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
10 #include "packet_locl.h"
12 #define DEFAULT_BUF_SIZE 256
14 int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
16 if (pkt->subs == NULL || len == 0)
19 if (SIZE_MAX - pkt->written < len)
22 if (pkt->written + len > pkt->maxsize)
25 if (pkt->buf->length - pkt->written < len) {
28 if (pkt->buf->length > SIZE_MAX / 2) {
31 if (pkt->buf->length == 0)
32 newlen = DEFAULT_BUF_SIZE;
34 newlen = pkt->buf->length * 2;
36 if (BUF_MEM_grow(pkt->buf, newlen) == 0)
38 if (pkt->curr == NULL) {
40 * Can happen if initialised with a BUF_MEM that hasn't been
43 pkt->curr = (unsigned char *)pkt->buf->data;
47 *allocbytes = pkt->curr;
53 static size_t maxmaxsize(size_t lenbytes)
55 if (lenbytes >= sizeof(size_t) || lenbytes == 0)
58 return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
61 int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
68 pkt->curr = (unsigned char *)buf->data;
70 pkt->maxsize = maxmaxsize(lenbytes);
72 pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
73 if (pkt->subs == NULL)
79 pkt->subs->pwritten = lenbytes;
80 pkt->subs->lenbytes = lenbytes;
82 if (!WPACKET_allocate_bytes(pkt, lenbytes, &(pkt->subs->packet_len))) {
83 OPENSSL_free(pkt->subs);
91 int WPACKET_init(WPACKET *pkt, BUF_MEM *buf)
93 return WPACKET_init_len(pkt, buf, 0);
96 int WPACKET_set_packet_len(WPACKET *pkt, unsigned char *packet_len,
101 /* We only allow this to be set once */
102 if (pkt->subs == NULL || pkt->subs->lenbytes != 0)
105 pkt->subs->lenbytes = lenbytes;
106 pkt->subs->packet_len = packet_len;
108 maxmax = maxmaxsize(lenbytes);
109 if (pkt->maxsize > maxmax)
110 pkt->maxsize = maxmax;
115 int WPACKET_set_flags(WPACKET *pkt, unsigned int flags)
117 if (pkt->subs == NULL)
120 pkt->subs->flags = flags;
127 * Internal helper function used by WPACKET_close() and WPACKET_finish() to
128 * close a sub-packet and write out its length if necessary.
130 static int wpacket_intern_close(WPACKET *pkt)
133 WPACKET_SUB *sub = pkt->subs;
135 packlen = pkt->written - sub->pwritten;
137 && sub->flags & OPENSSL_WPACKET_FLAGS_NON_ZERO_LENGTH)
141 && sub->flags & OPENSSL_WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
142 /* Deallocate any bytes allocated for the length of the WPACKET */
143 if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
144 pkt->written -= sub->lenbytes;
145 pkt->curr -= sub->lenbytes;
148 /* Don't write out the packet length */
149 sub->packet_len = NULL;
152 /* Write out the WPACKET length if needed */
153 if (sub->packet_len != NULL) {
156 lenbytes = sub->lenbytes;
158 for (; lenbytes > 0; lenbytes--) {
159 sub->packet_len[lenbytes - 1]
160 = (unsigned char)(packlen & 0xff);
165 * We've extended beyond the max allowed for the number of len bytes
171 pkt->subs = sub->parent;
177 int WPACKET_close(WPACKET *pkt)
179 if (pkt->subs == NULL || pkt->subs->parent == NULL)
182 return wpacket_intern_close(pkt);
185 int WPACKET_finish(WPACKET *pkt)
189 if (pkt->subs == NULL || pkt->subs->parent != NULL)
192 ret = wpacket_intern_close(pkt);
195 OPENSSL_free(pkt->subs);
201 int WPACKET_start_sub_packet_len(WPACKET *pkt, size_t lenbytes)
205 if (pkt->subs == NULL)
208 sub = OPENSSL_zalloc(sizeof(*sub));
212 sub->parent = pkt->subs;
214 sub->pwritten = pkt->written + lenbytes;
215 sub->lenbytes = lenbytes;
218 sub->packet_len = NULL;
222 if (!WPACKET_allocate_bytes(pkt, lenbytes, &sub->packet_len)) {
229 int WPACKET_start_sub_packet(WPACKET *pkt)
231 return WPACKET_start_sub_packet_len(pkt, 0);
234 int WPACKET_put_bytes(WPACKET *pkt, unsigned int val, size_t bytes)
238 if (bytes > sizeof(unsigned int)
239 || !WPACKET_allocate_bytes(pkt, bytes, &data))
243 for (; bytes > 0; bytes--) {
244 *data = (unsigned char)(val & 0xff);
249 /* Check whether we could fit the value in the assigned number of bytes */
256 int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
261 if (pkt->subs == NULL)
264 /* Find the WPACKET_SUB for the top level */
265 for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent);
267 lenbytes = sub->lenbytes;
269 lenbytes = sizeof(pkt->maxsize);
271 if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
274 pkt->maxsize = maxsize;
279 int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
286 if (!WPACKET_allocate_bytes(pkt, len, &dest))
289 memcpy(dest, src, len);
294 int WPACKET_sub_memcpy(WPACKET *pkt, const void *src, size_t len, size_t lenbytes)
296 if (!WPACKET_start_sub_packet_len(pkt, lenbytes)
297 || !WPACKET_memcpy(pkt, src, len)
298 || !WPACKET_close(pkt))
304 int WPACKET_get_total_written(WPACKET *pkt, size_t *written)
309 *written = pkt->written;
314 int WPACKET_get_length(WPACKET *pkt, size_t *len)
316 if (pkt->subs == NULL || len == NULL)
319 *len = pkt->written - pkt->subs->pwritten;
324 void WPACKET_cleanup(WPACKET *pkt)
326 WPACKET_SUB *sub, *parent;
328 for (sub = pkt->subs; sub != NULL; sub = parent) {
329 parent = sub->parent;