1
0
md5/md5.hpp

128 lines
3.0 KiB
C++

#pragma once
#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <cstring>
#include <cstdint>
#include <bit>
#include <format>
class MD5 {
private:
static constexpr uint32_t S[64] = {
7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21
};
static constexpr uint32_t K[64] = {
0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
};
uint32_t h[4] = {0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476};
static uint32_t F(uint32_t x, uint32_t y, uint32_t z) {
return (x & y) | (~x & z);
}
static uint32_t G(uint32_t x, uint32_t y, uint32_t z) {
return (x & z) | (y & ~z);
}
static uint32_t H(uint32_t x, uint32_t y, uint32_t z) {
return x ^ y ^ z;
}
static uint32_t I(uint32_t x, uint32_t y, uint32_t z) {
return y ^ (x | ~z);
}
void processBlock(const uint8_t* block) {
uint32_t w[16];
std::memcpy(w, block, 64);
uint32_t a = h[0], b = h[1], c = h[2], d = h[3];
for (int i = 0; i < 64; ++i) {
uint32_t f, g;
if (i < 16) {
f = F(b, c, d);
g = i;
} else if (i < 32) {
f = G(b, c, d);
g = (5 * i + 1) % 16;
} else if (i < 48) {
f = H(b, c, d);
g = (3 * i + 5) % 16;
} else {
f = I(b, c, d);
g = (7 * i) % 16;
}
f += a + K[i] + w[g];
a = d;
d = c;
c = b;
b += std::rotl(f, S[i]);
}
h[0] += a;
h[1] += b;
h[2] += c;
h[3] += d;
}
public:
std::string hash(const std::string& input) {
h[0] = 0x67452301;
h[1] = 0xefcdab89;
h[2] = 0x98badcfe;
h[3] = 0x10325476;
std::vector<uint8_t> data(input.begin(), input.end());
uint64_t originalLength = data.size() * 8;
data.push_back(0x80);
while (data.size() % 64 != 56) {
data.push_back(0);
}
for (int i = 0; i < 8; ++i) {
data.push_back((originalLength >> (i * 8)) & 0xff);
}
for (size_t i = 0; i < data.size(); i += 64) {
processBlock(&data[i]);
}
std::string result;
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
uint8_t byte = (h[i] >> (j * 8)) & 0xff;
result += std::format("{:02x}", byte);
}
}
return result;
}
};