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/*
* Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <assert.h>
#include "packet_locl.h"
#define DEFAULT_BUF_SIZE 256
int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
{
if (!WPACKET_reserve_bytes(pkt, len, allocbytes))
return 0;
pkt->written += len;
pkt->curr += len;
return 1;
}
int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
unsigned char **allocbytes, size_t lenbytes)
{
if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
|| !WPACKET_allocate_bytes(pkt, len, allocbytes)
|| !WPACKET_close(pkt))
return 0;
return 1;
}
#define GETBUF(p) (((p)->staticbuf != NULL) \
? (p)->staticbuf : (unsigned char *)(p)->buf->data)
int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
{
/* Internal API, so should not fail */
assert(pkt->subs != NULL && len != 0);
if (pkt->subs == NULL || len == 0)
return 0;
if (pkt->maxsize - pkt->written < len)
return 0;
if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {
size_t newlen;
size_t reflen;
reflen = (len > pkt->buf->length) ? len : pkt->buf->length;
if (reflen > SIZE_MAX / 2) {
newlen = SIZE_MAX;
} else {
newlen = reflen * 2;
if (newlen < DEFAULT_BUF_SIZE)
newlen = DEFAULT_BUF_SIZE;
}
if (BUF_MEM_grow(pkt->buf, newlen) == 0)
return 0;
}
if (allocbytes != NULL)
*allocbytes = WPACKET_get_curr(pkt);
return 1;
}
int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
unsigned char **allocbytes, size_t lenbytes)
{
if (!WPACKET_reserve_bytes(pkt, lenbytes + len, allocbytes))
return 0;
*allocbytes += lenbytes;
return 1;
}
static size_t maxmaxsize(size_t lenbytes)
{
if (lenbytes >= sizeof(size_t) || lenbytes == 0)
return SIZE_MAX;
return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
}
static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes)
{
unsigned char *lenchars;
pkt->curr = 0;
pkt->written = 0;
pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
if (pkt->subs == NULL)
return 0;
if (lenbytes == 0)
return 1;
pkt->subs->pwritten = lenbytes;
pkt->subs->lenbytes = lenbytes;
if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) {
OPENSSL_free(pkt->subs);
pkt->subs = NULL;
return 0;
}
pkt->subs->packet_len = lenchars - GETBUF(pkt);
return 1;
}
int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
size_t lenbytes)
{
size_t max = maxmaxsize(lenbytes);
/* Internal API, so should not fail */
assert(buf != NULL && len > 0);
if (buf == NULL || len == 0)
return 0;
pkt->staticbuf = buf;
pkt->buf = NULL;
pkt->maxsize = (max < len) ? max : len;
return wpacket_intern_init_len(pkt, lenbytes);
}
int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
{
/* Internal API, so should not fail */
assert(buf != NULL);
if (buf == NULL)
return 0;
pkt->staticbuf = NULL;
pkt->buf = buf;
pkt->maxsize = maxmaxsize(lenbytes);
return wpacket_intern_init_len(pkt, lenbytes);
}
int WPACKET_init(WPACKET *pkt, BUF_MEM *buf)
{
return WPACKET_init_len(pkt, buf, 0);
}
int WPACKET_set_flags(WPACKET *pkt, unsigned int flags)
{
/* Internal API, so should not fail */
assert(pkt->subs != NULL);
if (pkt->subs == NULL)
return 0;
pkt->subs->flags = flags;
return 1;
}
/* Store the |value| of length |len| at location |data| */
static int put_value(unsigned char *data, size_t value, size_t len)
{
for (data += len - 1; len > 0; len--) {
*data = (unsigned char)(value & 0xff);
data--;
value >>= 8;
}
/* Check whether we could fit the value in the assigned number of bytes */
if (value > 0)
return 0;
return 1;
}
/*
* Internal helper function used by WPACKET_close(), WPACKET_finish() and
* WPACKET_fill_lengths() to close a sub-packet and write out its length if
* necessary. If |doclose| is 0 then it goes through the motions of closing
* (i.e. it fills in all the lengths), but doesn't actually close anything.
*/
static int wpacket_intern_close(WPACKET *pkt, WPACKET_SUB *sub, int doclose)
{
size_t packlen = pkt->written - sub->pwritten;
if (packlen == 0
&& (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0)
return 0;
if (packlen == 0
&& sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
/* We can't handle this case. Return an error */
if (!doclose)
return 0;
/* Deallocate any bytes allocated for the length of the WPACKET */
if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
pkt->written -= sub->lenbytes;
pkt->curr -= sub->lenbytes;
}
/* Don't write out the packet length */
sub->packet_len = 0;
sub->lenbytes = 0;
}
/* Write out the WPACKET length if needed */
if (sub->lenbytes > 0
&& !put_value(&GETBUF(pkt)[sub->packet_len], packlen,
sub->lenbytes))
return 0;
if (doclose) {
pkt->subs = sub->parent;
OPENSSL_free(sub);
}
return 1;
}
int WPACKET_fill_lengths(WPACKET *pkt)
{
WPACKET_SUB *sub;
assert(pkt->subs != NULL);
if (pkt->subs == NULL)
return 0;
sub = pkt->subs;
do {
if (!wpacket_intern_close(pkt, sub, 0))
return 0;
sub = sub->parent;
} while (sub !=
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