/*

* Streebog

* (C) 2017 Ribose Inc.

*

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

*/

#ifndef BOTAN_STREEBOG_H_

#define BOTAN_STREEBOG_H_

#include <botan/hash.h>

#include <botan/internal/alignment_buffer.h>

namespace Botan {

/**

* Streebog (GOST R 34.11-2012)

* RFC 6986

*/

class Streebog final : public HashFunction {

   public:

      size_t output_length() const override { return m_output_bits / 8; }

      std::unique_ptr<HashFunction> new_object() const override { return std::make_unique<Streebog>(m_output_bits); }

      void clear() override;

      std::string name() const override;

      size_t hash_block_size() const override { return 64; }

      std::unique_ptr<HashFunction> copy_state() const override;

      explicit Streebog(size_t output_bits);

   protected:

      void add_data(std::span<const uint8_t> input) override;

      void final_result(std::span<uint8_t> out) override;

      void compress(const uint8_t input[], bool lastblock = false);

      void compress_64(const uint64_t input[], bool lastblock = false);

   private:

      const size_t m_output_bits;

      uint64_t m_count;

      AlignmentBuffer<uint8_t, 64> m_buffer;

      secure_vector<uint64_t> m_h;

      secure_vector<uint64_t> m_S;

};

}  // namespace Botan

#endif