allocator.h

Author: dawesc

Diff for: include/json/allocator.h

@@ -0,0 +1,94 @@
+// Copyright 2007-2010 Baptiste Lepilleur
+// Distributed under MIT license, or public domain if desired and
+// recognized in your jurisdiction.
+// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
+
+#ifndef CPPTL_JSON_ALLOCATOR_H_INCLUDED
+#define CPPTL_JSON_ALLOCATOR_H_INCLUDED
+
+#include <cstring>
+#include <memory>
+
+namespace Json {
+template<typename T>
+class SecureAllocator {
+	public:
+		// Type definitions
+		using value_type      = T;
+		using pointer         = T*;
+		using const_pointer   = const T*;
+		using reference       = T&;
+		using const_reference = const T&;
+		using size_type       = std::size_t;
+		using difference_type = std::ptrdiff_t;
+
+		/**
+		 * Allocate memory for N items using the standard allocator.
+		 */
+		pointer allocate(size_type n) {
+			// allocate using "global operator new"
+			return static_cast<pointer>(::operator new(n * sizeof(T)));
+		}
+
+		/**
+		 * Release memory which was allocated for N items at pointer P.
+		 *
+		 * The memory block is filled with zeroes before being released.
+		 * The pointer argument is tagged as "volatile" to prevent the
+		 * compiler optimizing out this critical step.
+		 */
+		void deallocate(volatile pointer p, size_type n) {
+			std::memset(p, 0, n * sizeof(T));
+			// free using "global operator delete"
+			::operator delete(p);
+		}
+
+		/**
+		 * Construct an item in-place at pointer P.
+		 */
+		template<typename... Args>
+		void construct(pointer p, Args&&... args) {
+			// construct using "placement new" and "perfect forwarding"
+			::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
+		}
+
+		size_type max_size() const {
+			return size_t(-1) / sizeof(T);
+		}
+
+		pointer address( reference x ) const {
+			return std::addressof(x);
+		}
+
+		const_pointer address( const_reference x ) const {
+			return std::addressof(x);
+		}
+
+		/**
+		 * Destroy an item in-place at pointer P.
+		 */
+		void destroy(pointer p) {
+			// destroy using "explicit destructor"
+			p->~T();
+		}
+
+		// Boilerplate
+		SecureAllocator() {}
+		template<typename U> SecureAllocator(const SecureAllocator<U>&) {}
+		template<typename U> struct rebind { using other = SecureAllocator<U>; };
+};
+
+
+template<typename T, typename U>
+bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+	return true;
+}
+
+template<typename T, typename U>
+bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+	return false;
+}
+
+} //namespace Json
+
+#endif // CPPTL_JSON_ALLOCATOR_H_INCLUDED

Diff for: include/json/config.h

@@ -119,6 +119,16 @@
 #  define JSON_USE_INT64_DOUBLE_CONVERSION 1
 #endif
 
+// If non-zero, the library zeroes any memory that it has allocated before
+// it frees its
+#ifndef JSON_USE_SECURE_MEMORY
+#define JSON_USE_SECURE_MEMORY 0
+#endif
+
+#if JSON_USE_SECURE_MEMORY
+#include "allocator.h" //typedef Allocator
+#endif
+
 namespace Json {
 typedef int Int;
 typedef unsigned int UInt;
@@ -139,11 +149,19 @@ typedef Int64 LargestInt;
 typedef UInt64 LargestUInt;
 #define JSON_HAS_INT64
 #endif // if defined(JSON_NO_INT64)
+#if JSON_USE_SECURE_MEMORY
+#define JSONCPP_STRING        std::basic_string<char, std::char_traits<char>, SecureAllocator<char> >
+#define JSONCPP_OSTRINGSTREAM std::basic_ostringstream<char, std::char_traits<char>, SecureAllocator<char> >
+#define JSONCPP_OSTREAM       std::basic_ostream<char, std::char_traits<char>>
+#define JSONCPP_ISTRINGSTREAM std::basic_istringstream<char, std::char_traits<char>, SecureAllocator<char> >
+#define JSONCPP_ISTREAM       std::istream
+#else
 #define JSONCPP_STRING        std::string
 #define JSONCPP_OSTRINGSTREAM std::ostringstream
 #define JSONCPP_OSTREAM       std::ostream
 #define JSONCPP_ISTRINGSTREAM std::istringstream
 #define JSONCPP_ISTREAM       std::istream
+#endif // if JSON_USE_SECURE_MEMORY
 } // end namespace Json
 
 #endif // JSON_CONFIG_H_INCLUDED