text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2017-2019 The GreenVenturesChain Developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "hash.h"
  
  inline uint32_t ROTL32(uint32_t x, int8_t r) { return (x << r) | (x >> (32 - r)); }
  
  uint32_t MurmurHash3(uint32_t nHashSeed, const vector<uint8_t> &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 int32_t nblocks = vDataToHash.size() / 4;
  
      //----------
      // body
      const uint32_t *blocks = (const uint32_t *)(&vDataToHash[0] + nblocks * 4);
  
      for (int32_t i = -nblocks; i; i++) {
          uint32_t k1 = blocks[i];
  
          k1 *= c1;
          k1 = ROTL32(k1, 15);
          k1 *= c2;
  
          h1 ^= k1;
          h1 = ROTL32(h1, 13);
          h1 = h1 * 5 + 0xe6546b64;
      }
  
      //----------
      // tail
      const uint8_t *tail = (const uint8_t *)(&vDataToHash[0] + nblocks * 4);
  
      uint32_t k1 = 0;
  
      switch (vDataToHash.size() & 3) {
          case 3:
              k1 ^= tail[2] << 16;  // Falls through
          case 2:
              k1 ^= tail[1] << 8;  // Falls through
          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;
  }
  
  int32_t HMAC_SHA512_Init(HMAC_SHA512_CTX *pctx, const void *pkey, size_t len) {
      uint8_t key[128];
      if (len <= 128) {
          memcpy(key, pkey, len);
          memset(key + len, 0, 128 - len);
      } else {
          SHA512_CTX ctxKey;
          SHA512_Init(&ctxKey);
          SHA512_Update(&ctxKey, pkey, len);
          SHA512_Final(key, &ctxKey);
          memset(key + 64, 0, 64);
      }
  
      for (int32_t n = 0; n < 128; n++) key[n] ^= 0x5c;
      SHA512_Init(&pctx->ctxOuter);
      SHA512_Update(&pctx->ctxOuter, key, 128);
  
      for (int32_t n = 0; n < 128; n++) key[n] ^= 0x5c ^ 0x36;
      SHA512_Init(&pctx->ctxInner);
      return SHA512_Update(&pctx->ctxInner, key, 128);
  }
  
  int32_t HMAC_SHA512_Update(HMAC_SHA512_CTX *pctx, const void *pdata, size_t len) {
      return SHA512_Update(&pctx->ctxInner, pdata, len);
  }
  
  int32_t HMAC_SHA512_Final(uint8_t *pmd, HMAC_SHA512_CTX *pctx) {
      uint8_t buf[64];
      SHA512_Final(buf, &pctx->ctxInner);
      SHA512_Update(&pctx->ctxOuter, buf, 64);
      return SHA512_Final(pmd, &pctx->ctxOuter);
  }
  