curl.hpp

//
// MIT License
//
// Copyright (c) 2017-2018 Thibault Martinez and Simon Ninon
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
//

#pragma once

#include <algorithm>

#include <iota/constants.hpp>
#include <iota/types/trits.hpp>

namespace IOTA {

namespace Crypto {

class Curl {
public:
  Curl();
  ~Curl() = default;

public:
  void reset();

  void absorb(const Types::Trits& trits, std::size_t offset = 0, std::size_t length = 0);

  void squeeze(Types::Trits& trits, std::size_t offset = 0, std::size_t length = 0);

private:
  void transform();

  template <typename T>
  static void arrayCopy(const typename std::vector<T>::const_iterator& input,
                        const typename std::vector<T>::iterator& output, std::size_t length) {
    std::transform(input, input + length, output, [](T c) { return c; });
  }

private:
  static const std::size_t StateLength = 3 * TritHashLength;

  static const std::size_t NumberOfRounds = 81;

  static int TruthTable[];

private:
  std::vector<int8_t> state_;

  std::vector<int8_t> scratchpad_;
};

}  // namespace Crypto

}  // namespace IOTA