feat: mmkv 加密数据库解析

algo/qmc/qmc.go

@@ -16,6 +16,9 @@ import (
 	"unlock-music.dev/cli/internal/sniff"
 )
 
+var VaultPath = ""
+var VaultKey = ""
+
 type Decoder struct {
 	raw    io.ReadSeeker // raw is the original file reader
 	params *common.DecoderParams
@@ -140,11 +143,32 @@ func (d *Decoder) searchKey() (err error) {
 		return err
 	}
 
-	switch string(suffixBuf) {
+	switch string(bytes.ReplaceAll(suffixBuf, []byte{0x00}, []byte{})) {
 	case "QTag":
 		return d.readRawMetaQTag()
 	case "STag":
 		return errors.New("qmc: file with 'STag' suffix doesn't contains media key")
+	case "cex":
+		d.decodedKey, err = readKeyFromMMKVCustom(d)
+		if err == nil {
+			suffix := []byte{0x63, 0x65, 0x78, 0x00} // cex
+			for i := 0; i <= 3; i++ {
+				// 末尾的信息数据每192字节出现一次，故只要循环判断末尾不为musicex时即为歌曲数据
+				musicexLen, err := d.raw.Seek(int64(-(192*i)-4), io.SeekEnd)
+				if err != nil {
+					return fmt.Errorf("get musicexLen error: %w", err)
+				}
+				buf, err := io.ReadAll(io.LimitReader(d.raw, 4))
+				if err != nil {
+					return fmt.Errorf("get musicex error: %w", err)
+				}
+				if !bytes.Equal(buf, suffix) {
+					d.audioLen = int(musicexLen) + 4
+					return nil
+				}
+			}
+		}
+		return err
 	default:
 		size := binary.LittleEndian.Uint32(suffixBuf)