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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