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-rw-r--r--internal/nametransform/diriv.go32
1 files changed, 25 insertions, 7 deletions
diff --git a/internal/nametransform/diriv.go b/internal/nametransform/diriv.go
index 00d059f..e74592a 100644
--- a/internal/nametransform/diriv.go
+++ b/internal/nametransform/diriv.go
@@ -90,7 +90,8 @@ func WriteDirIV(dir string) error {
return nil
}
-// EncryptPathDirIV - encrypt relative plaintext path using EME with DirIV.
+// EncryptPathDirIV - encrypt relative plaintext path "plainPath" using EME with
+// DirIV. "rootDir" is the backing storage root directory.
// Components that are longer than 255 bytes are hashed if be.longnames == true.
func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cipherPath string, err error) {
// Empty string means root directory
@@ -103,7 +104,8 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
if len(baseName) > syscall.NAME_MAX {
return "", syscall.ENAMETOOLONG
}
- // Check if the DirIV is cached
+ // Check if the DirIV is cached. This catches the case of the user iterating
+ // over files in a directory pretty well.
parentDir := filepath.Dir(plainPath)
iv, cParentDir := be.DirIVCache.lookup(parentDir)
if iv != nil {
@@ -114,10 +116,27 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
cipherPath = filepath.Join(cParentDir, cBaseName)
return cipherPath, nil
}
- // Not cached - walk the directory tree
- var wd = rootDir
- var encryptedNames []string
+ // We have to walk the directory tree, in the worst case starting at the root
+ // directory.
+ wd := rootDir
plainNames := strings.Split(plainPath, "/")
+ // So the DirIV we need is not cached. But maybe one level higher is
+ // cached. Then we can skip a few items in the directory walk.
+ // The catches the case of walking directories recursively.
+ parentDir2 := filepath.Dir(parentDir)
+ iv, cParentDir = be.DirIVCache.lookup(parentDir2)
+ if iv != nil {
+ parentDirBase := filepath.Base(parentDir)
+ cBaseName := be.EncryptName(parentDirBase, iv)
+ if be.longNames && len(cBaseName) > syscall.NAME_MAX {
+ cBaseName = be.HashLongName(cBaseName)
+ }
+ wd = filepath.Join(wd, cParentDir, cBaseName)
+ cipherPath = filepath.Join(cParentDir, cBaseName)
+ skip := len(strings.Split(cipherPath, "/"))
+ plainNames = plainNames[skip:]
+ }
+ // Walk the directory tree starting at "wd"
for _, plainName := range plainNames {
iv, err = ReadDirIV(wd)
if err != nil {
@@ -127,10 +146,9 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
if be.longNames && len(encryptedName) > syscall.NAME_MAX {
encryptedName = be.HashLongName(encryptedName)
}
- encryptedNames = append(encryptedNames, encryptedName)
+ cipherPath = filepath.Join(cipherPath, encryptedName)
wd = filepath.Join(wd, encryptedName)
}
- cipherPath = filepath.Join(encryptedNames...)
// Cache the final DirIV
cParentDir = filepath.Dir(cipherPath)
be.DirIVCache.store(parentDir, iv, cParentDir)