Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2019 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_SECURE_H
       7             : #define BITCOIN_SUPPORT_ALLOCATORS_SECURE_H
       8             : 
       9             : #include <support/lockedpool.h>
      10             : #include <support/cleanse.h>
      11             : 
      12             : #include <string>
      13             : 
      14             : //
      15             : // Allocator that locks its contents from being paged
      16             : // out of memory and clears its contents before deletion.
      17             : //
      18             : template <typename T>
      19             : struct secure_allocator : public std::allocator<T> {
      20             :     // MSVC8 default copy constructor is broken
      21             :     typedef std::allocator<T> base;
      22             :     typedef typename base::size_type size_type;
      23             :     typedef typename base::difference_type difference_type;
      24             :     typedef typename base::pointer pointer;
      25             :     typedef typename base::const_pointer const_pointer;
      26             :     typedef typename base::reference reference;
      27             :     typedef typename base::const_reference const_reference;
      28             :     typedef typename base::value_type value_type;
      29     1184351 :     secure_allocator() noexcept {}
      30      115209 :     secure_allocator(const secure_allocator& a) noexcept : base(a) {}
      31             :     template <typename U>
      32             :     secure_allocator(const secure_allocator<U>& a) noexcept : base(a)
      33             :     {
      34             :     }
      35     1299560 :     ~secure_allocator() noexcept {}
      36             :     template <typename _Other>
      37             :     struct rebind {
      38             :         typedef secure_allocator<_Other> other;
      39             :     };
      40             : 
      41     1220163 :     T* allocate(std::size_t n, const void* hint = 0)
      42             :     {
      43     1220163 :         T* allocation = static_cast<T*>(LockedPoolManager::Instance().alloc(sizeof(T) * n));
      44     1220163 :         if (!allocation) {
      45           0 :             throw std::bad_alloc();
      46             :         }
      47     1220163 :         return allocation;
      48             :     }
      49             : 
      50     1220163 :     void deallocate(T* p, std::size_t n)
      51             :     {
      52     1220163 :         if (p != nullptr) {
      53     1220163 :             memory_cleanse(p, sizeof(T) * n);
      54     1220163 :         }
      55     1220163 :         LockedPoolManager::Instance().free(p);
      56     1220163 :     }
      57             : };
      58             : 
      59             : // This is exactly like std::string, but with a custom allocator.
      60             : typedef std::basic_string<char, std::char_traits<char>, secure_allocator<char> > SecureString;
      61             : 
      62             : #endif // BITCOIN_SUPPORT_ALLOCATORS_SECURE_H