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#include "ruby/missing.h"
#include <string.h>
#ifdef _WIN32
#include <windows.h>
#endif
/*
*BSD have explicit_bzero().
Windows, OS-X have memset_s().
Linux has none. *Sigh*
*/
/*
* Following URL explain why memset_s is added to the standard.
* http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1381.pdf
*/
#ifndef FUNC_UNOPTIMIZED
# define FUNC_UNOPTIMIZED(x) x
#endif
#ifndef HAVE_EXPLICIT_BZERO
/* Similar to bzero(), but have a guarantee not to be eliminated from compiler
optimization. */
#ifndef HAVE_MEMSET_S
FUNC_UNOPTIMIZED(void explicit_bzero(void *b, size_t len));
#endif
#undef explicit_bzero
void
explicit_bzero(void *b, size_t len)
{
#ifdef HAVE_MEMSET_S
memset_s(b, len, 0, len);
#elif defined SecureZeroMemory
SecureZeroMemory(b, len);
#else
{
/*
* TODO: volatile is not enough if compiler have a LTO (link time
* optimization)
*/
volatile char* p = (volatile char*)b;
while(len) {
*p = 0;
p++;
len--;
}
}
#endif
}
#endif
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