mirror of
git://git.gnupg.org/gnupg.git
synced 2024-10-31 20:08:43 +01:00
119 lines
2.9 KiB
C
119 lines
2.9 KiB
C
/* membuf.c - A simple implementation of a dynamic buffer.
|
|
* Copyright (C) 2001, 2003, 2009 Free Software Foundation, Inc.
|
|
*
|
|
* This file is part of GnuPG.
|
|
*
|
|
* GnuPG is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* GnuPG is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <config.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
|
|
#include "membuf.h"
|
|
|
|
#include "util.h"
|
|
|
|
|
|
/* A simple implementation of a dynamic buffer. Use init_membuf() to
|
|
create a buffer, put_membuf to append bytes and get_membuf to
|
|
release and return the buffer. Allocation errors are detected but
|
|
only returned at the final get_membuf(), this helps not to clutter
|
|
the code with out of core checks. */
|
|
|
|
void
|
|
init_membuf (membuf_t *mb, int initiallen)
|
|
{
|
|
mb->len = 0;
|
|
mb->size = initiallen;
|
|
mb->out_of_core = 0;
|
|
mb->buf = xtrymalloc (initiallen);
|
|
if (!mb->buf)
|
|
mb->out_of_core = errno;
|
|
}
|
|
|
|
/* Same as init_membuf but allocates the buffer in secure memory. */
|
|
void
|
|
init_membuf_secure (membuf_t *mb, int initiallen)
|
|
{
|
|
mb->len = 0;
|
|
mb->size = initiallen;
|
|
mb->out_of_core = 0;
|
|
mb->buf = xtrymalloc_secure (initiallen);
|
|
if (!mb->buf)
|
|
mb->out_of_core = errno;
|
|
}
|
|
|
|
|
|
void
|
|
put_membuf (membuf_t *mb, const void *buf, size_t len)
|
|
{
|
|
if (mb->out_of_core)
|
|
return;
|
|
|
|
if (mb->len + len >= mb->size)
|
|
{
|
|
char *p;
|
|
|
|
mb->size += len + 1024;
|
|
p = xtryrealloc (mb->buf, mb->size);
|
|
if (!p)
|
|
{
|
|
mb->out_of_core = errno ? errno : ENOMEM;
|
|
/* Wipe out what we already accumulated. This is required
|
|
in case we are storing sensitive data here. The membuf
|
|
API does not provide another way to cleanup after an
|
|
error. */
|
|
wipememory (mb->buf, mb->len);
|
|
return;
|
|
}
|
|
mb->buf = p;
|
|
}
|
|
memcpy (mb->buf + mb->len, buf, len);
|
|
mb->len += len;
|
|
}
|
|
|
|
|
|
void
|
|
put_membuf_str (membuf_t *mb, const char *string)
|
|
{
|
|
put_membuf (mb, string, strlen (string));
|
|
}
|
|
|
|
|
|
void *
|
|
get_membuf (membuf_t *mb, size_t *len)
|
|
{
|
|
char *p;
|
|
|
|
if (mb->out_of_core)
|
|
{
|
|
if (mb->buf)
|
|
{
|
|
wipememory (mb->buf, mb->len);
|
|
xfree (mb->buf);
|
|
mb->buf = NULL;
|
|
}
|
|
errno = mb->out_of_core;
|
|
return NULL;
|
|
}
|
|
|
|
p = mb->buf;
|
|
if (len)
|
|
*len = mb->len;
|
|
mb->buf = NULL;
|
|
mb->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */
|
|
return p;
|
|
}
|