@misc{3320, author = {{Rautenberg, Kai}}, publisher = {{Universität Paderborn}}, title = {{{Korrektheitsbeweise für Muster von Servicekompositionen}}}, year = {{2018}}, } @inproceedings{3414, abstract = {{Over the years, Design by Contract (DbC) has evolved as a powerful concept for program documentation, testing, and verification. Contracts formally specify assertions on (mostly) object-oriented programs: pre- and postconditions of methods, class invariants, allowed call orders, etc. Missing in the long list of properties specifiable by contracts are, however, method correlations: DbC languages fall short on stating assertions relating methods. In this paper, we propose the novel concept of inter-method contract, allowing precisely for expressing method correlations.We present JMC as a language for specifying and JMCTest as a tool for dynamically checking inter-method contracts on Java programs. JMCTest fully automatically generates objects on which the contracted methods are called and the validity of the contract is checked. Using JMCTest, we detected that large Java code bases (e.g. JBoss, Java RT) frequently violate standard inter-method contracts. In comparison to other verification tools inspecting (some) inter-method contracts, JMCTest can find bugs that remain undetected by those tools.}}, author = {{Börding, Paul and Haltermann, Jan Frederik and Jakobs, Marie-Christine and Wehrheim, Heike}}, booktitle = {{Proceedings of the IFIP International Conference on Testing Software and Systems (ICTSS 2018)}}, location = {{Cádiz, Spain}}, pages = {{39----55}}, publisher = {{Springer}}, title = {{{JMCTest: Automatically Testing Inter-Method Contracts in Java}}}, volume = {{11146}}, year = {{2018}}, } @inbook{3536, author = {{Schellhorn, Gerhard and Wedel, Monika and Travkin, Oleg and König, Jürgen and Wehrheim, Heike}}, booktitle = {{Software Engineering and Formal Methods}}, isbn = {{9783319929699}}, issn = {{0302-9743}}, pages = {{105--120}}, publisher = {{Springer International Publishing}}, title = {{{FastLane Is Opaque – a Case Study in Mechanized Proofs of Opacity}}}, doi = {{10.1007/978-3-319-92970-5_7}}, year = {{2018}}, } @article{3153, author = {{Doherty, Simon and Derrick, John and Dongol, Brijesh and Wehrheim, Heike}}, journal = {{CoRR}}, title = {{{Causal Linearizability: Compositionality for Partially Ordered Executions}}}, year = {{2018}}, } @unpublished{2711, abstract = {{In recent years, researchers have developed a number of tools to conduct taint analysis of Android applications. While all the respective papers aim at providing a thorough empirical evaluation, comparability is hindered by varying or unclear evaluation targets. Sometimes, the apps used for evaluation are not precisely described. In other cases, authors use an established benchmark but cover it only partially. In yet other cases, the evaluations differ in terms of the data leaks searched for, or lack a ground truth to compare against. All those limitations make it impossible to truly compare the tools based on those published evaluations. We thus present ReproDroid, a framework allowing the accurate comparison of Android taint analysis tools. ReproDroid supports researchers in inferring the ground truth for data leaks in apps, in automatically applying tools to benchmarks, and in evaluating the obtained results. We use ReproDroid to comparatively evaluate on equal grounds the six prominent taint analysis tools Amandroid, DIALDroid, DidFail, DroidSafe, FlowDroid and IccTA. The results are largely positive although four tools violate some promises concerning features and accuracy. Finally, we contribute to the area of unbiased benchmarking with a new and improved version of the open test suite DroidBench.}}, author = {{Pauck, Felix and Bodden, Eric and Wehrheim, Heike}}, booktitle = {{arXiv:1804.02903}}, title = {{{Do Android Taint Analysis Tools Keep their Promises?}}}, year = {{2018}}, } @inproceedings{5774, abstract = {{Information flow analysis investigates the flow of data in applications, checking in particular for flows from private sources to public sinks. Flow- and path-sensitive analyses are, however, often too costly to be performed every time a security-critical application is run. In this paper, we propose a variant of proof carrying code for information flow security. To this end, we develop information flow (IF) certificates which get attached to programs as well as a method for IF certificate validation. We prove soundness of our technique, i.e., show it to be tamper-free. The technique is implemented within the program analysis tool CPAchecker. Our experiments confirm that the use of certificates pays off for costly analysis runs.}}, author = {{Töws, Manuel and Wehrheim, Heike}}, booktitle = {{Theoretical Aspects of Computing – ICTAC 2018}}, isbn = {{9783030025076}}, issn = {{0302-9743}}, pages = {{435--454}}, publisher = {{Springer International Publishing}}, title = {{{Information Flow Certificates}}}, doi = {{10.1007/978-3-030-02508-3_23}}, year = {{2018}}, } @inproceedings{4999, author = {{Pauck, Felix and Bodden, Eric and Wehrheim, Heike}}, booktitle = {{Proceedings of the 2018 26th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering - ESEC/FSE 2018}}, isbn = {{9781450355735}}, publisher = {{ACM Press}}, title = {{{Do Android taint analysis tools keep their promises?}}}, doi = {{10.1145/3236024.3236029}}, year = {{2018}}, } @article{6828, author = {{Derrick, John and Doherty, Simon and Dongol, Brijesh and Schellhorn, Gerhard and Travkin, Oleg and Wehrheim, Heike}}, journal = {{Formal Asp. Comput.}}, number = {{5}}, pages = {{597--625}}, title = {{{Mechanized proofs of opacity: a comparison of two techniques}}}, doi = {{10.1007/s00165-017-0433-3}}, volume = {{30}}, year = {{2018}}, } @inproceedings{6836, author = {{Doherty, Simon and Dongol, Brijesh and Wehrheim, Heike and Derrick, John}}, booktitle = {{Integrated Formal Methods - 14th International Conference, {IFM} 2018, Maynooth, Ireland, September 5-7, 2018, Proceedings}}, pages = {{110--129}}, title = {{{Making Linearizability Compositional for Partially Ordered Executions}}}, doi = {{10.1007/978-3-319-98938-9\_7}}, year = {{2018}}, } @inproceedings{6838, author = {{Doherty, Simon and Dongol, Brijesh and Wehrheim, Heike and Derrick, John}}, booktitle = {{Integrated Formal Methods - 14th International Conference, {IFM} 2018, Maynooth, Ireland, September 5-7, 2018, Proceedings}}, pages = {{110--129}}, title = {{{Making Linearizability Compositional for Partially Ordered Executions}}}, doi = {{10.1007/978-3-319-98938-9\_7}}, year = {{2018}}, } @inproceedings{6839, author = {{Doherty, Simon and Dongol, Brijesh and Wehrheim, Heike and Derrick, John}}, booktitle = {{32nd International Symposium on Distributed Computing, {DISC} 2018, New Orleans, LA, USA, October 15-19, 2018}}, pages = {{45:1--45:3}}, title = {{{Brief Announcement: Generalising Concurrent Correctness to Weak Memory}}}, doi = {{10.4230/LIPIcs.DISC.2018.45}}, year = {{2018}}, } @article{1043, abstract = {{Approximate computing (AC) is an emerging paradigm for energy-efficient computation. The basic idea of AC is to sacrifice high precision for low energy by allowing hardware to carry out “approximately correct” calculations. This provides a major challenge for software quality assurance: programs successfully verified to be correct might be erroneous on approximate hardware. In this letter, we present a novel approach for determining under what conditions a software verification result is valid for approximate hardware. To this end, we compute the allowed tolerances for AC hardware from successful verification runs. More precisely, we derive a set of constraints which—when met by the AC hardware—guarantees the verification result to carry over to AC. On the practical side, we furthermore: 1) show how to extract tolerances from verification runs employing predicate abstraction as verification technology and 2) show how to check such constraints on hardware designs. We have implemented all techniques, and exemplify them on example C programs and a number of recently proposed approximate adders.}}, author = {{Isenberg, Tobias and Jakobs, Marie-Christine and Pauck, Felix and Wehrheim, Heike}}, issn = {{1943-0663}}, journal = {{IEEE Embedded Systems Letters}}, pages = {{22--25}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Validity of Software Verification Results on Approximate Hardware}}}, doi = {{10.1109/LES.2017.2758200}}, year = {{2018}}, } @inproceedings{1096, abstract = {{to appear}}, author = {{Beyer, Dirk and Jakobs, Marie-Christine and Lemberger, Thomas and Wehrheim, Heike}}, booktitle = {{Proceedings of the 40th International Conference on Software Engineering (ICSE)}}, location = {{Gothenburg, Sweden}}, pages = {{1182----1193}}, publisher = {{ACM}}, title = {{{Reducer-Based Construction of Conditional Verifiers}}}, year = {{2018}}, } @misc{3512, author = {{Börding, Paul}}, publisher = {{Universität Paderborn}}, title = {{{Testing Java Method Contracts}}}, year = {{2017}}, } @inproceedings{3155, author = {{Töws, Manuel and Wehrheim, Heike}}, booktitle = {{Formal Methods and Software Engineering - 19th International Conference on Formal Engineering Methods, {ICFEM} 2017, Xi'an, China, November 13-17, 2017, Proceedings}}, editor = {{Duan, Zhenhua and Ong, Luke}}, pages = {{362----378}}, title = {{{Policy Dependent and Independent Information Flow Analyses}}}, doi = {{10.1007/978-3-319-68690-5_22}}, year = {{2017}}, } @inproceedings{3156, author = {{König, Jürgen and Wehrheim, Heike}}, booktitle = {{Theoretical Aspects of Computing - {ICTAC} 2017 - 14th International Colloquium, Hanoi, Vietnam, October 23-27, 2017, Proceedings}}, editor = {{Van Hung, Dang and Kapur, Deepak}}, pages = {{118----135}}, title = {{{Value-Based or Conflict-Based? Opacity Definitions for STMs}}}, doi = {{10.1007/978-3-319-67729-3_8}}, year = {{2017}}, } @inproceedings{114, abstract = {{Proof witnesses are proof artifacts showing correctness of programs wrt. safety properties. The recent past has seen a rising interest in witnesses as (a) proofs in a proof-carrying-code context, (b) certificates for the correct functioning of verification tools, or simply (c) exchange formats for (partial) verification results. As witnesses in all theses scenarios need to be stored and processed, witnesses are required to be as small as possible. However, software verification tools – the prime suppliers of witnesses – do not necessarily construct small witnesses. In this paper, we present a formal account of proof witnesses. We introduce the concept of weakenings, reducing the complexity of proof witnesses while preserving the ability of witnessing safety. We develop aweakening technique for a specific class of program analyses, and prove it to be sound. Finally, we experimentally demonstrate our weakening technique to indeed achieve a size reduction of proof witnesses.}}, author = {{Jakobs, Marie-Christine and Wehrheim, Heike}}, booktitle = {{NASA Formal Methods: 9th International Symposium}}, editor = {{Barrett, Clark and Davies, Misty and Kahsai, Temesghen}}, pages = {{389--403}}, title = {{{Compact Proof Witnesses}}}, doi = {{10.1007/978-3-319-57288-8_28}}, year = {{2017}}, } @inproceedings{115, abstract = {{Whenever customers have to decide between different instances of the same product, they are interested in buying the best product. In contrast, companies are interested in reducing the construction effort (and usually as a consequence thereof, the quality) to gain profit. The described setting is widely known as opposed preferences in quality of the product and also applies to the context of service-oriented computing. In general, service-oriented computing emphasizes the construction of large software systems out of existing services, where services are small and self-contained pieces of software that adhere to a specified interface. Several implementations of the same interface are considered as several instances of the same service. Thereby, customers are interested in buying the best service implementation for their service composition wrt. to metrics, such as costs, energy, memory consumption, or execution time. One way to ensure the service quality is to employ certificates, which can come in different kinds: Technical certificates proving correctness can be automatically constructed by the service provider and again be automatically checked by the user. Digital certificates allow proof of the integrity of a product. Other certificates might be rolled out if service providers follow a good software construction principle, which is checked in annual audits. Whereas all of these certificates are handled differently in service markets, what they have in common is that they influence the buying decisions of customers. In this paper, we review state-of-the-art developments in certification with respect to service-oriented computing. We not only discuss how certificates are constructed and handled in service-oriented computing but also review the effects of certificates on the market from an economic perspective.}}, author = {{Jakobs, Marie-Christine and Krämer, Julia and van Straaten, Dirk and Lettmann, Theodor}}, booktitle = {{The Ninth International Conferences on Advanced Service Computing (SERVICE COMPUTATION)}}, editor = {{Marcelo De Barros, Janusz Klink,Tadeus Uhl, Thomas Prinz}}, pages = {{7--12}}, title = {{{Certification Matters for Service Markets}}}, year = {{2017}}, } @article{90, abstract = {{We propose and extend an approach for the verification of safety properties for parameterized timed systems modeled as networks of timed automata. For this task, we introduce an incremental workflow that is based on our algorithm IC3 with Zones. It proceeds in a cycle in which single models of the system are verified, and the verification results are employed for the reasoning about the entire system. Starting with the smallest instances, the verification of the safety property is carried out fast and efficient. On successful verification, the algorithm produces an inductive strengthening of the safety property. We reuse this result and try to reason about the entire parameterized timed system. To this end, we extrapolate the inductive strengthening into a candidate for the next-larger model. In case this candidate is a valid inductive strengthening for the next larger model, our main theorem reasons about all models of the parameterized timed system, stating that the safety property holds true for all models. Otherwise, the main cycle starts over with the verification of the next larger model. This workflow is iterated indefinitely, until able to reason about the entire parameterized timed system, until a counterexample trace is found, or until the single models become too large to be handled in the verification. We reuse the intermediate results in a Feedback-loop in order to accelerate the verification runs for the single models. Furthermore, we consider an extended formalism in comparison to our previous publications.}}, author = {{Isenberg, Tobias}}, journal = {{ACM Transactions on Embedded Computing Systems}}, number = {{2}}, pages = {{47:1--47:24}}, publisher = {{ACM}}, title = {{{Incremental Inductive Verification of Parameterized Timed Systems}}}, doi = {{10.1145/2984640}}, year = {{2017}}, } @inproceedings{5769, abstract = {{Information Flow Analysis (IFA) aims at detecting illegal flows of information between program entities. “Legality” is therein specified in terms of various security policies. For the analysis, this opens up two possibilities: building generic, policy independent and building specific, policy dependent IFAs. While the former needs to track all dependencies between program entities, the latter allows for a reduced and thus more efficient analysis. In this paper, we start out by formally defining a policy independent information flow analysis. Next, we show how to specialize this IFA via policy specific variable tracking, and prove soundness of the specialization. We furthermore investigate refinement relationships between policies, allowing an IFA for one policy to be employed for its refinements. As policy refinement depends on concrete program entities, we additionally propose a precomputation of policy refinement conditions, enabling an efficient refinement check for concrete programs.}}, author = {{Töws, Manuel and Wehrheim, Heike}}, booktitle = {{Formal Methods and Software Engineering - 19th International Conference on Formal Engineering Methods (ICFEM 2017)}}, isbn = {{9783319686899}}, issn = {{0302-9743}}, pages = {{362--378}}, publisher = {{Springer International Publishing}}, title = {{{Policy Dependent and Independent Information Flow Analyses}}}, doi = {{10.1007/978-3-319-68690-5_22}}, year = {{2017}}, }