Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2022 The Bitcoin Core developers
       3             : // Distributed under the MIT software license, see the accompanying
       4             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       5             : 
       6             : #ifndef BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
       7             : #define BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
       8             : 
       9             : #include <support/cleanse.h>
      10             : 
      11             : #include <memory>
      12             : #include <vector>
      13             : 
      14             : template <typename T>
      15             : struct zero_after_free_allocator {
      16             :     using value_type = T;
      17             : 
      18             :     zero_after_free_allocator() noexcept = default;
      19             :     template <typename U>
      20             :     zero_after_free_allocator(const zero_after_free_allocator<U>&) noexcept
      21             :     {
      22             :     }
      23             : 
      24      114257 :     T* allocate(std::size_t n)
      25             :     {
      26      114257 :         return std::allocator<T>{}.allocate(n);
      27           0 :     }
      28             : 
      29      114257 :     void deallocate(T* p, std::size_t n)
      30             :     {
      31      114257 :         if (p != nullptr)
      32      114257 :             memory_cleanse(p, sizeof(T) * n);
      33      114257 :         std::allocator<T>{}.deallocate(p, n);
      34      114257 :     }
      35             : 
      36             :     template <typename U>
      37             :     friend bool operator==(const zero_after_free_allocator&, const zero_after_free_allocator<U>&) noexcept
      38             :     {
      39             :         return true;
      40             :     }
      41             :     template <typename U>
      42             :     friend bool operator!=(const zero_after_free_allocator&, const zero_after_free_allocator<U>&) noexcept
      43             :     {
      44             :         return false;
      45             :     }
      46             : };
      47             : 
      48             : /** Byte-vector that clears its contents before deletion. */
      49             : using SerializeData = std::vector<std::byte, zero_after_free_allocator<std::byte>>;
      50             : 
      51             : #endif // BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H