Bitcoin Core  0.18.99
P2P Digital Currency
secure.h
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2018 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  secure_allocator() noexcept {}
30  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  ~secure_allocator() noexcept {}
36  template <typename _Other>
37  struct rebind {
39  };
40 
41  T* allocate(std::size_t n, const void* hint = 0)
42  {
43  T* allocation = static_cast<T*>(LockedPoolManager::Instance().alloc(sizeof(T) * n));
44  if (!allocation) {
45  throw std::bad_alloc();
46  }
47  return allocation;
48  }
49 
50  void deallocate(T* p, std::size_t n)
51  {
52  if (p != nullptr) {
53  memory_cleanse(p, sizeof(T) * n);
54  }
56  }
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
base::const_reference const_reference
Definition: secure.h:27
base::pointer pointer
Definition: secure.h:24
static LockedPoolManager & Instance()
Return the current instance, or create it once.
Definition: lockedpool.h:222
base::size_type size_type
Definition: secure.h:22
std::basic_string< char, std::char_traits< char >, secure_allocator< char > > SecureString
Definition: secure.h:60
base::value_type value_type
Definition: secure.h:28
secure_allocator< _Other > other
Definition: secure.h:38
secure_allocator() noexcept
Definition: secure.h:29
void memory_cleanse(void *ptr, size_t len)
Secure overwrite a buffer (possibly containing secret data) with zero-bytes.
Definition: cleanse.cpp:14
void * alloc(size_t size)
Allocate size bytes from this arena.
Definition: lockedpool.cpp:287
secure_allocator(const secure_allocator &a) noexcept
Definition: secure.h:30
base::reference reference
Definition: secure.h:26
std::allocator< T > base
Definition: secure.h:21
base::const_pointer const_pointer
Definition: secure.h:25
void free(void *ptr)
Free a previously allocated chunk of memory.
Definition: lockedpool.cpp:309
secure_allocator(const secure_allocator< U > &a) noexcept
Definition: secure.h:32
T * allocate(std::size_t n, const void *hint=0)
Definition: secure.h:41
base::difference_type difference_type
Definition: secure.h:23
void deallocate(T *p, std::size_t n)
Definition: secure.h:50
~secure_allocator() noexcept
Definition: secure.h:35