Java as a specification language for hardware-software systems

The Android operating system dominates the smartphone market. Thus, to service the market, the number of Android applications has risen dramatically. These applications are processing a great amount of sensitive data, which could result in various concerns including data leakage and privacy violations. For example, applications may misuse the sensitive data stored on Android devices and violate the privacy of the user. Therefore, it is essential to maintain user privacy and protect sensitive data from leakage. Static data flow analysis approaches are used for analyzing Android applications to uncover security and privacy issues. However, these approaches frequently generate false alarms, given the different challenges created by Android applications, such as inter-component communication (ICC), reflection, and implicit flow. This work presents the DroidRista approach for conducting static data flow analysis on Android applications to detect sensitive data leakage. DroidRista analyzes ICC, reflection, and implicit flow in Android applications. To evaluate the performance of DroidRista, it was tested on three data sets. The results demonstrate improved performance in terms of detecting data leakage compared to existing static data flow analysis approaches.

As Android becomes popular, Android security acquires more and more attentions. This paper proposes a new system design strategy for dissemination of high fidelity applications. We propose to use static and dynamic data flow analysis on Android applications to detect about how the apps leverage users'/enterprises' sensitive data. Also, we plan to build up a cloud-based back-end to safeguard mobile devices. The new secure system framework will not only analyze an individual app isolatedly, but also analyze the correlation between apps.

Static and dynamic program analysis techniques are important research areas in software security. Static analysis helps us locate vulnerabilities in a software by looking at the source code. Dynamic analysis helps us reason about the behavior of the software from information gathered at run-time. In this thesis, we are focusing on data flow analysis and heap analysis which are key static and dynamic program analysis techniques respectively.
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\nIn the first part of this thesis, we aim at detecting vulnerabilities in Android applications which have capability leaks. The security of the Android platform relies mainly on sandboxing applications and restricting their capabilities such that no application, by default, can perform any operations that would adversely impact other applications, the operating system, or the user. However, a recent research reported that a genuine but vulnerable application may leak its capabilities. When being leveraged, other applications can gain extra capabilities which they are not granted originally. We present DroidChecker, an Android application analyzing tool which searches for the aforementioned vulnerability in Android applications. DroidChecker uses interprocedural control flow graph searching and static taint checking to detect exploitable data paths in an Android application. We analyzed more than 1100 Android applications using DroidChecker and found 6 previously unknown vulnerable applications including the renowned Adobe Photoshop Express application. We also developed a malicious application that exploits the previously unknown vulnerability found in the Adobe Photoshop Express application. We showed that the malicious application, which is not granted any permissions, can access contacts on the phone with just a few lines of code.
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\nIn the second part of this thesis, we explore the use of heap analysis to extract software birthmarks. There are techniques like code obfuscation and watermarking which can make the source code of a program difficult to understand by humans and prove the ownership of the program. However, code obfuscation cannot avoid the source code being copied and a watermark can be defaced. A birthmark is a group of unique characteristics a program possesses that can be used to identify the program. We propose two novel dynamic birthmark systems based on the run-time heap. A dynamic birthmark is one that is extracted when the program is executing. Since it is based on the run-time behavior of the program, semantics-preserving transformations of the code like obfuscation cannot defeat dynamic birthmarks. In this regard, dynamic birthmarks are more robust compared with static birthmarks.
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\nTo the best of our knowledge, these are the first birthmark systems using heap analysis as the underlying technique. The basic idea is to take snapshots of the heap while the program is running. From the snapshots, heap graphs are constructed to model the referencing structure between objects. After going through some filtering and referencing processes, they become the birthmarks. The two birthmark systems have been devised to extract birthmarks for Java programs and JavaScript programs respectively. While the underlying ideas of the two birthmark systems are similar, the differences in nature of the two programming languages led to different implementation designs.

Static data flow analysis is an indispensable tool for finding potentially malicious data leaks in software programs. Programs, nowadays often consisting of millions of lines of code, have grown much too large to allow for a complete manual inspection. ...

Programmable hardware built on a regular architecture can partially alleviate the problem of increased defect densities associated with transistor scaling by dynamically wiring around the defects [1]. The fine granularity of FPGAs is however unsuitable for effectively exploiting runtime reconfiguration because of the high overheads involved. A coarse grain reconfigurable array with malleable communication links - reMORPH - is proposed in this paper. The compute tile uses DSP48E and BRAM embedded blocks in a Xilinx FPGA and has a very low footprint of about 200 slice LUTs. The semi-systolic near neighbour communication interconnect can be dynamically reconfigured for each “epoch” of computation. The “epoch” or phases of the application are obtained via profiling or static data flow analysis. Some of the links between the compute tiles are changed during the reconfiguration phase which drastically reduces the context switch overhead enabling high performance/area applications to be built on this fabric.

For many real-time applications (e.g. command, control, and communications), parallel computers offer a natural computing platform. However, very little attention has been paid to the specification requirements of real-time systems implemented on parallel machines. Towards this end, we propose a specification language PRETSEL (Parallel Real-Time Specification Language). The PRETSEL specification language is based on a traditional two-level view of parallel computing whereby a parallel computation is viewed as a collection of interacting (data) parallel algorithms. This view is naturally reflected in PRETSEL syntax where at the lower level various constructs are provided for the specification of a data-parallel real-time algorithm (data-parallelism). At the upper level another set of constructs is provided to combine such tasks in a variety of way (task-parallelism). Furthermore, the PRETSEL language allows for the specification of performance requirements. PRETSEL is currently being evaluated for real-time avionics applications. We describe the syntax and operational semantics of PRETSEL and establish results relating the functional and the temporal behaviors.

Process-driven applications evolve rapidly through the interaction between executable BPMN (Business Process Modeling and Notation) models, business tasks, and external services. Given these components operate on some shared process data, it is imperative to recover the latent data by visiting relation, which is known as data flow among these tasks. Data flow will benefit some typical applications including data flow anomaly checking and data privacy protection. However, in most cases, the complete data flow in a business process is not explicitly defined but hidden in model elements such as form declarations, variable declarations, and program code. Some methods to recovering data flow based on process model analysis of source code have some drawbacks; i.e., for security reasons, users do not want to provide source code but only encapsulated methods; therefore, data flows are difficult to analyze. We propose a method to generate running logs that are used to produce a complete data flow picture combined with the static code analysis method. This method combines the simple and easy-to-use characteristics of static code analysis methods and makes up for the shortcomings of static code analysis methods that cannot adapt to complex business processes, and as a result, the analyzed data flow is inaccurate. Moreover, a holistic framework is proposed to generate the data flow graph. The prototype system designed on Camunda and Flowable BPM (business process management) engine proves the applicability of the solution. The effectiveness of our method is validated on the prototype system.

This paper presents and evaluates a set of analyses designed to reduce synchronization overhead in Java programs. Monitor-based synchronization in Java often causes significant overhead, accounting for 5-10% of total execution time in our benchmark applications. To reduce this overhead, programmers often try to eliminate unnecessary lock operations by hand. Such manual optimizations are tedious, error-prone, and often result in poorly structured and less reusable programs. Our approach replaces manual optimizations with static analyses that automatically find and remove unnecessary synchronization from Java programs. These analyses optimize cases where a monitor is entered multiple times by a single thread, where one monitor is nested within another, and where a monitor is accessible by only one thread. A partial implementation of our analyses eliminates up to 70% of synchronization overhead and improves running time by up to 5% for several already hand-optimized benchmarks. Thus, our automated analyses have the potential to significantly improve the performance of Java applications while enabling programmers to design simpler and more reusable multithreaded code.

This paper provides a brief survey of languages used for developing operating systems. The paper discusses the issues involved in deciding on the use of a higher level language, including the technical, management, psychological factors, and the advantages and disadvantages. The major part of the paper discusses specific languages which have been used, and the major systems which have been developed using them. General comments and future trends are indicated, with a discussion of desirable characteristics, the non-universality of a single systems programming language, system specification languages, machine independence, and operating system writing systems. An appendix lists languages known to have been used for writing either compilers and/or operating systems, and indicates references for them.

Static analyzers have become increasingly popular both as developer tools and as subjects of empirical studies. Whereas static analysis tools exist for disparate programming languages, the bulk of the empirical research has focused on the popular Java programming language. In this paper, we investigate to what extent some known results about using static analyzers for Java change when considering C#-another popular object-oriented language. To this end, we combine two replications of previous Java studies. First, we study which static analysis tools are most widely used among C# developers, and which warnings are more commonly reported by these tools on open-source C# projects. Second, we develop and empirically evaluate EagleRepair: a technique to automatically fix code in response to static analysis warnings; this is a replication of our previous work for Java [20]. Our replication indicates, among other things, that 1) static code analysis is fairly popular among C# developers too; 2) Re-Sharper is the most widely used static analyzer for C#; 3) several static analysis rules are commonly violated in both Java and C# projects; 4) automatically generating fixes to static code analysis warnings with good precision is feasible in C#. The EagleRepair tool developed for this research is available as open source.

In this paper, we propose a software vulnerability checker which takes rules describing vulnerability patterns and a source program as input and detects locations and paths of the patterns in the program. Simple and flow patterns for vulnerabilities are described as rules in the specification language we designed. The lightweight control and data flow analysis is necessary to detect flow patterns. Newly discovered vulnerability patterns can easily be added to the existing rules. We implement the detector in three parts: a pattern matcher which finds locations of vulnerabilities in source program, a flow graph constructor which extracts the control flow and data flow from the program, and a flow analyzer which finds program's vulnerable execution paths.

Synchronous programming languages are well-suited for the design of safety-critical real-time embedded systems. However, the compilers and synthesis procedures are challenged by the synchronous programming paradigm and have to solve additional problems like causality and schizophrenia problems. Algorithms to solve these basic compilation problems have already become mature, but code optimization still lacks behind. Often, code optimization is left to the back-end tools like compilers for sequential software or hardware synthesis tools. In this paper, we develop a static analysis procedure to introduce code optimization techniques to synchronous languages. We develop specialized code optimization procedures that can be applied to all kinds of synchronous languages. Similar to the code optimization techniques used for the compilation of sequential software, our procedures are also based on a static data-flow analysis that is adapted to the synchronous programing model.

Mark Watson Morgan Kaufmann Publishers, San Francisco, 1997, 377 pp. ISBN 1-55860-420-0, $44.95 This book is well written and organized to cover how to apply AI (Artificial Intelligence) techniques for practical Internet and Intranet tools by using the Java programming language. In the book, the author uses neural network and genetic algorithms to develop distributed systems that are applied for the Internet and Intranets, such as client/server model and information retrieval tool and so on. Part 1 begins with a good general introduction to AI. The history and survey of Artificial Intelligence research are given briefly. In addition, symbolic processing versus neural networks approaches are discussed. This author opts to use neural network to develop example Internet/Intranet systems in the book. Part 2 consists of Java programs developed for AI, neural networks, genetic algorithms, natural language processing, and expert systems. Chapter 2 illustrates Graphical User Interface (GUI) class that is derived from Applet and Canvas classes in Java, which is used in most example programs in the book. Chapter 3 introduces a frame data structure that is used as a message in distributed systems in the later chapters. Chapter 4 shows neural network classes developed in Java and its theory and implementation. Chapter 5 explains the genetic algorithms and the Java genetic algorithm classes. Chapter 6 describes how to develop and implement natural language processing classes using Java. Chapter 7 shows how to share data objects in distributed systems. For example, distributed AI agent classes are developed to share data objects, WWW data collection agent classes are shown to retrieve documents in the Internet, and small POP (Post Office Protocol) mail classes are developed to send and receive mails. Chapter 8 illustrates how to develop expert systems by using Java Jess, which is based on OPS5/CLIPS expert systems. Part 3 explains how to generate and implement the projects using the Java classes that are developed in Part 2. Chapter 9 shows the project that demonstrates the use of genetic algorithms in chapter 5 to control enemy ships in a scrolling arcade game. Chapter 10 describes the real-time handwriting recognition system developed by using the neural network classes in chapter 4. Chapter 11 illustrates a greedy algorithm to optimize neural networks that is based on the author’s hand-tuning neural training data. Chapter 12 improves neural network training data by applying genetic algorithms, to discard bad training data and to avoid discarding good training data. Chapter 13 describes the distributed natural language processing system that uses natural language processing classes in chapter 6. The data structures in chapter 2 are used to store historical data in a separate server application on any other computer in the Internet or Intranets. The final chapter provides the design and implementation of a complete agent-based information retrieval tool for the Internet. The retrieved documents are stored in ASCII or HTML format. This book is a very good reference book for anyone interested in developing systems using Java in distributed environments, especially applying AI techniques. Also, the author provides the CD-ROM that includes the source code for Java classes developed in the book. Haklin Kimm, University of Tennessee

Modern programs make extensive use of reusable software libraries. For example, a study of a number of large Java applications shows that between 17% and 30% of the classes in those applications use container classes defined in the java.util package. Given this extensive code reuse in Java programs, it is important for the interfaces of reusable classes to be well documented. An interface is well documented if it satisfies the following requirements: (1) the documentation completely describes how to use the interface; (2) the documentation is clear; (3) the documentation is unambiguous; and (4) any deviation between the documentation and the code is machine detectable. Unfortunately, documentation in natural language, which is the norm, does not satisfy the above requirements. Formal specifications can satisfy them but they are difficult to develop, requiring significant effort on the part of programmers. To address the practical difficulties with formal specifications, we describe and evaluate a tool to help programmers write and debug algebraic specifications. Given an algebraic specification of a class, our interpreter generates a prototype that can be used within an application like a regular Java class. When running an application that uses the prototype, the interpreter prints error messages that tell the developer in which way the specification is incomplete or inconsistent with a hand-coded implementation of the class. We use case studies to demonstrate the usefulness of our system.

SOFL is a formal language and method for system specification and design. It was developed by integrating Petri Nets, Data Flow Diagrams, and VDM-SL. As the major feature of the original SOFL method is to use structured techniques for analysis and specification, and object-oriented techniques for design and implementation, SOFL has its own implementation language that is similar to C++. However during our recent work of applying SOFL to software systems, the transformation of structured specifications to object-oriented implementations creates some difficulties, simply because of paradigms mismatch. In this paper we extend SOFL to a formal object-oriented language and method while keeping its structured features. This will allow powerful object-oriented reuse mechanisms, such as class inheritance and object composition, to be utilized in the early phases, and transformation from SOFL specifications to commercial object-oriented programming languages to be readily achieved.