diff --git a/utils.go b/utils.go
index 101c16b..9be5d50 100644
--- a/utils.go
+++ b/utils.go
@@ -59,10 +59,10 @@ func FsEntry2Name(entry os.DirEntry) string {
 }
 
 func DecodeBase64String(str string) (string, error) {
-	data, err := base64.StdEncoding.DecodeString(str)
+	data, err := base64.URLEncoding.DecodeString(str)
 	return string(data), err
 }
 
 func EncodeBase64String(str string) string {
-	return base64.StdEncoding.EncodeToString([]byte(str))
+	return base64.URLEncoding.EncodeToString([]byte(str))
 }