/*

* Keccak

* (C) 2010,2016 Jack Lloyd

*

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

*/

#include <botan/internal/keccak.h>

#include <botan/internal/sha3.h>

#include <botan/exceptn.h>

#include <botan/internal/loadstor.h>

namespace Botan {

std::unique_ptr<HashFunction> Keccak_1600::copy_state() const

   {

   return std::make_unique<Keccak_1600>(*this);

   }

Keccak_1600::Keccak_1600(size_t output_bits) :

   m_output_bits(output_bits),

   m_bitrate(1600 - 2*output_bits),

   m_S(25),

   m_S_pos(0)

   {

   // We only support the parameters for the SHA-3 proposal

   if(output_bits != 224 && output_bits != 256 &&

      output_bits != 384 && output_bits != 512)

      throw Invalid_Argument("Keccak_1600: Invalid output length " +

                             std::to_string(output_bits));

   }

std::string Keccak_1600::name() const

   {

   return "Keccak-1600(" + std::to_string(m_output_bits) + ")";

   }

std::unique_ptr<HashFunction> Keccak_1600::new_object() const

   {

   return std::make_unique<Keccak_1600>(m_output_bits);

   }

void Keccak_1600::clear()

   {

   zeroise(m_S);

   m_S_pos = 0;

   }

void Keccak_1600::add_data(const uint8_t input[], size_t length)

   {

   m_S_pos = SHA_3::absorb(m_bitrate, m_S, m_S_pos, input, length);

   }

void Keccak_1600::final_result(uint8_t output[])

   {

   SHA_3::finish(m_bitrate, m_S, m_S_pos, 0x01, 0x80);

   /*

   * We never have to run the permutation again because we only support

   * limited output lengths

   */

   copy_out_vec_le(output, m_output_bits/8, m_S);

   clear();

   }

}