Dynamic Protocol Reverse Engineering a Grammatical Inference Approach

Round trip engineering of software from source code and reverse engineering of software from binary files have both been extensively studied and the state-of-practice have documented tools and techniques. Forward engineering of protocols has also been extensively studied and there are firmly established techniques for generating correct protocols. While observation of protocol behavior for performance testing has been studied and techniques established, reverse engineering of protocol control flow from observations of protocol behavior has not received the same level of attention. State-of-practice in reverse engineering the control flow of computer network protocols is comprised of mostly ad hoc approaches. We examine state-of-practice tools and techniques used in three open source projects: Pidgin, Samba, and rdesktop . We examine techniques proposed by computational learning researchers for grammatical inference. We propose to extend the state-of-art by inferring protocol control flow using grammatical inference inspired techniques to reverse engineer automata representations from captured data flows. We present evidence that grammatical inference is applicable to the problem domain under consideration

JTorX: Exploring Model-Based Testing

The overall goal of the work described in this thesis is: ``To design a flexible tool for state-of-the-art model-based derivation and automatic application of black-box tests for reactive systems, usable both for education and outside an academic context.'' From this goal, we derive functional and non-functional design requirements. The core of the thesis is a discussion of the design, in which we show how the functional requirements are fulfilled. In addition, we provide evidence to validate the non-functional requirements, in the form of case studies and responses to a tool user questionnaire. We describe the overall architecture of our tool, and discuss three usage scenarios which are necessary to fulfill the functional requirements: random on-line testing, guided on-line testing, and off-line test derivation and execution. With on-line testing, test derivation and test execution takes place in an integrated manner: a next test step is only derived when it is necessary for execution. With random testing, during test derivation a random walk through the model is done. With guided testing, during test derivation additional (guidance) information is used, to guide the derivation through specific paths in the model. With off-line testing, test derivation and test execution take place as separate activities. In our architecture we identify two major components: a test derivation engine, which synthesizes test primitives from a given model and from optional test guidance information, and a test execution engine, which contains the functionality to connect the test tool to the system under test. We refer to this latter functionality as the ``adapter''. In the description of the test derivation engine, we look at the same three usage scenarios, and we discuss support for visualization, and for dealing with divergence in the model. In the description of the test execution engine, we discuss three example adapter instances, and then generalise this to a general adapter design. We conclude with a description of extensions to deal with symbolic treatment of data and time

7e Nederlandse testdag, Eindhoven, 8 November 2001 : proceedings

These are the proceedings of the seventh edition of the Nederlandse Testdag (a.k.a. Dutch Testing Day), held on November 8, 2001 in Eindhoven, The Netherlands. The increase in the complexity of software and hardware systems was the predominant concern in the software design of the last decades. This increase is still going on today. and mastering this complexity is possible, only by investigating, discussing and evaluating methods and techniques for testing such systems. The Nederlandse Testdag serves as a forum in which researchers from the industry and the academia discuss and present their latest experiences and theories in the area of testing. The initiative for organising the Nederlandse Testdag is, and has always been, the result of the combined efforts of the Dutch academia and the industry. The Nederlandse Testdag is an annual event which was first held in 1995. This year's edition again consists of one invited presentation by Jens Grabowski, on ITCN-3. and six regular presentations, both from the academia and from the industry. The presentations capture a broad field of the entire testing spectrum. In the presentation by Martin Gijsen (CMG), test automation for Graphical User Interface (GUI), dedicated and embedded systems according to the TestFrame methodology is explained. Klaas Mateboer (Collis) presents the test-tool Conclusion. René de Vries (University of Twente) reports on specification testing in practice and illustrates this by means of an example. In the presentation by Loe Feijs (Eindhoven University of Technology), testing is related to game-theory. Marcel Verhoef (Chess) and Bertil Oving (NLR) present their experiences using real-time simulation, UML and VDM to obtain more reliable spacecraft avionics. Finally, Ben van Buitenen (Baan), provides an insight in service pack testing: how to efficiently test customised software components and packages. The organisation of the Nederlandse Testdag is grateful for the sponsorship it received from the Eindhoven University of Technology, the Eindhoven Embedded Systems Institute, and the financial support from Dutch Research School IPA. We are very much indebted to CMG and Telelogic's willingness to sponsor this event financially. Over the years, both companies have profiled themselves as companies investing both time and resources in advancing the current state in testing. Finally, the organisation thanks Marcella de Rooij and EIize Russell for their organisational assistance

Modelling and Analysis of Network Security Policies

Nowadays, computers and network communications have a pervasive presence in all our daily activities. Their correct configuration in terms of security is becoming more and more complex due to the growing number and variety of services present in a network. Generally, the security configuration of a computer network is dictated by specifying the policies of the security controls (e.g. firewall, VPN gateway) in the network. This implies that the specification of the network security policies is a crucial step to avoid errors in network configuration (e.g., blocking legitimate traffic, permitting unwanted traffic or sending insecure data). In the literature, an anomaly is an incorrect policy specification that an administrator may introduce in the network. In this thesis, we indicate as policy anomaly any conflict (e.g. two triggered policy rules enforcing contradictory actions), error (e.g. a policy cannot be enforced because it requires a cryptographic algorithm not supported by the security controls) or sub-optimization (e.g. redundant policies) that may arise in the policy specification phase. Security administrators, thus, have to face the hard job of correctly specifying the policies, which requires a high level of competence. Several studies have confirmed, in fact, that many security breaches and breakdowns are attributable to administrators’ responsibilities. Several approaches have been proposed to analyze the presence of anomalies among policy rules, in order to enforce a correct security configuration. However, we have identified two limitations of such approaches. On one hand, current literature identifies only the anomalies among policies of a single security technology (i.e., IPsec, TLS), while a network is generally configured with many technologies. On the other hand, existing approaches work on a single policy type, also named domain (i.e., filtering, communication protection). Unfortunately, the complexity of real systems is not self-contained and each network security control may affect the behavior of other controls in the same network. The objective of this PhD work was to investigate novel approaches for modelling security policies and their anomalies, and formal techniques of anomaly analysis. We present in this dissertation our contributions to the current policy analysis state of the art and the achieved results. A first contribution was the definition of a new class of policy anomalies, i.e. the inter-technology anomalies, which arises in a set of policies of multiple security technologies. We provided also a formal model able to detect these new types of anomalies. One of the results achieved by applying the inter-technology analysis to the communication protection policies was to categorize twelve new types of anomalies. The second result of this activity was derived from an empirical assessment that proved the practical significance of detecting such new anomalies. The second contribution of this thesis was the definition of a newly-defined type of policy analysis, named inter-domain analysis, which identifies any anomaly that may arise among different policy domains. We improved the state of the art by proposing a possible model to detect the inter-domain anomalies, which is a generalization of the aforementioned inter-technology model. In particular, we defined the Unified Model for Policy Analysis (UMPA) to perform the inter-domain analysis by extending the analysis model applied for a single policy domain to comprehensive analysis of anomalies among many policy domains. The result of this last part of our dissertation was to improve the effectiveness of the analysis process. Thanks to the inter-domain analysis, indeed, administrators can detect in a simple and customizable way a greater set of anomalies than the sets they could detect by running individually any other model