File: [local] / src / usr.bin / sudo / Attic / zero_bytes.c (download)
Revision 1.1, Mon Jan 5 00:23:57 2004 UTC (20 years, 5 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_3_6_BASE, OPENBSD_3_6, OPENBSD_3_5_BASE, OPENBSD_3_5
Get rid of volatile variables that were a vain attempt to prevent the
compiler from optimizing away memset() calls. Instead, add a new function,
zero_bytes(), to clear buffers with sensitive contents.
Taken from the sudo cvs repo, man.
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/*
* Copyright (c) 1999, 2001 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 4. Products derived from this software may not be called "Sudo" nor
* may "Sudo" appear in their names without specific prior written
* permission from the author.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include "config.h"
#ifndef lint
static const char rcsid[] = "$Sudo: zero_bytes.c,v 1.1 2003/12/31 22:46:08 millert Exp $";
#endif /* lint */
/*
* Like bzero(3) but with a volatile pointer. The hope is that
* the compiler will not be able to optimize away this function.
*/
void
zero_bytes(v, n)
volatile VOID *v;
size_t n;
{
volatile char *p, *ep;
for (p = v, ep = p + n; p < ep; p++)
*p = 0;
return;
}