fortuna/fortuna.cpp

#ifndef FORTUNA_FORTUNA_CPP
#define FORTUNA_FORTUNA_CPP

#include "fortuna.h"
#include "util.h"

#include <cryptopp/cryptlib.h>
#include <fmt/chrono.h>

namespace fortuna {
	static constexpr const unsigned int min_pool_size{64};


	Fortuna::Fortuna() {
		try {
			initialize_prng();
		} catch(CryptoPP::Exception& e) {
			fmt::print(stderr, "{}\n", e.what());
		}
	}
	Fortuna::~Fortuna() = default;


	auto Fortuna::random_data(unsigned int n_bytes) -> void {
		const auto start{std::chrono::system_clock::now()};
		fmt::print("random_data starting - {}\n", start);
		auto now{std::chrono::steady_clock::now()};
		auto elapsed {
			std::chrono::duration_cast<std::chrono::milliseconds>(
				std::chrono::steady_clock::now().time_since_epoch() -
				now.time_since_epoch()
			)
		};
		fmt::print("last_reseed: {} ago\n", elapsed);
		const int pools_to_use{ffsll(static_cast<int>(get_reseed_ctr()))};
		std::string s;

		if (R.pools[0].get_s_length() >= min_pool_size && elapsed > R.Gen.reseed_interval) {
			for (int i = 0; i < static_cast<int>(pools_to_use); ++i) {
				if (R.reseed_ctr % static_cast<int>(pow(2,i)) == 0) {
					try {
						s.append(fortuna::Util::do_sha(R.pools[i].get_s()));
						R.pools[i].clear_pool();
					} catch(std::exception& e) {
						fmt::print("{}\n", e.what());
					}
				}
			}
			incr_reseed_ctr();
			R.Gen.reseed(s);
			R.last_reseed = std::chrono::steady_clock::now();
			s.clear();
		}

		std::string n{R.Gen.generate_random_data(n_bytes)};
		fmt::print("got you {} proper bytes from generate_random_data -> {}\n",
				n_bytes, n);
		n.clear();

		const auto end{std::chrono::system_clock::now()};
		std::chrono::duration<float> diff = end-start;
		fmt::print("random_data done - {}\n", end);
		fmt::print("getting random data took {:.{}f}s\n", diff.count(), 12);
	} //random_data

} // namespace fortuna

#endif//FORTUNA_FORTUNA_CPP