/*

* (C) 2017 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#include <botan/mem_ops.h>

#include <botan/internal/ct_utils.h>

#include <cstdlib>

#include <new>

#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)

  #include <botan/internal/locking_allocator.h>

#endif

namespace Botan {

BOTAN_MALLOC_FN void* allocate_memory(size_t elems, size_t elem_size)

   {

   if(elems == 0 || elem_size == 0)

      return nullptr;

   // Some calloc implementations do not check for overflow (?!?)

   const size_t total_size = elems * elem_size;

   if(total_size < elems || total_size < elem_size)

      throw std::bad_alloc();

#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)

   if(void* p = mlock_allocator::instance().allocate(elems, elem_size))

      return p;

#endif

#if defined(BOTAN_TARGET_OS_HAS_ALLOC_CONCEAL)

   void *ptr = ::calloc_conceal(elems, elem_size);

#else

   void* ptr = std::calloc(elems, elem_size);

#endif

   if(!ptr)

      throw std::bad_alloc();

   return ptr;

   }

void deallocate_memory(void* p, size_t elems, size_t elem_size)

   {

   if(p == nullptr)

      return;

   secure_scrub_memory(p, elems * elem_size);

#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)

   if(mlock_allocator::instance().deallocate(p, elems, elem_size))

      return;

#endif

   std::free(p);

   }

void initialize_allocator()

   {

#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)

   mlock_allocator::instance();

#endif

   }

uint8_t ct_compare_u8(const uint8_t x[],

                      const uint8_t y[],

                      size_t len)

   {

   volatile uint8_t difference = 0;

   for(size_t i = 0; i != len; ++i)

      difference = difference | (x[i] ^ y[i]);

   return CT::Mask<uint8_t>::is_zero(difference).value();

   }

}