src/crypto/sha256.cpp

   1 // Copyright (c) 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 "crypto/sha256.h"
   6
   7 #include "crypto/common.h"
   8
   9 #include <string.h>
  10
  11 // Internal implementation code.
  12 namespace
  13 {
  14 /// Internal SHA-256 implementation.
  15 namespace sha256
  16 {
  17 uint32_t inline Ch(uint32_t x, uint32_t y, uint32_t z) { return z ^ (x & (y ^ z)); }
  18 uint32_t inline Maj(uint32_t x, uint32_t y, uint32_t z) { return (x & y) | (z & (x | y)); }
  19 uint32_t inline Sigma0(uint32_t x) { return (x >> 2 | x << 30) ^ (x >> 13 | x << 19) ^ (x >> 22 | x << 10); }
  20 uint32_t inline Sigma1(uint32_t x) { return (x >> 6 | x << 26) ^ (x >> 11 | x << 21) ^ (x >> 25 | x << 7); }
  21 uint32_t inline sigma0(uint32_t x) { return (x >> 7 | x << 25) ^ (x >> 18 | x << 14) ^ (x >> 3); }
  22 uint32_t inline sigma1(uint32_t x) { return (x >> 17 | x << 15) ^ (x >> 19 | x << 13) ^ (x >> 10); }
  23
  24 /** One round of SHA-256. */
  25 void inline Round(uint32_t a, uint32_t b, uint32_t c, uint32_t& d, uint32_t e, uint32_t f, uint32_t g, uint32_t& h, uint32_t k, uint32_t w)
  26 {
  27     uint32_t t1 = h + Sigma1(e) + Ch(e, f, g) + k + w;
  28     uint32_t t2 = Sigma0(a) + Maj(a, b, c);
  29     d += t1;
  30     h = t1 + t2;
  31 }
  32
  33 /** Initialize SHA-256 state. */
  34 void inline Initialize(uint32_t* s)
  35 {
  36     s[0] = 0x6a09e667ul;
  37     s[1] = 0xbb67ae85ul;
  38     s[2] = 0x3c6ef372ul;
  39     s[3] = 0xa54ff53aul;
  40     s[4] = 0x510e527ful;
  41     s[5] = 0x9b05688cul;
  42     s[6] = 0x1f83d9abul;
  43     s[7] = 0x5be0cd19ul;
  44 }
  45
  46 /** Perform one SHA-256 transformation, processing a 64-byte chunk. */
  47 void Transform(uint32_t* s, const unsigned char* chunk)
  48 {
  49     uint32_t a = s[0], b = s[1], c = s[2], d = s[3], e = s[4], f = s[5], g = s[6], h = s[7];
  50     uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;
  51
  52     Round(a, b, c, d, e, f, g, h, 0x428a2f98, w0 = ReadBE32(chunk + 0));
  53     Round(h, a, b, c, d, e, f, g, 0x71374491, w1 = ReadBE32(chunk + 4));
  54     Round(g, h, a, b, c, d, e, f, 0xb5c0fbcf, w2 = ReadBE32(chunk + 8));
  55     Round(f, g, h, a, b, c, d, e, 0xe9b5dba5, w3 = ReadBE32(chunk + 12));
  56     Round(e, f, g, h, a, b, c, d, 0x3956c25b, w4 = ReadBE32(chunk + 16));
  57     Round(d, e, f, g, h, a, b, c, 0x59f111f1, w5 = ReadBE32(chunk + 20));
  58     Round(c, d, e, f, g, h, a, b, 0x923f82a4, w6 = ReadBE32(chunk + 24));
  59     Round(b, c, d, e, f, g, h, a, 0xab1c5ed5, w7 = ReadBE32(chunk + 28));
  60     Round(a, b, c, d, e, f, g, h, 0xd807aa98, w8 = ReadBE32(chunk + 32));
  61     Round(h, a, b, c, d, e, f, g, 0x12835b01, w9 = ReadBE32(chunk + 36));
  62     Round(g, h, a, b, c, d, e, f, 0x243185be, w10 = ReadBE32(chunk + 40));
  63     Round(f, g, h, a, b, c, d, e, 0x550c7dc3, w11 = ReadBE32(chunk + 44));
  64     Round(e, f, g, h, a, b, c, d, 0x72be5d74, w12 = ReadBE32(chunk + 48));
  65     Round(d, e, f, g, h, a, b, c, 0x80deb1fe, w13 = ReadBE32(chunk + 52));
  66     Round(c, d, e, f, g, h, a, b, 0x9bdc06a7, w14 = ReadBE32(chunk + 56));
  67     Round(b, c, d, e, f, g, h, a, 0xc19bf174, w15 = ReadBE32(chunk + 60));
  68
  69     Round(a, b, c, d, e, f, g, h, 0xe49b69c1, w0 += sigma1(w14) + w9 + sigma0(w1));
  70     Round(h, a, b, c, d, e, f, g, 0xefbe4786, w1 += sigma1(w15) + w10 + sigma0(w2));
  71     Round(g, h, a, b, c, d, e, f, 0x0fc19dc6, w2 += sigma1(w0) + w11 + sigma0(w3));
  72     Round(f, g, h, a, b, c, d, e, 0x240ca1cc, w3 += sigma1(w1) + w12 + sigma0(w4));
  73     Round(e, f, g, h, a, b, c, d, 0x2de92c6f, w4 += sigma1(w2) + w13 + sigma0(w5));
  74     Round(d, e, f, g, h, a, b, c, 0x4a7484aa, w5 += sigma1(w3) + w14 + sigma0(w6));
  75     Round(c, d, e, f, g, h, a, b, 0x5cb0a9dc, w6 += sigma1(w4) + w15 + sigma0(w7));
  76     Round(b, c, d, e, f, g, h, a, 0x76f988da, w7 += sigma1(w5) + w0 + sigma0(w8));
  77     Round(a, b, c, d, e, f, g, h, 0x983e5152, w8 += sigma1(w6) + w1 + sigma0(w9));
  78     Round(h, a, b, c, d, e, f, g, 0xa831c66d, w9 += sigma1(w7) + w2 + sigma0(w10));
  79     Round(g, h, a, b, c, d, e, f, 0xb00327c8, w10 += sigma1(w8) + w3 + sigma0(w11));
  80     Round(f, g, h, a, b, c, d, e, 0xbf597fc7, w11 += sigma1(w9) + w4 + sigma0(w12));
  81     Round(e, f, g, h, a, b, c, d, 0xc6e00bf3, w12 += sigma1(w10) + w5 + sigma0(w13));
  82     Round(d, e, f, g, h, a, b, c, 0xd5a79147, w13 += sigma1(w11) + w6 + sigma0(w14));
  83     Round(c, d, e, f, g, h, a, b, 0x06ca6351, w14 += sigma1(w12) + w7 + sigma0(w15));
  84     Round(b, c, d, e, f, g, h, a, 0x14292967, w15 += sigma1(w13) + w8 + sigma0(w0));
  85
  86     Round(a, b, c, d, e, f, g, h, 0x27b70a85, w0 += sigma1(w14) + w9 + sigma0(w1));
  87     Round(h, a, b, c, d, e, f, g, 0x2e1b2138, w1 += sigma1(w15) + w10 + sigma0(w2));
  88     Round(g, h, a, b, c, d, e, f, 0x4d2c6dfc, w2 += sigma1(w0) + w11 + sigma0(w3));
  89     Round(f, g, h, a, b, c, d, e, 0x53380d13, w3 += sigma1(w1) + w12 + sigma0(w4));
  90     Round(e, f, g, h, a, b, c, d, 0x650a7354, w4 += sigma1(w2) + w13 + sigma0(w5));
  91     Round(d, e, f, g, h, a, b, c, 0x766a0abb, w5 += sigma1(w3) + w14 + sigma0(w6));
  92     Round(c, d, e, f, g, h, a, b, 0x81c2c92e, w6 += sigma1(w4) + w15 + sigma0(w7));
  93     Round(b, c, d, e, f, g, h, a, 0x92722c85, w7 += sigma1(w5) + w0 + sigma0(w8));
  94     Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1, w8 += sigma1(w6) + w1 + sigma0(w9));
  95     Round(h, a, b, c, d, e, f, g, 0xa81a664b, w9 += sigma1(w7) + w2 + sigma0(w10));
  96     Round(g, h, a, b, c, d, e, f, 0xc24b8b70, w10 += sigma1(w8) + w3 + sigma0(w11));
  97     Round(f, g, h, a, b, c, d, e, 0xc76c51a3, w11 += sigma1(w9) + w4 + sigma0(w12));
  98     Round(e, f, g, h, a, b, c, d, 0xd192e819, w12 += sigma1(w10) + w5 + sigma0(w13));
  99     Round(d, e, f, g, h, a, b, c, 0xd6990624, w13 += sigma1(w11) + w6 + sigma0(w14));
 100     Round(c, d, e, f, g, h, a, b, 0xf40e3585, w14 += sigma1(w12) + w7 + sigma0(w15));
 101     Round(b, c, d, e, f, g, h, a, 0x106aa070, w15 += sigma1(w13) + w8 + sigma0(w0));
 102
 103     Round(a, b, c, d, e, f, g, h, 0x19a4c116, w0 += sigma1(w14) + w9 + sigma0(w1));
 104     Round(h, a, b, c, d, e, f, g, 0x1e376c08, w1 += sigma1(w15) + w10 + sigma0(w2));
 105     Round(g, h, a, b, c, d, e, f, 0x2748774c, w2 += sigma1(w0) + w11 + sigma0(w3));
 106     Round(f, g, h, a, b, c, d, e, 0x34b0bcb5, w3 += sigma1(w1) + w12 + sigma0(w4));
 107     Round(e, f, g, h, a, b, c, d, 0x391c0cb3, w4 += sigma1(w2) + w13 + sigma0(w5));
 108     Round(d, e, f, g, h, a, b, c, 0x4ed8aa4a, w5 += sigma1(w3) + w14 + sigma0(w6));
 109     Round(c, d, e, f, g, h, a, b, 0x5b9cca4f, w6 += sigma1(w4) + w15 + sigma0(w7));
 110     Round(b, c, d, e, f, g, h, a, 0x682e6ff3, w7 += sigma1(w5) + w0 + sigma0(w8));
 111     Round(a, b, c, d, e, f, g, h, 0x748f82ee, w8 += sigma1(w6) + w1 + sigma0(w9));
 112     Round(h, a, b, c, d, e, f, g, 0x78a5636f, w9 += sigma1(w7) + w2 + sigma0(w10));
 113     Round(g, h, a, b, c, d, e, f, 0x84c87814, w10 += sigma1(w8) + w3 + sigma0(w11));
 114     Round(f, g, h, a, b, c, d, e, 0x8cc70208, w11 += sigma1(w9) + w4 + sigma0(w12));
 115     Round(e, f, g, h, a, b, c, d, 0x90befffa, w12 += sigma1(w10) + w5 + sigma0(w13));
 116     Round(d, e, f, g, h, a, b, c, 0xa4506ceb, w13 += sigma1(w11) + w6 + sigma0(w14));
 117     Round(c, d, e, f, g, h, a, b, 0xbef9a3f7, w14 + sigma1(w12) + w7 + sigma0(w15));
 118     Round(b, c, d, e, f, g, h, a, 0xc67178f2, w15 + sigma1(w13) + w8 + sigma0(w0));
 119
 120     s[0] += a;
 121     s[1] += b;
 122     s[2] += c;
 123     s[3] += d;
 124     s[4] += e;
 125     s[5] += f;
 126     s[6] += g;
 127     s[7] += h;
 128 }
 129
 130 } // namespace sha256
 131 } // namespace
 132
 133
 134 ////// SHA-256
 135
 136 CSHA256::CSHA256() : bytes(0)
 137 {
 138     sha256::Initialize(s);
 139 }
 140
 141 CSHA256& CSHA256::Write(const unsigned char* data, size_t len)
 142 {
 143     const unsigned char* end = data + len;
 144     size_t bufsize = bytes % 64;
 145     if (bufsize && bufsize + len >= 64) {
 146         // Fill the buffer, and process it.
 147         memcpy(buf + bufsize, data, 64 - bufsize);
 148         bytes += 64 - bufsize;
 149         data += 64 - bufsize;
 150         sha256::Transform(s, buf);
 151         bufsize = 0;
 152     }
 153     while (end >= data + 64) {
 154         // Process full chunks directly from the source.
 155         sha256::Transform(s, data);
 156         bytes += 64;
 157         data += 64;
 158     }
 159     if (end > data) {
 160         // Fill the buffer with what remains.
 161         memcpy(buf + bufsize, data, end - data);
 162         bytes += end - data;
 163     }
 164     return *this;
 165 }
 166
 167 void CSHA256::Finalize(unsigned char hash[OUTPUT_SIZE])
 168 {
 169     static const unsigned char pad[64] = {0x80};
 170     unsigned char sizedesc[8];
 171     WriteBE64(sizedesc, bytes << 3);
 172     Write(pad, 1 + ((119 - (bytes % 64)) % 64));
 173     Write(sizedesc, 8);
 174     WriteBE32(hash, s[0]);
 175     WriteBE32(hash + 4, s[1]);
 176     WriteBE32(hash + 8, s[2]);
 177     WriteBE32(hash + 12, s[3]);
 178     WriteBE32(hash + 16, s[4]);
 179     WriteBE32(hash + 20, s[5]);
 180     WriteBE32(hash + 24, s[6]);
 181     WriteBE32(hash + 28, s[7]);
 182 }
 183
 184 CSHA256& CSHA256::Reset()
 185 {
 186     bytes = 0;
 187     sha256::Initialize(s);
 188     return *this;
 189 }