Crypto++  5.6.4
Free C++ class library of cryptographic schemes
secblock.h
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1 // secblock.h - written and placed in the public domain by Wei Dai
2 
3 //! \file secblock.h
4 //! \brief Classes and functions for secure memory allocations.
5 
6 #ifndef CRYPTOPP_SECBLOCK_H
7 #define CRYPTOPP_SECBLOCK_H
8 
9 #include "config.h"
10 #include "stdcpp.h"
11 #include "misc.h"
12 
13 #if CRYPTOPP_MSC_VERSION
14 # pragma warning(push)
15 # pragma warning(disable: 4700)
16 # if (CRYPTOPP_MSC_VERSION >= 1400)
17 # pragma warning(disable: 6386)
18 # endif
19 #endif
20 
21 NAMESPACE_BEGIN(CryptoPP)
22 
23 // ************** secure memory allocation ***************
24 
25 //! \class AllocatorBase
26 //! \brief Base class for all allocators used by SecBlock
27 //! \tparam T the class or type
28 template<class T>
30 {
31 public:
32  typedef T value_type;
33  typedef size_t size_type;
34 #ifdef CRYPTOPP_MSVCRT6
35  typedef ptrdiff_t difference_type;
36 #else
37  typedef std::ptrdiff_t difference_type;
38 #endif
39  typedef T * pointer;
40  typedef const T * const_pointer;
41  typedef T & reference;
42  typedef const T & const_reference;
43 
44  pointer address(reference r) const {return (&r);}
45  const_pointer address(const_reference r) const {return (&r); }
46  void construct(pointer p, const T& val) {new (p) T(val);}
47  void destroy(pointer p) {CRYPTOPP_UNUSED(p); p->~T();}
48 
49  //! \brief Returns the maximum number of elements the allocator can provide
50  //! \returns the maximum number of elements the allocator can provide
51  //! \details Internally, preprocessor macros are used rather than std::numeric_limits
52  //! because the latter is \a not a \a constexpr. Some compilers, like Clang, do not
53  //! optimize it well under all circumstances. Compilers like GCC, ICC and MSVC appear
54  //! to optimize it well in either form.
55  CRYPTOPP_CONSTEXPR size_type max_size() const {return (SIZE_MAX/sizeof(T));}
56 
57 #if defined(CRYPTOPP_CXX11_VARIADIC_TEMPLATES) || defined(CRYPTOPP_DOXYGEN_PROCESSING)
58 
59  //! \brief Constructs a new U using variadic arguments
60  //! \tparam U the type to be forwarded
61  //! \tparam Args the arguments to be forwarded
62  //! \param ptr pointer to type U
63  //! \param args variadic arguments
64  //! \details This is a C++11 feature. It is available when CRYPTOPP_CXX11_VARIADIC_TEMPLATES
65  //! is defined. The define is controlled by compiler versions detected in config.h.
66  template<typename U, typename... Args>
67  void construct(U* ptr, Args&&... args) {::new ((void*)ptr) U(std::forward<Args>(args)...);}
68 
69  //! \brief Destroys an U constructed with variadic arguments
70  //! \tparam U the type to be forwarded
71  //! \details This is a C++11 feature. It is available when CRYPTOPP_CXX11_VARIADIC_TEMPLATES
72  //! is defined. The define is controlled by compiler versions detected in config.h.
73  template<typename U>
74  void destroy(U* ptr) {if(ptr) ptr->~U();}
75 
76 #endif
77 
78 protected:
79 
80  //! \brief Verifies the allocator can satisfy a request based on size
81  //! \param size the size of the allocation, in elements
82  //! \throws InvalidArgument
83  //! \details CheckSize verifies the number of elements requested is valid.
84  //! \details If size is greater than max_size(), then InvalidArgument is thrown.
85  //! The library throws InvalidArgument if the size is too large to satisfy.
86  //! \details Internally, preprocessor macros are used rather than std::numeric_limits
87  //! because the latter is \a not a \a constexpr. Some compilers, like Clang, do not
88  //! optimize it well under all circumstances. Compilers like GCC, ICC and MSVC appear
89  //! to optimize it well in either form.
90  //! \note size is the count of elements, and not the number of bytes
91  static void CheckSize(size_t size)
92  {
93  // C++ throws std::bad_alloc (C++03) or std::bad_array_new_length (C++11) here.
94  if (size > (SIZE_MAX/sizeof(T)))
95  throw InvalidArgument("AllocatorBase: requested size would cause integer overflow");
96  }
97 };
98 
99 #define CRYPTOPP_INHERIT_ALLOCATOR_TYPES \
100 typedef typename AllocatorBase<T>::value_type value_type;\
101 typedef typename AllocatorBase<T>::size_type size_type;\
102 typedef typename AllocatorBase<T>::difference_type difference_type;\
103 typedef typename AllocatorBase<T>::pointer pointer;\
104 typedef typename AllocatorBase<T>::const_pointer const_pointer;\
105 typedef typename AllocatorBase<T>::reference reference;\
106 typedef typename AllocatorBase<T>::const_reference const_reference;
107 
108 //! \brief Reallocation function
109 //! \tparam T the class or type
110 //! \tparam A the class or type's allocator
111 //! \param alloc the allocator
112 //! \param oldPtr the previous allocation
113 //! \param oldSize the size of the previous allocation
114 //! \param newSize the new, requested size
115 //! \param preserve flag that indicates if the old allocation should be preserved
116 //! \note oldSize and newSize are the count of elements, and not the
117 //! number of bytes.
118 template <class T, class A>
119 typename A::pointer StandardReallocate(A& alloc, T *oldPtr, typename A::size_type oldSize, typename A::size_type newSize, bool preserve)
120 {
121  CRYPTOPP_ASSERT((oldPtr && oldSize) || !(oldPtr || oldSize));
122  if (oldSize == newSize)
123  return oldPtr;
124 
125  if (preserve)
126  {
127  typename A::pointer newPointer = alloc.allocate(newSize, NULL);
128  const size_t copySize = STDMIN(oldSize, newSize) * sizeof(T);
129 
130  if (oldPtr && newPointer) {memcpy_s(newPointer, copySize, oldPtr, copySize);}
131  alloc.deallocate(oldPtr, oldSize);
132  return newPointer;
133  }
134  else
135  {
136  alloc.deallocate(oldPtr, oldSize);
137  return alloc.allocate(newSize, NULL);
138  }
139 }
140 
141 //! \class AllocatorWithCleanup
142 //! \brief Allocates a block of memory with cleanup
143 //! \tparam T class or type
144 //! \tparam T_Align16 boolean that determines whether allocations should be aligned on 16-byte boundaries
145 //! \details If T_Align16 is true, then AllocatorWithCleanup calls AlignedAllocate()
146 //! for memory allocations. If T_Align16 is false, then AllocatorWithCleanup() calls
147 //! UnalignedAllocate() for memory allocations.
148 //! \details Template parameter T_Align16 is effectively controlled by cryptlib.h and mirrors
149 //! CRYPTOPP_BOOL_ALIGN16. CRYPTOPP_BOOL_ALIGN16 is often used as the template parameter.
150 template <class T, bool T_Align16 = false>
151 class AllocatorWithCleanup : public AllocatorBase<T>
152 {
153 public:
154  CRYPTOPP_INHERIT_ALLOCATOR_TYPES
155 
156  //! \brief Allocates a block of memory
157  //! \param ptr the size of the allocation
158  //! \param size the size of the allocation, in elements
159  //! \returns a memory block
160  //! \throws InvalidArgument
161  //! \details allocate() first checks the size of the request. If it is non-0
162  //! and less than max_size(), then an attempt is made to fulfill the request using either
163  //! AlignedAllocate() or UnalignedAllocate().
164  //! \details AlignedAllocate() is used if T_Align16 is true.
165  //! UnalignedAllocate() used if T_Align16 is false.
166  //! \details This is the C++ *Placement New* operator. ptr is not used, and the function
167  //! CRYPTOPP_ASSERTs in Debug builds if ptr is non-NULL.
168  //! \sa CallNewHandler() for the methods used to recover from a failed
169  //! allocation attempt.
170  //! \note size is the count of elements, and not the number of bytes
171  pointer allocate(size_type size, const void *ptr = NULL)
172  {
173  CRYPTOPP_UNUSED(ptr); CRYPTOPP_ASSERT(ptr == NULL);
174  this->CheckSize(size);
175  if (size == 0)
176  return NULL;
177 
178 #if CRYPTOPP_BOOL_ALIGN16
179  // TODO: should this need the test 'size*sizeof(T) >= 16'?
180  if (T_Align16 && size*sizeof(T) >= 16)
181  return (pointer)AlignedAllocate(size*sizeof(T));
182 #endif
183 
184  return (pointer)UnalignedAllocate(size*sizeof(T));
185  }
186 
187  //! \brief Deallocates a block of memory
188  //! \param ptr the pointer for the allocation
189  //! \param size the size of the allocation, in elements
190  //! \details Internally, SecureWipeArray() is called before deallocating the memory.
191  //! Once the memory block is wiped or zeroized, AlignedDeallocate() or
192  //! UnalignedDeallocate() is called.
193  //! \details AlignedDeallocate() is used if T_Align16 is true.
194  //! UnalignedDeallocate() used if T_Align16 is false.
195  void deallocate(void *ptr, size_type size)
196  {
197  CRYPTOPP_ASSERT((ptr && size) || !(ptr || size));
198  SecureWipeArray((pointer)ptr, size);
199 
200 #if CRYPTOPP_BOOL_ALIGN16
201  if (T_Align16 && size*sizeof(T) >= 16)
202  return AlignedDeallocate(ptr);
203 #endif
204 
205  UnalignedDeallocate(ptr);
206  }
207 
208  //! \brief Reallocates a block of memory
209  //! \param oldPtr the previous allocation
210  //! \param oldSize the size of the previous allocation
211  //! \param newSize the new, requested size
212  //! \param preserve flag that indicates if the old allocation should be preserved
213  //! \returns pointer to the new memory block
214  //! \details Internally, reallocate() calls StandardReallocate().
215  //! \details If preserve is true, then index 0 is used to begin copying the
216  //! old memory block to the new one. If the block grows, then the old array
217  //! is copied in its entirety. If the block shrinks, then only newSize
218  //! elements are copied from the old block to the new one.
219  //! \note oldSize and newSize are the count of elements, and not the
220  //! number of bytes.
221  pointer reallocate(T *oldPtr, size_type oldSize, size_type newSize, bool preserve)
222  {
223  CRYPTOPP_ASSERT((oldPtr && oldSize) || !(oldPtr || oldSize));
224  return StandardReallocate(*this, oldPtr, oldSize, newSize, preserve);
225  }
226 
227  //! \brief Template class memeber Rebind
228  //! \tparam T allocated class or type
229  //! \tparam T_Align16 boolean that determines whether allocations should be aligned on 16-byte boundaries
230  //! \tparam U bound class or type
231  //! \details Rebind allows a container class to allocate a different type of object
232  //! to store elements. For example, a std::list will allocate std::list_node to
233  //! store elements in the list.
234  //! \details VS.NET STL enforces the policy of "All STL-compliant allocators
235  //! have to provide a template class member called rebind".
236  template <class U> struct rebind { typedef AllocatorWithCleanup<U, T_Align16> other; };
237 #if _MSC_VER >= 1500
239  template <class U, bool A> AllocatorWithCleanup(const AllocatorWithCleanup<U, A> &) {}
240 #endif
241 };
242 
243 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<byte>;
244 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<word16>;
245 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<word32>;
246 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<word64>;
247 #if defined(CRYPTOPP_WORD128_AVAILABLE)
248 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<word128, true>; // for Integer
249 #endif
250 #if CRYPTOPP_BOOL_X86
251 CRYPTOPP_DLL_TEMPLATE_CLASS AllocatorWithCleanup<word, true>; // for Integer
252 #endif
253 
254 //! \class NullAllocator
255 //! \brief NULL allocator
256 //! \tparam T class or type
257 //! \details A NullAllocator is useful for fixed-size, stack based allocations
258 //! (i.e., static arrays used by FixedSizeAllocatorWithCleanup).
259 //! \details A NullAllocator always returns 0 for max_size(), and always returns
260 //! NULL for allocation requests. Though the allocator does not allocate at
261 //! runtime, it does perform a secure wipe or zeroization during cleanup.
262 template <class T>
263 class NullAllocator : public AllocatorBase<T>
264 {
265 public:
266  //LCOV_EXCL_START
267  CRYPTOPP_INHERIT_ALLOCATOR_TYPES
268 
269  // TODO: should this return NULL or throw bad_alloc? Non-Windows C++ standard
270  // libraries always throw. And late mode Windows throws. Early model Windows
271  // (circa VC++ 6.0) returned NULL.
272  pointer allocate(size_type n, const void* unused = NULL)
273  {
274  CRYPTOPP_UNUSED(n); CRYPTOPP_UNUSED(unused);
275  CRYPTOPP_ASSERT(false); return NULL;
276  }
277 
278  void deallocate(void *p, size_type n)
279  {
280  CRYPTOPP_UNUSED(p); CRYPTOPP_UNUSED(n);
281  CRYPTOPP_ASSERT(false);
282  }
283 
284  CRYPTOPP_CONSTEXPR size_type max_size() const {return 0;}
285  //LCOV_EXCL_STOP
286 };
287 
288 //! \class FixedSizeAllocatorWithCleanup
289 //! \brief Static secure memory block with cleanup
290 //! \tparam T class or type
291 //! \tparam S fixed-size of the stack-based memory block, in elements
292 //! \tparam A AllocatorBase derived class for allocation and cleanup
293 //! \details FixedSizeAllocatorWithCleanup provides a fixed-size, stack-
294 //! based allocation at compile time. The class can grow its memory
295 //! block at runtime if a suitable allocator is available. If size
296 //! grows beyond S and a suitable allocator is available, then the
297 //! statically allocated array is obsoleted.
298 //! \note This allocator can't be used with standard collections because
299 //! they require that all objects of the same allocator type are equivalent.
300 template <class T, size_t S, class A = NullAllocator<T>, bool T_Align16 = false>
301 class FixedSizeAllocatorWithCleanup : public AllocatorBase<T>
302 {
303 public:
304  CRYPTOPP_INHERIT_ALLOCATOR_TYPES
305 
306  //! \brief Constructs a FixedSizeAllocatorWithCleanup
307  FixedSizeAllocatorWithCleanup() : m_allocated(false) {}
308 
309  //! \brief Allocates a block of memory
310  //! \param size size of the memory block, in elements
311  //! \details FixedSizeAllocatorWithCleanup provides a fixed-size, stack-based
312  //! allocation at compile time. If size is less than or equal to
313  //! <tt>S</tt>, then a pointer to the static array is returned.
314  //! \details The class can grow its memory block at runtime if a suitable
315  //! allocator is available. If size grows beyond S and a suitable
316  //! allocator is available, then the statically allocated array is
317  //! obsoleted. If a suitable allocator is \a not available, as with a
318  //! NullAllocator, then the function returns NULL and a runtime error
319  //! eventually occurs.
320  //! \sa reallocate(), SecBlockWithHint
321  pointer allocate(size_type size)
322  {
323  CRYPTOPP_ASSERT(IsAlignedOn(m_array, 8));
324 
325  if (size <= S && !m_allocated)
326  {
327  m_allocated = true;
328  return GetAlignedArray();
329  }
330  else
331  return m_fallbackAllocator.allocate(size);
332  }
333 
334  //! \brief Allocates a block of memory
335  //! \param size size of the memory block, in elements
336  //! \param hint an unused hint
337  //! \details FixedSizeAllocatorWithCleanup provides a fixed-size, stack-
338  //! based allocation at compile time. If size is less than or equal to
339  //! S, then a pointer to the static array is returned.
340  //! \details The class can grow its memory block at runtime if a suitable
341  //! allocator is available. If size grows beyond S and a suitable
342  //! allocator is available, then the statically allocated array is
343  //! obsoleted. If a suitable allocator is \a not available, as with a
344  //! NullAllocator, then the function returns NULL and a runtime error
345  //! eventually occurs.
346  //! \sa reallocate(), SecBlockWithHint
347  pointer allocate(size_type size, const void *hint)
348  {
349  if (size <= S && !m_allocated)
350  {
351  m_allocated = true;
352  return GetAlignedArray();
353  }
354  else
355  return m_fallbackAllocator.allocate(size, hint);
356  }
357 
358  //! \brief Deallocates a block of memory
359  //! \param ptr a pointer to the memory block to deallocate
360  //! \param size size of the memory block, in elements
361  //! \details The memory block is wiped or zeroized before deallocation.
362  //! If the statically allocated memory block is active, then no
363  //! additional actions are taken after the wipe.
364  //! \details If a dynamic memory block is active, then the pointer and
365  //! size are passed to the allocator for deallocation.
366  void deallocate(void *ptr, size_type size)
367  {
368  if (ptr == GetAlignedArray())
369  {
370  CRYPTOPP_ASSERT(size <= S);
371  CRYPTOPP_ASSERT(m_allocated);
372  m_allocated = false;
373  SecureWipeArray((pointer)ptr, size);
374  }
375  else
376  m_fallbackAllocator.deallocate(ptr, size);
377  }
378 
379  //! \brief Reallocates a block of memory
380  //! \param oldPtr the previous allocation
381  //! \param oldSize the size of the previous allocation
382  //! \param newSize the new, requested size
383  //! \param preserve flag that indicates if the old allocation should be preserved
384  //! \returns pointer to the new memory block
385  //! \details FixedSizeAllocatorWithCleanup provides a fixed-size, stack-
386  //! based allocation at compile time. If size is less than or equal to
387  //! S, then a pointer to the static array is returned.
388  //! \details The class can grow its memory block at runtime if a suitable
389  //! allocator is available. If size grows beyond S and a suitable
390  //! allocator is available, then the statically allocated array is
391  //! obsoleted. If a suitable allocator is \a not available, as with a
392  //! NullAllocator, then the function returns NULL and a runtime error
393  //! eventually occurs.
394  //! \note size is the count of elements, and not the number of bytes.
395  //! \sa reallocate(), SecBlockWithHint
396  pointer reallocate(pointer oldPtr, size_type oldSize, size_type newSize, bool preserve)
397  {
398  if (oldPtr == GetAlignedArray() && newSize <= S)
399  {
400  CRYPTOPP_ASSERT(oldSize <= S);
401  if (oldSize > newSize)
402  SecureWipeArray(oldPtr+newSize, oldSize-newSize);
403  return oldPtr;
404  }
405 
406  pointer newPointer = allocate(newSize, NULL);
407  if (preserve && newSize)
408  {
409  const size_t copySize = STDMIN(oldSize, newSize);
410  memcpy_s(newPointer, sizeof(T)*newSize, oldPtr, sizeof(T)*copySize);
411  }
412  deallocate(oldPtr, oldSize);
413  return newPointer;
414  }
415 
416  CRYPTOPP_CONSTEXPR size_type max_size() const {return STDMAX(m_fallbackAllocator.max_size(), S);}
417 
418 private:
419 
420 #ifdef __BORLANDC__
421  T* GetAlignedArray() {return m_array;}
422  T m_array[S];
423 #else
424  T* GetAlignedArray() {return (CRYPTOPP_BOOL_ALIGN16 && T_Align16) ? (T*)(void *)(((byte *)m_array) + (0-(size_t)m_array)%16) : m_array;}
425  CRYPTOPP_ALIGN_DATA(8) T m_array[(CRYPTOPP_BOOL_ALIGN16 && T_Align16) ? S+8/sizeof(T) : S];
426 #endif
427 
428  A m_fallbackAllocator;
429  bool m_allocated;
430 };
431 
432 //! \class SecBlock
433 //! \brief Secure memory block with allocator and cleanup
434 //! \tparam T a class or type
435 //! \tparam A AllocatorWithCleanup derived class for allocation and cleanup
436 template <class T, class A = AllocatorWithCleanup<T> >
437 class SecBlock
438 {
439 public:
440  typedef typename A::value_type value_type;
441  typedef typename A::pointer iterator;
442  typedef typename A::const_pointer const_iterator;
443  typedef typename A::size_type size_type;
444 
445  //! \brief Construct a SecBlock with space for size elements.
446  //! \param size the size of the allocation, in elements
447  //! \throws std::bad_alloc
448  //! \details The elements are not initialized.
449  //! \note size is the count of elements, and not the number of bytes
450  explicit SecBlock(size_type size=0)
451  : m_size(size), m_ptr(m_alloc.allocate(size, NULL)) { }
452 
453  //! \brief Copy construct a SecBlock from another SecBlock
454  //! \param t the other SecBlock
455  //! \throws std::bad_alloc
457  : m_size(t.m_size), m_ptr(m_alloc.allocate(t.m_size, NULL)) {
458  CRYPTOPP_ASSERT((!t.m_ptr && !m_size) || (t.m_ptr && m_size));
459  if (t.m_ptr) {memcpy_s(m_ptr, m_size*sizeof(T), t.m_ptr, t.m_size*sizeof(T));}
460  }
461 
462  //! \brief Construct a SecBlock from an array of elements.
463  //! \param ptr a pointer to an array of T
464  //! \param len the number of elements in the memory block
465  //! \throws std::bad_alloc
466  //! \details If <tt>ptr!=NULL</tt> and <tt>len!=0</tt>, then the block is initialized from the pointer ptr.
467  //! If <tt>ptr==NULL</tt> and <tt>len!=0</tt>, then the block is initialized to 0.
468  //! Otherwise, the block is empty and \a not initialized.
469  //! \note size is the count of elements, and not the number of bytes
470  SecBlock(const T *ptr, size_type len)
471  : m_size(len), m_ptr(m_alloc.allocate(len, NULL)) {
472  CRYPTOPP_ASSERT((!m_ptr && !m_size) || (m_ptr && m_size));
473  if (ptr && m_ptr)
474  memcpy_s(m_ptr, m_size*sizeof(T), ptr, len*sizeof(T));
475  else if (m_size)
476  memset(m_ptr, 0, m_size*sizeof(T));
477  }
478 
479  ~SecBlock()
480  {m_alloc.deallocate(m_ptr, m_size);}
481 
482 #ifdef __BORLANDC__
483  operator T *() const
484  {return (T*)m_ptr;}
485 #else
486  operator const void *() const
487  {return m_ptr;}
488  operator void *()
489  {return m_ptr;}
490 
491  operator const T *() const
492  {return m_ptr;}
493  operator T *()
494  {return m_ptr;}
495 #endif
496 
497  //! \brief Provides an iterator pointing to the first element in the memory block
498  //! \returns iterator pointing to the first element in the memory block
499  iterator begin()
500  {return m_ptr;}
501  //! \brief Provides a constant iterator pointing to the first element in the memory block
502  //! \returns constant iterator pointing to the first element in the memory block
503  const_iterator begin() const
504  {return m_ptr;}
505  //! \brief Provides an iterator pointing beyond the last element in the memory block
506  //! \returns iterator pointing beyond the last element in the memory block
507  iterator end()
508  {return m_ptr+m_size;}
509  //! \brief Provides a constant iterator pointing beyond the last element in the memory block
510  //! \returns constant iterator pointing beyond the last element in the memory block
511  const_iterator end() const
512  {return m_ptr+m_size;}
513 
514  //! \brief Provides a pointer to the first element in the memory block
515  //! \returns pointer to the first element in the memory block
516  typename A::pointer data() {return m_ptr;}
517  //! \brief Provides a pointer to the first element in the memory block
518  //! \returns constant pointer to the first element in the memory block
519  typename A::const_pointer data() const {return m_ptr;}
520 
521  //! \brief Provides the count of elements in the SecBlock
522  //! \returns number of elements in the memory block
523  //! \note the return value is the count of elements, and not the number of bytes
524  size_type size() const {return m_size;}
525  //! \brief Determines if the SecBlock is empty
526  //! \returns true if number of elements in the memory block is 0, false otherwise
527  bool empty() const {return m_size == 0;}
528 
529  //! \brief Provides a byte pointer to the first element in the memory block
530  //! \returns byte pointer to the first element in the memory block
531  byte * BytePtr() {return (byte *)m_ptr;}
532  //! \brief Return a byte pointer to the first element in the memory block
533  //! \returns constant byte pointer to the first element in the memory block
534  const byte * BytePtr() const {return (const byte *)m_ptr;}
535  //! \brief Provides the number of bytes in the SecBlock
536  //! \return the number of bytes in the memory block
537  //! \note the return value is the number of bytes, and not count of elements.
538  size_type SizeInBytes() const {return m_size*sizeof(T);}
539 
540  //! \brief Set contents and size from an array
541  //! \param ptr a pointer to an array of T
542  //! \param len the number of elements in the memory block
543  //! \details If the memory block is reduced in size, then the reclaimed memory is set to 0.
544  void Assign(const T *ptr, size_type len)
545  {
546  New(len);
547  if (m_ptr && ptr && len)
548  {memcpy_s(m_ptr, m_size*sizeof(T), ptr, len*sizeof(T));}
549  }
550 
551  //! \brief Copy contents from another SecBlock
552  //! \param t the other SecBlock
553  //! \details Assign checks for self assignment.
554  //! \details If the memory block is reduced in size, then the reclaimed memory is set to 0.
555  void Assign(const SecBlock<T, A> &t)
556  {
557  if (this != &t)
558  {
559  New(t.m_size);
560  if (m_ptr && t.m_ptr && t.m_size)
561  {memcpy_s(m_ptr, m_size*sizeof(T), t, t.m_size*sizeof(T));}
562  }
563  }
564 
565  //! \brief Assign contents from another SecBlock
566  //! \param t the other SecBlock
567  //! \details Internally, operator=() calls Assign().
568  //! \details If the memory block is reduced in size, then the reclaimed memory is set to 0.
570  {
571  // Assign guards for self-assignment
572  Assign(t);
573  return *this;
574  }
575 
576  //! \brief Append contents from another SecBlock
577  //! \param t the other SecBlock
578  //! \details Internally, this SecBlock calls Grow and then appends t.
580  {
581  CRYPTOPP_ASSERT((!t.m_ptr && !t.m_size) || (t.m_ptr && t.m_size));
582 
583  if(t.m_size)
584  {
585  const size_type oldSize = m_size;
586  if(this != &t) // s += t
587  {
588  Grow(m_size+t.m_size);
589  memcpy_s(m_ptr+oldSize, (m_size-oldSize)*sizeof(T), t.m_ptr, t.m_size*sizeof(T));
590  }
591  else // t += t
592  {
593  Grow(m_size*2);
594  memcpy_s(m_ptr+oldSize, (m_size-oldSize)*sizeof(T), m_ptr, oldSize*sizeof(T));
595  }
596  }
597  return *this;
598  }
599 
600  //! \brief Construct a SecBlock from this and another SecBlock
601  //! \param t the other SecBlock
602  //! \returns a newly constructed SecBlock that is a conacentation of this and t
603  //! \details Internally, a new SecBlock is created from this and a concatenation of t.
605  {
606  CRYPTOPP_ASSERT((!m_ptr && !m_size) || (m_ptr && m_size));
607  CRYPTOPP_ASSERT((!t.m_ptr && !t.m_size) || (t.m_ptr && t.m_size));
608  if(!t.m_size) return SecBlock(*this);
609 
610  SecBlock<T, A> result(m_size+t.m_size);
611  if(m_size) {memcpy_s(result.m_ptr, result.m_size*sizeof(T), m_ptr, m_size*sizeof(T));}
612  memcpy_s(result.m_ptr+m_size, (result.m_size-m_size)*sizeof(T), t.m_ptr, t.m_size*sizeof(T));
613  return result;
614  }
615 
616  //! \brief Bitwise compare two SecBlocks
617  //! \param t the other SecBlock
618  //! \returns true if the size and bits are equal, false otherwise
619  //! \details Uses a constant time compare if the arrays are equal size. The constant time
620  //! compare is VerifyBufsEqual() found in misc.h.
621  //! \sa operator!=()
622  bool operator==(const SecBlock<T, A> &t) const
623  {
624  return m_size == t.m_size &&
625  VerifyBufsEqual(reinterpret_cast<const byte*>(m_ptr), reinterpret_cast<const byte*>(t.m_ptr), m_size*sizeof(T));
626  }
627 
628  //! \brief Bitwise compare two SecBlocks
629  //! \param t the other SecBlock
630  //! \returns true if the size and bits are equal, false otherwise
631  //! \details Uses a constant time compare if the arrays are equal size. The constant time
632  //! compare is VerifyBufsEqual() found in misc.h.
633  //! \details Internally, operator!=() returns the inverse of operator==().
634  //! \sa operator==()
635  bool operator!=(const SecBlock<T, A> &t) const
636  {
637  return !operator==(t);
638  }
639 
640  //! \brief Change size without preserving contents
641  //! \param newSize the new size of the memory block
642  //! \details Old content is \a not preserved. If the memory block is reduced in size,
643  //! then the reclaimed memory is set to 0. If the memory block grows in size, then
644  //! the new memory is \a not initialized.
645  //! \details Internally, this SecBlock calls reallocate().
646  //! \sa New(), CleanNew(), Grow(), CleanGrow(), resize()
647  void New(size_type newSize)
648  {
649  m_ptr = m_alloc.reallocate(m_ptr, m_size, newSize, false);
650  m_size = newSize;
651  }
652 
653  //! \brief Change size without preserving contents
654  //! \param newSize the new size of the memory block
655  //! \details Old content is \a not preserved. If the memory block is reduced in size,
656  //! then the reclaimed content is set to 0. If the memory block grows in size, then
657  //! the new memory is initialized to 0.
658  //! \details Internally, this SecBlock calls New().
659  //! \sa New(), CleanNew(), Grow(), CleanGrow(), resize()
660  void CleanNew(size_type newSize)
661  {
662  New(newSize);
663  if (m_ptr) {memset_z(m_ptr, 0, m_size*sizeof(T));}
664  }
665 
666  //! \brief Change size and preserve contents
667  //! \param newSize the new size of the memory block
668  //! \details Old content is preserved. New content is not initialized.
669  //! \details Internally, this SecBlock calls reallocate() when size must increase. If the
670  //! size does not increase, then Grow() does not take action. If the size must
671  //! change, then use resize().
672  //! \sa New(), CleanNew(), Grow(), CleanGrow(), resize()
673  void Grow(size_type newSize)
674  {
675  if (newSize > m_size)
676  {
677  m_ptr = m_alloc.reallocate(m_ptr, m_size, newSize, true);
678  m_size = newSize;
679  }
680  }
681 
682  //! \brief Change size and preserve contents
683  //! \param newSize the new size of the memory block
684  //! \details Old content is preserved. New content is initialized to 0.
685  //! \details Internally, this SecBlock calls reallocate() when size must increase. If the
686  //! size does not increase, then CleanGrow() does not take action. If the size must
687  //! change, then use resize().
688  //! \sa New(), CleanNew(), Grow(), CleanGrow(), resize()
689  void CleanGrow(size_type newSize)
690  {
691  if (newSize > m_size)
692  {
693  m_ptr = m_alloc.reallocate(m_ptr, m_size, newSize, true);
694  memset_z(m_ptr+m_size, 0, (newSize-m_size)*sizeof(T));
695  m_size = newSize;
696  }
697  }
698 
699  //! \brief Change size and preserve contents
700  //! \param newSize the new size of the memory block
701  //! \details Old content is preserved. If the memory block grows in size, then
702  //! new memory is \a not initialized.
703  //! \details Internally, this SecBlock calls reallocate().
704  //! \sa New(), CleanNew(), Grow(), CleanGrow(), resize()
705  void resize(size_type newSize)
706  {
707  m_ptr = m_alloc.reallocate(m_ptr, m_size, newSize, true);
708  m_size = newSize;
709  }
710 
711  //! \brief Swap contents with another SecBlock
712  //! \param b the other SecBlock
713  //! \details Internally, std::swap() is called on m_alloc, m_size and m_ptr.
715  {
716  // Swap must occur on the allocator in case its FixedSize that spilled into the heap.
717  std::swap(m_alloc, b.m_alloc);
718  std::swap(m_size, b.m_size);
719  std::swap(m_ptr, b.m_ptr);
720  }
721 
722 // protected:
723  A m_alloc;
724  size_type m_size;
725  T *m_ptr;
726 };
727 
728 #ifdef CRYPTOPP_DOXYGEN_PROCESSING
729 //! \class SecByteBlock
730 //! \brief \ref SecBlock "SecBlock<byte>" typedef.
731 class SecByteBlock : public SecBlock<byte> {};
732 //! \class SecWordBlock
733 //! \brief \ref SecBlock "SecBlock<word>" typedef.
734 class SecWordBlock : public SecBlock<word> {};
735 //! \class AlignedSecByteBlock
736 //! \brief SecBlock using \ref AllocatorWithCleanup "AllocatorWithCleanup<byte, true>" typedef
737 class AlignedSecByteBlock : public SecBlock<byte, AllocatorWithCleanup<byte, true> > {};
738 #else
742 #endif
743 
744 // No need for move semantics on derived class *if* the class does not add any
745 // data members; see http://stackoverflow.com/q/31755703, and Rule of {0|3|5}.
746 
747 //! \class FixedSizeSecBlock
748 //! \brief Fixed size stack-based SecBlock
749 //! \tparam T class or type
750 //! \tparam S fixed-size of the stack-based memory block, in elements
751 //! \tparam A AllocatorBase derived class for allocation and cleanup
752 template <class T, unsigned int S, class A = FixedSizeAllocatorWithCleanup<T, S> >
753 class FixedSizeSecBlock : public SecBlock<T, A>
754 {
755 public:
756  //! \brief Construct a FixedSizeSecBlock
757  explicit FixedSizeSecBlock() : SecBlock<T, A>(S) {}
758 };
759 
760 //! \class FixedSizeAlignedSecBlock
761 //! \brief Fixed size stack-based SecBlock with 16-byte alignment
762 //! \tparam T class or type
763 //! \tparam S fixed-size of the stack-based memory block, in elements
764 //! \tparam A AllocatorBase derived class for allocation and cleanup
765 template <class T, unsigned int S, bool T_Align16 = true>
766 class FixedSizeAlignedSecBlock : public FixedSizeSecBlock<T, S, FixedSizeAllocatorWithCleanup<T, S, NullAllocator<T>, T_Align16> >
767 {
768 };
769 
770 //! \class SecBlockWithHint
771 //! \brief Stack-based SecBlock that grows into the heap
772 //! \tparam T class or type
773 //! \tparam S fixed-size of the stack-based memory block, in elements
774 //! \tparam A AllocatorBase derived class for allocation and cleanup
775 template <class T, unsigned int S, class A = FixedSizeAllocatorWithCleanup<T, S, AllocatorWithCleanup<T> > >
776 class SecBlockWithHint : public SecBlock<T, A>
777 {
778 public:
779  //! construct a SecBlockWithHint with a count of elements
780  explicit SecBlockWithHint(size_t size) : SecBlock<T, A>(size) {}
781 };
782 
783 template<class T, bool A, class U, bool B>
784 inline bool operator==(const CryptoPP::AllocatorWithCleanup<T, A>&, const CryptoPP::AllocatorWithCleanup<U, B>&) {return (true);}
785 template<class T, bool A, class U, bool B>
786 inline bool operator!=(const CryptoPP::AllocatorWithCleanup<T, A>&, const CryptoPP::AllocatorWithCleanup<U, B>&) {return (false);}
787 
788 NAMESPACE_END
789 
790 NAMESPACE_BEGIN(std)
791 template <class T, class A>
792 inline void swap(CryptoPP::SecBlock<T, A> &a, CryptoPP::SecBlock<T, A> &b)
793 {
794  a.swap(b);
795 }
796 
797 #if defined(_STLP_DONT_SUPPORT_REBIND_MEMBER_TEMPLATE) || (defined(_STLPORT_VERSION) && !defined(_STLP_MEMBER_TEMPLATE_CLASSES))
798 // working for STLport 5.1.3 and MSVC 6 SP5
799 template <class _Tp1, class _Tp2>
800 inline CryptoPP::AllocatorWithCleanup<_Tp2>&
801 __stl_alloc_rebind(CryptoPP::AllocatorWithCleanup<_Tp1>& __a, const _Tp2*)
802 {
803  return (CryptoPP::AllocatorWithCleanup<_Tp2>&)(__a);
804 }
805 #endif
806 
807 NAMESPACE_END
808 
809 #if CRYPTOPP_MSC_VERSION
810 # pragma warning(pop)
811 #endif
812 
813 #endif
iterator end()
Provides an iterator pointing beyond the last element in the memory block.
Definition: secblock.h:507
An invalid argument was detected.
Definition: cryptlib.h:187
Base class for all allocators used by SecBlock.
Definition: secblock.h:29
void swap(SecBlock< T, A > &b)
Swap contents with another SecBlock.
Definition: secblock.h:714
Stack-based SecBlock that grows into the heap.
Definition: secblock.h:776
void destroy(U *ptr)
Destroys an U constructed with variadic arguments.
Definition: secblock.h:74
Utility functions for the Crypto++ library.
void construct(U *ptr, Args &&...args)
Constructs a new U using variadic arguments.
Definition: secblock.h:67
void AlignedDeallocate(void *ptr)
Frees a buffer allocated with AlignedAllocate.
FixedSizeSecBlock()
Construct a FixedSizeSecBlock.
Definition: secblock.h:757
void CleanNew(size_type newSize)
Change size without preserving contents.
Definition: secblock.h:660
bool operator!=(const SecBlock< T, A > &t) const
Bitwise compare two SecBlocks.
Definition: secblock.h:635
A::const_pointer data() const
Provides a pointer to the first element in the memory block.
Definition: secblock.h:519
bool empty() const
Determines if the SecBlock is empty.
Definition: secblock.h:527
SecBlock< T, A > & operator=(const SecBlock< T, A > &t)
Assign contents from another SecBlock.
Definition: secblock.h:569
void resize(size_type newSize)
Change size and preserve contents.
Definition: secblock.h:705
SecBlock< T, A > & operator+=(const SecBlock< T, A > &t)
Append contents from another SecBlock.
Definition: secblock.h:579
void CleanGrow(size_type newSize)
Change size and preserve contents.
Definition: secblock.h:689
void Assign(const SecBlock< T, A > &t)
Copy contents from another SecBlock.
Definition: secblock.h:555
SecBlock< T, A > operator+(const SecBlock< T, A > &t)
Construct a SecBlock from this and another SecBlock.
Definition: secblock.h:604
SecBlock(size_type size=0)
Construct a SecBlock with space for size elements.
Definition: secblock.h:450
const_iterator begin() const
Provides a constant iterator pointing to the first element in the memory block.
Definition: secblock.h:503
Secure memory block with allocator and cleanup.
Definition: secblock.h:437
void memcpy_s(void *dest, size_t sizeInBytes, const void *src, size_t count)
Bounds checking replacement for memcpy()
Definition: misc.h:356
size_type size() const
Provides the count of elements in the SecBlock.
Definition: secblock.h:524
Library configuration file.
STL namespace.
pointer allocate(size_type size, const void *hint)
Allocates a block of memory.
Definition: secblock.h:347
void New(size_type newSize)
Change size without preserving contents.
Definition: secblock.h:647
SecBlock typedef.
Definition: secblock.h:731
pointer reallocate(T *oldPtr, size_type oldSize, size_type newSize, bool preserve)
Reallocates a block of memory.
Definition: secblock.h:221
size_type max_size() const
Returns the maximum number of elements the allocator can provide.
Definition: secblock.h:55
bool operator==(const OID &lhs, const OID &rhs)
Compare two OIDs for equality.
Static secure memory block with cleanup.
Definition: secblock.h:301
Allocates a block of memory with cleanup.
Definition: secblock.h:151
void deallocate(void *ptr, size_type size)
Deallocates a block of memory.
Definition: secblock.h:366
bool operator!=(const OID &lhs, const OID &rhs)
Compare two OIDs for inequality.
void SecureWipeArray(T *buf, size_t n)
Sets each element of an array to 0.
Definition: misc.h:1185
bool IsAlignedOn(const void *ptr, unsigned int alignment)
Determines whether ptr is aligned to a minimum value.
Definition: misc.h:916
const_iterator end() const
Provides a constant iterator pointing beyond the last element in the memory block.
Definition: secblock.h:511
void * UnalignedAllocate(size_t size)
Allocates a buffer.
Definition: misc.cpp:253
Template class memeber Rebind.
Definition: secblock.h:236
A::pointer data()
Provides a pointer to the first element in the memory block.
Definition: secblock.h:516
void Assign(const T *ptr, size_type len)
Set contents and size from an array.
Definition: secblock.h:544
pointer reallocate(pointer oldPtr, size_type oldSize, size_type newSize, bool preserve)
Reallocates a block of memory.
Definition: secblock.h:396
Fixed size stack-based SecBlock with 16-byte alignment.
Definition: secblock.h:766
SecBlock using AllocatorWithCleanup typedef.
Definition: secblock.h:737
pointer allocate(size_type size, const void *ptr=NULL)
Allocates a block of memory.
Definition: secblock.h:171
Fixed size stack-based SecBlock.
Definition: secblock.h:753
SecBlock(const SecBlock< T, A > &t)
Copy construct a SecBlock from another SecBlock.
Definition: secblock.h:456
void * memset_z(void *ptr, int value, size_t num)
Memory block initializer and eraser that attempts to survive optimizations.
Definition: misc.h:451
const T & STDMIN(const T &a, const T &b)
Replacement function for std::min.
Definition: misc.h:467
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:62
void deallocate(void *ptr, size_type size)
Deallocates a block of memory.
Definition: secblock.h:195
iterator begin()
Provides an iterator pointing to the first element in the memory block.
Definition: secblock.h:499
const byte * BytePtr() const
Return a byte pointer to the first element in the memory block.
Definition: secblock.h:534
NULL allocator.
Definition: secblock.h:263
SecBlockWithHint(size_t size)
construct a SecBlockWithHint with a count of elements
Definition: secblock.h:780
A::pointer StandardReallocate(A &alloc, T *oldPtr, typename A::size_type oldSize, typename A::size_type newSize, bool preserve)
Reallocation function.
Definition: secblock.h:119
bool VerifyBufsEqual(const byte *buf1, const byte *buf2, size_t count)
Performs a near constant-time comparison of two equally sized buffers.
Definition: misc.cpp:96
SecBlock(const T *ptr, size_type len)
Construct a SecBlock from an array of elements.
Definition: secblock.h:470
pointer allocate(size_type size)
Allocates a block of memory.
Definition: secblock.h:321
const T & STDMAX(const T &a, const T &b)
Replacement function for std::max.
Definition: misc.h:477
void Grow(size_type newSize)
Change size and preserve contents.
Definition: secblock.h:673
Crypto++ library namespace.
bool operator==(const SecBlock< T, A > &t) const
Bitwise compare two SecBlocks.
Definition: secblock.h:622
size_type SizeInBytes() const
Provides the number of bytes in the SecBlock.
Definition: secblock.h:538
FixedSizeAllocatorWithCleanup()
Constructs a FixedSizeAllocatorWithCleanup.
Definition: secblock.h:307
void UnalignedDeallocate(void *ptr)
Frees a buffer allocated with UnalignedAllocate.
Definition: misc.cpp:261
SecBlock typedef.
Definition: secblock.h:734
void * AlignedAllocate(size_t size)
Allocates a buffer on 16-byte boundary.
#define SIZE_MAX
The maximum value of a machine word.
Definition: misc.h:95
byte * BytePtr()
Provides a byte pointer to the first element in the memory block.
Definition: secblock.h:531