sha256比特币原版c++代码

sha256是一个计算hash 的过程，比特币的算法核心就是计算sha256。

sha256.h

// Copyright (c) 2014-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_CRYPTO_SHA256_H
#define BITCOIN_CRYPTO_SHA256_H

#include <cstdlib>
#include <stdint.h>
#include <string>

/** A hasher class for SHA-256. */
class CSHA256
{
private:
    uint32_t s[8];
    unsigned char buf[64];
    uint64_t bytes{0};

public:
    static const size_t OUTPUT_SIZE = 32;

    CSHA256();
    CSHA256& Write(const unsigned char* data, size_t len);
    void Finalize(unsigned char hash[OUTPUT_SIZE]);
    CSHA256& Reset();
};

namespace sha256_implementation {
enum UseImplementation : uint8_t {
    STANDARD = 0,
    USE_SSE4 = 1 << 0,
    USE_AVX2 = 1 << 1,
    USE_SHANI = 1 << 2,
    USE_SSE4_AND_AVX2 = USE_SSE4 | USE_AVX2,
    USE_SSE4_AND_SHANI = USE_SSE4 | USE_SHANI,
    USE_ALL = USE_SSE4 | USE_AVX2 | USE_SHANI,
};
}

/** Autodetect the best available SHA256 implementation.
 *  Returns the name of the implementation.
 */
std::string SHA256AutoDetect(sha256_implementation::UseImplementation use_implementation = sha256_implementation::USE_ALL);

/** Compute multiple double-SHA256's of 64-byte blobs.
 *  output:  pointer to a blocks*32 byte output buffer
 *  input:   pointer to a blocks*64 byte input buffer
 *  blocks:  the number of hashes to compute.
 */
void SHA256D64(unsigned char* output, const unsigned char* input, size_t blocks);

#endif // BITCOIN_CRYPTO_SHA256_H

sha256.cpp

// Copyright (c) 2014-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "sha256.h"
//#include <crypto/common.h>
#include <assert.h>
#include <string.h>

#include "common.h"
//#include "cpuid.h"

#if defined(__linux__) && defined(ENABLE_ARM_SHANI) && !defined(BUILD_BITCOIN_INTERNAL)
#include <sys/auxv.h>
#include <asm/hwcap.h>
#endif

#if defined(MAC_OSX) && defined(ENABLE_ARM_SHANI) && !defined(BUILD_BITCOIN_INTERNAL)
#include <sys/types.h>
#include <sys/sysctl.h>
#endif

#if defined(__x86_64__) || defined(__amd64__) || defined(__i386__)
#if defined(USE_ASM)
namespace sha256_sse4
{
void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks);
}
#endif
#endif

namespace sha256d64_sse41
{
void Transform_4way(unsigned char* out, const unsigned char* in);
}

namespace sha256d64_avx2
{
void Transform_8way(unsigned char* out, const unsigned char* in);
}

namespace sha256d64_x86_shani
{
void Transform_2way(unsigned char* out, const unsigned char* in);
}

namespace sha256_x86_shani
{
void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks);
}

namespace sha256_arm_shani
{
void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks);
}

namespace sha256d64_arm_shani
{
void Transform_2way(unsigned char* out, const unsigned char* in);
}

// Internal implementation code.
namespace
{
/// Internal SHA-256 implementation.
namespace sha256
{
uint32_t inline Ch(uint32_t x, uint32_t y, uint32_t z) { return z ^ (x & (y ^ z)); }
uint32_t inline Maj(uint32_t x, uint32_t y, uint32_t z) { return (x & y) | (z & (x | y)); }
uint32_t inline Sigma0(uint32_t x) { return (x >> 2 | x << 30) ^ (x >> 13 | x << 19) ^ (x >> 22 | x << 10); }
uint32_t inline Sigma1(uint32_t x) { return (x >> 6 | x << 26) ^ (x >> 11 | x << 21) ^ (x >> 25 | x << 7); }
uint32_t inline sigma0(uint32_t x) { return (x >> 7 | x << 25) ^ (x >> 18 | x << 14) ^ (x >> 3); }
uint32_t inline sigma1(uint32_t x) { return (x >> 17 | x << 15) ^ (x >> 19 | x << 13) ^ (x >> 10); }

/** One round of SHA-256. */
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 t1 = h + Sigma1(e) + Ch(e, f, g) + k;
    uint32_t t2 = Sigma0(a) + Maj(a, b, c);
    d += t1;
    h = t1 + t2;
}

/** Initialize SHA-256 state. */
void inline Initialize(uint32_t* s)
{
    s[0] = 0x6a09e667ul;
    s[1] = 0xbb67ae85ul;
    s[2] = 0x3c6ef372ul;
    s[3] = 0xa54ff53aul;
    s[4] = 0x510e527ful;
    s[5] = 0x9b05688cul;
    s[6] = 0x1f83d9abul;
    s[7] = 0x5be0cd19ul;
}

/** Perform a number of SHA-256 transformations, processing 64-byte chunks. */
void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks)
{
    while (blocks--) {
        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];
        uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;

        Round(a, b, c, d, e, f, g, h, 0x428a2f98 + (w0 = ReadBE32(chunk + 0)));
        Round(h, a, b, c, d, e, f, g, 0x71374491 + (w1 = ReadBE32(chunk + 4)));
        Round(g, h, a, b, c, d, e, f, 0xb5c0fbcf + (w2 = ReadBE32(chunk + 8)));
        Round(f, g, h, a, b, c, d, e, 0xe9b5dba5 + (w3 = ReadBE32(chunk + 12)));
        Round(e, f, g, h, a, b, c, d, 0x3956c25b + (w4 = ReadBE32(chunk + 16)));
        Round(d, e, f, g, h, a, b, c, 0x59f111f1 + (w5 = ReadBE32(chunk + 20)));
        Round(c, d, e, f, g, h, a, b, 0x923f82a4 + (w6 = ReadBE32(chunk + 24)));
        Round(b, c, d, e, f, g, h, a, 0xab1c5ed5 + (w7 = ReadBE32(chunk + 28)));
        Round(a, b, c, d, e, f, g, h, 0xd807aa98 + (w8 = ReadBE32(chunk + 32)));
        Round(h, a, b, c, d, e, f, g, 0x12835b01 + (w9 = ReadBE32(chunk + 36)));
        Round(g, h, a, b, c, d, e, f, 0x243185be + (w10 = ReadBE32(chunk + 40)));
        Round(f, g, h, a, b, c, d, e, 0x550c7dc3 + (w11 = ReadBE32(chunk + 44)));
        Round(e, f, g, h, a, b, c, d, 0x72be5d74 + (w12 = ReadBE32(chunk + 48)));
        Round(d, e, f, g, h, a, b, c, 0x80deb1fe + (w13 = ReadBE32(chunk + 52)));
        Round(c, d, e, f, g, h, a, b, 0x9bdc06a7 + (w14 = ReadBE32(chunk + 56)));
        Round(b, c, d, e, f, g, h, a, 0xc19bf174 + (w15 = ReadBE32(chunk + 60)));

        Round(a, b, c, d, e, f, g, h, 0xe49b69c1 + (w0 += sigma1(w14) + w9 + sigma0(w1)));
        Round(h, a, b, c, d, e, f, g, 0xefbe4786 + (w1 += sigma1(w15) + w10 + sigma0(w2)));
        Round(g, h, a, b, c, d, e, f, 0x0fc19dc6 + (w2 += sigma1(w0) + w11 + sigma0(w3)));
        Round(f, g, h, a, b, c, d, e, 0x240ca1cc + (w3 += sigma1(w1) + w12 + sigma0(w4)));
        Round(e, f, g, h, a, b, c, d, 0x2de92c6f + (w4 += sigma1(w2) + w13 + sigma0(w5)));
        Round(d, e, f, g, h, a, b, c, 0x4a7484aa + (w5 += sigma1(w3) + w14 + sigma0(w6)));
        Round(c, d, e, f, g, h, a, b, 0x5cb0a9dc + (w6 += sigma1(w4) + w15 + sigma0(w7)));
        Round(b, c, d, e, f, g, h, a, 0x76f988da + (w7 += sigma1(w5) + w0 + sigma0(w8)));
        Round(a, b, c, d, e, f, g, h, 0x983e5152 + (w8 += sigma1(w6) + w1 + sigma0(w9)));
        Round(h, a, b, c, d, e, f, g, 0xa831c66d + (w9 += sigma1(w7) + w2 + sigma0(w10)));
        Round(g, h, a, b, c, d, e, f, 0xb00327c8 + (w10 += sigma1(w8) + w3 + sigma0(w11)));
        Round(f, g, h, a, b, c, d, e, 0xbf597fc7 + (w11 += sigma1(w9) + w4 + sigma0(w12)));
        Round(e, f, g, h, a, b, c, d, 0xc6e00bf3 + (w12 += sigma1(w10) + w5 + sigma0(w13)));
        Round(d, e, f, g, h, a, b, c, 0xd5a79147 + (w13 += sigma1(w11) + w6 + sigma0(w14)));
        Round(c, d, e, f, g, h, a, b, 0x06ca6351 + (w14 += sigma1(w12) + w7 + sigma0(w15)));
        Round(b, c, d, e, f, g, h, a, 0x14292967 + (w15 += sigma1(w13) + w8 + sigma0(w0)));

        Round(a, b, c, d, e, f, g, h, 0x27b70a85 + (w0 += sigma1(w14) + w9 + sigma0(w1)));
        Round(h, a, b, c, d, e, f, g, 0x2e1b2138 + (w1 += sigma1(w15) + w10 + sigma0(w2)));
        Round(g, h, a, b, c, d, e, f, 0x4d2c6dfc + (w2 += sigma1(w0) + w11 + sigma0(w3)));
        Round(f, g, h, a, b, c, d, e, 0x53380d13 + (w3 += sigma1(w1) + w12 + sigma0(w4)));
        Round(e, f, g, h, a, b, c, d, 0x650a7354 + (w4 += sigma1(w2) + w13 + sigma0(w5)));
        Round(d, e, f, g, h, a, b, c, 0x766a0abb + (w5 += sigma1(w3) + w14 + sigma0(w6)));
        Round(c, d, e, f, g, h, a, b, 0x81c2c92e + (w6 += sigma1(w4) + w15 + sigma0(w7)));
        Round(b, c, d, e, f, g, h, a, 0x92722c85 + (w7 += sigma1(w5) + w0 + sigma0(w8)));
        Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1 + (w8 += sigma1(w6) + w1 + sigma0(w9)));
        Round(h, a, b, c, d, e, f, g, 0xa81a664b + (w9 += sigma1(w7) + w2 + sigma0(w10)));
        Round(g, h, a, b, c, d, e, f, 0xc24b8b70 + (w10 += sigma1(w8) + w3 + sigma0(w11)));
        Round(f, g, h, a, b, c, d, e, 0xc76c51a3 + (w11 += sigma1(w9) + w4 + sigma0(w12)));
        Round(e, f, g, h, a, b, c, d, 0xd192e819 + (w12 += sigma1(w10) + w5 + sigma0(w13)));
        Round(d, e, f, g, h, a, b, c, 0xd6990624 + (w13 += sigma1(w11) + w6 + sigma0(w14)));
        Round(c, d, e, f, g, h, a, b, 0xf40e3585 + (w14 += sigma1(w12) + w7 + sigma0(w15)));
        Round(b, c, d, e, f, g, h, a, 0x106aa070 + (w15 += sigma1(w13) + w8 + sigma0(w0)));

        Round(a, b, c, d, e, f, g, h, 0x19a4c116 + (w0 += sigma1(w14) + w9 + sigma0(w1)));
        Round(h, a, b, c, d, e, f, g, 0x1e376c08 + (w1 += sigma1(w15) + w10 + sigma0(w2)));
        Round(g, h, a, b, c, d, e, f, 0x2748774c + (w2 += sigma1(w0) + w11 + sigma0(w3)));
        Round(f, g, h, a, b, c, d, e, 0x34b0bcb5 + (w3 += sigma1(w1) + w12 + sigma0(w4)));
        Round(e, f, g, h, a, b, c, d, 0x391c0cb3 + (w4 += sigma1(w2) + w13 + sigma0(w5)));
        Round(d, e, f, g, h, a, b, c, 0x4ed8aa4a + (w5 += sigma1(w3) + w14 + sigma0(w6)));
        Round(c, d, e, f, g, h, a, b, 0x5b9cca4f + (w6 += sigma1(w4) + w15 + sigma0(w7)));
        Round(b, c, d, e, f, g, h, a, 0x682e6ff3 + (w7 += sigma1(w5) + w0 + sigma0(w8)));
        Round(a, b, c, d, e, f, g, h, 0x748f82ee + (w8 += sigma1(w6) + w1 + sigma0(w9)));
        Round(h, a, b, c, d, e, f, g, 0x78a5636f + (w9 += sigma1(w7) + w2 + sigma0(w10)));
        Round(g, h, a, b, c, d, e, f, 0x84c87814 + (w10 += sigma1(w8) + w3 + sigma0(w11)));
        Round(f, g, h, a, b, c, d, e, 0x8cc70208 + (w11 += sigma1(w9) + w4 + sigma0(w12)));
        Round(e, f, g, h, a, b, c, d, 0x90befffa + (w12 += sigma1(w10) + w5 + sigma0(w13)));
        Round(d, e, f, g, h, a, b, c, 0xa4506ceb + (w13 += sigma1(w11) + w6 + sigma0(w14)));
        Round(c, d, e, f, g, h, a, b, 0xbef9a3f7 + (w14 + sigma1(w12) + w7 + sigma0(w15)));
        Round(b, c, d, e, f, g, h, a, 0xc67178f2 + (w15 + sigma1(w13) + w8 + sigma0(w0)));

        s[0] += a;
        s[1] += b;
        s[2] += c;
        s[3] += d;
        s[4] += e;
        s[5] += f;
        s[6] += g;
        s[7] += h;
        chunk += 64;
    }
}

void TransformD64(unsigned char* out, const unsigned char* in)
{
    // Transform 1
    uint32_t a = 0x6a09e667ul;
    uint32_t b = 0xbb67ae85ul;
    uint32_t c = 0x3c6ef372ul;
    uint32_t d = 0xa54ff53aul;
    uint32_t e = 0x510e527ful;
    uint32_t f = 0x9b05688cul;
    uint32_t g = 0x1f83d9abul;
    uint32_t h = 0x5be0cd19ul;

    uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;

    Round(a, b, c, d, e, f, g, h, 0x428a2f98ul + (w0 = ReadBE32(in + 0)));
    Round(h, a, b, c, d, e, f, g, 0x71374491ul + (w1 = ReadBE32(in + 4)));
    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcful + (w2 = ReadBE32(in + 8)));
    Round(f, g, h, a, b, c, d, e, 0xe9b5dba5ul + (w3 = ReadBE32(in + 12)));
    Round(e, f, g, h, a, b, c, d, 0x3956c25bul + (w4 = ReadBE32(in + 16)));
    Round(d, e, f, g, h, a, b, c, 0x59f111f1ul + (w5 = ReadBE32(in + 20)));
    Round(c, d, e, f, g, h, a, b, 0x923f82a4ul + (w6 = ReadBE32(in + 24)));
    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5ul + (w7 = ReadBE32(in + 28)));
    Round(a, b, c, d, e, f, g, h, 0xd807aa98ul + (w8 = ReadBE32(in + 32)));
    Round(h, a, b, c, d, e, f, g, 0x12835b01ul + (w9 = ReadBE32(in + 36)));
    Round(g, h, a, b, c, d, e, f, 0x243185beul + (w10 = ReadBE32(in + 40)));
    Round(f, g, h, a, b, c, d, e, 0x550c7dc3ul + (w11 = ReadBE32(in + 44)));
    Round(e, f, g, h, a, b, c, d, 0x72be5d74ul + (w12 = ReadBE32(in + 48)));
    Round(d, e, f, g, h, a, b, c, 0x80deb1feul + (w13 = ReadBE32(in + 52)));
    Round(c, d, e, f, g, h, a, b, 0x9bdc06a7ul + (w14 = ReadBE32(in + 56)));
    Round(b, c, d, e, f, g, h, a, 0xc19bf174ul + (w15 = ReadBE32(in + 60)));
    Round(a, b, c, d, e, f, g, h, 0xe49b69c1ul + (w0 += sigma1(w14) + w9 + sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0xefbe4786ul + (w1 += sigma1(w15) + w10 + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x0fc19dc6ul + (w2 += sigma1(w0) + w11 + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x240ca1ccul + (w3 += sigma1(w1) + w12 + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x2de92c6ful + (w4 += sigma1(w2) + w13 + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x4a7484aaul + (w5 += sigma1(w3) + w14 + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x5cb0a9dcul + (w6 += sigma1(w4) + w15 + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x76f988daul + (w7 += sigma1(w5) + w0 + sigma0(w8)));
    Round(a, b, c, d, e, f, g, h, 0x983e5152ul + (w8 += sigma1(w6) + w1 + sigma0(w9)));
    Round(h, a, b, c, d, e, f, g, 0xa831c66dul + (w9 += sigma1(w7) + w2 + sigma0(w10)));
    Round(g, h, a, b, c, d, e, f, 0xb00327c8ul + (w10 += sigma1(w8) + w3 + sigma0(w11)));
    Round(f, g, h, a, b, c, d, e, 0xbf597fc7ul + (w11 += sigma1(w9) + w4 + sigma0(w12)));
    Round(e, f, g, h, a, b, c, d, 0xc6e00bf3ul + (w12 += sigma1(w10) + w5 + sigma0(w13)));
    Round(d, e, f, g, h, a, b, c, 0xd5a79147ul + (w13 += sigma1(w11) + w6 + sigma0(w14)));
    Round(c, d, e, f, g, h, a, b, 0x06ca6351ul + (w14 += sigma1(w12) + w7 + sigma0(w15)));
    Round(b, c, d, e, f, g, h, a, 0x14292967ul + (w15 += sigma1(w13) + w8 + sigma0(w0)));
    Round(a, b, c, d, e, f, g, h, 0x27b70a85ul + (w0 += sigma1(w14) + w9 + sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0x2e1b2138ul + (w1 += sigma1(w15) + w10 + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x4d2c6dfcul + (w2 += sigma1(w0) + w11 + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x53380d13ul + (w3 += sigma1(w1) + w12 + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x650a7354ul + (w4 += sigma1(w2) + w13 + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x766a0abbul + (w5 += sigma1(w3) + w14 + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x81c2c92eul + (w6 += sigma1(w4) + w15 + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x92722c85ul + (w7 += sigma1(w5) + w0 + sigma0(w8)));
    Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1ul + (w8 += sigma1(w6) + w1 + sigma0(w9)));
    Round(h, a, b, c, d, e, f, g, 0xa81a664bul + (w9 += sigma1(w7) + w2 + sigma0(w10)));
    Round(g, h, a, b, c, d, e, f, 0xc24b8b70ul + (w10 += sigma1(w8) + w3 + sigma0(w11)));
    Round(f, g, h, a, b, c, d, e, 0xc76c51a3ul + (w11 += sigma1(w9) + w4 + sigma0(w12)));
    Round(e, f, g, h, a, b, c, d, 0xd192e819ul + (w12 += sigma1(w10) + w5 + sigma0(w13)));
    Round(d, e, f, g, h, a, b, c, 0xd6990624ul + (w13 += sigma1(w11) + w6 + sigma0(w14)));
    Round(c, d, e, f, g, h, a, b, 0xf40e3585ul + (w14 += sigma1(w12) + w7 + sigma0(w15)));
    Round(b, c, d, e, f, g, h, a, 0x106aa070ul + (w15 += sigma1(w13) + w8 + sigma0(w0)));
    Round(a, b, c, d, e, f, g, h, 0x19a4c116ul + (w0 += sigma1(w14) + w9 + sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0x1e376c08ul + (w1 += sigma1(w15) + w10 + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x2748774cul + (w2 += sigma1(w0) + w11 + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x34b0bcb5ul + (w3 += sigma1(w1) + w12 + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x391c0cb3ul + (w4 += sigma1(w2) + w13 + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x4ed8aa4aul + (w5 += sigma1(w3) + w14 + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x5b9cca4ful + (w6 += sigma1(w4) + w15 + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x682e6ff3ul + (w7 += sigma1(w5) + w0 + sigma0(w8)));
    Round(a, b, c, d, e, f, g, h, 0x748f82eeul + (w8 += sigma1(w6) + w1 + sigma0(w9)));
    Round(h, a, b, c, d, e, f, g, 0x78a5636ful + (w9 += sigma1(w7) + w2 + sigma0(w10)));
    Round(g, h, a, b, c, d, e, f, 0x84c87814ul + (w10 += sigma1(w8) + w3 + sigma0(w11)));
    Round(f, g, h, a, b, c, d, e, 0x8cc70208ul + (w11 += sigma1(w9) + w4 + sigma0(w12)));
    Round(e, f, g, h, a, b, c, d, 0x90befffaul + (w12 += sigma1(w10) + w5 + sigma0(w13)));
    Round(d, e, f, g, h, a, b, c, 0xa4506cebul + (w13 += sigma1(w11) + w6 + sigma0(w14)));
    Round(c, d, e, f, g, h, a, b, 0xbef9a3f7ul + (w14 + sigma1(w12) + w7 + sigma0(w15)));
    Round(b, c, d, e, f, g, h, a, 0xc67178f2ul + (w15 + sigma1(w13) + w8 + sigma0(w0)));

    a += 0x6a09e667ul;
    b += 0xbb67ae85ul;
    c += 0x3c6ef372ul;
    d += 0xa54ff53aul;
    e += 0x510e527ful;
    f += 0x9b05688cul;
    g += 0x1f83d9abul;
    h += 0x5be0cd19ul;

    uint32_t t0 = a, t1 = b, t2 = c, t3 = d, t4 = e, t5 = f, t6 = g, t7 = h;

    // Transform 2
    Round(a, b, c, d, e, f, g, h, 0xc28a2f98ul);
    Round(h, a, b, c, d, e, f, g, 0x71374491ul);
    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcful);
    Round(f, g, h, a, b, c, d, e, 0xe9b5dba5ul);
    Round(e, f, g, h, a, b, c, d, 0x3956c25bul);
    Round(d, e, f, g, h, a, b, c, 0x59f111f1ul);
    Round(c, d, e, f, g, h, a, b, 0x923f82a4ul);
    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5ul);
    Round(a, b, c, d, e, f, g, h, 0xd807aa98ul);
    Round(h, a, b, c, d, e, f, g, 0x12835b01ul);
    Round(g, h, a, b, c, d, e, f, 0x243185beul);
    Round(f, g, h, a, b, c, d, e, 0x550c7dc3ul);
    Round(e, f, g, h, a, b, c, d, 0x72be5d74ul);
    Round(d, e, f, g, h, a, b, c, 0x80deb1feul);
    Round(c, d, e, f, g, h, a, b, 0x9bdc06a7ul);
    Round(b, c, d, e, f, g, h, a, 0xc19bf374ul);
    Round(a, b, c, d, e, f, g, h, 0x649b69c1ul);
    Round(h, a, b, c, d, e, f, g, 0xf0fe4786ul);
    Round(g, h, a, b, c, d, e, f, 0x0fe1edc6ul);
    Round(f, g, h, a, b, c, d, e, 0x240cf254ul);
    Round(e, f, g, h, a, b, c, d, 0x4fe9346ful);
    Round(d, e, f, g, h, a, b, c, 0x6cc984beul);
    Round(c, d, e, f, g, h, a, b, 0x61b9411eul);
    Round(b, c, d, e, f, g, h, a, 0x16f988faul);
    Round(a, b, c, d, e, f, g, h, 0xf2c65152ul);
    Round(h, a, b, c, d, e, f, g, 0xa88e5a6dul);
    Round(g, h, a, b, c, d, e, f, 0xb019fc65ul);
    Round(f, g, h, a, b, c, d, e, 0xb9d99ec7ul);
    Round(e, f, g, h, a, b, c, d, 0x9a1231c3ul);
    Round(d, e, f, g, h, a, b, c, 0xe70eeaa0ul);
    Round(c, d, e, f, g, h, a, b, 0xfdb1232bul);
    Round(b, c, d, e, f, g, h, a, 0xc7353eb0ul);
    Round(a, b, c, d, e, f, g, h, 0x3069bad5ul);
    Round(h, a, b, c, d, e, f, g, 0xcb976d5ful);
    Round(g, h, a, b, c, d, e, f, 0x5a0f118ful);
    Round(f, g, h, a, b, c, d, e, 0xdc1eeefdul);
    Round(e, f, g, h, a, b, c, d, 0x0a35b689ul);
    Round(d, e, f, g, h, a, b, c, 0xde0b7a04ul);
    Round(c, d, e, f, g, h, a, b, 0x58f4ca9dul);
    Round(b, c, d, e, f, g, h, a, 0xe15d5b16ul);
    Round(a, b, c, d, e, f, g, h, 0x007f3e86ul);
    Round(h, a, b, c, d, e, f, g, 0x37088980ul);
    Round(g, h, a, b, c, d, e, f, 0xa507ea32ul);
    Round(f, g, h, a, b, c, d, e, 0x6fab9537ul);
    Round(e, f, g, h, a, b, c, d, 0x17406110ul);
    Round(d, e, f, g, h, a, b, c, 0x0d8cd6f1ul);
    Round(c, d, e, f, g, h, a, b, 0xcdaa3b6dul);
    Round(b, c, d, e, f, g, h, a, 0xc0bbbe37ul);
    Round(a, b, c, d, e, f, g, h, 0x83613bdaul);
    Round(h, a, b, c, d, e, f, g, 0xdb48a363ul);
    Round(g, h, a, b, c, d, e, f, 0x0b02e931ul);
    Round(f, g, h, a, b, c, d, e, 0x6fd15ca7ul);
    Round(e, f, g, h, a, b, c, d, 0x521afacaul);
    Round(d, e, f, g, h, a, b, c, 0x31338431ul);
    Round(c, d, e, f, g, h, a, b, 0x6ed41a95ul);
    Round(b, c, d, e, f, g, h, a, 0x6d437890ul);
    Round(a, b, c, d, e, f, g, h, 0xc39c91f2ul);
    Round(h, a, b, c, d, e, f, g, 0x9eccabbdul);
    Round(g, h, a, b, c, d, e, f, 0xb5c9a0e6ul);
    Round(f, g, h, a, b, c, d, e, 0x532fb63cul);
    Round(e, f, g, h, a, b, c, d, 0xd2c741c6ul);
    Round(d, e, f, g, h, a, b, c, 0x07237ea3ul);
    Round(c, d, e, f, g, h, a, b, 0xa4954b68ul);
    Round(b, c, d, e, f, g, h, a, 0x4c191d76ul);

    w0 = t0 + a;
    w1 = t1 + b;
    w2 = t2 + c;
    w3 = t3 + d;
    w4 = t4 + e;
    w5 = t5 + f;
    w6 = t6 + g;
    w7 = t7 + h;

    // Transform 3
    a = 0x6a09e667ul;
    b = 0xbb67ae85ul;
    c = 0x3c6ef372ul;
    d = 0xa54ff53aul;
    e = 0x510e527ful;
    f = 0x9b05688cul;
    g = 0x1f83d9abul;
    h = 0x5be0cd19ul;

    Round(a, b, c, d, e, f, g, h, 0x428a2f98ul + w0);
    Round(h, a, b, c, d, e, f, g, 0x71374491ul + w1);
    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcful + w2);
    Round(f, g, h, a, b, c, d, e, 0xe9b5dba5ul + w3);
    Round(e, f, g, h, a, b, c, d, 0x3956c25bul + w4);
    Round(d, e, f, g, h, a, b, c, 0x59f111f1ul + w5);
    Round(c, d, e, f, g, h, a, b, 0x923f82a4ul + w6);
    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5ul + w7);
    Round(a, b, c, d, e, f, g, h, 0x5807aa98ul);
    Round(h, a, b, c, d, e, f, g, 0x12835b01ul);
    Round(g, h, a, b, c, d, e, f, 0x243185beul);
    Round(f, g, h, a, b, c, d, e, 0x550c7dc3ul);
    Round(e, f, g, h, a, b, c, d, 0x72be5d74ul);
    Round(d, e, f, g, h, a, b, c, 0x80deb1feul);
    Round(c, d, e, f, g, h, a, b, 0x9bdc06a7ul);
    Round(b, c, d, e, f, g, h, a, 0xc19bf274ul);
    Round(a, b, c, d, e, f, g, h, 0xe49b69c1ul + (w0 += sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0xefbe4786ul + (w1 += 0xa00000ul + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x0fc19dc6ul + (w2 += sigma1(w0) + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x240ca1ccul + (w3 += sigma1(w1) + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x2de92c6ful + (w4 += sigma1(w2) + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x4a7484aaul + (w5 += sigma1(w3) + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x5cb0a9dcul + (w6 += sigma1(w4) + 0x100ul + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x76f988daul + (w7 += sigma1(w5) + w0 + 0x11002000ul));
    Round(a, b, c, d, e, f, g, h, 0x983e5152ul + (w8 = 0x80000000ul + sigma1(w6) + w1));
    Round(h, a, b, c, d, e, f, g, 0xa831c66dul + (w9 = sigma1(w7) + w2));
    Round(g, h, a, b, c, d, e, f, 0xb00327c8ul + (w10 = sigma1(w8) + w3));
    Round(f, g, h, a, b, c, d, e, 0xbf597fc7ul + (w11 = sigma1(w9) + w4));
    Round(e, f, g, h, a, b, c, d, 0xc6e00bf3ul + (w12 = sigma1(w10) + w5));
    Round(d, e, f, g, h, a, b, c, 0xd5a79147ul + (w13 = sigma1(w11) + w6));
    Round(c, d, e, f, g, h, a, b, 0x06ca6351ul + (w14 = sigma1(w12) + w7 + 0x400022ul));
    Round(b, c, d, e, f, g, h, a, 0x14292967ul + (w15 = 0x100ul + sigma1(w13) + w8 + sigma0(w0)));
    Round(a, b, c, d, e, f, g, h, 0x27b70a85ul + (w0 += sigma1(w14) + w9 + sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0x2e1b2138ul + (w1 += sigma1(w15) + w10 + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x4d2c6dfcul + (w2 += sigma1(w0) + w11 + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x53380d13ul + (w3 += sigma1(w1) + w12 + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x650a7354ul + (w4 += sigma1(w2) + w13 + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x766a0abbul + (w5 += sigma1(w3) + w14 + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x81c2c92eul + (w6 += sigma1(w4) + w15 + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x92722c85ul + (w7 += sigma1(w5) + w0 + sigma0(w8)));
    Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1ul + (w8 += sigma1(w6) + w1 + sigma0(w9)));
    Round(h, a, b, c, d, e, f, g, 0xa81a664bul + (w9 += sigma1(w7) + w2 + sigma0(w10)));
    Round(g, h, a, b, c, d, e, f, 0xc24b8b70ul + (w10 += sigma1(w8) + w3 + sigma0(w11)));
    Round(f, g, h, a, b, c, d, e, 0xc76c51a3ul + (w11 += sigma1(w9) + w4 + sigma0(w12)));
    Round(e, f, g, h, a, b, c, d, 0xd192e819ul + (w12 += sigma1(w10) + w5 + sigma0(w13)));
    Round(d, e, f, g, h, a, b, c, 0xd6990624ul + (w13 += sigma1(w11) + w6 + sigma0(w14)));
    Round(c, d, e, f, g, h, a, b, 0xf40e3585ul + (w14 += sigma1(w12) + w7 + sigma0(w15)));
    Round(b, c, d, e, f, g, h, a, 0x106aa070ul + (w15 += sigma1(w13) + w8 + sigma0(w0)));
    Round(a, b, c, d, e, f, g, h, 0x19a4c116ul + (w0 += sigma1(w14) + w9 + sigma0(w1)));
    Round(h, a, b, c, d, e, f, g, 0x1e376c08ul + (w1 += sigma1(w15) + w10 + sigma0(w2)));
    Round(g, h, a, b, c, d, e, f, 0x2748774cul + (w2 += sigma1(w0) + w11 + sigma0(w3)));
    Round(f, g, h, a, b, c, d, e, 0x34b0bcb5ul + (w3 += sigma1(w1) + w12 + sigma0(w4)));
    Round(e, f, g, h, a, b, c, d, 0x391c0cb3ul + (w4 += sigma1(w2) + w13 + sigma0(w5)));
    Round(d, e, f, g, h, a, b, c, 0x4ed8aa4aul + (w5 += sigma1(w3) + w14 + sigma0(w6)));
    Round(c, d, e, f, g, h, a, b, 0x5b9cca4ful + (w6 += sigma1(w4) + w15 + sigma0(w7)));
    Round(b, c, d, e, f, g, h, a, 0x682e6ff3ul + (w7 += sigma1(w5) + w0 + sigma0(w8)));
    Round(a, b, c, d, e, f, g, h, 0x748f82eeul + (w8 += sigma1(w6) + w1 + sigma0(w9)));
    Round(h, a, b, c, d, e, f, g, 0x78a5636ful + (w9 += sigma1(w7) + w2 + sigma0(w10)));
    Round(g, h, a, b, c, d, e, f, 0x84c87814ul + (w10 += sigma1(w8) + w3 + sigma0(w11)));
    Round(f, g, h, a, b, c, d, e, 0x8cc70208ul + (w11 += sigma1(w9) + w4 + sigma0(w12)));
    Round(e, f, g, h, a, b, c, d, 0x90befffaul + (w12 += sigma1(w10) + w5 + sigma0(w13)));
    Round(d, e, f, g, h, a, b, c, 0xa4506cebul + (w13 += sigma1(w11) + w6 + sigma0(w14)));
    Round(c, d, e, f, g, h, a, b, 0xbef9a3f7ul + (w14 + sigma1(w12) + w7 + sigma0(w15)));
    Round(b, c, d, e, f, g, h, a, 0xc67178f2ul + (w15 + sigma1(w13) + w8 + sigma0(w0)));

    // Output
    WriteBE32(out + 0, a + 0x6a09e667ul);
    WriteBE32(out + 4, b + 0xbb67ae85ul);
    WriteBE32(out + 8, c + 0x3c6ef372ul);
    WriteBE32(out + 12, d + 0xa54ff53aul);
    WriteBE32(out + 16, e + 0x510e527ful);
    WriteBE32(out + 20, f + 0x9b05688cul);
    WriteBE32(out + 24, g + 0x1f83d9abul);
    WriteBE32(out + 28, h + 0x5be0cd19ul);
}

} // namespace sha256

typedef void (*TransformType)(uint32_t*, const unsigned char*, size_t);
typedef void (*TransformD64Type)(unsigned char*, const unsigned char*);

template<TransformType tr>
void TransformD64Wrapper(unsigned char* out, const unsigned char* in)
{
    uint32_t s[8];
    static const unsigned char padding1[64] = {
        0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0
    };
    unsigned char buffer2[64] = {
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0
    };
    sha256::Initialize(s);
    tr(s, in, 1);
    tr(s, padding1, 1);
    WriteBE32(buffer2 + 0, s[0]);
    WriteBE32(buffer2 + 4, s[1]);
    WriteBE32(buffer2 + 8, s[2]);
    WriteBE32(buffer2 + 12, s[3]);
    WriteBE32(buffer2 + 16, s[4]);
    WriteBE32(buffer2 + 20, s[5]);
    WriteBE32(buffer2 + 24, s[6]);
    WriteBE32(buffer2 + 28, s[7]);
    sha256::Initialize(s);
    tr(s, buffer2, 1);
    WriteBE32(out + 0, s[0]);
    WriteBE32(out + 4, s[1]);
    WriteBE32(out + 8, s[2]);
    WriteBE32(out + 12, s[3]);
    WriteBE32(out + 16, s[4]);
    WriteBE32(out + 20, s[5]);
    WriteBE32(out + 24, s[6]);
    WriteBE32(out + 28, s[7]);
}

TransformType Transform = sha256::Transform;
TransformD64Type TransformD64 = sha256::TransformD64;
TransformD64Type TransformD64_2way = nullptr;
TransformD64Type TransformD64_4way = nullptr;
TransformD64Type TransformD64_8way = nullptr;

bool SelfTest() {
    // Input state (equal to the initial SHA256 state)
    static const uint32_t init[8] = {
        0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, 0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul
    };
    // Some random input data to test with
    static const unsigned char data[641] = "-" // Intentionally not aligned
        "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do "
        "eiusmod tempor incididunt ut labore et dolore magna aliqua. Et m"
        "olestie ac feugiat sed lectus vestibulum mattis ullamcorper. Mor"
        "bi blandit cursus risus at ultrices mi tempus imperdiet nulla. N"
        "unc congue nisi vita suscipit tellus mauris. Imperdiet proin fer"
        "mentum leo vel orci. Massa tempor nec feugiat nisl pretium fusce"
        " id velit. Telus in metus vulputate eu scelerisque felis. Mi tem"
        "pus imperdiet nulla malesuada pellentesque. Tristique magna sit.";
    // Expected output state for hashing the i*64 first input bytes above (excluding SHA256 padding).
    static const uint32_t result[9][8] = {
        {0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, 0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul},
        {0x91f8ec6bul, 0x4da10fe3ul, 0x1c9c292cul, 0x45e18185ul, 0x435cc111ul, 0x3ca26f09ul, 0xeb954caeul, 0x402a7069ul},
        {0xcabea5acul, 0x374fb97cul, 0x182ad996ul, 0x7bd69cbful, 0x450ff900ul, 0xc1d2be8aul, 0x6a41d505ul, 0xe6212dc3ul},
        {0xbcff09d6ul, 0x3e76f36eul, 0x3ecb2501ul, 0x78866e97ul, 0xe1c1e2fdul, 0x32f4eafful, 0x8aa6c4e5ul, 0xdfc024bcul},
        {0xa08c5d94ul, 0x0a862f93ul, 0x6b7f2f40ul, 0x8f9fae76ul, 0x6d40439ful, 0x79dcee0cul, 0x3e39ff3aul, 0xdc3bdbb1ul},
        {0x216a0895ul, 0x9f1a3662ul, 0xe99946f9ul, 0x87ba4364ul, 0x0fb5db2cul, 0x12bed3d3ul, 0x6689c0c7ul, 0x292f1b04ul},
        {0xca3067f8ul, 0xbc8c2656ul, 0x37cb7e0dul, 0x9b6b8b0ful, 0x46dc380bul, 0xf1287f57ul, 0xc42e4b23ul, 0x3fefe94dul},
        {0x3e4c4039ul, 0xbb6fca8cul, 0x6f27d2f7ul, 0x301e44a4ul, 0x8352ba14ul, 0x5769ce37ul, 0x48a1155ful, 0xc0e1c4c6ul},
        {0xfe2fa9ddul, 0x69d0862bul, 0x1ae0db23ul, 0x471f9244ul, 0xf55c0145ul, 0xc30f9c3bul, 0x40a84ea0ul, 0x5b8a266cul},
    };
    // Expected output for each of the individual 8 64-byte messages under full double SHA256 (including padding).
    static const unsigned char result_d64[256] = {
        0x09, 0x3a, 0xc4, 0xd0, 0x0f, 0xf7, 0x57, 0xe1, 0x72, 0x85, 0x79, 0x42, 0xfe, 0xe7, 0xe0, 0xa0,
        0xfc, 0x52, 0xd7, 0xdb, 0x07, 0x63, 0x45, 0xfb, 0x53, 0x14, 0x7d, 0x17, 0x22, 0x86, 0xf0, 0x52,
        0x48, 0xb6, 0x11, 0x9e, 0x6e, 0x48, 0x81, 0x6d, 0xcc, 0x57, 0x1f, 0xb2, 0x97, 0xa8, 0xd5, 0x25,
        0x9b, 0x82, 0xaa, 0x89, 0xe2, 0xfd, 0x2d, 0x56, 0xe8, 0x28, 0x83, 0x0b, 0xe2, 0xfa, 0x53, 0xb7,
        0xd6, 0x6b, 0x07, 0x85, 0x83, 0xb0, 0x10, 0xa2, 0xf5, 0x51, 0x3c, 0xf9, 0x60, 0x03, 0xab, 0x45,
        0x6c, 0x15, 0x6e, 0xef, 0xb5, 0xac, 0x3e, 0x6c, 0xdf, 0xb4, 0x92, 0x22, 0x2d, 0xce, 0xbf, 0x3e,
        0xe9, 0xe5, 0xf6, 0x29, 0x0e, 0x01, 0x4f, 0xd2, 0xd4, 0x45, 0x65, 0xb3, 0xbb, 0xf2, 0x4c, 0x16,
        0x37, 0x50, 0x3c, 0x6e, 0x49, 0x8c, 0x5a, 0x89, 0x2b, 0x1b, 0xab, 0xc4, 0x37, 0xd1, 0x46, 0xe9,
        0x3d, 0x0e, 0x85, 0xa2, 0x50, 0x73, 0xa1, 0x5e, 0x54, 0x37, 0xd7, 0x94, 0x17, 0x56, 0xc2, 0xd8,
        0xe5, 0x9f, 0xed, 0x4e, 0xae, 0x15, 0x42, 0x06, 0x0d, 0x74, 0x74, 0x5e, 0x24, 0x30, 0xce, 0xd1,
        0x9e, 0x50, 0xa3, 0x9a, 0xb8, 0xf0, 0x4a, 0x57, 0x69, 0x78, 0x67, 0x12, 0x84, 0x58, 0xbe, 0xc7,
        0x36, 0xaa, 0xee, 0x7c, 0x64, 0xa3, 0x76, 0xec, 0xff, 0x55, 0x41, 0x00, 0x2a, 0x44, 0x68, 0x4d,
        0xb6, 0x53, 0x9e, 0x1c, 0x95, 0xb7, 0xca, 0xdc, 0x7f, 0x7d, 0x74, 0x27, 0x5c, 0x8e, 0xa6, 0x84,
        0xb5, 0xac, 0x87, 0xa9, 0xf3, 0xff, 0x75, 0xf2, 0x34, 0xcd, 0x1a, 0x3b, 0x82, 0x2c, 0x2b, 0x4e,
        0x6a, 0x46, 0x30, 0xa6, 0x89, 0x86, 0x23, 0xac, 0xf8, 0xa5, 0x15, 0xe9, 0x0a, 0xaa, 0x1e, 0x9a,
        0xd7, 0x93, 0x6b, 0x28, 0xe4, 0x3b, 0xfd, 0x59, 0xc6, 0xed, 0x7c, 0x5f, 0xa5, 0x41, 0xcb, 0x51
    };


    // Test Transform() for 0 through 8 transformations.
    for (size_t i = 0; i <= 8; ++i) {
        uint32_t state[8];
        std::copy(init, init + 8, state);
        Transform(state, data + 1, i);
        if (!std::equal(state, state + 8, result[i])) return false;
    }

    // Test TransformD64
    unsigned char out[32];
    TransformD64(out, data + 1);
    if (!std::equal(out, out + 32, result_d64)) return false;

    // Test TransformD64_2way, if available.
    if (TransformD64_2way) {
        unsigned char out[64];
        TransformD64_2way(out, data + 1);
        if (!std::equal(out, out + 64, result_d64)) return false;
    }

    // Test TransformD64_4way, if available.
    if (TransformD64_4way) {
        unsigned char out[128];
        TransformD64_4way(out, data + 1);
        if (!std::equal(out, out + 128, result_d64)) return false;
    }

    // Test TransformD64_8way, if available.
    if (TransformD64_8way) {
        unsigned char out[256];
        TransformD64_8way(out, data + 1);
        if (!std::equal(out, out + 256, result_d64)) return false;
    }

    return true;
}

#if defined(USE_ASM) && (defined(__x86_64__) || defined(__amd64__) || defined(__i386__))
/** Check whether the OS has enabled AVX registers. */
bool AVXEnabled()
{
    uint32_t a, d;
    __asm__("xgetbv" : "=a"(a), "=d"(d) : "c"(0));
    return (a & 6) == 6;
}
#endif
} // namespace


std::string SHA256AutoDetect(sha256_implementation::UseImplementation use_implementation)
{
    std::string ret = "standard";
    Transform = sha256::Transform;
    TransformD64 = sha256::TransformD64;
    TransformD64_2way = nullptr;
    TransformD64_4way = nullptr;
    TransformD64_8way = nullptr;

#if defined(USE_ASM) && defined(HAVE_GETCPUID)
    bool have_sse4 = false;
    bool have_xsave = false;
    bool have_avx = false;
    [[maybe_unused]] bool have_avx2 = false;
    [[maybe_unused]] bool have_x86_shani = false;
    [[maybe_unused]] bool enabled_avx = false;

    uint32_t eax, ebx, ecx, edx;
    GetCPUID(1, 0, eax, ebx, ecx, edx);
    if (use_implementation & sha256_implementation::USE_SSE4) {
        have_sse4 = (ecx >> 19) & 1;
    }
    have_xsave = (ecx >> 27) & 1;
    have_avx = (ecx >> 28) & 1;
    if (have_xsave && have_avx) {
        enabled_avx = AVXEnabled();
    }
    if (have_sse4) {
        GetCPUID(7, 0, eax, ebx, ecx, edx);
        if (use_implementation & sha256_implementation::USE_AVX2) {
            have_avx2 = (ebx >> 5) & 1;
        }
        if (use_implementation & sha256_implementation::USE_SHANI) {
            have_x86_shani = (ebx >> 29) & 1;
        }
    }

#if defined(ENABLE_X86_SHANI) && !defined(BUILD_BITCOIN_INTERNAL)
    if (have_x86_shani) {
        Transform = sha256_x86_shani::Transform;
        TransformD64 = TransformD64Wrapper<sha256_x86_shani::Transform>;
        TransformD64_2way = sha256d64_x86_shani::Transform_2way;
        ret = "x86_shani(1way,2way)";
        have_sse4 = false; // Disable SSE4/AVX2;
        have_avx2 = false;
    }
#endif

    if (have_sse4) {
#if defined(__x86_64__) || defined(__amd64__)
        Transform = sha256_sse4::Transform;
        TransformD64 = TransformD64Wrapper<sha256_sse4::Transform>;
        ret = "sse4(1way)";
#endif
#if defined(ENABLE_SSE41) && !defined(BUILD_BITCOIN_INTERNAL)
        TransformD64_4way = sha256d64_sse41::Transform_4way;
        ret += ",sse41(4way)";
#endif
    }

#if defined(ENABLE_AVX2) && !defined(BUILD_BITCOIN_INTERNAL)
    if (have_avx2 && have_avx && enabled_avx) {
        TransformD64_8way = sha256d64_avx2::Transform_8way;
        ret += ",avx2(8way)";
    }
#endif
#endif // defined(USE_ASM) && defined(HAVE_GETCPUID)

#if defined(ENABLE_ARM_SHANI) && !defined(BUILD_BITCOIN_INTERNAL)
    bool have_arm_shani = false;
    if (use_implementation & sha256_implementation::USE_SHANI) {
#if defined(__linux__)
#if defined(__arm__) // 32-bit
        if (getauxval(AT_HWCAP2) & HWCAP2_SHA2) {
            have_arm_shani = true;
        }
#endif
#if defined(__aarch64__) // 64-bit
        if (getauxval(AT_HWCAP) & HWCAP_SHA2) {
            have_arm_shani = true;
        }
#endif
#endif

#if defined(MAC_OSX)
        int val = 0;
        size_t len = sizeof(val);
        if (sysctlbyname("hw.optional.arm.FEAT_SHA256", &val, &len, nullptr, 0) == 0) {
            have_arm_shani = val != 0;
        }
#endif
    }

    if (have_arm_shani) {
        Transform = sha256_arm_shani::Transform;
        TransformD64 = TransformD64Wrapper<sha256_arm_shani::Transform>;
        TransformD64_2way = sha256d64_arm_shani::Transform_2way;
        ret = "arm_shani(1way,2way)";
    }
#endif

    assert(SelfTest());
    return ret;
}

// SHA-256

CSHA256::CSHA256()
{
    sha256::Initialize(s);
}

CSHA256& CSHA256::Write(const unsigned char* data, size_t len)
{
    const unsigned char* end = data + len;
    size_t bufsize = bytes % 64;
    if (bufsize && bufsize + len >= 64) {
        // Fill the buffer, and process it.
        memcpy(buf + bufsize, data, 64 - bufsize);
        bytes += 64 - bufsize;
        data += 64 - bufsize;
        Transform(s, buf, 1);
        bufsize = 0;
    }
    if (end - data >= 64) {
        size_t blocks = (end - data) / 64;
        Transform(s, data, blocks);
        data += 64 * blocks;
        bytes += 64 * blocks;
    }
    if (end > data) {
        // Fill the buffer with what remains.
        memcpy(buf + bufsize, data, end - data);
        bytes += end - data;
    }
    return *this;
}

void CSHA256::Finalize(unsigned char hash[OUTPUT_SIZE])
{
    static const unsigned char pad[64] = {0x80};
    unsigned char sizedesc[8];
    WriteBE64(sizedesc, bytes << 3);
    Write(pad, 1 + ((119 - (bytes % 64)) % 64));
    Write(sizedesc, 8);
    WriteBE32(hash, s[0]);
    WriteBE32(hash + 4, s[1]);
    WriteBE32(hash + 8, s[2]);
    WriteBE32(hash + 12, s[3]);
    WriteBE32(hash + 16, s[4]);
    WriteBE32(hash + 20, s[5]);
    WriteBE32(hash + 24, s[6]);
    WriteBE32(hash + 28, s[7]);
}

CSHA256& CSHA256::Reset()
{
    bytes = 0;
    sha256::Initialize(s);
    return *this;
}

void SHA256D64(unsigned char* out, const unsigned char* in, size_t blocks)
{
    if (TransformD64_8way) {
        while (blocks >= 8) {
            TransformD64_8way(out, in);
            out += 256;
            in += 512;
            blocks -= 8;
        }
    }
    if (TransformD64_4way) {
        while (blocks >= 4) {
            TransformD64_4way(out, in);
            out += 128;
            in += 256;
            blocks -= 4;
        }
    }
    if (TransformD64_2way) {
        while (blocks >= 2) {
            TransformD64_2way(out, in);
            out += 64;
            in += 128;
            blocks -= 2;
        }
    }
    while (blocks) {
        TransformD64(out, in);
        out += 32;
        in += 64;
        --blocks;
    }
}

common.h

#include <endian.h>




uint32_t static inline ReadBE32(const unsigned char* ptr)
{
    uint32_t x;
    memcpy(&x, ptr, 4);
    return be32toh(x);
}

uint64_t static inline ReadBE64(const unsigned char* ptr)
{
    uint64_t x;
    memcpy(&x, ptr, 8);
    return be64toh(x);
}

void static inline WriteBE32(unsigned char* ptr, uint32_t x)
{
    uint32_t v = htobe32(x);
    memcpy(ptr, &v, 4);
}

void static inline WriteBE64(unsigned char* ptr, uint64_t x)
{
    uint64_t v = htobe64(x);
    memcpy(ptr, &v, 8);
}

main.cpp

#include "sha256.h"
//#include "uint256.h"


#include <iostream>
#include <string>
#include <vector>
#include <array>

using namespace std;


void printArray(array<uint8_t, 32> &result)
{
    for(int i=0; i<result.size();i++)
    {
        printf("%02x", result[i]);
    }
   
}



int main(int argc,  char** argv)
{
    string str = "123";
    if(argc > 1){
        str = argv[1];
    }


    cout<<"str:"<< str <<endl;

    //vector<uint8_t> result;
    array<uint8_t, 32> result{};
    //result.resize(32);


    CSHA256().Write((const unsigned char*) str.c_str(), str.size()).Finalize(result.data());
    printArray(result);
    printf("\n");

    int N = 1000000000;
    for(int i=0;i<N;i++)
    {
        string s  = str+ to_string(i);
        array<uint8_t, 32> result{};
        CSHA256().Write((const unsigned char*) s.c_str(), s.size()).Finalize(result.data());
        if(result[0] == 0x00 && result[1] == 0x00 && result[2] == 0x00)
        {
            cout<<"s: "<<s <<"," <<i << endl;
            printArray(result);
            printf("\n");
            
            break;
        }
    }







    cout<<endl;

    return 0;
}

build

g++ -O3 main.cpp sha256.cpp   -o main

run

./main  

模拟比特币挖矿时的hash计算过程。