Fundamental Approaches to Software Engineering

This open access book constitutes the proceedings of the 25th International Conference on Fundamental Approaches to Software Engineering, FASE 2022, which was held during April 4-5, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 17 regular papers presented in this volume were carefully reviewed and selected from 64 submissions. The proceedings also contain 3 contributions from the Test-Comp Competition. The papers deal with the foundations on which software engineering is built, including topics like software engineering as an engineering discipline, requirements engineering, software architectures, software quality, model-driven development, software processes, software evolution, AI-based software engineering, and the specification, design, and implementation of particular classes of systems, such as (self-)adaptive, collaborative, AI, embedded, distributed, mobile, pervasive, cyber-physical, or service-oriented applications

Security Testing: A Survey

Identifying vulnerabilities and ensuring security functionality by security testing is a widely applied measure to evaluate and improve the security of software. Due to the openness of modern software-based systems, applying appropriate security testing techniques is of growing importance and essential to perform effective and efficient security testing. Therefore, an overview of actual security testing techniques is of high value both for researchers to evaluate and refine the techniques and for practitioners to apply and disseminate them. This chapter fulfills this need and provides an overview of recent security testing techniques. For this purpose, it first summarize the required background of testing and security engineering. Then, basics and recent developments of security testing techniques applied during the secure software development lifecycle, i.e., model-based security testing, code-based testing and static analysis, penetration testing and dynamic analysis, as well as security regression testing are discussed. Finally, the security testing techniques are illustrated by adopting them for an example three-tiered web-based business application

A Security Verification Framework for SysML Activity Diagrams

UML and SysML play a central role in modern software and systems engineering. They are considered as the de facto standard for modeling software and systems. Today’s systems are created from a myriad of interacting parts that are combined to produce visible behavior. The main difficulty arises from the different ways in modeling each component and the way they interact with each other. Moreover, nowadays secure software has become an essential part in industrial development. One challenge in academia as well as in industry is to produce a secure product. Another challenge is to prove its correctness especially when the software environment is imprecise and uncertain. The aim of this thesis is to provide a practical and formal framework that enables security risk assessment and security requirements verification on a system modeled as a composition of UML/SysML behavioral diagrams. Our main contribution is a novel approach to automatically verify security of systems on their design models based on security requirements, probabilistic adversarial interactions between potential attackers and the system’s models. These structures are shaped to provide an elegant way to define the combination between different kinds of diagrams. We rely on stochastic security templates to specify security properties and a standard catalogue of attack patterns to build a library of attacks design patterns. The result of the interaction between selected attack scenarios and the composed diagrams with the instantiated security properties are used to quantify security risk by applying probabilistic model-checker. To handle the verification process scalability, our approach allows the verification of large system efficiently by optimizing and avoiding the global model construction. To demonstrate the effectiveness of our approach, we apply our methodology on academia as well as industrial benchmarks

Efficiency Improvements in the Quality Assurance Process for Data Races

As the usage of concurrency in software has gained importance in the last years, and is still rising, new types of defects increasingly appeared in software. One of the most prominent and critical types of such new defect types are data races. Although research resulted in an increased effectiveness of dynamic quality assurance regarding data races, the efficiency in the quality assurance process still is a factor preventing widespread practical application. First, dynamic quality assurance techniques used for the detection of data races are inefficient. Too much effort is needed for conducting dynamic quality assurance. Second, dynamic quality assurance techniques used for the analysis of reported data races are inefficient. Too much effort is needed for analyzing reported data races and identifying issues in the source code. The goal of this thesis is to enable efficiency improvements in the process of quality assurance for data races by: (1) analyzing the representation of the dynamic behavior of a system under test. The results are used to focus instrumentation of this system, resulting in a lower runtime overhead during test execution compared to a full instrumentation of this system. (2) Analyzing characteristics and preprocessing of reported data races. The results of the preprocessing are then provided to developers and quality assurance personnel, enabling an analysis and debugging process, which is more efficient than traditional analysis of data race reports. Besides dynamic data race detection, which is complemented by the solution, all steps in the process of dynamic quality assurance for data races are discussed in this thesis. The solution for analyzing UML Activities for nodes possibly executing in parallel to other nodes or themselves is based on a formal foundation using graph theory. A major problem that has been solved in this thesis was the handling of cycles within UML Activities. This thesis provides a dynamic limit for the number of cycle traversals, based on the elements of each UML Activity to be analyzed and their semantics. Formal proofs are provided with regard to the creation of directed acyclic graphs and with regard to their analysis concerning the identification of elements that may be executed in parallel to other elements. Based on an examination of the characteristics of data races and data race reports, the results of dynamic data race detection are preprocessed and the outcome of this preprocessing is presented to users for further analysis. This thesis further provides an exemplary application of the solution idea, of the results of analyzing UML Activities, and an exemplary examination of the efficiency improvement of the dynamic data race detection, which showed a reduction in the runtime overhead of 44% when using the focused instrumentation compared to full instrumentation. Finally, a controlled experiment has been set up and conducted to examine the effects of the preprocessing of reported data races on the efficiency of analyzing data race reports. The results show that the solution presented in this thesis enables efficiency improvements in the analysis of data race reports between 190% and 660% compared to using traditional approaches. Finally, opportunities for future work are shown, which may enable a broader usage of the results of this thesis and further improvements in the efficiency of quality assurance for data races.Da die Verwendung von Concurrency in Software in den letzten Jahren an Bedeutung gewonnen hat, und immer noch gewinnt, sind zunehmend neue Arten von Fehlern in Software aufgetaucht. Eine der prominentesten und kritischsten Arten solcher neuer Fehlertypen sind data races. Auch wenn die Forschung zu einer steigenden Effektivität von Verfahren der dynamischen Qualitätssicherung geführt hat, so ist die Effizienz im Prozess der Qualitätssicherung noch immer ein Faktor, der eine weitverbreitete praktische Anwendung verhindert. Zum einen wird zu viel Aufwand benötigt, um dynamische Qualitätssicherung durchzuführen. Zum anderen sind die Verfahren zur Analyse gemeldeter data races ineffizient; es wird zu viel Aufwand benötigt, um gemeldete data races zu analysieren und Probleme im Quellcode zu identifizieren. Das Ziel dieser Dissertation ist es, Effizienzsteigerungen im Qualitätssicherungsprozess für data races zu ermöglichen, durch: (1) Analyse der Repräsentation des dynamischen Verhaltens des zu testenden Systems. Mit den Ergebnissen wird die Instrumentierung dieses Systems fokussiert, so dass ein im Vergleich zur vollen Instrumentierung des Systems geringerer Mehraufwand an Laufzeit benötigt wird. (2) Analyse der Charakteristiken von und Vorverarbeitung der gemeldeten data races. Die Ergebnisse der Vorverarbeitung werden Mitarbeitenden in der Entwicklung und Qualitätssicherung präsentiert, so dass ein Analyse- und Fehlerbehebungsprozess ermöglicht wird, welcher effizienter als traditionelle Analysen gemeldeter data races ist. Mit Ausnahme der dynamischen data race Erkennung, welche durch die Lösung komplementiert wird, werden alle Schritte im Prozess der dynamischen Qualitätssicherung für data races in dieser Dissertation behandelt. Die Lösung zur Analyse von UML Aktivitäten auf Knoten, die möglicherweise parallel zu sich selbst oder anderen Knoten ausgeführt werden, basiert auf einer formalen Grundlage aus dem Bereich der Graphentheorie. Eines der Hauptprobleme, welches gelöst wurde, war die Verarbeitung von Zyklen innerhalb der UML Aktivitäten. Diese Dissertation führt ein dynamisches Limit für die Anzahl an Zyklusdurchläufen ein, welches die Elemente jeder zu analysierenden UML Aktivität sowie deren Semantiken berücksichtigt. Ebenso werden formale Beweise präsentiert in Bezug auf die Erstellung gerichteter azyklischer Graphen, sowie deren Analyse zur Identifizierung von Elementen, die parallel zu anderen Elementen ausgeführt werden können. Auf Basis einer Untersuchung von Charakteristiken von data races sowie Meldungen von data races werden die Ergebnisse der dynamischen Erkennung von data races vorverarbeitet, und das Ergebnis der Vorverarbeitung gemeldeter data races wird Benutzern zur weiteren Analyse präsentiert. Diese Dissertation umfasst weiterhin eine exemplarische Anwendung der Lösungsidee und der Analyse von UML Aktivitäten, sowie eine exemplarische Untersuchung der Effizienzsteigerung der dynamischen Erkennung von data races. Letztere zeigte eine Reduktion des Mehraufwands an Laufzeit von 44% bei fokussierter Instrumentierung im Vergleich zu voller Instrumentierung auf. Abschließend wurde ein kontrolliertes Experiment aufgesetzt und durchgeführt, um die Effekte der Vorverarbeitung gemeldeter data races auf die Effizienz der Analyse dieser gemeldeten data races zu untersuchen. Die Ergebnisse zeigen, dass die in dieser Dissertation vorgestellte Lösung verglichen mit traditionellen Ansätzen Effizienzsteigerungen in der Analyse gemeldeter data races von 190% bis zu 660% ermöglicht. Abschließend werden Möglichkeiten für zukünftige Arbeiten vorgestellt, welche eine breitere Anwendung der Ergebnisse dieser Dissertation ebenso wie weitere Effizienzsteigerungen im Qualitätssicherungsprozess für data races ermöglichen können

Towards a Model-Centric Software Testing Life Cycle for Early and Consistent Testing Activities

The constant improvement of the available computing power nowadays enables the accomplishment of more and more complex tasks. The resulting implicit increase in the complexity of hardware and software solutions for realizing the desired functionality requires a constant improvement of the development methods used. On the one hand over the last decades the percentage of agile development practices, as well as testdriven development increases. On the other hand, this trend results in the need to reduce the complexity with suitable methods. At this point, the concept of abstraction comes into play, which manifests itself in model-based approaches such as MDSD or MBT. The thesis is motivated by the fact that the earliest possible detection and elimination of faults has a significant influence on product costs. Therefore, a holistic approach is developed in the context of model-driven development, which allows applying testing already in early phases and especially on the model artifacts, i.e. it provides a shift left of the testing activities. To comprehensively address the complexity problem, a modelcentric software testing life cycle is developed that maps the process steps and artifacts of classical testing to the model-level. Therefore, the conceptual basis is first created by putting the available model artifacts of all domains into context. In particular, structural mappings are specified across the included domain-specific model artifacts to establish a sufficient basis for all the process steps of the life cycle. Besides, a flexible metamodel including operational semantics is developed, which enables experts to carry out an abstract test execution on the modellevel. Based on this, approaches for test case management, automated test case generation, evaluation of test cases, and quality verification of test cases are developed. In the context of test case management, a mechanism is realized that enables the selection, prioritization, and reduction of Test Model artifacts usable for test case generation. I.e. a targeted set of test cases is generated satisfying quality criteria like coverage at the model-level. These quality requirements are accomplished by using a mutation-based analysis of the identified test cases, which builds on the model basis. As the last step of the model-centered software testing life cycle two approaches are presented, allowing an abstract execution of the test cases in the model context through structural analysis and a form of model interpretation concerning data flow information. All the approaches for accomplishing the problem are placed in the context of related work, as well as examined for their feasibility by of a prototypical implementation within the Architecture And Analysis Framework. Subsequently, the described approaches and their concepts are evaluated by qualitative as well as quantitative evaluation. Moreover, case studies show the practical applicability of the approach