ZLib

main.cpp

// Decoding.
bytes_t crypt = {120, 156, 251, 255, 127, 100, 3, 0, 8, 0, 255, 1};
bytes_t plain(196864);
z_stream stream;
inflateInit(&stream);
stream.next_in = crypt.data();
stream.avail_in = crypt.size();
stream.next_out = plain.data();
stream.avail_out = plain.size();
int ret = inflate(&stream, Z_FINISH);
inflateEnd(&stream);
if (ret == Z_STREAM_END) {
    plain.resize(stream.total_out);
    std::cout << "plain = ";
    for (int i = 0; i < plain.size(); i++)
        std::cout << (int) plain[i] << " ";
    std::cout << std::endl;
}
// Encoding.
bytes_t encrypt(plain.size());
stream = z_stream();
deflateInit(&stream, Z_DEFAULT_COMPRESSION);
stream.next_in = plain.data();
stream.avail_in = plain.size();
stream.next_out = encrypt.data();
stream.avail_out = encrypt.size();
ret = deflate(&stream, Z_FINISH);
deflateEnd(&stream);
if (ret == Z_STREAM_END) {
    encrypt.resize(stream.total_out);
    std::cout << "crypt = ";
    for (int i = 0; i < encrypt.size(); i++)
        std::cout << (int) encrypt[i] << " ";
    std::cout << std::endl;
}