/*

* System RNG interface

* (C) 2014,2015 Jack Lloyd

*

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

*/

#ifndef BOTAN_SYSTEM_RNG_H_

#define BOTAN_SYSTEM_RNG_H_

#include <botan/rng.h>

namespace Botan {

/**

* Return a shared reference to a global PRNG instance provided by the

* operating system. For instance might be instantiated by /dev/urandom

* or CryptGenRandom.

*/

BOTAN_PUBLIC_API(2, 0) RandomNumberGenerator& system_rng();

/*

* Instantiable reference to the system RNG.

*/

class BOTAN_PUBLIC_API(2, 0) System_RNG final : public RandomNumberGenerator {

   public:

      std::string name() const override { return system_rng().name(); }

      bool is_seeded() const override { return system_rng().is_seeded(); }

      bool accepts_input() const override { return system_rng().accepts_input(); }

      void clear() override { system_rng().clear(); }

   protected:

      void fill_bytes_with_input(std::span<uint8_t> out, std::span<const uint8_t> in) override {

         system_rng().randomize_with_input(out, in);

      }

};

}  // namespace Botan

#endif