sha256实现代码（C++模板类）
程序员文章站
2024-03-19 14:18:34
...
目前在网上找到的比较高效稳定的一个生成sha256的代码，只包含头文件就可以了，简单易用，同时方便学习
可以从stl的各种容器，std::string，字符串，文件流等生成sha256，经过测试比较稳定：
头文件picosha2.h
#ifndef PICOSHA2_H
#define PICOSHA2_H
// picosha2:20140213
#ifndef PICOSHA2_BUFFER_SIZE_FOR_INPUT_ITERATOR
#define PICOSHA2_BUFFER_SIZE_FOR_INPUT_ITERATOR \
1048576 //=1024*1024: default is 1MB memory
#endif
#include <algorithm>
#include <cassert>
#include <iterator>
#include <sstream>
#include <vector>
namespace picosha2 {
typedef unsigned long word_t;
typedef unsigned char byte_t;
static const size_t k_digest_size = 32;
namespace detail {
inline byte_t mask_8bit(byte_t x) { return x & 0xff; }
inline word_t mask_32bit(word_t x) { return x & 0xffffffff; }
const word_t add_constant[64] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 };
const word_t initial_message_digest[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372,
0xa54ff53a, 0x510e527f, 0x9b05688c,
0x1f83d9ab, 0x5be0cd19 };
inline word_t ch(word_t x, word_t y, word_t z) { return (x & y) ^ ((~x) & z); }
inline word_t maj(word_t x, word_t y, word_t z) {
return (x & y) ^ (x & z) ^ (y & z);
}
inline word_t rotr(word_t x, std::size_t n) {
assert(n < 32);
return mask_32bit((x >> n) | (x << (32 - n)));
}
inline word_t bsig0(word_t x) { return rotr(x, 2) ^ rotr(x, 13) ^ rotr(x, 22); }
inline word_t bsig1(word_t x) { return rotr(x, 6) ^ rotr(x, 11) ^ rotr(x, 25); }
inline word_t shr(word_t x, std::size_t n) {
assert(n < 32);
return x >> n;
}
inline word_t ssig0(word_t x) { return rotr(x, 7) ^ rotr(x, 18) ^ shr(x, 3); }
inline word_t ssig1(word_t x) { return rotr(x, 17) ^ rotr(x, 19) ^ shr(x, 10); }
template <typename RaIter1, typename RaIter2>
void hash256_block(RaIter1 message_digest, RaIter2 first, RaIter2 last) {
assert(first + 64 == last);
static_cast<void>(last); // for avoiding unused-variable warning
word_t w[64];
std::fill(w, w + 64, 0);
for (std::size_t i = 0; i < 16; ++i) {
w[i] = (static_cast<word_t>(mask_8bit(*(first + i * 4))) << 24) |
(static_cast<word_t>(mask_8bit(*(first + i * 4 + 1))) << 16) |
(static_cast<word_t>(mask_8bit(*(first + i * 4 + 2))) << 8) |
(static_cast<word_t>(mask_8bit(*(first + i * 4 + 3))));
}
for (std::size_t i = 16; i < 64; ++i) {
w[i] = mask_32bit(ssig1(w[i - 2]) + w[i - 7] + ssig0(w[i - 15]) +
w[i - 16]);
}
word_t a = *message_digest;
word_t b = *(message_digest + 1);
word_t c = *(message_digest + 2);
word_t d = *(message_digest + 3);
word_t e = *(message_digest + 4);
word_t f = *(message_digest + 5);
word_t g = *(message_digest + 6);
word_t h = *(message_digest + 7);
for (std::size_t i = 0; i < 64; ++i) {
word_t temp1 = h + bsig1(e) + ch(e, f, g) + add_constant[i] + w[i];
word_t temp2 = bsig0(a) + maj(a, b, c);
h = g;
g = f;
f = e;
e = mask_32bit(d + temp1);
d = c;
c = b;
b = a;
a = mask_32bit(temp1 + temp2);
}
*message_digest += a;
*(message_digest + 1) += b;
*(message_digest + 2) += c;
*(message_digest + 3) += d;
*(message_digest + 4) += e;
*(message_digest + 5) += f;
*(message_digest + 6) += g;
*(message_digest + 7) += h;
for (std::size_t i = 0; i < 8; ++i) {
*(message_digest + i) = mask_32bit(*(message_digest + i));
}
}
} // namespace detail
template <typename InIter>
void output_hex(InIter first, InIter last, std::ostream& os) {
os.setf(std::ios::hex, std::ios::basefield);
while (first != last) {
os.width(2);
os.fill('0');
os << static_cast<unsigned int>(*first);
++first;
}
os.setf(std::ios::dec, std::ios::basefield);
}
template <typename InIter>
void bytes_to_hex_string(InIter first, InIter last, std::string& hex_str) {
std::ostringstream oss;
output_hex(first, last, oss);
hex_str.assign(oss.str());
}
template <typename InContainer>
void bytes_to_hex_string(const InContainer& bytes, std::string& hex_str) {
bytes_to_hex_string(bytes.begin(), bytes.end(), hex_str);
}
template <typename InIter>
std::string bytes_to_hex_string(InIter first, InIter last) {
std::string hex_str;
bytes_to_hex_string(first, last, hex_str);
return hex_str;
}
template <typename InContainer>
std::string bytes_to_hex_string(const InContainer& bytes) {
std::string hex_str;
bytes_to_hex_string(bytes, hex_str);
return hex_str;
}
class hash256_one_by_one {
public:
hash256_one_by_one() { init(); }
void init() {
buffer_.clear();
std::fill(data_length_digits_, data_length_digits_ + 4, 0);
std::copy(detail::initial_message_digest,
detail::initial_message_digest + 8, h_);
}
template <typename RaIter>
void process(RaIter first, RaIter last) {
add_to_data_length(std::distance(first, last));
std::copy(first, last, std::back_inserter(buffer_));
std::size_t i = 0;
for (; i + 64 <= buffer_.size(); i += 64) {
detail::hash256_block(h_, buffer_.begin() + i,
buffer_.begin() + i + 64);
}
buffer_.erase(buffer_.begin(), buffer_.begin() + i);
}
void finish() {
byte_t temp[64];
std::fill(temp, temp + 64, 0);
std::size_t remains = buffer_.size();
std::copy(buffer_.begin(), buffer_.end(), temp);
temp[remains] = 0x80;
if (remains > 55) {
std::fill(temp + remains + 1, temp + 64, 0);
detail::hash256_block(h_, temp, temp + 64);
std::fill(temp, temp + 64 - 4, 0);
}
else {
std::fill(temp + remains + 1, temp + 64 - 4, 0);
}
write_data_bit_length(&(temp[56]));
detail::hash256_block(h_, temp, temp + 64);
}
template <typename OutIter>
void get_hash_bytes(OutIter first, OutIter last) const {
for (const word_t* iter = h_; iter != h_ + 8; ++iter) {
for (std::size_t i = 0; i < 4 && first != last; ++i) {
*(first++) = detail::mask_8bit(
static_cast<byte_t>((*iter >> (24 - 8 * i))));
}
}
}
private:
void add_to_data_length(word_t n) {
word_t carry = 0;
data_length_digits_[0] += n;
for (std::size_t i = 0; i < 4; ++i) {
data_length_digits_[i] += carry;
if (data_length_digits_[i] >= 65536u) {
carry = data_length_digits_[i] >> 16;
data_length_digits_[i] &= 65535u;
}
else {
break;
}
}
}
void write_data_bit_length(byte_t* begin) {
word_t data_bit_length_digits[4];
std::copy(data_length_digits_, data_length_digits_ + 4,
data_bit_length_digits);
// convert byte length to bit length (multiply 8 or shift 3 times left)
word_t carry = 0;
for (std::size_t i = 0; i < 4; ++i) {
word_t before_val = data_bit_length_digits[i];
data_bit_length_digits[i] <<= 3;
data_bit_length_digits[i] |= carry;
data_bit_length_digits[i] &= 65535u;
carry = (before_val >> (16 - 3)) & 65535u;
}
// write data_bit_length
for (int i = 3; i >= 0; --i) {
(*begin++) = static_cast<byte_t>(data_bit_length_digits[i] >> 8);
(*begin++) = static_cast<byte_t>(data_bit_length_digits[i]);
}
}
std::vector<byte_t> buffer_;
word_t data_length_digits_[4]; // as 64bit integer (16bit x 4 integer)
word_t h_[8];
};
inline void get_hash_hex_string(const hash256_one_by_one& hasher,
std::string& hex_str) {
byte_t hash[k_digest_size];
hasher.get_hash_bytes(hash, hash + k_digest_size);
return bytes_to_hex_string(hash, hash + k_digest_size, hex_str);
}
inline std::string get_hash_hex_string(const hash256_one_by_one& hasher) {
std::string hex_str;
get_hash_hex_string(hasher, hex_str);
return hex_str;
}
namespace impl {
template <typename RaIter, typename OutIter>
void hash256_impl(RaIter first, RaIter last, OutIter first2, OutIter last2, int,
std::random_access_iterator_tag) {
hash256_one_by_one hasher;
// hasher.init();
hasher.process(first, last);
hasher.finish();
hasher.get_hash_bytes(first2, last2);
}
template <typename InputIter, typename OutIter>
void hash256_impl(InputIter first, InputIter last, OutIter first2,
OutIter last2, int buffer_size, std::input_iterator_tag) {
std::vector<byte_t> buffer(buffer_size);
hash256_one_by_one hasher;
// hasher.init();
while (first != last) {
int size = buffer_size;
for (int i = 0; i != buffer_size; ++i, ++first) {
if (first == last) {
size = i;
break;
}
buffer[i] = *first;
}
hasher.process(buffer.begin(), buffer.begin() + size);
}
hasher.finish();
hasher.get_hash_bytes(first2, last2);
}
}
template <typename InIter, typename OutIter>
void hash256(InIter first, InIter last, OutIter first2, OutIter last2,
int buffer_size = PICOSHA2_BUFFER_SIZE_FOR_INPUT_ITERATOR) {
picosha2::impl::hash256_impl(
first, last, first2, last2, buffer_size,
typename std::iterator_traits<InIter>::iterator_category());
}
template <typename InIter, typename OutContainer>
void hash256(InIter first, InIter last, OutContainer& dst) {
hash256(first, last, dst.begin(), dst.end());
}
template <typename InContainer, typename OutIter>
void hash256(const InContainer& src, OutIter first, OutIter last) {
hash256(src.begin(), src.end(), first, last);
}
template <typename InContainer, typename OutContainer>
void hash256(const InContainer& src, OutContainer& dst) {
hash256(src.begin(), src.end(), dst.begin(), dst.end());
}
template <typename InIter>
void hash256_hex_string(InIter first, InIter last, std::string& hex_str) {
byte_t hashed[k_digest_size];
hash256(first, last, hashed, hashed + k_digest_size);
std::ostringstream oss;
output_hex(hashed, hashed + k_digest_size, oss);
hex_str.assign(oss.str());
}
template <typename InIter>
std::string hash256_hex_string(InIter first, InIter last) {
std::string hex_str;
hash256_hex_string(first, last, hex_str);
return hex_str;
}
inline void hash256_hex_string(const std::string& src, std::string& hex_str) {
hash256_hex_string(src.begin(), src.end(), hex_str);
}
template <typename InContainer>
void hash256_hex_string(const InContainer& src, std::string& hex_str) {
hash256_hex_string(src.begin(), src.end(), hex_str);
}
template <typename InContainer>
std::string hash256_hex_string(const InContainer& src) {
return hash256_hex_string(src.begin(), src.end());
}
} // namespace picosha2
#endif // PICOSHA2_H使用用例main.cpp：
#include <iostream>
#include <fstream>
#include "picosha2.h"
// 从string生成
void from_string()
{
std::string src_str = "Hello";
std::string hash_hex_str;
std::vector<unsigned char> hash(picosha2::k_digest_size);
picosha2::hash256(src_str.begin(), src_str.end(), hash.begin(), hash.end());
hash_hex_str = picosha2::bytes_to_hex_string(hash.begin(), hash.end());
std::cout << hash_hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
picosha2::hash256_hex_string(src_str, hash_hex_str);
std::cout << hash_hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
hash_hex_str = picosha2::hash256_hex_string(src_str);
std::cout << hash_hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
src_str = "Hello!";//add '!'
hash_hex_str = picosha2::hash256_hex_string(src_str.begin(), src_str.end());
std::cout << hash_hex_str << std::endl;
//this output is "334d016f755cd6dc58c53a86e183882f8ec14f52fb05345887c8a5edd42c87b7"
}
//从字节数组读取
void from_bytes()
{
std::vector<unsigned char> src_vect(5, '\0');
src_vect.at(0) = 'H';
src_vect.at(1) = 'e';
src_vect.at(2) = 'l';
src_vect.at(3) = 'l';
src_vect.at(4) = 'o';
std::string hash_hex_str;
picosha2::hash256_hex_string(src_vect, hash_hex_str);
std::cout << hash_hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
std::vector<unsigned char> _src_vect(picosha2::k_digest_size, '\0');
_src_vect.at(0) = 'H';
_src_vect.at(1) = 'e';
_src_vect.at(2) = 'l';
_src_vect.at(3) = 'l';
_src_vect.at(4) = 'o';
hash_hex_str = picosha2::hash256_hex_string(_src_vect);
std::cout << hash_hex_str << std::endl;
//this output is "cd4895ecd6438e664b91e74f0e632438cd092e27da585f77854e5c28239d2f76"
unsigned char src_c_array[5] = { 'H','e','l','l','o' };
picosha2::hash256_hex_string(src_c_array, src_c_array + 5, hash_hex_str);
std::cout << hash_hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
unsigned char _src_c_array[picosha2::k_digest_size] = { 'H','e','l','l','o' };
hash_hex_str = picosha2::hash256_hex_string(_src_c_array, _src_c_array + picosha2::k_digest_size);
std::cout << hash_hex_str << std::endl;
//this output is "cd4895ecd6438e664b91e74f0e632438cd092e27da585f77854e5c28239d2f76"
}
//从文件读取
void from_file()
{
std::ifstream ifs;
ifs.open("file.txt", std::ios::binary); //file data is "Hello"
std::vector<unsigned char> hash(picosha2::k_digest_size);
picosha2::hash256(std::istreambuf_iterator<char>(ifs), std::istreambuf_iterator<char>(), hash.begin(), hash.end());
std::string hex_str = picosha2::bytes_to_hex_string(hash.begin(), hash.end());
std::cout << hex_str << std::endl;
//this output is "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
}
//从标准输入读取
void from_input()
{
std::cout << "Input freely. To get hash, input \"hash!\". " << std::endl;
picosha2::hash256_one_by_one hasher;
while (true) {
hasher.init(); //reset hasher state
while (true) {
std::string line;
std::getline(std::cin, line);
if (line == "hash!") {
break;
}
hasher.process(line.begin(), line.end());
}
hasher.finish();
std::string hex_str;
picosha2::get_hash_hex_string(hasher, hex_str);
std::cout << hex_str << std::endl;
}
}
int main(int argc, char* argv[])
{
from_string();
from_bytes();
from_file();
from_input();
return 0;
}代码来自github：
https://github.com/okdshin/PicoSHA2
上一篇： spring security中 BCrypt密码加密算法
下一篇： STM32的DAC输出驱动电压
推荐阅读