feat: udpates

encfs/file.go

@@ -1,28 +1,121 @@
 package encfs
 
 import (
+	"crypto/rand"
+	"encoding/json"
+	"errors"
+	"io"
 	"os"
 	"syscall"
 
 	"github.com/spf13/afero"
 )
 
-type EncFile struct {
-	isDir  bool
-	closed bool
-	file   *os.File
+const EncFileExt = ".__encfile"
+
+var (
+	ErrFileForbiddenFileExt = errors.New("File ext is forbidden")
+)
+
+type EncFileMeta struct {
+	Name string `json:"name"`
+	Iv   []byte `json:"iv"`
 }
 
-func NewEncFile(file *os.File) (*EncFile, error) {
+func newEncFileMeta(name string) (*EncFileMeta, error) {
+	iv := make([]byte, 16)
+	_, err := rand.Read(iv)
+	if err != nil {
+		return nil, err
+	}
+	encFileMeta := &EncFileMeta{
+		Name: name,
+		Iv:   iv,
+	}
+	encFileMetaName := name + EncFileExt
+	encFileMetaFile, err := os.Create(encFileMetaName)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		_ = encFileMetaFile.Close()
+	}()
+	encFileMetaBytes, err := marshalEncFileMeta(encFileMeta)
+	if err != nil {
+		return nil, err
+	}
+	_, err = encFileMetaFile.Write(encFileMetaBytes)
+	if err != nil {
+		return nil, err
+	}
+	return encFileMeta, nil
+}
+
+func openEncFileMeta(name string) (*EncFileMeta, error) {
+	encFileMetaName := name + "." + EncFileExt
+	encFileMetaFile, err := os.Open(encFileMetaName)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	defer func() {
+		_ = encFileMetaFile.Close()
+	}()
+	encFileMetaBytes, err := io.ReadAll(encFileMetaFile)
+	if err != nil {
+		return nil, err
+	}
+	encFileMeta, err := unmarchalEncFileMeta(encFileMetaBytes)
+	if err != nil {
+		return nil, err
+	}
+	return encFileMeta, nil
+}
+
+func marshalEncFileMeta(encFileMeata *EncFileMeta) ([]byte, error) {
+	return json.Marshal(encFileMeata)
+}
+
+func unmarchalEncFileMeta(data []byte) (*EncFileMeta, error) {
+	var encFileMeta EncFileMeta
+	err := json.Unmarshal(data, &encFileMeta)
+	if err != nil {
+		return nil, err
+	}
+	return &encFileMeta, nil
+}
+
+type EncFile struct {
+	isDir       bool
+	closed      bool
+	encFileMeta *EncFileMeta
+	file        *os.File
+}
+
+func NewEncFile(name string, file *os.File, isCreate bool) (*EncFile, error) {
 	fileInfo, err := file.Stat()
 	if err != nil {
 		return nil, err
 	}
 	isDir := fileInfo.IsDir()
+	var encFileMeta *EncFileMeta = nil
+	if !isDir {
+		if isCreate {
+			encFileMeta, err = newEncFileMeta(name)
+		} else {
+			encFileMeta, err = openEncFileMeta(name)
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
 	return &EncFile{
-		isDir:  isDir,
-		closed: false,
-		file:   file,
+		isDir:       isDir,
+		closed:      false,
+		encFileMeta: encFileMeta,
+		file:        file,
 	}, nil
 }