Reverse engineering refers to the duplication of another producer’s product following a thorough examination of its construction or composition. It involves taking apart the product to understand how it works so as to enhance or duplicate such a product. It makes it possible to understand the basic working principle and structure of the systems under study. The practice, which was copied from old industries, is now widely used in both computer hardware and software. Reverse engineering can be applied to different aspects of software as well as hardware development activities to convey various meaning. In the context of software engineering, reverse engineering entails taking a software system and analyzing it to trace it back to the original design and implementation information. It is used to fix certain bugs in software as well as to enhance product features in both hardware and software. For instance, a programmer writes codes in a sophisticated language like C, C++, Python, etc. and because computers do not speak these languages, the code written in these programming languages are assembled in a machine-specific format so as to interpret them into a low-level language that the machine could understand.
There are two forms of reverse engineering. Under the first, the source code is available, but the high-level aspects of the program are not. Therefore, efforts are made to discover the source code for the software under development. The efforts made in uncovering such source code are regarded as reverse engineering. In the second, the software’s source code is not available any longer. Consequent upon this, efforts are made to discover the possible source code. Such process is termed as reverse engineering. To help prevent copyright infringement, reverse engineering utilizes a technique known as clean room design. The main reasons for reverse engineering are to audit the security, take away the copy protection, modify the embedded systems, as well as include additional features not having to spend much alongside other related activities.
Reverse engineering is used in software design to enable the programmer or developer to incorporate new features into existing software whether the source code is known or not. Various techniques are adopted to make this a possibility. In software testing, reverse engineering aids testers’ understanding of viral and other malware code. In software security, reverse engineering is widely used to ensure that the system lacks any major security flaws or vulnerability. It helps to make a system robust, thereby protecting it from hackers and spyware. Some developers even go as far as hacking their system so as to identify vulnerabilities – a system referred to as ethical hacking.
Reverse engineering tools
The process of reverse engineering involves using certain tools which consist of:
- Disassemblers. Disassemblers are used to disect binary codes into assembly codes. They are also employed in extracting strings, functions (both imported and exported), libraries, etc. they help to convert the machine language into a more user-friendly format. Different disassemblers are used for various purposes.
- Debuggers. Debuggers contribute to expanding the functionality of disassemblers by supporting the CPU registers, hex dumping of programs, view of the stack, among other things. Programmers use debuggers to set breakpoints as well as edit assembly codes at run time. They are used in analyzing binaries the same way disassemblers are. Also, they let the reverser step through the code by running a line at a time so as to investigate the results.
- Hex Editors. Hex editors allow programmers to view and edit binaries according to software requirements. They help make it possible to manipulate the fundamental binary data that makes up a computer file. Moreover, because they are used to edit binary files, they are sometimes referred to as a binary editor or a binary file editor.
- PE and Resource Viewer. This tool allows programmers to view and edit resources that are embedded in the EXE file. They let them change icons, edit menu, version information, dialog, etc. PE Explorer makes it easy to translate applications that do not have source codes. All that you need to do is replace text resources with their translated versions, then resize buttons, forms, etc.
Reverse engineering software allows programmers to manipulate raw data into a useful form, thanks to the development of various digitizing devices. Reverse engineering is a powerful tool which hackers could use to compromise any security system.
Black-box testing helps to examine the functionality of an application depending on its specifications and without peering into its internal workings or structures. It is sometimes called Specifications based testing. This method of testing is usually applied to all levels of software testing such as integration, unit, system, as well as acceptance. It is made of mostly higher-level testing and is also dominant in unit testing. Here, test cases are centered around specifications, design parameters, and requirements. Tests used are fundamentally functional in nature, although non-functional tests may also be used. Usual black-box test design techniques comprise of all-pairs testing, decision table testing, equivalence partitioning, cause-effect graph, boundary value analysis, error guessing, use case testing, state transition testing, user story testing, combining technique, and domain analysis. Black box testing involves analyzing a running program by probing it with different inputs. Bear in mind that black box testing can be done even without access to the binary code.
The white box testing method of testing software tests the internal workings or structures of an application, as against its functionality (that is, black-box testing). Here, an inner aspect of the system and programming skills are used in designing test cases. The tester selects inputs to exercise paths via the code to determine the right outputs. White-box testing can be applied to the system, integration, and unit levels of the software testing process. Its design techniques consist of code coverage criteria like data flow testing, control flow testing, branch testing, decision coverage, statement coverage, modified condition and decision coverage, path testing, prime path testing. White box testing is usually very useful in locating programming errors and implementation errors in software. There are two kinds of white box testing tools: those that need the source code and those that decompile the binary code automatically and continue from there.