mlock() all private keys in memory

Inline comment and idea come from the encprivkeys branch
by Matt Corallo <matt@bluematt.me>.
This commit is contained in:
Dylan Noblesmith 2011-06-24 03:03:17 +00:00 committed by Matt Corallo
parent acd6501610
commit c1aacf0be3

View file

@ -28,6 +28,18 @@ typedef unsigned long long uint64;
#if defined(_MSC_VER) && _MSC_VER < 1300
#define for if (false) ; else for
#endif
#ifdef __WXMSW__
// This is used to attempt to keep keying material out of swap
// Note that VirtualLock does not provide this as a guarantee on Windows,
// but, in practice, memory that has been VirtualLock'd almost never gets written to
// the pagefile except in rare circumstances where memory is extremely low.
#define mlock(p, n) VirtualLock((p), (n));
#define munlock(p, n) VirtualUnlock((p), (n));
#else
#include <sys/mman.h>
#endif
class CScript;
class CDataStream;
class CAutoFile;
@ -755,7 +767,8 @@ struct ser_streamplaceholder
//
// Allocator that clears its contents before deletion
// Allocator that locks its contents from being paged
// out of memory and clears its contents before deletion.
//
template<typename T>
struct secure_allocator : public std::allocator<T>
@ -777,10 +790,22 @@ struct secure_allocator : public std::allocator<T>
template<typename _Other> struct rebind
{ typedef secure_allocator<_Other> other; };
T* allocate(std::size_t n, const void *hint = 0)
{
T *p;
p = std::allocator<T>::allocate(n, hint);
if (p != NULL)
mlock(p, sizeof(T) * n);
return p;
}
void deallocate(T* p, std::size_t n)
{
if (p != NULL)
{
memset(p, 0, sizeof(T) * n);
munlock(p, sizeof(T) * n);
}
std::allocator<T>::deallocate(p, n);
}
};