2 * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
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
11 #include "packet_locl.h"
13 #define DEFAULT_BUF_SIZE 256
15 int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
17 if (!WPACKET_reserve_bytes(pkt, len, allocbytes))
25 int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
26 unsigned char **allocbytes, size_t lenbytes)
28 if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
29 || !WPACKET_allocate_bytes(pkt, len, allocbytes)
30 || !WPACKET_close(pkt))
36 #define GETBUF(p) (((p)->staticbuf != NULL) \
37 ? (p)->staticbuf : (unsigned char *)(p)->buf->data)
39 int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
41 /* Internal API, so should not fail */
42 assert(pkt->subs != NULL && len != 0);
43 if (pkt->subs == NULL || len == 0)
46 if (pkt->maxsize - pkt->written < len)
49 if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {
53 reflen = (len > pkt->buf->length) ? len : pkt->buf->length;
55 if (reflen > SIZE_MAX / 2) {
59 if (newlen < DEFAULT_BUF_SIZE)
60 newlen = DEFAULT_BUF_SIZE;
62 if (BUF_MEM_grow(pkt->buf, newlen) == 0)
65 if (allocbytes != NULL)
66 *allocbytes = WPACKET_get_curr(pkt);
71 int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
72 unsigned char **allocbytes, size_t lenbytes)
74 if (!WPACKET_reserve_bytes(pkt, lenbytes + len, allocbytes))
77 *allocbytes += lenbytes;
82 static size_t maxmaxsize(size_t lenbytes)
84 if (lenbytes >= sizeof(size_t) || lenbytes == 0)
87 return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
90 static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes)
92 unsigned char *lenchars;
97 pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
98 if (pkt->subs == NULL)
104 pkt->subs->pwritten = lenbytes;
105 pkt->subs->lenbytes = lenbytes;
107 if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) {
108 OPENSSL_free(pkt->subs);
112 pkt->subs->packet_len = lenchars - GETBUF(pkt);
117 int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
120 size_t max = maxmaxsize(lenbytes);
122 /* Internal API, so should not fail */
123 assert(buf != NULL && len > 0);
124 if (buf == NULL || len == 0)
127 pkt->staticbuf = buf;
129 pkt->maxsize = (max < len) ? max : len;
131 return wpacket_intern_init_len(pkt, lenbytes);
134 int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
136 /* Internal API, so should not fail */
141 pkt->staticbuf = NULL;
143 pkt->maxsize = maxmaxsize(lenbytes);
145 return wpacket_intern_init_len(pkt, lenbytes);
148 int WPACKET_init(WPACKET *pkt, BUF_MEM *buf)
150 return WPACKET_init_len(pkt, buf, 0);
153 int WPACKET_set_flags(WPACKET *pkt, unsigned int flags)
155 /* Internal API, so should not fail */
156 assert(pkt->subs != NULL);
157 if (pkt->subs == NULL)
160 pkt->subs->flags = flags;
165 /* Store the |value| of length |len| at location |data| */
166 static int put_value(unsigned char *data, size_t value, size_t len)
168 for (data += len - 1; len > 0; len--) {
169 *data = (unsigned char)(value & 0xff);
174 /* Check whether we could fit the value in the assigned number of bytes */
183 * Internal helper function used by WPACKET_close(), WPACKET_finish() and
184 * WPACKET_fill_lengths() to close a sub-packet and write out its length if
185 * necessary. If |doclose| is 0 then it goes through the motions of closing
186 * (i.e. it fills in all the lengths), but doesn't actually close anything.
188 static int wpacket_intern_close(WPACKET *pkt, WPACKET_SUB *sub, int doclose)
190 size_t packlen = pkt->written - sub->pwritten;
193 && (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0)
197 && sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
198 /* We can't handle this case. Return an error */
202 /* Deallocate any bytes allocated for the length of the WPACKET */
203 if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
204 pkt->written -= sub->lenbytes;
205 pkt->curr -= sub->lenbytes;
208 /* Don't write out the packet length */
213 /* Write out the WPACKET length if needed */
214 if (sub->lenbytes > 0
215 && !put_value(&GETBUF(pkt)[sub->packet_len], packlen,
220 pkt->subs = sub->parent;
227 int WPACKET_fill_lengths(WPACKET *pkt)
231 assert(pkt->subs != NULL);
232 if (pkt->subs == NULL)
235 for (sub = pkt->subs; sub != NULL; sub = sub->parent) {
236 if (!wpacket_intern_close(pkt, sub, 0))
243 int WPACKET_close(WPACKET *pkt)
246 * Internal API, so should not fail - but we do negative testing of this
247 * so no assert (otherwise the tests fail)
249 if (pkt->subs == NULL || pkt->subs->parent == NULL)
252 return wpacket_intern_close(pkt, pkt->subs, 1);
255 int WPACKET_finish(WPACKET *pkt)
260 * Internal API, so should not fail - but we do negative testing of this
261 * so no assert (otherwise the tests fail)
263 if (pkt->subs == NULL || pkt->subs->parent != NULL)
266 ret = wpacket_intern_close(pkt, pkt->subs, 1);
268 OPENSSL_free(pkt->subs);
275 int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes)
278 unsigned char *lenchars;
280 /* Internal API, so should not fail */
281 assert(pkt->subs != NULL);
282 if (pkt->subs == NULL)
285 sub = OPENSSL_zalloc(sizeof(*sub));
289 sub->parent = pkt->subs;
291 sub->pwritten = pkt->written + lenbytes;
292 sub->lenbytes = lenbytes;
299 if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars))
301 /* Convert to an offset in case the underlying BUF_MEM gets realloc'd */
302 sub->packet_len = lenchars - GETBUF(pkt);
307 int WPACKET_start_sub_packet(WPACKET *pkt)
309 return WPACKET_start_sub_packet_len__(pkt, 0);
312 int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t size)
316 /* Internal API, so should not fail */
317 assert(size <= sizeof(unsigned int));
319 if (size > sizeof(unsigned int)
320 || !WPACKET_allocate_bytes(pkt, size, &data)
321 || !put_value(data, val, size))
327 int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
332 /* Internal API, so should not fail */
333 assert(pkt->subs != NULL);
334 if (pkt->subs == NULL)
337 /* Find the WPACKET_SUB for the top level */
338 for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent)
341 lenbytes = sub->lenbytes;
343 lenbytes = sizeof(pkt->maxsize);
345 if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
348 pkt->maxsize = maxsize;
353 int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
360 if (!WPACKET_allocate_bytes(pkt, len, &dest))
363 memcpy(dest, src, len);
368 int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
371 if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
372 || !WPACKET_memcpy(pkt, src, len)
373 || !WPACKET_close(pkt))
379 int WPACKET_get_total_written(WPACKET *pkt, size_t *written)
381 /* Internal API, so should not fail */
382 assert(written != NULL);
386 *written = pkt->written;
391 int WPACKET_get_length(WPACKET *pkt, size_t *len)
393 /* Internal API, so should not fail */
394 assert(pkt->subs != NULL && len != NULL);
395 if (pkt->subs == NULL || len == NULL)
398 *len = pkt->written - pkt->subs->pwritten;
403 unsigned char *WPACKET_get_curr(WPACKET *pkt)
405 return GETBUF(pkt) + pkt->curr;
408 void WPACKET_cleanup(WPACKET *pkt)
410 WPACKET_SUB *sub, *parent;
412 for (sub = pkt->subs; sub != NULL; sub = parent) {
413 parent = sub->parent;