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Reverse engineering can be used in many ways in the area of software development. Whether we are creating a genuine new system or modifying existing one , proper use of reverse engineering tools and techniques would definitely help during project designing and coding process. Reverse engineering has many areas of application related to software industry. [1]

Many academic projects suffer poor designing and coding techniques, and don’t have a clear understanding about objectives of the projects .this common problem forms the well known gap between software industry and academic projects. Using software reverse engineering concepts and tools this gap can be decreased effectively. Students can improve their level of development, designing and coding. Reversing process can be automated in the some extent with the tools available for modern programming languages such as c# .NET Dis#(http://netdecompiler.coml Reflector(www.reflector.com) [2]. Using these tools coding and designing information about the system can be easily obtained, and used in overall reverse engineering process. A complete framework has been established in this paper including concepts, steps and techniques for reverse engineering, which definitely lessen the gap between software industry and academics.

At first glance, it may seem that the need for SRE can be lessened by simply maintaining good documentation for all software that is written. If we provide the complete documentation of the system, it will definitely decrease

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need of that system. For example, even a company that has brought software to market may no longer understand it because the original designers and developers may have left, or components of the software may have been acquired from a vendor who is no longer in business. Need for reversing a project is never affected with documentation.

Although revering has its great use in designing and developing genuine systems, yet it can be used in harmful purposes like password cracking, unauthorized access, network intrusion and website hacking etc. Software Development process can be related with reverses engineering in the following cases.  Interoperability with proprietary Software: Develop applications or device drivers that interoperate (use) proprietary libraries in operating systems or application. During the development of a new system there may be situations when we have to interact with third party software for which no code is available now, this situation gives rise to the need of software reverse engineering .Effectively using reversing concepts codes are created to interact with proprietary software.[3]  Verification between implementation and design: Verify that code produced during the forward development process matches the envisioned design by reversing the code back into

 Evaluating software quality and robustness: Ensure the quality of software before purchasing it by performing heuristic analysis of the binaries to check for certain instruction sequences that appear in poor quality code. Many antivirus companies use this technique to ensure the binary pattern of a virus. Security checks can also be evaluated with the help of dissembler; low level memory operations can also be verified. Based on some previous experience quality indicator can be checked at low level.  Software maintenance and re- engineering: Maintenance requires more effect than developing the system itself. If the source code is lost, we have no options but reversing the whole project. Reverse engineering process can recover the design of legacy software module when source is not available to make possible the maintenance, evolution and reuse of the modules.

Reverse Engineering concepts can easily be applied in the development of a new academic project or in the maintenance of a legacy system. We can understand the design and functionality of the system while source code is not available. Although reverse engineering can effectively be used in many industry based projects, yet the concept of reverse engineering is completely applicable in academic projects.

Development of a project is never an easy task .The hindrances comes in many forms and flavor .While development of any project, it is a common challenge almost for the development final year students and the beginners. Some of the common problems can be stated as … 1) Projects don’t have a clear objective. 2) Projects are persistent, repeatable nature . 3) Hardly a project implements innovation.

Interoperabil ity with proprietary Software Verification between implementation and design Evaluating software quality and robustness Software maintenance and re- engineering

Software Reverse Engineer ing

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4) Short time schedule forces more concentration on coding rather designing of the project. 5) Probably 50% projects never completed during academic project schedule.

A Study shows that 51% academic projects have some of the above mentioned problems. These problems form the well known gap between industry and academic [4]. Intelligent use of reverse engineering can remove many of the above mentioned problems of academic projects. Proper use of reverse engineering tools and techniques can lead good design and coding process. While developing new projects a lot of designing and internal working information can easily be obtained by use of reversing a legacy product carefully .According to our requirements the extracted information can be applied intelligently to the new projects.

Software reverse engineering is differ from software engineering as-

Applies in modify or maintenance of the existing system Applies in creating a new system Evaluate goals and objectives of the system after implementation Goals and objectives are implemented in the system No use of life cycle methods Various development life cycles are available Extensive use of automated tools Less use of automated tools Documentation is not available. Provide well documentation ,client reviews etc

Reverse engineering in and of itself does not involve changing the subject system. It is a process of examination, not change or replication. [5] Before we go for reengineering targeted system it is good idea to clearly identify all the modules of the application. Software reengineering requires some prerequisites steps such as collecting all the possible information about the system itself, searching for documentation (if available) etc.

The very first step is to obtain all the possible information about the project to be reengineered .Preliminary information includes documentation, third party information about the project, user views and inbuilt help module. All this information should be collected in an easily understandable format. [6]

After collecting all the related information the second step should be carefully observe the input and output data flow of the of the current module we want to reengineered . I/O sequence can help to better understand the processing functions of the module.

Analyzing input output sequence carefully, note down basic model of input output data flow certainly helps in understanding the processing function of the module. Generic processing function can be designed for data flow.

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Having done with preliminary analysis of the module we can design a visual presentation for that module, diagram may show data flow of the module in graphical format. Understand and extract 5the design of targeted system. [7]

Now pseudo code can be written for every function of the module. There is no need till now to choose a specific language, generic types and methods are very useful to understand generic processing function.

The underlying algorithm can be coded in pseudo code at this level9. This later can easily be translated into any programming language. Functions are coded without using any specific type or syntax; it works just like a blueprint of the actual function.

Any suitable programming language can be selected to code the real working module or function obtained from the above steps .Higher level language can provide some support when we go to write actual code.

As a final step some comparison is needed between the module created by reverse engineering and the original working module module , if found some changes ,then the process would have to be repeated for better implementation of reverse engineering concepts. Obviously some intuition is required for proper implementation of reverse engineering concepts. Beside all these steps there are also some tools available which can help during reversing software.

A CASE STUDY:

Objective: Understanding the design of an application program and hence changing the code according to our requirements or using this knowledge in creating a new legacy system. Our targeted system is Magazine Subscription management developed in C#.NET 2005 and MS-Access as backend database. This simple module manages the subscription data of a Magazine. This module saves data of customers and prints some simple reports based on the selection. Many tools are available for browsing class information, and source codes for c# .NET.

TOOLS:

.net reflector is a very powerful class browser, analyzer and decompiler for .net environment Reflector can be used for showing the assembly, class and function information of the .NET module The latest version of the Reflector can be obtained from: http://www.aisto.com/roeder/dotnet.

Dis # is also a class browser, analyzer and decompiler for c# .net environment. Dis# allows editing names in decompiled code and persisting changes in project file. Dis # can be obtained from the following link: http://netdecompiler.com/download.html. As we know c# is a popular language for application development now a day’s .it is widely used in academic and professional environment for developing many database driven applications.

1) Analyze and identify all the modules of the application 2) Disassemble the module using .NET Reflector 3) Understand and change the hidden code of the module [function] 4) Recompile and understand the functioning of the code to use it. Many tools are available today for decompiling and analyzing code written in high level languages such as c# .These tools are powerful and sophisticated to work as class browser, decompiler and are very helpful in software reverse engineering [8]. Following two tools are very popular for c# .net project reverse engineering.

Dis # can translate c#.net assembly into human readable formate.it can decompile classes, methods, emus, and other elements of c# .NET compiled project. It has a very

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impressive interface and for decompiled classes and methods. The primary interface for the application is shown in the figure 1 below. Figure 1 When we open this magazine subscription management t project developed in c# .NET and MS Access, with Dis# firstly it looks like as following figure: This simple application works with MS Access database as background. Subscription detail for magazine customers can be saved searched, and some reporting features. This small application is a good example to work as a module of large project. Dis# is capable to browse all the information about classes, forms and reports of the module. By selecting any class, forms or reports (browsed in a clear way) we can see the code behind it (as in Figure 2) .Properties classes and forms are well arranged in a hierarchal manner so it is easy to browse and locate the desired object. When we select an object in the left pane of Dis# tool it can unhide the background code of that object. As we can see in the following snap- Figure2 The above screen shot of Dis# shows the code of method “file_name” .All the extracted code are well formatted and self described, and can easily be understood by reading carefully .Classes ,functions and properties can be documented manually during the code reveal process. Here we can create dummy application by using RAD (rapid application development) tools and can obtain a lot of information about designing a coding of the application. [8] Using .NET Reflector: When we open the current module with another tool, it looks like -

Results are comparable in the following cases

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1. Since reflector supports different version of .net framework (including framework 1.0 to latest version i.e. 4.0) so if the targeted system updated, changes can be reflected easily. 2. Reflector can decompile different languages selected by the user. Depending upon the requirements any of the tools can be selected to decompile the c#.net application. If the project is complex and developed using different .NET supported language then Reflector would preferred.

This simple case study shows the traditional power of reverse engineering in the area of academic project development. Carefully using these tools and techniques student can get a real touch of industry based projects which can definitely improve their level of knowledge and understanding the working of a good software project. These concepts can lessen the gap between software industry and academics, as well as student can learn the complex process of designing and integrating industry oriented applications using available tools.

[1] http://reversingproject.info/ as retrieved on 27th September 2011. [2] http://netdecompiler.com/ “owner of Dis# decompiler” as retrieved on 27th September 2011. [3] CEM KANER, J.D., (1998). Ph.D. ARTICLE 2B and REVERSE ENGINEERING, http://www.kaner.com/pdfs/ RevEngShort.pdf as retrieved on 27th September 2011 [4] www.it-cortex.com (The Robins-Gioia survey, 2001), as retrieved on 25 September 2011. [5] Chikofsky, E.J.; J.H. Cross II (1990). "Reverse Engineering and Design Recovery: Taxonomy in IEEE Software". IEEE Computer Society: 13–17

[6] SOFTWARE—PRACTICE AND EXPERIENCE, VOL. 21(12), 1349–1364 (DECEMBER 1991)

[7] SOFTWARE—PRACTICE AND EXPERIENCE, VOL. 21(12), 1349–1364 (DECEMBER 1991) Software Reverse Engineering: A Case Study, ERIC J. BYRNE, Department of Computing and Information Science, Kansas State University, Nichols, Hall, Manhattan, Kansas 66506, U.S.A.

[8] Paolo Tonella and Alessandra Potrich (2005), Reverse Engineering of Object Oriented Code, Springer, New York, USA, ISBN: 0-387-40295-0.