text: // Copyright (c) 2013-2016 The Bitcoin Core developers
  // Copyright (c) 2017 The Bull Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "hash.h"
  #include "crypto/common.h"
  #include "crypto/hmac_sha512.h"
  #include "pubkey.h"
  
  //TODO remove these
  double algoHashTotal[16];
  int algoHashHits[16];
  
  inline uint32_t ROTL32(uint32_t x, int8_t r)
  {
      return (x << r) | (x >> (32 - r));
  }
  
  unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash)
  {
      // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
      uint32_t h1 = nHashSeed;
      const uint32_t c1 = 0xcc9e2d51;
      const uint32_t c2 = 0x1b873593;
  
      const int nblocks = vDataToHash.size() / 4;
  
      //----------
      // body
      const uint8_t* blocks = vDataToHash.data();
  
      for (int i = 0; i < nblocks; ++i) {
          uint32_t k1 = ReadLE32(blocks + i*4);
  
          k1 *= c1;
          k1 = ROTL32(k1, 15);
          k1 *= c2;
  
          h1 ^= k1;
          h1 = ROTL32(h1, 13);
          h1 = h1 * 5 + 0xe6546b64;
      }
  
      //----------
      // tail
      const uint8_t* tail = vDataToHash.data() + nblocks * 4;
  
      uint32_t k1 = 0;
  
      switch (vDataToHash.size() & 3) {
          case 3:
              k1 ^= tail[2] << 16;
          case 2:
              k1 ^= tail[1] << 8;
          case 1:
              k1 ^= tail[0];
              k1 *= c1;
              k1 = ROTL32(k1, 15);
              k1 *= c2;
              h1 ^= k1;
      }
  
      //----------
      // finalization
      h1 ^= vDataToHash.size();
      h1 ^= h1 >> 16;
      h1 *= 0x85ebca6b;
      h1 ^= h1 >> 13;
      h1 *= 0xc2b2ae35;
      h1 ^= h1 >> 16;
  
      return h1;
  }
  
  void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
  {
      unsigned char num[4];
      num[0] = (nChild >> 24) & 0xFF;
      num[1] = (nChild >> 16) & 0xFF;
      num[2] = (nChild >>  8) & 0xFF;
      num[3] = (nChild >>  0) & 0xFF;
      CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output);
  }
  
  #define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
  
  #define SIPROUND do { \
      v0 += v1; v1 = ROTL(v1, 13); v1 ^= v0; \
      v0 = ROTL(v0, 32); \
      v2 += v3; v3 = ROTL(v3, 16); v3 ^= v2; \
      v0 += v3; v3 = ROTL(v3, 21); v3 ^= v0; \
      v2 += v1; v1 = ROTL(v1, 17); v1 ^= v2; \
      v2 = ROTL(v2, 32); \
  } while (0)
  
  CSipHasher::CSipHasher(uint64_t k0, uint64_t k1)
  {
      v[0] = 0x736f6d6570736575ULL ^ k0;
      v[1] = 0x646f72616e646f6dULL ^ k1;
      v[2] = 0x6c7967656e657261ULL ^ k0;
      v[3] = 0x7465646279746573ULL ^ k1;
      count = 0;
      tmp = 0;
  }
  
  CSipHasher& CSipHasher::Write(uint64_t data)
  {
      uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
  
      assert(count % 8 == 0);
  
      v3 ^= data;
      SIPROUND;
      SIPROUND;
      v0 ^= data;
  
      v[0] = v0;
      v[1] = v1;
      v[2] = v2;
      v[3] = v3;
  
      count += 8;
      return *this;
  }
  
  CSipHasher& CSipHasher::Write(const unsigned char* data, size_t size)
  {
      uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
      uint64_t t = tmp;
      int c = count;
  
      while (size--) {
          t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
          c++;
          if ((c & 7) == 0) {
              v3 ^= t;
              SIPROUND;
              SIPROUND;
              v0 ^= t;
              t = 0;
          }
      }
  
      v[0] = v0;
      v[1] = v1;
      v[2] = v2;
      v[3] = v3;
      count = c;
      tmp = t;
  
      return *this;
  }
  
  uint64_t CSipHasher::Finalize() const
  {
      uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
  
      uint64_t t = tmp | (((uint64_t)count) << 56);
  
      v3 ^= t;
      SIPROUND;
      SIPROUND;
      v0 ^= t;
      v2 ^= 0xFF;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      return v0 ^ v1 ^ v2 ^ v3;
  }
  
  uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val)
  {
      /* Specialized implementation for efficiency */
      uint64_t d = val.GetUint64(0);
  
      uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
      uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
      uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
      uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
  
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(1);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(2);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(3);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      v3 ^= ((uint64_t)4) << 59;
      SIPROUND;
      SIPROUND;
      v0 ^= ((uint64_t)4) << 59;
      v2 ^= 0xFF;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      return v0 ^ v1 ^ v2 ^ v3;
  }
  
  uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra)
  {
      /* Specialized implementation for efficiency */
      uint64_t d = val.GetUint64(0);
  
      uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
      uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
      uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
      uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
  
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(1);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(2);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = val.GetUint64(3);
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      d = (((uint64_t)36) << 56) | extra;
      v3 ^= d;
      SIPROUND;
      SIPROUND;
      v0 ^= d;
      v2 ^= 0xFF;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      SIPROUND;
      return v0 ^ v1 ^ v2 ^ v3;
  }
  