An automated model-based test oracle for access control systems

In the context of XACML-based access control systems, an intensive testing activity is among the most adopted means to assure that sensible information or resources are correctly accessed. Unfortunately, it requires a huge effort for manual inspection of results: thus automated verdict derivation is a key aspect for improving the cost-effectiveness of testing. To this purpose, we introduce XACMET, a novel approach for automated model-based oracle definition. XACMET defines a typed graph, called the XAC-Graph, that models the XACML policy evaluation. The expected verdict of a specific request execution can thus be automatically derived by executing the corresponding path in such graph. Our validation of the XACMET prototype implementation confirms the effectiveness of the proposed approach.Comment: 7 page

FAST Approaches to Scalable Similarity-based Test Case Prioritization

Many test case prioritization criteria have been proposed for speeding up fault detection. Among them, similarity-based approaches give priority to the test cases that are the most dissimilar from those already selected. However, the proposed criteria do not scale up to handle the many thousands or even some millions test suite sizes of modern industrial systems and simple heuristics are used instead. We introduce the FAST family of test case prioritization techniques that radically changes this landscape by borrowing algorithms commonly exploited in the big data domain to find similar items. FAST techniques provide scalable similarity-based test case prioritization in both white-box and black-box fashion. The results from experimentation on real world C and Java subjects show that the fastest members of the family outperform other black-box approaches in efficiency with no significant impact on effectiveness, and also outperform white-box approaches, including greedy ones, if preparation time is not counted. A simulation study of scalability shows that one FAST technique can prioritize a million test cases in less than 20 minutes

Automatic XACML requests generation for policy testing

Abstract-Access control policies are usually specified by the XACML language. However, policy definition could be an error prone process, because of the many constraints and rules that have to be specified. In order to increase the confidence on defined XACML policies, an accurate testing activity could be a valid solution. The typical policy testing is performed by deriving specific test cases, i.e. XACML requests, that are executed by means of a PDP implementation, so to evidence possible security lacks or problems. Thus the fault detection effectiveness of derived test suite is a fundamental property. To evaluate the performance of the applied test strategy and consequently of the test suite, a commonly adopted methodology is using mutation testing. In this paper, we propose two different methodologies for deriving XACML requests, that are defined independently from the policy under test. The proposals exploit the values of the XACML policy for better customizing the generated requests and providing a more effective test suite. The proposed methodologies have been compared in terms of their fault detection effectiveness by the application of mutation testing on a set of real policies

EDUFYSoS: A Factory of Educational System of Systems Case Studies

We propose a factory of educational System of Systems (SoS) case studies that can be used for evaluating SoS research results, in particular in SoS testing. The factory includes a first set of constituent systems that can collaborate within different SoS architectures to accomplish different missions. In the paper, we introduce three possible SoSs and outline their missions. For more detailed descriptions, diagrams and the source code, we refer to the online repository of EDUFYSoS. The factory is meant to provide an extensible playground, which we aim to grow to include more systems and other missions with the support of the community.Ministero dell'Università e della Ricerca (Italia) SISMA 201752ENY

A Delphi study to recognize and assess systems of systems vulnerabilities

Context: System of Systems (SoS) is an emerging paradigm by which independent systems collaborate by sharing resources and processes to achieve objectives that they could not achieve on their own. In this context, a number of emergent behaviors may arise that can undermine the security of the constituent systems. Objective: We apply the Delphi method with the aims to improve our understanding of SoS security and related problems, and to investigate their possible causes and remedies. Method: Experts on SoS expressed their opinions and reached consensus in a series of rounds by following a structured questionnaire. Results: The results show that the experts found more consensus in disagreement than in agreement about some SoS characteristics, and on how SoS vulnerabilities could be identified and prevented. Conclusions: From this study we learn that more work is needed to reach a shared understanding of SoS vul nerabilities, and we leverage expert feedback to outline some future research directions.Ministerio de Ciencia, Innovación y Universidades PID2019-105455GB-C3

Security Assessment of Systems of Systems

Engineering Systems of Systems is one of the new chal-lenges of the last few years. This depends on the increasing number of systems that must interact one with another to achieve a goal. One peculiarity of Systems of Systems is that they are made of systems able to live on their own with well-established functionalities and requirements, and that are not necessarily aware of the joint mission or prepared to collaborate. In this emergent scenario, securi-ty is one crucial aspect that must be considered from the very beginning. In fact, the security of a System of Sys-tems is not automatically granted even if the security of each constituent system is guaranteed. The aim of this paper is to address the problem of assessing security properties in Systems of Systems. We discuss the specific security aspects of such emergent systems, and propose the TeSSoS approach, which includes modelling and testing security properties in Systems of Systems and introduces the Red and Blue Requirements Specification concepts.Ministerio dell'Universitá e della Ricerca (Italia) GAUSS 2015KWREMXMinisterio de Economía y Competitividad TIN2016-76956-C3-2-R (POLOLAS

Digital persona portrayal: Identifying pluridentity vulnerabilities in digital life

The increasing use of the Internet for social purposes enriches the data available online about all of us and promotes the concept of the Digital Persona. Actually, most of us are represented online by more than one identity, what we define here as a Pluridentity . This trend brings increased risks: it is well known that the security of a Digital Persona can be exploited if its data and security are not effectively managed. In this paper, we focus specifically on a new type of digital attack that can be perpetrated by combining pieces of data belonging to one same Pluridentity in order to profile their target. Some victims can be so accurately depicted when looking at their Pluridentity that by using the gathered information attackers can execute very personalized social engineering attacks, or even bypass otherwise safe security mecha- nisms. We characterize these Pluridentity attacks as a security issue of a virtual System of Systems, whose constituent systems are the individual identities and the humans themselves. We present a strategy to identify vulnerabilities caused by overexposure due to the combination of data from the constituent iden- tities of a Pluridentity. To this end we introduce the Digital Persona Portrayal Metamodel, and the related Digital Pluridentity Persona Portrayal Analysis process that supports the architecting of data from differ- ent identities: such model and process can be used to identify the vulnerabilities of a Pluridentity due to its exploitation as a System of Systems. The approach has been validated on the Pluridentities of seven- teen candidates selected from a data leak, by retrieving the data of their Digital Personae, and matching them against the security mechanisms of their Pluridentities. After analyzing the results for some of the analyzed subjects we could detect several vulnerabilities.Ministerio dell'Universitá e della Ricerca (Italia) GAUSS 2015KWREMXMinisterio de Economía y Competitividad TIN2016-76956-C3-2-R (POLOLAS

A systematic review on cloud testing

A systematic literature review is presented that surveyed the topic of cloud testing over the period (2012-2017). Cloud testing can refer either to testing cloud-based systems (testing of the cloud), or to leveraging the cloud for testing purposes (testing in the cloud): both approaches (and their combination into testing of the cloud in the cloud) have drawn research interest. An extensive paper search was conducted by both automated query of popular digital libraries and snowballing, which resulted into the final selection of 147 primary studies. Along the survey a framework has been incrementally derived that classifies cloud testing research along six main areas and their topics. The paper includes a detailed analysis of the selected primary studies to identify trends and gaps, as well as an extensive report of the state of art as it emerges by answering the identified Research Questions. We find that cloud testing is an active research field, although not all topics have received so far enough attention, and conclude by presenting the most relevant open research challenges for each area of the classification framework.This paper describes research work mostly undertaken in the context of the European Project H2020 731535: ElasTest. This work has also been partially supported by: the Italian MIUR PRIN 2015 Project: GAUSS; the Regional Government of Madrid (CM) under project Cloud4BigData (S2013/ICE-2894) cofunded by FSE & FEDER; and the Spanish Government under project LERNIM (RTC-2016-4674-7) cofunded by the Ministry of Economy and Competitiveness, FEDER & AEI

Model-Based Testing for the Cloud

Software in the cloud is characterised by the need to be highly adaptive and continuously available. Incremental changes are applied to the deployed system and need to be tested in the field. Different configurations need to be tested. Higher quality standards regarding both functional and non-functional properties are put on those systems, as they often face large and diverse customer bases and/or are used as services from different peer service implementations. The properties of interest include interoperability, privacy, security, reliability, performance, resource use, timing constraints, service dependencies, availability, and so on. This paper discusses the state of the art in model-based testing of cloud systems. It focuses on two central aspects of the problem domain: (a) dealing with the adaptive and dynamic character of cloud software when tested with model-based testing, by developing new online and offline test strategies, and (b) dealing with the variety of modeling concerns for functional and non-functional properties, by devising a unified framework for them where this is possible. Having discussed the state of the art we identify challenges and future directions