crack-crc32.cpp

#include <atomic>
#include <chrono>
#include <cstdint>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <string>
#include <thread>
#include <vector>

static constexpr const uint32_t crc_table[256] = {
  0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
  0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
  0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
  0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
  0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
  0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
  0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
  0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
  0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
  0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
  0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
  0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
  0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
  0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
  0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
  0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
  0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
  0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
  0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
  0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
  0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
  0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
  0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
  0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
  0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
  0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
  0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
  0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
  0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
  0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
  0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
  0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
  0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
  0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
  0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
  0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
  0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
  0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
  0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
  0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
  0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
  0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
  0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
  0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
  0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
  0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
  0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
  0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
  0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
  0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
  0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
  0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
  0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
  0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
  0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
  0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
  0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
  0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
  0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
  0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
  0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
  0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
  0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
  0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
};

void usage(const char* argv0) {
  std::cout << argv0 << ": DATA1 CRC1" << std::endl;
}

uint32_t calculate_crc32(const uint8_t *data, size_t length, uint32_t seed = 0) {
  uint32_t crc = ~seed;
  const uint8_t *const end = data + length;

  while (data != end)
    crc = crc_table[(crc & 0xFF) ^ *data++] ^ (crc >> 8);

  return ~crc;
}

struct Worker {
  std::thread thread;
  std::atomic<uint32_t> seed;
  uint32_t end_seed;
  std::vector<uint8_t> buffer;
  uint32_t expected;
  uint32_t prev_seed;
  std::chrono::time_point<std::chrono::high_resolution_clock> prev_check_time;
};

void check_range(Worker &w) {
  for (; w.seed <= w.end_seed; w.seed++) {
    if (w.expected == calculate_crc32(w.buffer.data(), w.buffer.size(), w.seed)) {
      std::cout << "Seed 0x" << std::hex << std::setw(8) << std::setfill('0') << w.seed << " matched" << std::endl;
    }
  }
}

int main(int argc, const char *const *const argv) {
  using namespace std::chrono_literals;

  if (argc != 3) {
    usage(argv[0]);
    return EXIT_FAILURE;
  }

  const char *const f1 = argv[1];
  const uint32_t expected1 = std::stoi(argv[2], 0, 16);

  std::ifstream f(f1, std::ios::binary);
  std::vector<unsigned char> buffer(std::istreambuf_iterator<char>(f), {});
  std::cout << "Read " << buffer.size() << "-bytes" << std::endl;
  std::cout << "Expecting 0x" << std::hex << std::setw(8) << std::setfill('0') << expected1 << std::endl;

  const unsigned int pool_size = 8;
  std::vector<Worker> workers(pool_size);
  for (unsigned int i = 0; i != pool_size; i++) {
    static constexpr const uint64_t max = 0x100000000ULL;
    const uint32_t begin = (i * max) / pool_size;
    Worker &worker = workers[i];
    worker.seed = worker.prev_seed = begin;
    worker.buffer = buffer;
    worker.end_seed = worker.seed + max / pool_size - 1;
    worker.expected = expected1;
    worker.prev_check_time = std::chrono::high_resolution_clock::now();
    worker.thread = std::thread(check_range, std::ref(worker));
  }

  bool any_busy;
  do {
    std::this_thread::sleep_for(1s);

    any_busy = false;

    unsigned int seeds_processed = 0;
    for (Worker &worker : workers) {
      any_busy = any_busy || worker.thread.joinable();
      const auto now = std::chrono::high_resolution_clock::now();
      const uint32_t cur_seed = worker.seed;
      seeds_processed += cur_seed - worker.prev_seed;
      worker.prev_seed = cur_seed;
    }

    std::cerr << std::dec << seeds_processed << " H/s" << std::endl;

  } while (any_busy);

  return EXIT_SUCCESS;
}