Fix traversal checks and USB config unquoting

Author: cursoragent

snapshots.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -179,7 +180,7 @@ func safeJoin(base, name string) (string, error) {
 	if filepath.IsAbs(cleanName) {
 		return "", fmt.Errorf("absolute paths are not allowed")
 	}
-	if cleanName == ".." || len(cleanName) >= 3 && cleanName[:3] == ".."+string(filepath.Separator) {
+	if cleanName == ".." || strings.HasPrefix(cleanName, ".."+string(filepath.Separator)) {
 		return "", fmt.Errorf("path traversal is not allowed")
 	}
 
@@ -188,7 +189,7 @@ func safeJoin(base, name string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	if rel == ".." || len(rel) >= 3 && rel[:3] == ".."+string(filepath.Separator) {
+	if rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
 		return "", fmt.Errorf("resolved path escapes restore directory")
 	}
 

usb_fixtures.go

@@ -28,8 +28,8 @@ func validateFixtureLayoutDir(layoutDir string) error {
 }
 
 type USBVolumeOptions struct {
-	LayoutDir string
-	Strategy  string
+	LayoutDir      string
+	Strategy       string
 	CreateReposDir bool
 }
 
@@ -109,7 +109,7 @@ func readUSBVolumeConfigBytes(data []byte) (USBVolumeConfig, error) {
 			continue
 		}
 		key = strings.TrimSpace(key)
-		val = strings.Trim(strings.TrimSpace(val), "\"")
+		val = strings.TrimSpace(val)
 		switch key {
 		case "schema_version":
 			n, err := strconv.Atoi(val)
@@ -118,6 +118,9 @@ func readUSBVolumeConfigBytes(data []byte) (USBVolumeConfig, error) {
 			}
 			cfg.SchemaVersion = n
 		case "layout_dir":
+			if unquoted, err := strconv.Unquote(val); err == nil {
+				val = unquoted
+			}
 			if err := validateFixtureLayoutDir(val); err != nil {
 				return cfg, fmt.Errorf("layout_dir: %w", err)
 			}
@@ -127,8 +130,14 @@ func readUSBVolumeConfigBytes(data []byte) (USBVolumeConfig, error) {
 				cfg.LayoutDir = filepath.Clean(val)
 			}
 		case "strategy":
+			if unquoted, err := strconv.Unquote(val); err == nil {
+				val = unquoted
+			}
 			cfg.Strategy = val
 		case "created_at":
+			if unquoted, err := strconv.Unquote(val); err == nil {
+				val = unquoted
+			}
 			if val == "" {
 				return cfg, fmt.Errorf("created_at: empty value")
 			}

usb_fixtures_test.go

@@ -41,6 +41,23 @@ func TestReadWriteUSBVolumeConfig(t *testing.T) {
 	}
 }
 
+func TestReadWriteUSBVolumeConfig_preservesEscapedChars(t *testing.T) {
+	root := t.TempDir()
+	WriteUSBVolumeConfig(t, root, USBVolumeConfig{
+		SchemaVersion: 1,
+		LayoutDir:     `repo\"dir\path`,
+		Strategy:      `mirror\"strategy\mode`,
+	})
+
+	cfg := ReadUSBVolumeConfig(t, root)
+	if cfg.LayoutDir != `repo\"dir\path` {
+		t.Fatalf("layout mismatch: got %q", cfg.LayoutDir)
+	}
+	if cfg.Strategy != `mirror\"strategy\mode` {
+		t.Fatalf("strategy mismatch: got %q", cfg.Strategy)
+	}
+}
+
 func TestValidateFixtureLayoutDir(t *testing.T) {
 	t.Parallel()
 	root := t.TempDir()