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() and WPACKET_finish() to
184 * close a sub-packet and write out its length if necessary.
186 static int wpacket_intern_close(WPACKET *pkt)
188 WPACKET_SUB *sub = pkt->subs;
189 size_t packlen = pkt->written - sub->pwritten;
192 && (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0)
196 && sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
197 /* Deallocate any bytes allocated for the length of the WPACKET */
198 if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
199 pkt->written -= sub->lenbytes;
200 pkt->curr -= sub->lenbytes;
203 /* Don't write out the packet length */
208 /* Write out the WPACKET length if needed */
209 if (sub->lenbytes > 0
210 && !put_value(&GETBUF(pkt)[sub->packet_len], packlen,
214 pkt->subs = sub->parent;
220 int WPACKET_close(WPACKET *pkt)
223 * Internal API, so should not fail - but we do negative testing of this
224 * so no assert (otherwise the tests fail)
226 if (pkt->subs == NULL || pkt->subs->parent == NULL)
229 return wpacket_intern_close(pkt);
232 int WPACKET_finish(WPACKET *pkt)
237 * Internal API, so should not fail - but we do negative testing of this
238 * so no assert (otherwise the tests fail)
240 if (pkt->subs == NULL || pkt->subs->parent != NULL)
243 ret = wpacket_intern_close(pkt);
245 OPENSSL_free(pkt->subs);
252 int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes)
255 unsigned char *lenchars;
257 /* Internal API, so should not fail */
258 assert(pkt->subs != NULL);
259 if (pkt->subs == NULL)
262 sub = OPENSSL_zalloc(sizeof(*sub));
266 sub->parent = pkt->subs;
268 sub->pwritten = pkt->written + lenbytes;
269 sub->lenbytes = lenbytes;
276 if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars))
278 /* Convert to an offset in case the underlying BUF_MEM gets realloc'd */
279 sub->packet_len = lenchars - GETBUF(pkt);
284 int WPACKET_start_sub_packet(WPACKET *pkt)
286 return WPACKET_start_sub_packet_len__(pkt, 0);
289 int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t size)
293 /* Internal API, so should not fail */
294 assert(size <= sizeof(unsigned int));
296 if (size > sizeof(unsigned int)
297 || !WPACKET_allocate_bytes(pkt, size, &data)
298 || !put_value(data, val, size))
304 int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
309 /* Internal API, so should not fail */
310 assert(pkt->subs != NULL);
311 if (pkt->subs == NULL)
314 /* Find the WPACKET_SUB for the top level */
315 for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent)
318 lenbytes = sub->lenbytes;
320 lenbytes = sizeof(pkt->maxsize);
322 if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
325 pkt->maxsize = maxsize;
330 int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
337 if (!WPACKET_allocate_bytes(pkt, len, &dest))
340 memcpy(dest, src, len);
345 int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
348 if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
349 || !WPACKET_memcpy(pkt, src, len)
350 || !WPACKET_close(pkt))
356 int WPACKET_get_total_written(WPACKET *pkt, size_t *written)
358 /* Internal API, so should not fail */
359 assert(written != NULL);
363 *written = pkt->written;
368 int WPACKET_get_length(WPACKET *pkt, size_t *len)
370 /* Internal API, so should not fail */
371 assert(pkt->subs != NULL && len != NULL);
372 if (pkt->subs == NULL || len == NULL)
375 *len = pkt->written - pkt->subs->pwritten;
380 unsigned char *WPACKET_get_curr(WPACKET *pkt)
382 return GETBUF(pkt) + pkt->curr;
385 void WPACKET_cleanup(WPACKET *pkt)
387 WPACKET_SUB *sub, *parent;
389 for (sub = pkt->subs; sub != NULL; sub = parent) {
390 parent = sub->parent;