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-rw-r--r--src/allocators.h119
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diff --git a/src/allocators.h b/src/allocators.h
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+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2012 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+#ifndef BITCOIN_ALLOCATORS_H
+#define BITCOIN_ALLOCATORS_H
+
+#include <string>
+
+#ifdef WIN32
+#define _WIN32_WINNT 0x0501
+#define WIN32_LEAN_AND_MEAN 1
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#include <windows.h>
+// 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>
+#include <limits.h>
+/* This comes from limits.h if it's not defined there set a sane default */
+#ifndef PAGESIZE
+#include <unistd.h>
+#define PAGESIZE sysconf(_SC_PAGESIZE)
+#endif
+#define mlock(a,b) \
+ mlock(((void *)(((size_t)(a)) & (~((PAGESIZE)-1)))),\
+ (((((size_t)(a)) + (b) - 1) | ((PAGESIZE) - 1)) + 1) - (((size_t)(a)) & (~((PAGESIZE) - 1))))
+#define munlock(a,b) \
+ munlock(((void *)(((size_t)(a)) & (~((PAGESIZE)-1)))),\
+ (((((size_t)(a)) + (b) - 1) | ((PAGESIZE) - 1)) + 1) - (((size_t)(a)) & (~((PAGESIZE) - 1))))
+#endif
+
+//
+// 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>
+{
+ // MSVC8 default copy constructor is broken
+ typedef std::allocator<T> base;
+ typedef typename base::size_type size_type;
+ typedef typename base::difference_type difference_type;
+ typedef typename base::pointer pointer;
+ typedef typename base::const_pointer const_pointer;
+ typedef typename base::reference reference;
+ typedef typename base::const_reference const_reference;
+ typedef typename base::value_type value_type;
+ secure_allocator() throw() {}
+ secure_allocator(const secure_allocator& a) throw() : base(a) {}
+ template <typename U>
+ secure_allocator(const secure_allocator<U>& a) throw() : base(a) {}
+ ~secure_allocator() throw() {}
+ 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);
+ }
+};
+
+
+//
+// Allocator that clears its contents before deletion.
+//
+template<typename T>
+struct zero_after_free_allocator : public std::allocator<T>
+{
+ // MSVC8 default copy constructor is broken
+ typedef std::allocator<T> base;
+ typedef typename base::size_type size_type;
+ typedef typename base::difference_type difference_type;
+ typedef typename base::pointer pointer;
+ typedef typename base::const_pointer const_pointer;
+ typedef typename base::reference reference;
+ typedef typename base::const_reference const_reference;
+ typedef typename base::value_type value_type;
+ zero_after_free_allocator() throw() {}
+ zero_after_free_allocator(const zero_after_free_allocator& a) throw() : base(a) {}
+ template <typename U>
+ zero_after_free_allocator(const zero_after_free_allocator<U>& a) throw() : base(a) {}
+ ~zero_after_free_allocator() throw() {}
+ template<typename _Other> struct rebind
+ { typedef zero_after_free_allocator<_Other> other; };
+
+ void deallocate(T* p, std::size_t n)
+ {
+ if (p != NULL)
+ memset(p, 0, sizeof(T) * n);
+ std::allocator<T>::deallocate(p, n);
+ }
+};
+
+// This is exactly like std::string, but with a custom allocator.
+// (secure_allocator<> is defined in serialize.h)
+typedef std::basic_string<char, std::char_traits<char>, secure_allocator<char> > SecureString;
+
+#endif