// keccak.cpp - modified by Wei Dai from Ronny Van Keer's public domain

//              sha3-simple.c. All modifications here are placed in the

//              public domain by Wei Dai.

//              Keccack core function moved to keccakc.cpp in AUG 2018

//              by Jeffrey Walton. Separating the core file allows both

//              SHA3 and Keccack to share the core implementation.

/*

The Keccak sponge function, designed by Guido Bertoni, Joan Daemen,

Michael Peeters and Gilles Van Assche. For more information, feedback or

questions, please refer to our website: http://keccak.noekeon.org/

Implementation by Ronny Van Keer, hereby denoted as "the implementer".

To the extent possible under law, the implementer has waived all copyright

and related or neighboring rights to the source code in this file.

http://creativecommons.org/publicdomain/zero/1.0/

*/

#include "pch.h"

#include "keccak.h"

NAMESPACE_BEGIN(CryptoPP)

// The Keccak core function

extern void KeccakF1600(word64 *state);

void Keccak::Update(const byte *input, size_t length)

{

    CRYPTOPP_ASSERT(!(input == NULLPTR && length != 0));

    if (length == 0) { return; }

    size_t spaceLeft;

    while (length >= (spaceLeft = r() - m_counter))

    {

        if (spaceLeft)

            xorbuf(m_state.BytePtr() + m_counter, input, spaceLeft);

        KeccakF1600(m_state);

        input += spaceLeft;

        length -= spaceLeft;

        m_counter = 0;

    }

    if (length)

        xorbuf(m_state.BytePtr() + m_counter, input, length);

    m_counter += (unsigned int)length;

}

void Keccak::Restart()

{

    std::memset(m_state, 0, m_state.SizeInBytes());

    m_counter = 0;

}

void Keccak::TruncatedFinal(byte *hash, size_t size)

{

    CRYPTOPP_ASSERT(hash != NULLPTR);

    ThrowIfInvalidTruncatedSize(size);

    m_state.BytePtr()[m_counter] ^= 0x01;

    m_state.BytePtr()[r()-1] ^= 0x80;

    KeccakF1600(m_state);

    std::memcpy(hash, m_state, size);

    Restart();

}

NAMESPACE_END