Controlling the Attack Surface of Object-Oriented Refactorings

Sebastian Ruland,Malte Lochau,Sven Peldszus,Erhan Leblebici,Géza Kulcsár

doi:10.1007/978-3-319-89363-1_3

Sebastian Ruland, Malte Lochau + Show 3 more

Open Access

https://doi.org/10.1007/978-3-319-89363-1_3

Copy DOI

Abstract

Refactorings constitute an effective means to improve quality and maintainability of evolving object-oriented programs. Search-based techniques have shown promising results in finding optimal sequences of behavior-preserving program transformations that (1) maximize code-quality metrics and (2) minimize the number of changes. However, the impact of refactorings on extra-functional properties like security has received little attention so far. To this end, we propose as a further objective to minimize the attack surface of programs (i.e., to maximize strictness of declared accessibility of class members). Minimizing the attack surface naturally competes with applicability of established MoveMethod refactorings for improving coupling/cohesion metrics. Our tool implementation is based on an EMF meta-model for Java-like programs and utilizes MOMoT, a search-based model-transformation framework. Our experimental results gained from a collection of real-world Java programs show the impact of attack surface minimization on design-improving refactorings by using different accessibility-control strategies. We further compare the results to those of existing refactoring tools.

Highlights

The essential activity in designing object-oriented programs is to identify class candidates and to assign responsibility to them
An appropriate solution to this Class-Responsibility-Assignment (CRA) problem, on the one hand, intuitively reflects the problem domain and, on the other hand, exhibits acceptable quality measures [4]. In this context, refactoring has become a key technique for agile software development: productive program-evolution phases are interleaved with behavior-preserving code transformations for updating CRA decisions, to proactively maintain, or even improve, code-quality metrics [13,29]
As modifier public has a considerably negative influence on the attack surface, we study the impact of increasing the penalty for public in ω, as compared to the other modifiers

Summary

Introduction

The essential activity in designing object-oriented programs is to identify class candidates and to assign responsibility (i.e., data and operations) to them. An appropriate solution to this Class-Responsibility-Assignment (CRA) problem, on the one hand, intuitively reflects the problem domain and, on the other hand, exhibits acceptable quality measures [4]. In this context, refactoring has become a key technique for agile software development: productive program-evolution phases are interleaved with behavior-preserving code transformations for updating CRA decisions, to proactively maintain, or even improve, code-quality metrics [13,29]. Central class MailApp is responsible for handling objects of classes Message and Contact both encapsulating application data and operations to access those attributes. The text of a message may be formatted as plain String, or it may be converted into HTML using method plainToHtml()

Objectives

Methods

Results

Discussion

Conclusion