disallow reserved names

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

changelog/unreleased/disallow-reserved-names.md

@@ -0,0 +1,5 @@
+Bugfix: Disallow reserved filenames
+
+We now disallow the reserved `..` and `.` filenames. They are only allowed as destinations of move or copy operations.
+
+https://github.com/cs3org/reva/pull/4740

internal/http/services/owncloud/ocdav/copy.go

@@ -95,7 +95,7 @@ func (s *svc) handlePathCopy(w http.ResponseWriter, r *http.Request, ns string)
 		return
 	}
 
-	if err := ValidateName(path.Base(dst), s.nameValidators); err != nil {
+	if err := ValidateDestination(path.Base(dst), s.nameValidators); err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		b, err := errors.Marshal(http.StatusBadRequest, "destination failed naming rules", "")
 		errors.HandleWebdavError(appctx.GetLogger(ctx), w, b, err)

internal/http/services/owncloud/ocdav/move.go

@@ -67,7 +67,7 @@ func (s *svc) handlePathMove(w http.ResponseWriter, r *http.Request, ns string)
 		return
 	}
 
-	if err := ValidateName(path.Base(dstPath), s.nameValidators); err != nil {
+	if err := ValidateDestination(path.Base(dstPath), s.nameValidators); err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		b, err := errors.Marshal(http.StatusBadRequest, "destination naming rules", "")
 		errors.HandleWebdavError(appctx.GetLogger(ctx), w, b, err)

internal/http/services/owncloud/ocdav/tus.go

@@ -58,21 +58,15 @@ func (s *svc) handlePathTusPost(w http.ResponseWriter, r *http.Request, ns strin
 
 	// read filename from metadata
 	meta := tusd.ParseMetadataHeader(r.Header.Get(net.HeaderUploadMetadata))
-	if err := ValidateName(path.Base(meta["filename"]), s.nameValidators); err != nil {
-		w.WriteHeader(http.StatusPreconditionFailed)
-		return
-	}
 
 	// append filename to current dir
-	fn := path.Join(ns, r.URL.Path, meta["filename"])
-
-	sublog := appctx.GetLogger(ctx).With().Str("path", fn).Logger()
-	// check tus headers?
-
 	ref := &provider.Reference{
-		// FIXME ResourceId?
-		Path: fn,
+		// a path based request has no resource id, so we can only provide a path. The gateway has te figure out which provider is responsible
+		Path: path.Join(ns, r.URL.Path, meta["filename"]),
 	}
+
+	sublog := appctx.GetLogger(ctx).With().Str("path", r.URL.Path).Str("filename", meta["filename"]).Logger()
+
 	s.handleTusPost(ctx, w, r, meta, ref, sublog)
 }
 
@@ -82,19 +76,15 @@ func (s *svc) handleSpacesTusPost(w http.ResponseWriter, r *http.Request, spaceI
 
 	// read filename from metadata
 	meta := tusd.ParseMetadataHeader(r.Header.Get(net.HeaderUploadMetadata))
-	if err := ValidateName(path.Base(meta["filename"]), s.nameValidators); err != nil {
-		w.WriteHeader(http.StatusPreconditionFailed)
-		return
-	}
-
-	sublog := appctx.GetLogger(ctx).With().Str("spaceid", spaceID).Str("path", r.URL.Path).Logger()
 
 	ref, err := spacelookup.MakeStorageSpaceReference(spaceID, path.Join(r.URL.Path, meta["filename"]))
 	if err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
 
+	sublog := appctx.GetLogger(ctx).With().Str("spaceid", spaceID).Str("path", r.URL.Path).Str("filename", meta["filename"]).Logger()
+
 	s.handleTusPost(ctx, w, r, meta, &ref, sublog)
 }
 
@@ -116,6 +106,10 @@ func (s *svc) handleTusPost(ctx context.Context, w http.ResponseWriter, r *http.
 		w.WriteHeader(http.StatusPreconditionFailed)
 		return
 	}
+	if err := ValidateName(path.Base(meta["filename"]), s.nameValidators); err != nil {
+		w.WriteHeader(http.StatusPreconditionFailed)
+		return
+	}
 
 	// Test if the target is a secret filedrop
 	var isSecretFileDrop bool

internal/http/services/owncloud/ocdav/validation.go

@@ -27,6 +27,9 @@ func ValidatorsFromConfig(c *config.Config) []Validator {
 
 // ValidateName will validate a file or folder name, returning an error when it is not accepted
 func ValidateName(name string, validators []Validator) error {
+	if err := notReserved()(name); err != nil {
+		return fmt.Errorf("name validation failed: %w", err)
+	}
 	for _, v := range validators {
 		if err := v(name); err != nil {
 			return fmt.Errorf("name validation failed: %w", err)
@@ -35,6 +38,25 @@ func ValidateName(name string, validators []Validator) error {
 	return nil
 }
 
+// ValidateDestination will validate a file or folder destination name (which can be . or ..), returning an error when it is not accepted
+func ValidateDestination(name string, validators []Validator) error {
+	for _, v := range validators {
+		if err := v(name); err != nil {
+			return fmt.Errorf("name validation failed: %w", err)
+		}
+	}
+	return nil
+}
+
+func notReserved() Validator {
+	return func(s string) error {
+		if s == ".." || s == "." {
+			return errors.New(". and .. are reserved names")
+		}
+		return nil
+	}
+}
+
 func notEmpty() Validator {
 	return func(s string) error {
 		if strings.TrimSpace(s) == "" {