Line data    Source code

       1             : // Copyright (c) 2020 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 <span.h>
       9             : 
      10             : #include <stdint.h>
      11             : #include <stdlib.h>
      12             : 
      13             : //! The Keccak-f[1600] transform.
      14             : void KeccakF(uint64_t (&st)[25]);
      15             : 
      16             : class SHA3_256
      17             : {
      18             : private:
      19        1584 :     uint64_t m_state[25] = {0};
      20             :     unsigned char m_buffer[8];
      21          66 :     unsigned m_bufsize = 0;
      22          66 :     unsigned m_pos = 0;
      23             : 
      24             :     //! Sponge rate in bits.
      25             :     static constexpr unsigned RATE_BITS = 1088;
      26             : 
      27             :     //! Sponge rate expressed as a multiple of the buffer size.
      28             :     static constexpr unsigned RATE_BUFFERS = RATE_BITS / (8 * sizeof(m_buffer));
      29             : 
      30             :     static_assert(RATE_BITS % (8 * sizeof(m_buffer)) == 0, "Rate must be a multiple of 8 bytes");
      31             : 
      32             : public:
      33             :     static constexpr size_t OUTPUT_SIZE = 32;
      34             : 
      35         198 :     SHA3_256() {}
      36             :     SHA3_256& Write(Span<const unsigned char> data);
      37             :     SHA3_256& Finalize(Span<unsigned char> output);
      38             :     SHA3_256& Reset();
      39             : };
      40             : 
      41             : #endif // BITCOIN_CRYPTO_SHA3_H