Line data    Source code

       1              : // Copyright (c) 2020-present The Bitcoin Core developers
       2              : // Distributed under the MIT software license, see the accompanying
       3              : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4              : 
       5              : #ifndef BITCOIN_CRYPTO_SHA3_H
       6              : #define BITCOIN_CRYPTO_SHA3_H
       7              : 
       8              : #include <cstdint>
       9              : #include <cstdlib>
      10              : #include <span>
      11              : 
      12              : //! The Keccak-f[1600] transform.
      13              : void KeccakF(uint64_t (&st)[25]);
      14              : 
      15              : class SHA3_256
      16              : {
      17              : private:
      18              :     uint64_t m_state[25] = {0};
      19              :     unsigned char m_buffer[8];
      20              :     unsigned m_bufsize = 0;
      21              :     unsigned m_pos = 0;
      22              : 
      23              :     //! Sponge rate in bits.
      24              :     static constexpr unsigned RATE_BITS = 1088;
      25              : 
      26              :     //! Sponge rate expressed as a multiple of the buffer size.
      27              :     static constexpr unsigned RATE_BUFFERS = RATE_BITS / (8 * sizeof(m_buffer));
      28              : 
      29              :     static_assert(RATE_BITS % (8 * sizeof(m_buffer)) == 0, "Rate must be a multiple of 8 bytes");
      30              : 
      31              : public:
      32              :     static constexpr size_t OUTPUT_SIZE = 32;
      33              : 
      34        68770 :     SHA3_256() = default;
      35              :     SHA3_256& Write(std::span<const unsigned char> data);
      36              :     SHA3_256& Finalize(std::span<unsigned char> output);
      37              :     SHA3_256& Reset();
      38              : };
      39              : 
      40              : #endif // BITCOIN_CRYPTO_SHA3_H