package wiiudownloader import ( "bytes" "crypto/aes" "crypto/cipher" "encoding/binary" "encoding/hex" "fmt" "os" "path/filepath" "strings" "time" "github.com/cavaliergopher/grab/v3" ) const ( maxRetries = 5 retryDelay = 5 * time.Second bufferSize = 1048576 ) type ProgressReporter interface { SetGameTitle(title string) UpdateDownloadProgress(resp *grab.Response, filePath string) UpdateDecryptionProgress(progress float64) Cancelled() bool } func downloadFile(progressWindow ProgressReporter, client *grab.Client, downloadURL string, dstPath string, doRetries bool) error { filePath := filepath.Base(dstPath) for attempt := 1; attempt <= maxRetries; attempt++ { req, err := grab.NewRequest(dstPath, downloadURL) if err != nil { return err } req.BufferSize = bufferSize resp := client.Do(req) progressWindow.UpdateDownloadProgress(resp, filePath) t := time.NewTicker(500 * time.Millisecond) defer t.Stop() Loop: for { select { case <-t.C: progressWindow.UpdateDownloadProgress(resp, filePath) if progressWindow.Cancelled() { resp.Cancel() break Loop } case <-resp.Done: if err := resp.Err(); err != nil { if doRetries && attempt < maxRetries { time.Sleep(retryDelay) break Loop } return fmt.Errorf("download error after %d attempts: %+v", attempt, err) } break Loop } } } return nil } func DownloadTitle(titleID string, outputDirectory string, doDecryption bool, progressReporter ProgressReporter, deleteEncryptedContents bool, logger *Logger) error { titleEntry := getTitleEntryFromTid(titleID) progressReporter.SetGameTitle(titleEntry.Name) outputDir := strings.TrimRight(outputDirectory, "/\\") baseURL := fmt.Sprintf("http://ccs.cdn.c.shop.nintendowifi.net/ccs/download/%s", titleID) titleIDBytes, err := hex.DecodeString(titleID) if err != nil { return err } if err := os.MkdirAll(outputDir, os.ModePerm); err != nil { return err } client := grab.NewClient() client.BufferSize = bufferSize tmdPath := filepath.Join(outputDir, "title.tmd") if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "tmd"), tmdPath, true); err != nil { return err } tmdData, err := os.ReadFile(tmdPath) if err != nil { return err } var titleVersion uint16 if err := binary.Read(bytes.NewReader(tmdData[476:478]), binary.BigEndian, &titleVersion); err != nil { return err } tikPath := filepath.Join(outputDir, "title.tik") if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%s", baseURL, "cetk"), tikPath, false); err != nil { titleKey, err := GenerateKey(titleID) if err != nil { return err } if err := GenerateTicket(tikPath, titleEntry.TitleID, titleKey, titleVersion); err != nil { return err } } tikData, err := os.ReadFile(tikPath) if err != nil { return err } encryptedTitleKey := tikData[0x1BF : 0x1BF+0x10] var contentCount uint16 if err := binary.Read(bytes.NewReader(tmdData[478:480]), binary.BigEndian, &contentCount); err != nil { return err } cert, err := GenerateCert(tmdData, contentCount, progressReporter, client) if err != nil { return err } certPath := filepath.Join(outputDir, "title.cert") certFile, err := os.Create(certPath) if err != nil { return err } if err := binary.Write(certFile, binary.BigEndian, cert.Bytes()); err != nil { return err } defer certFile.Close() logger.Info("Certificate saved to %v \n", certPath) c, err := aes.NewCipher(commonKey) if err != nil { return fmt.Errorf("failed to create AES cipher: %w", err) } decryptedTitleKey := make([]byte, len(encryptedTitleKey)) cbc := cipher.NewCBCDecrypter(c, append(titleIDBytes, make([]byte, 8)...)) cbc.CryptBlocks(decryptedTitleKey, encryptedTitleKey) cipherHashTree, err := aes.NewCipher(decryptedTitleKey) if err != nil { return fmt.Errorf("failed to create AES cipher: %w", err) } var id uint32 var content contentInfo tmdDataReader := bytes.NewReader(tmdData) for i := 0; i < int(contentCount); i++ { offset := 2820 + (48 * i) tmdDataReader.Seek(int64(offset), 0) if err := binary.Read(tmdDataReader, binary.BigEndian, &id); err != nil { return err } filePath := filepath.Join(outputDir, fmt.Sprintf("%08X.app", id)) if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%08X", baseURL, id), filePath, true); err != nil { return err } if tmdData[offset+7]&0x2 == 2 { filePath = filepath.Join(outputDir, fmt.Sprintf("%08X.h3", id)) if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%08X.h3", baseURL, id), filePath, true); err != nil { return err } content.Hash = tmdData[offset+16 : offset+0x14] content.ID = fmt.Sprintf("%08X", id) tmdDataReader.Seek(int64(offset+8), 0) if err := binary.Read(tmdDataReader, binary.BigEndian, &content.Size); err != nil { return err } if err := checkContentHashes(outputDirectory, content, &cipherHashTree); err != nil { if progressReporter.Cancelled() { break } return err } } if progressReporter.Cancelled() { break } } if doDecryption && !progressReporter.Cancelled() { if err := DecryptContents(outputDir, progressReporter, deleteEncryptedContents); err != nil { return err } } return nil }