/*
* (C) 2017 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/mem_ops.h>
#include <cstdlib>

#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)
  #include <botan/locking_allocator.h>
#endif

namespace Botan {

BOTAN_MALLOC_FN void* allocate_memory(size_t elems, size_t elem_size)
   {
#if defined(BOTAN_HAS_LOCKING_ALLOCATOR)
   if(void* p = mlock_allocator::instance().allocate(elems, elem_size))
      return p;
#endif

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

bool constant_time_compare(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 |= (x[i] ^ y[i]);

   return difference == 0;
   }

}