text: /*
   * Keccak
   * (C) 2010 Jack Lloyd
   *
   * Botan is released under the Simplified BSD License (see license.txt)
   */
  
  #ifndef BOTAN_KECCAK_H_
  #define BOTAN_KECCAK_H_
  
  #include <botan/hash.h>
  #include <botan/secmem.h>
  #include <string>
  
  namespace Botan
  {
  
  /**
   * Keccak[1600], a SHA-3 candidate
   */
  class Keccak_1600 final : public HashFunction
  {
    public:
      /**
       * @param output_bits the size of the hash output; must be one of
       *                    224, 256, 384, or 512
       */
      explicit Keccak_1600(size_t output_bits = 512);
  
      size_t hash_block_size() const override
      {
          return m_bitrate / 8;
      }
      size_t output_length() const override
      {
          return m_output_bits / 8;
      }
  
      HashFunction *clone() const override;
      std::unique_ptr<HashFunction> copy_state() const override;
      std::string name() const override;
      void clear() override;
  
    private:
      void add_data(const uint8_t input[], size_t length) override;
      void final_result(uint8_t out[]) override;
  
      size_t m_output_bits, m_bitrate;
      secure_vector<uint64_t> m_S;
      size_t m_S_pos;
  };
  
  } // namespace Botan
  
  #endif
  