goldberg_emulator/sha/sha1.hpp

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2021-09-19 07:07:19 +02:00
/*
sha1.hpp - source code of
============
SHA-1 in C++
============
100% Public Domain.
Original C Code
-- Steve Reid <steve@edmweb.com>
Small changes to fit into bglibs
-- Bruce Guenter <bruce@untroubled.org>
Translation to simpler C++ Code
-- Volker Diels-Grabsch <v@njh.eu>
Safety fixes
-- Eugene Hopkinson <slowriot at voxelstorm dot com>
Header-only library
-- Zlatko Michailov <zlatko@michailov.org>
*/
#ifndef SHA1_HPP
#define SHA1_HPP
#include <cstdint>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>
class SHA1
{
public:
SHA1();
void update(const std::string &s);
void update(std::istream &is);
std::string final();
static std::string from_file(const std::string &filename);
private:
uint32_t digest[5];
std::string buffer;
uint64_t transforms;
};
static const size_t BLOCK_INTS = 16; /* number of 32bit integers per SHA1 block */
static const size_t BLOCK_BYTES = BLOCK_INTS * 4;
inline static void reset(uint32_t digest[], std::string &buffer, uint64_t &transforms)
{
/* SHA1 initialization constants */
digest[0] = 0x67452301;
digest[1] = 0xefcdab89;
digest[2] = 0x98badcfe;
digest[3] = 0x10325476;
digest[4] = 0xc3d2e1f0;
/* Reset counters */
buffer = "";
transforms = 0;
}
inline static uint32_t rol(const uint32_t value, const size_t bits)
{
return (value << bits) | (value >> (32 - bits));
}
inline static uint32_t blk(const uint32_t block[BLOCK_INTS], const size_t i)
{
return rol(block[(i+13)&15] ^ block[(i+8)&15] ^ block[(i+2)&15] ^ block[i], 1);
}
/*
* (R0+R1), R2, R3, R4 are the different operations used in SHA1
*/
inline static void R0(const uint32_t block[BLOCK_INTS], const uint32_t v, uint32_t &w, const uint32_t x, const uint32_t y, uint32_t &z, const size_t i)
{
z += ((w&(x^y))^y) + block[i] + 0x5a827999 + rol(v, 5);
w = rol(w, 30);
}
inline static void R1(uint32_t block[BLOCK_INTS], const uint32_t v, uint32_t &w, const uint32_t x, const uint32_t y, uint32_t &z, const size_t i)
{
block[i] = blk(block, i);
z += ((w&(x^y))^y) + block[i] + 0x5a827999 + rol(v, 5);
w = rol(w, 30);
}
inline static void R2(uint32_t block[BLOCK_INTS], const uint32_t v, uint32_t &w, const uint32_t x, const uint32_t y, uint32_t &z, const size_t i)
{
block[i] = blk(block, i);
z += (w^x^y) + block[i] + 0x6ed9eba1 + rol(v, 5);
w = rol(w, 30);
}
inline static void R3(uint32_t block[BLOCK_INTS], const uint32_t v, uint32_t &w, const uint32_t x, const uint32_t y, uint32_t &z, const size_t i)
{
block[i] = blk(block, i);
z += (((w|x)&y)|(w&x)) + block[i] + 0x8f1bbcdc + rol(v, 5);
w = rol(w, 30);
}
inline static void R4(uint32_t block[BLOCK_INTS], const uint32_t v, uint32_t &w, const uint32_t x, const uint32_t y, uint32_t &z, const size_t i)
{
block[i] = blk(block, i);
z += (w^x^y) + block[i] + 0xca62c1d6 + rol(v, 5);
w = rol(w, 30);
}
/*
* Hash a single 512-bit block. This is the core of the algorithm.
*/
inline static void transform(uint32_t digest[], uint32_t block[BLOCK_INTS], uint64_t &transforms)
{
/* Copy digest[] to working vars */
uint32_t a = digest[0];
uint32_t b = digest[1];
uint32_t c = digest[2];
uint32_t d = digest[3];
uint32_t e = digest[4];
/* 4 rounds of 20 operations each. Loop unrolled. */
R0(block, a, b, c, d, e, 0);
R0(block, e, a, b, c, d, 1);
R0(block, d, e, a, b, c, 2);
R0(block, c, d, e, a, b, 3);
R0(block, b, c, d, e, a, 4);
R0(block, a, b, c, d, e, 5);
R0(block, e, a, b, c, d, 6);
R0(block, d, e, a, b, c, 7);
R0(block, c, d, e, a, b, 8);
R0(block, b, c, d, e, a, 9);
R0(block, a, b, c, d, e, 10);
R0(block, e, a, b, c, d, 11);
R0(block, d, e, a, b, c, 12);
R0(block, c, d, e, a, b, 13);
R0(block, b, c, d, e, a, 14);
R0(block, a, b, c, d, e, 15);
R1(block, e, a, b, c, d, 0);
R1(block, d, e, a, b, c, 1);
R1(block, c, d, e, a, b, 2);
R1(block, b, c, d, e, a, 3);
R2(block, a, b, c, d, e, 4);
R2(block, e, a, b, c, d, 5);
R2(block, d, e, a, b, c, 6);
R2(block, c, d, e, a, b, 7);
R2(block, b, c, d, e, a, 8);
R2(block, a, b, c, d, e, 9);
R2(block, e, a, b, c, d, 10);
R2(block, d, e, a, b, c, 11);
R2(block, c, d, e, a, b, 12);
R2(block, b, c, d, e, a, 13);
R2(block, a, b, c, d, e, 14);
R2(block, e, a, b, c, d, 15);
R2(block, d, e, a, b, c, 0);
R2(block, c, d, e, a, b, 1);
R2(block, b, c, d, e, a, 2);
R2(block, a, b, c, d, e, 3);
R2(block, e, a, b, c, d, 4);
R2(block, d, e, a, b, c, 5);
R2(block, c, d, e, a, b, 6);
R2(block, b, c, d, e, a, 7);
R3(block, a, b, c, d, e, 8);
R3(block, e, a, b, c, d, 9);
R3(block, d, e, a, b, c, 10);
R3(block, c, d, e, a, b, 11);
R3(block, b, c, d, e, a, 12);
R3(block, a, b, c, d, e, 13);
R3(block, e, a, b, c, d, 14);
R3(block, d, e, a, b, c, 15);
R3(block, c, d, e, a, b, 0);
R3(block, b, c, d, e, a, 1);
R3(block, a, b, c, d, e, 2);
R3(block, e, a, b, c, d, 3);
R3(block, d, e, a, b, c, 4);
R3(block, c, d, e, a, b, 5);
R3(block, b, c, d, e, a, 6);
R3(block, a, b, c, d, e, 7);
R3(block, e, a, b, c, d, 8);
R3(block, d, e, a, b, c, 9);
R3(block, c, d, e, a, b, 10);
R3(block, b, c, d, e, a, 11);
R4(block, a, b, c, d, e, 12);
R4(block, e, a, b, c, d, 13);
R4(block, d, e, a, b, c, 14);
R4(block, c, d, e, a, b, 15);
R4(block, b, c, d, e, a, 0);
R4(block, a, b, c, d, e, 1);
R4(block, e, a, b, c, d, 2);
R4(block, d, e, a, b, c, 3);
R4(block, c, d, e, a, b, 4);
R4(block, b, c, d, e, a, 5);
R4(block, a, b, c, d, e, 6);
R4(block, e, a, b, c, d, 7);
R4(block, d, e, a, b, c, 8);
R4(block, c, d, e, a, b, 9);
R4(block, b, c, d, e, a, 10);
R4(block, a, b, c, d, e, 11);
R4(block, e, a, b, c, d, 12);
R4(block, d, e, a, b, c, 13);
R4(block, c, d, e, a, b, 14);
R4(block, b, c, d, e, a, 15);
/* Add the working vars back into digest[] */
digest[0] += a;
digest[1] += b;
digest[2] += c;
digest[3] += d;
digest[4] += e;
/* Count the number of transformations */
transforms++;
}
inline static void buffer_to_block(const std::string &buffer, uint32_t block[BLOCK_INTS])
{
/* Convert the std::string (byte buffer) to a uint32_t array (MSB) */
for (size_t i = 0; i < BLOCK_INTS; i++)
{
block[i] = (buffer[4*i+3] & 0xff)
| (buffer[4*i+2] & 0xff)<<8
| (buffer[4*i+1] & 0xff)<<16
| (buffer[4*i+0] & 0xff)<<24;
}
}
inline SHA1::SHA1()
{
reset(digest, buffer, transforms);
}
inline void SHA1::update(const std::string &s)
{
std::istringstream is(s);
update(is);
}
inline void SHA1::update(std::istream &is)
{
while (true)
{
char sbuf[BLOCK_BYTES];
is.read(sbuf, BLOCK_BYTES - buffer.size());
buffer.append(sbuf, (std::size_t)is.gcount());
if (buffer.size() != BLOCK_BYTES)
{
return;
}
uint32_t block[BLOCK_INTS];
buffer_to_block(buffer, block);
transform(digest, block, transforms);
buffer.clear();
}
}
/*
* Add padding and return the message digest.
*/
inline std::string SHA1::final()
{
/* Total number of hashed bits */
uint64_t total_bits = (transforms*BLOCK_BYTES + buffer.size()) * 8;
/* Padding */
buffer += (char)0x80;
size_t orig_size = buffer.size();
while (buffer.size() < BLOCK_BYTES)
{
buffer += (char)0x00;
}
uint32_t block[BLOCK_INTS];
buffer_to_block(buffer, block);
if (orig_size > BLOCK_BYTES - 8)
{
transform(digest, block, transforms);
for (size_t i = 0; i < BLOCK_INTS - 2; i++)
{
block[i] = 0;
}
}
/* Append total_bits, split this uint64_t into two uint32_t */
block[BLOCK_INTS - 1] = (uint32_t)total_bits;
block[BLOCK_INTS - 2] = (uint32_t)(total_bits >> 32);
transform(digest, block, transforms);
unsigned char output[20];
for (size_t i = 0; i < sizeof(digest) / sizeof(digest[0]); i++)
{
output[i*4] = digest[i] >> 24;
output[i*4 + 1] = (digest[i] >> 16) & 0xFF;
output[i*4 + 2] = (digest[i] >> 8) & 0xFF;
output[i*4 + 3] = (digest[i]) & 0xFF;
}
/* Reset for next run */
reset(digest, buffer, transforms);
return std::string((char *)output, sizeof(output));
}
inline std::string SHA1::from_file(const std::string &filename)
{
std::ifstream stream(filename.c_str(), std::ios::binary);
SHA1 checksum;
checksum.update(stream);
return checksum.final();
}
#endif /* SHA1_HPP */