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
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 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 */
677int 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 */
682int 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 */
690int 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 */
696int 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 */
705int 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 */
712int 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 */
731int 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 */
741int 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 */
750int 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 */
784int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes);
785
786/*
787 * The "reserve_bytes" equivalent of WPACKET_sub_allocate_bytes__()
788 */
789int 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 */
811int 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 */
827int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize);
828
829/* Copy |len| bytes of data from |*src| into the WPACKET. */
830int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len);
831
832/* Set |len| bytes of data to |ch| into the WPACKET. */
833int 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 */
840int 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 */
857int 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 */
863int 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 */
869unsigned char *WPACKET_get_curr(WPACKET *pkt);
870
871/* Release resources in a WPACKET if a failure has occurred. */
872void WPACKET_cleanup(WPACKET *pkt);
873
874#endif                          /* OSSL_SSL_PACKET_LOCAL_H */
875