Bitcoin Core  0.20.99
P2P Digital Currency
hash.cpp
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1 // Copyright (c) 2013-2018 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 
9 #include <string>
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, Span<const 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  const uint32_t c1 = 0xcc9e2d51;
21  const uint32_t c2 = 0x1b873593;
22 
23  const int nblocks = vDataToHash.size() / 4;
24 
25  //----------
26  // body
27  const uint8_t* blocks = vDataToHash.data();
28 
29  for (int i = 0; i < nblocks; ++i) {
30  uint32_t k1 = ReadLE32(blocks + i*4);
31 
32  k1 *= c1;
33  k1 = ROTL32(k1, 15);
34  k1 *= c2;
35 
36  h1 ^= k1;
37  h1 = ROTL32(h1, 13);
38  h1 = h1 * 5 + 0xe6546b64;
39  }
40 
41  //----------
42  // tail
43  const uint8_t* tail = vDataToHash.data() + nblocks * 4;
44 
45  uint32_t k1 = 0;
46 
47  switch (vDataToHash.size() & 3) {
48  case 3:
49  k1 ^= tail[2] << 16;
50  case 2:
51  k1 ^= tail[1] << 8;
52  case 1:
53  k1 ^= tail[0];
54  k1 *= c1;
55  k1 = ROTL32(k1, 15);
56  k1 *= c2;
57  h1 ^= k1;
58  }
59 
60  //----------
61  // finalization
62  h1 ^= vDataToHash.size();
63  h1 ^= h1 >> 16;
64  h1 *= 0x85ebca6b;
65  h1 ^= h1 >> 13;
66  h1 *= 0xc2b2ae35;
67  h1 ^= h1 >> 16;
68 
69  return h1;
70 }
71 
72 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
73 {
74  unsigned char num[4];
75  num[0] = (nChild >> 24) & 0xFF;
76  num[1] = (nChild >> 16) & 0xFF;
77  num[2] = (nChild >> 8) & 0xFF;
78  num[3] = (nChild >> 0) & 0xFF;
79  CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output);
80 }
81 
83 {
84  uint256 result;
85  CSHA256().Write(input.begin(), 32).Finalize(result.begin());
86  return result;
87 }
88 
89 CHashWriter TaggedHash(const std::string& tag)
90 {
91  CHashWriter writer(SER_GETHASH, 0);
92  uint256 taghash;
93  CSHA256().Write((const unsigned char*)tag.data(), tag.size()).Finalize(taghash.begin());
94  writer << taghash << taghash;
95  return writer;
96 }
CHashWriter TaggedHash(const std::string &tag)
Return a CHashWriter primed for tagged hashes (as specified in BIP 340).
Definition: hash.cpp:89
void Finalize(unsigned char hash[OUTPUT_SIZE])
Definition: hmac_sha512.cpp:29
CSHA256 & Write(const unsigned char *data, size_t len)
Definition: sha256.cpp:637
CHMAC_SHA512 & Write(const unsigned char *data, size_t len)
Definition: hmac_sha512.h:24
constexpr std::size_t size() const noexcept
Definition: span.h:153
unsigned char * begin()
Definition: uint256.h:58
unsigned int MurmurHash3(unsigned int nHashSeed, Span< const unsigned char > vDataToHash)
Definition: hash.cpp:16
void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
Definition: hash.cpp:72
static const unsigned char k1[32]
unsigned int size() const
Definition: uint256.h:78
static uint32_t ReadLE32(const unsigned char *ptr)
Definition: common.h:24
256-bit opaque blob.
Definition: uint256.h:124
uint256 SHA256Uint256(const uint256 &input)
Single-SHA256 a 32-byte input (represented as uint256).
Definition: hash.cpp:82
constexpr C * data() const noexcept
Definition: span.h:140
A writer stream (for serialization) that computes a 256-bit hash.
Definition: hash.h:100
A Span is an object that can refer to a contiguous sequence of objects.
Definition: span.h:82
A hasher class for SHA-256.
Definition: sha256.h:13
uint32_t ROTL32(uint32_t x, int8_t r)
Definition: hash.cpp:11
A hasher class for HMAC-SHA-512.
Definition: hmac_sha512.h:14