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fortuna/fortuna.h
surtur 56d9631f84
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fortuna: add mtx_{accu,p_pools}, locks
2022-01-20 08:14:40 +01:00

148 lines
3.5 KiB
C++

#ifndef FORTUNA_FORTUNA_H
#define FORTUNA_FORTUNA_H
#include "accumulator.h"
#include "generator.h"
#include "pool.h"
#include <fmt/core.h>
#include <array>
#include <chrono>
#include <latch>
#include <memory>
#include <mutex>
#include <thread>
namespace fortuna {
class Fortuna {
public:
static constexpr const char NUM_OF_POOLS{32};
std::mutex mtx;
std::mutex mtx_random_data;
std::mutex mtx_p_pools;
std::mutex mtx_accu;
std::mutex print_mtx;
std::thread th_gen;
std::thread th_accu;
std::thread th_sfm;
std::thread th_urandom;
std::latch sync_point{5}; // 4 services + main thread
Fortuna();
~Fortuna() noexcept;
[[optimize_for_synchronized]] auto random_data(unsigned int) -> void;
auto set_reseed_ctr_to_null() -> void {
std::lock_guard<std::mutex> lg(mtx);
Fortuna::R.null_da_ctr();
}
auto incr_reseed_ctr() -> void {
std::lock_guard<std::mutex> lg(mtx);
++Fortuna::R.reseed_ctr;
}
auto get_reseed_ctr() const -> uint64_t {
return R.reseed_ctr;
}
auto initialize_prng() -> void {
// TODO(me): handle the reseeds here as per Cryptography Engineering,
// p. 153
set_reseed_ctr_to_null();
std::unique_lock<std::mutex> p_ul(print_mtx);
std::unique_lock<std::mutex> a_ul(mtx_accu, std::defer_lock);
std::unique_lock<std::mutex> pp_ul(mtx_p_pools, std::defer_lock);
try {
std::lock(a_ul, pp_ul);
R.initialize_pools();
fmt::print("[i] fortuna: pools initialized\n");
p_ul.unlock();
accumulator.set_pools_ptr(R._p_pools);
accumulator.set_gen(R.Gen);
a_ul.unlock();
// FIXME: bogus first reseed here, P_0 definitely hasn't collected
// enough entropy by now
incr_reseed_ctr();
p_ul.lock();
fmt::print("first reseed\n");
p_ul.unlock();
std::unique_lock<std::mutex> ul(mtx);
R.Gen.reseed("fortuna");
ul.unlock();
}
catch (std::exception& e) {
p_ul.try_lock();
fmt::print(
"{}\n[!] fortuna: fatal error, PRNG initialization FAILED!\n\n",
e.what());
}
p_ul.try_lock();
this->sync_point.count_down();
fmt::print("[*] fortuna: PRNG initialized\n");
}
auto generator_service(std::shared_ptr<fortuna::generator::Generator> Gen)
-> void;
auto accumulator_service() -> void;
auto seed_file_manager_service() -> void;
auto urandom_entropy_src_service() -> void;
// PRNG state
class R_state {
friend fortuna::Fortuna;
public:
R_state() noexcept {}
~R_state() noexcept = default;
protected:
auto null_da_ctr() -> void {
reseed_ctr = 0x00;
fmt::print("reseed_ctr set to 0x00\n");
}
auto initialize_pools() -> void {
for (unsigned int i = accumulator::Accumulator::init_pool_num;
i < Fortuna::NUM_OF_POOLS;
++i) {
this->_p_pools->at(i).initialize_pool(i);
}
}
private:
generator::Generator Gen;
uint64_t reseed_ctr{0x00};
// da_pools is to be used solely for creating a shared_ptr of the
// object: _p_pools. any further access to the structure should be
// facilitated by the subject _p_pools shared_ptr. to convey this,
// da_pools is declared const
const std::array<accumulator::Pool, Fortuna::NUM_OF_POOLS> da_pools;
// _p_pools points to the da_pools array of 32 Pool objects
std::shared_ptr<std::array<accumulator::Pool, Fortuna::NUM_OF_POOLS>>
_p_pools{std::make_shared<
std::array<accumulator::Pool, Fortuna::NUM_OF_POOLS>>()};
std::chrono::steady_clock::time_point last_reseed;
}; // class R_state
fortuna::Fortuna::R_state R;
fortuna::accumulator::Accumulator accumulator;
}; // class Fortuna
} // namespace fortuna
#endif // FORTUNA_FORTUNA_H