mirror of https://github.com/infosecn1nja/C3.git
125 lines
3.5 KiB
C++
125 lines
3.5 KiB
C++
#pragma once
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// For SecureZeroMemory
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#ifndef NOMINMAX
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# define NOMINMAX //< Exclude min and max macros from windows.h.
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#endif
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#define WIN32_LEAN_AND_MEAN //< Exclude rarely-used stuff from Windows headers.
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#include <windows.h>
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#include <string>
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// based on https://codereview.stackexchange.com/questions/107991/hacking-a-securestring-based-on-stdbasic-string-for-c
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namespace FSecure
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{
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/// Minimal allocator zeroing on deallocation
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/// @tparam T type to allocate
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template <typename T>
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struct SecureAllocator
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{
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using value_type = T;
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using propagate_on_container_move_assignment = typename std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment;
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/// Default constructor
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constexpr SecureAllocator() = default;
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/// Defaulted copy constructor
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/// @param other SecureAllocator
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constexpr SecureAllocator(const SecureAllocator&) = default;
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/// Other type constructor
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/// @tparam U - different type
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/// @param other SecureAllocator
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template <class U>
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constexpr SecureAllocator(const SecureAllocator<U>&) noexcept
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{
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}
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/// Allocate memory for n T objects
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/// @param n - count of T objects to allocate
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/// @returns pointer to allocated memory
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static T* allocate(std::size_t n)
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{
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return std::allocator<T>{}.allocate(n);
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}
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/// Clear and deallocate memory for n T objects
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/// @param p - memory pointer
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/// @param n - count of T objects to deallocate
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static void deallocate(T* p, std::size_t n) noexcept
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{
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SecureZeroMemory(p, n * sizeof * p);
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std::allocator<T>{}.deallocate(p, n);
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}
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};
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/// Equality operator
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/// @returns true
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template <typename T, typename U>
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constexpr bool operator== (const SecureAllocator<T>&, const SecureAllocator<U>&) noexcept
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{
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return true;
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}
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/// Inequality operator
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/// @returns false
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template <typename T, typename U>
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constexpr bool operator!= (const SecureAllocator<T>&, const SecureAllocator<U>&) noexcept
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{
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return false;
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}
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template<typename CharT>
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using BasicSecureString = std::basic_string<CharT, std::char_traits<CharT>, SecureAllocator<CharT>>;
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/// alias for string with SecureAllocator
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using SecureString = BasicSecureString<char>;
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/// alias for wstring with SecureAllocator
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using SecureWString = BasicSecureString<wchar_t>;
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}
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namespace std
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{
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/// Specialized SecureString destructor.
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/// Overwrites internal buffer (if SSO is in effect)
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template<>
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inline basic_string<char, std::char_traits<char>, FSecure::SecureAllocator<char>>::~basic_string() noexcept
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{
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// Clear internal buffer if SSO is in effect
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#if _MSC_VER >= 1920 // v142 toolset
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auto& _My_data = _Mypair._Myval2;
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#elif _MSC_VER >= 1910 // v141 toolset
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auto& _My_data = this->_Get_data();
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#elif
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#error Unsupported toolset
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#endif
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if (!_My_data._Large_string_engaged())
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SecureZeroMemory(_My_data._Bx._Buf, sizeof _My_data._Bx._Buf);
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// This is a copy of basic_string dtor
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_Tidy_deallocate();
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}
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/// Specialized SecureWString destructor.
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/// Overwrites internal buffer (if SSO is in effect)
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template<>
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inline basic_string<wchar_t, std::char_traits<wchar_t>, FSecure::SecureAllocator<wchar_t>>::~basic_string() noexcept
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{
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// Clear internal buffer if SSO is in effect
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#if _MSC_VER >= 1920 // v142 toolset
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auto& _My_data = _Mypair._Myval2;
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#elif _MSC_VER >= 1910 // v141 toolset
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auto& _My_data = this->_Get_data();
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#elif
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#error Unsupported toolset
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#endif
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if (!_My_data._Large_string_engaged())
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SecureZeroMemory(_My_data._Bx._Buf, sizeof _My_data._Bx._Buf);
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// This is a copy of basic_string dtor
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_Tidy_deallocate();
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}
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}
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