src/hash.cpp

   1 // Copyright (c) 2013-2014 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 #include "hash.h"
   6 #include "crypto/common.h"
   7 #include "crypto/hmac_sha512.h"
   8 #include "pubkey.h"
   9
  10
  11 inline uint32_t ROTL32(uint32_t x, int8_t r)
  12 {
  13     return (x << r) | (x >> (32 - r));
  14 }
  15
  16 unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash)
  17 {
  18     // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
  19     uint32_t h1 = nHashSeed;
  20     if (vDataToHash.size() > 0)
  21     {
  22         const uint32_t c1 = 0xcc9e2d51;
  23         const uint32_t c2 = 0x1b873593;
  24
  25         const int nblocks = vDataToHash.size() / 4;
  26
  27         //----------
  28         // body
  29         const uint8_t* blocks = &vDataToHash[0] + nblocks * 4;
  30
  31         for (int i = -nblocks; i; i++) {
  32             uint32_t k1 = ReadLE32(blocks + i*4);
  33
  34             k1 *= c1;
  35             k1 = ROTL32(k1, 15);
  36             k1 *= c2;
  37
  38             h1 ^= k1;
  39             h1 = ROTL32(h1, 13);
  40             h1 = h1 * 5 + 0xe6546b64;
  41         }
  42
  43         //----------
  44         // tail
  45         const uint8_t* tail = (const uint8_t*)(&vDataToHash[0] + nblocks * 4);
  46
  47         uint32_t k1 = 0;
  48
  49         switch (vDataToHash.size() & 3) {
  50         case 3:
  51             k1 ^= tail[2] << 16;
  52         case 2:
  53             k1 ^= tail[1] << 8;
  54         case 1:
  55             k1 ^= tail[0];
  56             k1 *= c1;
  57             k1 = ROTL32(k1, 15);
  58             k1 *= c2;
  59             h1 ^= k1;
  60         };
  61     }
  62
  63     //----------
  64     // finalization
  65     h1 ^= vDataToHash.size();
  66     h1 ^= h1 >> 16;
  67     h1 *= 0x85ebca6b;
  68     h1 ^= h1 >> 13;
  69     h1 *= 0xc2b2ae35;
  70     h1 ^= h1 >> 16;
  71
  72     return h1;
  73 }
  74
  75 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
  76 {
  77     unsigned char num[4];
  78     num[0] = (nChild >> 24) & 0xFF;
  79     num[1] = (nChild >> 16) & 0xFF;
  80     num[2] = (nChild >>  8) & 0xFF;
  81     num[3] = (nChild >>  0) & 0xFF;
  82     CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output);
  83 }