub-packet
681 */
682 int WPACKET_set_flags(WPACKET *pkt, unsigned int flags);
683
684 /*
685 * Closes the most recent sub-packet. It also writes out the length of the
686 * packet to the required location (normally the start of the WPACKET) if
687 * appropriate. The top level WPACKET should be closed using WPACKET_finish()
688 * instead of this function.
689 */
690 int WPACKET_close(WPACKET *pkt);
691
692 /*
693 * The same as WPACKET_close() but only for the top most WPACKET. Additionally
694 * frees memory resources for this WPACKET.
695 */
696 int WPACKET_finish(WPACKET *pkt);
697
698 /*
699 * Iterate through all the sub-packets and write out their lengths as if they
700 * were being closed. The lengths will be overwritten with the final lengths
701 * when the sub-packets are eventually closed (which may be different if more
702 * data is added to the WPACKET). This function fails if a sub-packet is of 0
703 * length and WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH is set.
704 */
705 int WPACKET_fill_lengths(WPACKET *pkt);
706
707 /*
708 * Initialise a new sub-packet. Additionally |lenbytes| of data is preallocated
709 * at the start of the sub-packet to store its length once we know it. Don't
710 * call this directly. Use the convenience macros below instead.
711 */
712 int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes);
713
714 /*
715 * Convenience macros for calling WPACKET_start_sub_packet_len with different
716 * lengths
717 */
718 #define WPACKET_start_sub_packet_u8(pkt) \
719 WPACKET_start_sub_packet_len__((pkt), 1)
720 #define WPACKET_start_sub_packet_u16(pkt) \
721 WPACKET_start_sub_packet_len__((pkt), 2)
722 #define WPACKET_start_sub_packet_u24(pkt) \
723 WPACKET_start_sub_packet_len__((pkt), 3)
724 #define WPACKET_start_sub_packet_u32(pkt) \
725 WPACKET_start_sub_packet_len__((pkt), 4)
726
727 /*
728 * Same as WPACKET_start_sub_packet_len__() except no bytes are pre-allocated
729 * for the sub-packet length.
730 */
731 int WPACKET_start_sub_packet(WPACKET *pkt);
732
733 /*
734 * Allocate bytes in the WPACKET for the output. This reserves the bytes
735 * and counts them as "written", but doesn't actually do the writing. A pointer
736 * to the allocated bytes is stored in |*allocbytes|. |allocbytes| may be NULL.
737 * WARNING: the allocated bytes must be filled in immediately, without further
738 * WPACKET_* calls. If not then the underlying buffer may be realloc'd and
739 * change its location.
740 */
741 int WPACKET_allocate_bytes(WPACKET *pkt, size_t len,
742 unsigned char **allocbytes);
743
744 /*
745 * The same as WPACKET_allocate_bytes() except additionally a new sub-packet is
746 * started for the allocated bytes, and then closed immediately afterwards. The
747 * number of length bytes for the sub-packet is in |lenbytes|. Don't call this
748 * directly. Use the convenience macros below instead.
749 */
750 int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
751 unsigned char **allocbytes, size_t lenbytes);
752
753 /*
754 * Convenience macros for calling WPACKET_sub_allocate_bytes with different
755 * lengths
756 */
757 #define WPACKET_sub_allocate_bytes_u8(pkt, len, bytes) \
758 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 1)
759 #define WPACKET_sub_allocate_bytes_u16(pkt, len, bytes) \
760 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 2)
761 #define WPACKET_sub_allocate_bytes_u24(pkt, len, bytes) \
762 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 3)
763 #define WPACKET_sub_allocate_bytes_u32(pkt, len, bytes) \
764 WPACKET_sub_allocate_bytes__((pkt), (len), (bytes), 4)
765
766 /*
767 * The same as WPACKET_allocate_bytes() except the reserved bytes are not
768 * actually counted as written. Typically this will be for when we don't know
769 * how big arbitrary data is going to be up front, but we do know what the
770 * maximum size will be. If this function is used, then it should be immediately
771 * followed by a WPACKET_allocate_bytes() call before any other WPACKET
772 * functions are called (unless the write to the allocated bytes is abandoned).
773 *
774 * For example: If we are generating a signature, then the size of that
775 * signature may not be known in advance. We can use WPACKET_reserve_bytes() to
776 * handle this:
777 *
778 * if (!WPACKET_sub_reserve_bytes_u16(&pkt, EVP_PKEY_size(pkey), &sigbytes1)
779 * || EVP_SignFinal(md_ctx, sigbytes1, &siglen, pkey) <= 0
780 * || !WPACKET_sub_allocate_bytes_u16(&pkt, siglen, &sigbytes2)
781 * || sigbytes1 != sigbytes2)
782 * goto err;
783 */
784 int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes);
785
786 /*
787 * The "reserve_bytes" equivalent of WPACKET_sub_allocate_bytes__()
788 */
789 int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
790 unsigned char **allocbytes, size_t lenbytes);
791
792 /*
793 * Convenience macros for WPACKET_sub_reserve_bytes with different lengths
794 */
795 #define WPACKET_sub_reserve_bytes_u8(pkt, len, bytes) \
796 WPACKET_reserve_bytes__((pkt), (len), (bytes), 1)
797 #define WPACKET_sub_reserve_bytes_u16(pkt, len, bytes) \
798 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 2)
799 #define WPACKET_sub_reserve_bytes_u24(pkt, len, bytes) \
800 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 3)
801 #define WPACKET_sub_reserve_bytes_u32(pkt, len, bytes) \
802 WPACKET_sub_reserve_bytes__((pkt), (len), (bytes), 4)
803
804 /*
805 * Write the value stored in |val| into the WPACKET. The value will consume
806 * |bytes| amount of storage. An error will occur if |val| cannot be
807 * accommodated in |bytes| storage, e.g. attempting to write the value 256 into
808 * 1 byte will fail. Don't call this directly. Use the convenience macros below
809 * instead.
810 */
811 int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t bytes);
812
813 /*
814 * Convenience macros for calling WPACKET_put_bytes with different
815 * lengths
816 */
817 #define WPACKET_put_bytes_u8(pkt, val) \
818 WPACKET_put_bytes__((pkt), (val), 1)
819 #define WPACKET_put_bytes_u16(pkt, val) \
820 WPACKET_put_bytes__((pkt), (val), 2)
821 #define WPACKET_put_bytes_u24(pkt, val) \
822 WPACKET_put_bytes__((pkt), (val), 3)
823 #define WPACKET_put_bytes_u32(pkt, val) \
824 WPACKET_put_bytes__((pkt), (val), 4)
825
826 /* Set a maximum size that we will not allow the WPACKET to grow beyond */
827 int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize);
828
829 /* Copy |len| bytes of data from |*src| into the WPACKET. */
830 int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len);
831
832 /* Set |len| bytes of data to |ch| into the WPACKET. */
833 int WPACKET_memset(WPACKET *pkt, int ch, size_t len);
834
835 /*
836 * Copy |len| bytes of data from |*src| into the WPACKET and prefix with its
837 * length (consuming |lenbytes| of data for the length). Don't call this
838 * directly. Use the convenience macros below instead.
839 */
840 int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
841 size_t lenbytes);
842
843 /* Convenience macros for calling WPACKET_sub_memcpy with different lengths */
844 #define WPACKET_sub_memcpy_u8(pkt, src, len) \
845 WPACKET_sub_memcpy__((pkt), (src), (len), 1)
846 #define WPACKET_sub_memcpy_u16(pkt, src, len) \
847 WPACKET_sub_memcpy__((pkt), (src), (len), 2)
848 #define WPACKET_sub_memcpy_u24(pkt, src, len) \
849 WPACKET_sub_memcpy__((pkt), (src), (len), 3)
850 #define WPACKET_sub_memcpy_u32(pkt, src, len) \
851 WPACKET_sub_memcpy__((pkt), (src), (len), 4)
852
853 /*
854 * Return the total number of bytes written so far to the underlying buffer
855 * including any storage allocated for length bytes
856 */
857 int WPACKET_get_total_written(WPACKET *pkt, size_t *written);
858
859 /*
860 * Returns the length of the current sub-packet. This excludes any bytes
861 * allocated for the length itself.
862 */
863 int WPACKET_get_length(WPACKET *pkt, size_t *len);
864
865 /*
866 * Returns a pointer to the current write location, but does not allocate any
867 * bytes.
868 */
869 unsigned char *WPACKET_get_curr(WPACKET *pkt);
870
871 /* Release resources in a WPACKET if a failure has occurred. */
872 void WPACKET_cleanup(WPACKET *pkt);
873
874 #endif /* OSSL_SSL_PACKET_LOCAL_H */
875