mirror of
https://github.com/XRPLF/rippled.git
synced 2026-07-25 16:10:57 +00:00
92 lines
2.0 KiB
C++
92 lines
2.0 KiB
C++
#pragma once
|
|
|
|
#include <xrpl/beast/hash/xxhasher.h>
|
|
|
|
#include <cstdint>
|
|
#include <mutex>
|
|
#include <random>
|
|
#include <utility>
|
|
|
|
namespace xrpl {
|
|
|
|
namespace detail {
|
|
|
|
using seed_pair = std::pair<std::uint64_t, std::uint64_t>;
|
|
|
|
template <bool = true>
|
|
seed_pair
|
|
makeSeedPair() noexcept
|
|
{
|
|
struct StateT
|
|
{
|
|
std::mutex mutex;
|
|
std::random_device rng;
|
|
std::mt19937_64 gen;
|
|
std::uniform_int_distribution<std::uint64_t> dist;
|
|
|
|
StateT() : gen(rng())
|
|
{
|
|
}
|
|
// state_t(state_t const&) = delete;
|
|
// state_t& operator=(state_t const&) = delete;
|
|
};
|
|
static StateT kState;
|
|
std::scoped_lock const lock(kState.mutex);
|
|
return {kState.dist(kState.gen), kState.dist(kState.gen)};
|
|
}
|
|
|
|
} // namespace detail
|
|
|
|
/**
|
|
* Seed functor once per construction
|
|
*
|
|
* A std compatible hash adapter that resists adversarial inputs.
|
|
* For this to work, T must implement in its own namespace:
|
|
*
|
|
* @code
|
|
*
|
|
* template <class Hasher>
|
|
* void
|
|
* hash_append (Hasher& h, T const& t) noexcept
|
|
* {
|
|
* // hash_append each base and member that should
|
|
* // participate in forming the hash
|
|
* using beast::hash_append;
|
|
* hash_append (h, static_cast<T::base1 const&>(t));
|
|
* hash_append (h, static_cast<T::base2 const&>(t));
|
|
* // ...
|
|
* hash_append (h, t.member1);
|
|
* hash_append (h, t.member2);
|
|
* // ...
|
|
* }
|
|
*
|
|
* @endcode
|
|
*
|
|
* Do not use any version of Murmur or CityHash for the Hasher
|
|
* template parameter (the hashing algorithm). For details
|
|
* see https://131002.net/siphash/#at
|
|
*/
|
|
|
|
template <class HashAlgorithm = beast::Xxhasher>
|
|
class HardenedHash
|
|
{
|
|
private:
|
|
detail::seed_pair seeds_{detail::makeSeedPair<>()};
|
|
|
|
public:
|
|
using result_type = HashAlgorithm::result_type;
|
|
|
|
HardenedHash() = default;
|
|
|
|
template <class T>
|
|
result_type
|
|
operator()(T const& t) const noexcept
|
|
{
|
|
HashAlgorithm h(seeds_.first, seeds_.second);
|
|
hash_append(h, t);
|
|
return static_cast<result_type>(h);
|
|
}
|
|
};
|
|
|
|
} // namespace xrpl
|