| 41 | }; |
| 42 | |
| 43 | int encode(Image &image, const std::array<std::uint8_t, 32> &password, const std::string &input, const std::string &output, Image::EncodingLevel level) { |
| 44 | // Open the data file |
| 45 | std::ifstream file(input, std::ios::in | std::ios::binary | std::ios::ate); |
| 46 | if (!file.is_open()) { |
| 47 | std::cerr << "ERROR: Unable to open file '" << input << "'" << std::endl; |
| 48 | return -1; |
| 49 | } |
| 50 | |
| 51 | std::cout << "* Image size: " << image.w() << "x" << image.h() << " pixels" << std::endl; |
| 52 | std::cout << "* Encoding level: " << level_to_str[static_cast<int>(level)] << std::endl; |
| 53 | |
| 54 | // Find the data and padded-data size |
| 55 | std::size_t size = file.tellg(); |
| 56 | std::size_t padded_size = size + 1; // At least one byte of padding |
| 57 | |
| 58 | if (padded_size % 16) |
| 59 | padded_size = (size / 16 + 1) * 16; |
| 60 | |
| 61 | // Find the maximum possible size for the file |
| 62 | unsigned int max_size = image.w()*image.h()*4/Image::encoded_size(1, level) - Image::encoded_size(sizeof(Header)+32, Image::EncodingLevel::Low); // FIXME |
| 63 | |
| 64 | std::cout << "* Max embed size: " << data_size(max_size) << std::endl; |
| 65 | std::cout << "* Embed size: " << data_size(size) << std::endl; |
| 66 | std::cout << "* Encrypted embed size: " << data_size(padded_size) << std::endl; |
| 67 | |
| 68 | // Make sure that it isn't too big |
| 69 | if (padded_size > max_size) { |
| 70 | std::cerr << "ERROR: Data-File too big, maximum possible size: " << (max_size / 1024) << " KiB" << std::endl; |
| 71 | return -1; |
| 72 | } |
| 73 | |
| 74 | // Read the data |
| 75 | auto padded_data = std::make_unique<uint8_t[]>(padded_size); |
| 76 | file.seekg(0, std::ios::beg); |
| 77 | file.read(reinterpret_cast<char*>(padded_data.get()), size); |
| 78 | file.close(); |
| 79 | |
| 80 | // Pad the data (#PKCS7) |
| 81 | std::uint8_t left = padded_size - size; |
| 82 | std::fill_n(padded_data.get() + size, left, left); |
| 83 | |
| 84 | // Pick a random offset inside the image to store the data |
| 85 | std::uint32_t offset; |
| 86 | Random random; |
| 87 | if (!random.get(&offset, sizeof(offset))) |
| 88 | { |
| 89 | std::cerr << "Unable to generate random number" << std::endl; |
| 90 | return -1; |
| 91 | } |
| 92 | |
| 93 | offset = (offset + Image::encoded_size(sizeof(Header) + 32, Image::EncodingLevel::Low)) % (Image::encoded_size(max_size - padded_size, level)); |
| 94 | |
| 95 | // Calculate a hash of the data |
| 96 | CRC32 crc; |
| 97 | crc.update(padded_data.get(), size); |
| 98 | |
| 99 | std::cout << "* Generated CRC32 checksum" << std::endl; |
| 100 | |