package pathfs_frontend import ( "os" "path/filepath" "time" "fmt" "github.com/hanwen/go-fuse/fuse" "github.com/hanwen/go-fuse/fuse/nodefs" "github.com/hanwen/go-fuse/fuse/pathfs" "github.com/rfjakob/gocryptfs/cryptfs" ) type FS struct { *cryptfs.CryptFS pathfs.FileSystem // loopbackFileSystem backing string // Backing directory } // Encrypted FUSE overlay filesystem func NewFS(key []byte, backing string, useOpenssl bool) *FS { return &FS{ CryptFS: cryptfs.NewCryptFS(key, useOpenssl), FileSystem: pathfs.NewLoopbackFileSystem(backing), backing: backing, } } // GetPath - get the absolute path of the backing file func (fs *FS) GetPath(relPath string) string { return filepath.Join(fs.backing, fs.EncryptPath(relPath)) } func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) { a, status := fs.FileSystem.GetAttr(fs.EncryptPath(name), context) if a == nil { return a, status } a.Size = fs.PlainSize(a.Size) return a, status } func (fs *FS) OpenDir(name string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) { cipherEntries, status := fs.FileSystem.OpenDir(fs.EncryptPath(name), context); var plain []fuse.DirEntry var skipped int if cipherEntries != nil { for i := range cipherEntries { n, err := fs.DecryptPath(cipherEntries[i].Name) if err != nil { fmt.Printf("Skipping invalid filename \"%s\": %s\n", cipherEntries[i].Name, err) skipped++ continue } cipherEntries[i].Name = n plain = append(plain, cipherEntries[i]) } } return plain, status } // We always need read access to do read-modify-write cycles func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) { newFlags = int(flags) if newFlags & os.O_WRONLY > 0 { writeOnly = true newFlags = newFlags ^ os.O_WRONLY | os.O_RDWR } // We also cannot open the file in append mode, we need to seek back for RMW newFlags = newFlags &^ os.O_APPEND return newFlags, writeOnly } func (fs *FS) Open(name string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) { cryptfs.Debug.Printf("Open(%s)\n", name) iflags, writeOnly := fs.mangleOpenFlags(flags) f, err := os.OpenFile(fs.GetPath(name), iflags, 0666) if err != nil { return nil, fuse.ToStatus(err) } return NewFile(f, writeOnly, fs.CryptFS), fuse.OK } func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) { iflags, writeOnly := fs.mangleOpenFlags(flags) f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode)) if err != nil { return nil, fuse.ToStatus(err) } return NewFile(f, writeOnly, fs.CryptFS), fuse.OK } func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Chmod(fs.EncryptPath(path), mode, context) } func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Chmod(fs.EncryptPath(path), gid, context) } func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Truncate(fs.EncryptPath(path), offset, context) } func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context) } func (fs *FS) Readlink(name string, context *fuse.Context) (out string, status fuse.Status) { dst, status := fs.FileSystem.Readlink(fs.EncryptPath(name), context) if status != fuse.OK { return "", status } dstPlain, err := fs.DecryptPath(dst) if err != nil { cryptfs.Warn.Printf("Failed decrypting symlink: %s\n", err.Error()) return "", fuse.EIO } return dstPlain, status } func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context) } func (fs *FS) Mkdir(path string, mode uint32, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Mkdir(fs.EncryptPath(path), mode, context) } func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Unlink(fs.EncryptPath(name), context) } func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Rmdir(fs.EncryptPath(name), context) } func (fs *FS) Symlink(pointedTo string, linkName string, context *fuse.Context) (code fuse.Status) { // TODO symlink encryption cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")\n", pointedTo, linkName) return fs.FileSystem.Symlink(fs.EncryptPath(pointedTo), fs.EncryptPath(linkName), context) } func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (codee fuse.Status) { return fs.FileSystem.Rename(fs.EncryptPath(oldPath), fs.EncryptPath(newPath), context) } func (fs *FS) Link(orig string, newName string, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context) } func (fs *FS) Access(name string, mode uint32, context *fuse.Context) (code fuse.Status) { return fs.FileSystem.Access(fs.EncryptPath(name), mode, context) } func (fs *FS) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) { return nil, fuse.ENOSYS } func (fs *FS) SetXAttr(name string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status { return fuse.ENOSYS } func (fs *FS) ListXAttr(name string, context *fuse.Context) ([]string, fuse.Status) { return nil, fuse.ENOSYS } func (fs *FS) RemoveXAttr(name string, attr string, context *fuse.Context) fuse.Status { return fuse.ENOSYS }