Unfinished work

downloader.go

@@ -0,0 +1,139 @@
+package wiiudownloader
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/cavaliergopher/grab/v3"
+)
+
+func downloadFile(client *grab.Client, url string, outputPath string) error {
+	req, err := grab.NewRequest(outputPath, url)
+	if err != nil {
+		return err
+	}
+	resp := client.Do(req)
+	if err := resp.Err(); err != nil {
+		return err
+	}
+
+	fmt.Printf("[Info] Download saved to ./%v \n", resp.Filename)
+	return nil
+}
+
+func DownloadTitle(titleID string, outputDirectory string, doDecryption bool) error {
+	outputDir := strings.TrimRight(outputDirectory, "/\\")
+	baseURL := fmt.Sprintf("http://ccs.cdn.c.shop.nintendowifi.net/ccs/download/%s", titleID)
+	titleKeyBytes, err := hex.DecodeString(titleID)
+	if err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(outputDir, os.ModePerm); err != nil {
+		return err
+	}
+
+	client := grab.NewClient()
+	downloadURL := fmt.Sprintf("%s/%s", baseURL, "tmd")
+	tmdPath := filepath.Join(outputDir, "title.tmd")
+	if err := downloadFile(client, downloadURL, tmdPath); 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")
+	downloadURL = fmt.Sprintf("%s/%s", baseURL, "cetk")
+	if err := downloadFile(client, downloadURL, tikPath); 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 := bytes.Buffer{}
+
+	cert0, err := getCert(tmdData, 0, contentCount)
+	if err != nil {
+		return err
+	}
+	cert.Write(cert0)
+
+	cert1, err := getCert(tmdData, 1, contentCount)
+	if err != nil {
+		return err
+	}
+	cert.Write(cert1)
+
+	defaultCert, err := getDefaultCert(client)
+	if err != nil {
+		return err
+	}
+	cert.Write(defaultCert)
+
+	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()
+	fmt.Printf("[Info] Certificate saved to ./%v \n", certPath)
+
+	for i := 0; i < int(contentCount); i++ {
+		offset := 2820 + (48 * i)
+		var id uint32
+		if err := binary.Read(bytes.NewReader(tmdData[offset:offset+4]), binary.BigEndian, &id); err != nil {
+			return err
+		}
+
+		appPath := filepath.Join(outputDir, fmt.Sprintf("%08X.app", id))
+		downloadURL = fmt.Sprintf("%s/%08X", baseURL, id)
+		if err := downloadFile(client, downloadURL, appPath); err != nil {
+			return err
+		}
+
+		if tmdData[offset+7]&0x2 == 2 {
+			h3Path := filepath.Join(outputDir, fmt.Sprintf("%08X.h3", id))
+			downloadURL = fmt.Sprintf("%s/%08X.h3", baseURL, id)
+			if err := downloadFile(client, downloadURL, h3Path); err != nil {
+				return err
+			}
+			var content contentInfo
+			content.Hash = tmdData[offset+16 : offset+0x14]
+			content.ID = fmt.Sprintf("%08X", id)
+			binary.Read(bytes.NewReader(tmdData[offset+8:offset+15]), binary.BigEndian, &content.Size)
+			if err := checkContentHashes(outputDirectory, encryptedTitleKey, titleKeyBytes, content); err != nil {
+				return err
+			}
+		}
+	}
+
+	if doDecryption {
+		decryptContents(outputDir)
+	}
+
+	return nil
+}