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 (pkt->maxsize - pkt->written < len)
22 if (pkt->buf->length - pkt->written < len) {
25 if (pkt->buf->length > SIZE_MAX / 2) {
28 newlen = (pkt->buf->length == 0) ? DEFAULT_BUF_SIZE
29 : pkt->buf->length * 2;
31 if (BUF_MEM_grow(pkt->buf, newlen) == 0)
35 *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;
41 static size_t maxmaxsize(size_t lenbytes)
43 if (lenbytes >= sizeof(size_t) || lenbytes == 0)
46 return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
49 int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
51 unsigned char *lenchars;
60 pkt->maxsize = maxmaxsize(lenbytes);
62 pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
63 if (pkt->subs == NULL)
69 pkt->subs->pwritten = lenbytes;
70 pkt->subs->lenbytes = lenbytes;
72 if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) {
73 OPENSSL_free(pkt->subs);
77 pkt->subs->packet_len = lenchars - (unsigned char *)pkt->buf->data;
82 int WPACKET_init(WPACKET *pkt, BUF_MEM *buf)
84 return WPACKET_init_len(pkt, buf, 0);
87 int WPACKET_set_flags(WPACKET *pkt, unsigned int flags)
89 if (pkt->subs == NULL)
92 pkt->subs->flags = flags;
99 * Internal helper function used by WPACKET_close() and WPACKET_finish() to
100 * close a sub-packet and write out its length if necessary.
102 static int wpacket_intern_close(WPACKET *pkt)
104 WPACKET_SUB *sub = pkt->subs;
105 size_t packlen = pkt->written - sub->pwritten;
108 && sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH)
112 && sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
113 /* Deallocate any bytes allocated for the length of the WPACKET */
114 if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
115 pkt->written -= sub->lenbytes;
116 pkt->curr -= sub->lenbytes;
119 /* Don't write out the packet length */
124 /* Write out the WPACKET length if needed */
125 if (sub->lenbytes > 0) {
128 for (lenbytes = sub->lenbytes; lenbytes > 0; lenbytes--) {
129 pkt->buf->data[sub->packet_len + lenbytes - 1]
130 = (unsigned char)(packlen & 0xff);
135 * We've extended beyond the max allowed for the number of len bytes
141 pkt->subs = sub->parent;
147 int WPACKET_close(WPACKET *pkt)
149 if (pkt->subs == NULL || pkt->subs->parent == NULL)
152 return wpacket_intern_close(pkt);
155 int WPACKET_finish(WPACKET *pkt)
159 if (pkt->subs == NULL || pkt->subs->parent != NULL)
162 ret = wpacket_intern_close(pkt);
164 OPENSSL_free(pkt->subs);
171 int WPACKET_start_sub_packet_len(WPACKET *pkt, size_t lenbytes)
174 unsigned char *lenchars;
176 if (pkt->subs == NULL)
179 sub = OPENSSL_zalloc(sizeof(*sub));
183 sub->parent = pkt->subs;
185 sub->pwritten = pkt->written + lenbytes;
186 sub->lenbytes = lenbytes;
193 if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars))
195 sub->packet_len = lenchars - (unsigned char *)pkt->buf->data;
200 int WPACKET_start_sub_packet(WPACKET *pkt)
202 return WPACKET_start_sub_packet_len(pkt, 0);
205 int WPACKET_put_bytes(WPACKET *pkt, unsigned int val, size_t size)
209 if (size > sizeof(unsigned int)
210 || !WPACKET_allocate_bytes(pkt, size, &data))
213 for (data += size - 1; size > 0; size--) {
214 *data = (unsigned char)(val & 0xff);
219 /* Check whether we could fit the value in the assigned number of bytes */
226 int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
231 if (pkt->subs == NULL)
234 /* Find the WPACKET_SUB for the top level */
235 for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent)
238 lenbytes = sub->lenbytes;
240 lenbytes = sizeof(pkt->maxsize);
242 if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
245 pkt->maxsize = maxsize;
250 int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
257 if (!WPACKET_allocate_bytes(pkt, len, &dest))
260 memcpy(dest, src, len);
265 int WPACKET_sub_memcpy(WPACKET *pkt, const void *src, size_t len, size_t lenbytes)
267 if (!WPACKET_start_sub_packet_len(pkt, lenbytes)
268 || !WPACKET_memcpy(pkt, src, len)
269 || !WPACKET_close(pkt))
275 int WPACKET_get_total_written(WPACKET *pkt, size_t *written)
280 *written = pkt->written;
285 int WPACKET_get_length(WPACKET *pkt, size_t *len)
287 if (pkt->subs == NULL || len == NULL)
290 *len = pkt->written - pkt->subs->pwritten;
295 void WPACKET_cleanup(WPACKET *pkt)
297 WPACKET_SUB *sub, *parent;
299 for (sub = pkt->subs; sub != NULL; sub = parent) {
300 parent = sub->parent;