The current software industry relies on the use of advanced production and development systems for its products. The production process is therefore refining its mechanisms, and it is with this in mind that different types of penetration test. These are verifications that are intended to go to establish the soundness and reliability of a code before it is released commercially.
Such testing techniques differ mainly in the amount of information available to the tester and to the privileges provided to him by the test principal. The goal is always to identify hypothetical flaws and vulnerabilities before cyber criminals do so.
Going into specifics, one of the most popular software testing methodologies is the so-called white box test o White box test, which assumes that we have the specifications of the software and the mechanisms by which the function was then implemented.
The metaphor of the transparent box means that it is possible to see its contents, but also to understand the methods by which it was placed inside. So let us try to understand how white box testing works and how it differs from its opposite, i.e., the black box testing.
What are white box tests?
White box testing is a special software testing methodology that is based on checking the design and internal structure of a software, unlike the external outputs or user experience that are tested by black box testing instead.
In fact, the expression white box test brings together a whole range of other tests, of which the most common ones are integration tests and unit tests. White box tests generally deal with verifying program code and therefore their execution requires a high level of computer programming knowledge.
As mentioned earlier, these types of tests are conducted by specialized personnel to stress a system and unearth any flaws and vulnerabilities that could be exploited by hackers and malicious parties. Performing the white box tests are the penetration tester, who are given information about the internal structure of the software.
Thus, it is not a simulated frontal attack in the strict sense, but rather a reasoned analysis of the behavior of the program being analyzed. It is possible to monitor the operation of the code, ensuring that the inputs produce the expected outputs.
Today, those involved in white box testing are primarily software engineers and developers because considerable expertise in computer code and coding techniques is required. As with other categories of software testing, one can rely on theautomation. If you want, you can choose between manual and automated testing, but increasingly companies prefer to automate it to reduce time and cut costs.
Types of white box tests
There are many different kinds of white box tests, and each category is designed to check different details and aspects of the internal composition Of the code. Here are what are the main white box tests you can conduct:
- Loop testing: is one of the most important white box tests because its purpose is to identify loops found within the software code. Loops are found in code algorithms, and with such a test it is possible to check their validity and see if there are areas where the code needs to be corrected;
- Path test: known as path testing, is a form of testing that exploits the control structure of software. The developer uses that structure to build a control-flow graph and evaluate various paths in the graph. Simply put, path testing makes sure that the system follows all the right steps according to the conditions set by the data;
- Conditional test: This type of test is used to understand whether the logical conditions for code values are false or true. It is useful for indicating to the developer whether the software code is logical, that is, whether it meets the logical programming requirements;
- Unit testing: In this case, the tester checks individual modules or components of the program to make sure they are working properly before integrating them with each other. So small segments of code are tested at a time and it is easier to find errors and bugs when they occur;
- Mutation testing: With the following test, software mutations and alterations are analyzed. Developers or engineers insert small changes to the code to understand if a bug can be generated from this. If the test case passes, it means that there is some flaw in the code since it should not pass after the changes are added;
- Integration test: Integration testing aims to check whether different program modules work well when integrated with other modules. For example, when a database retrieves information online, integration tests check that the data is accurate and goes to update consistently.
The benefits of white box testing
White box tests allow developers to be able to test more code elements and therefore are a more comprehensive category of testing on average as we can learn much more information about how the code works. Indeed, efficient and accurate code is critical to developing a quality program. Let us see what are the most important advantages of relying on white box testing.
- Maximizing test coverage: white box testing can help to maximize test coverage as much as possible. Going to analyze most of the software code generally increases the chances of finding errors or bugs. In short, with white box tests you can map the code in its entirety;
- Identify system defects and bugs: The main benefit of white box tests is related to the fact that they go to test internal functionality, and it is therefore easier for developers to unearth bugs and errors that would otherwise remain buried in the code. In addition to identifying errors, it is also easier to accurately understand the location of the bug due to the specific nature of these tests;
- Simplicity of automation: Automating white box tests is fairly easy, especially if they are unit tests, i.e., those that go to test small chunks of code at a time. For that reason, unit tests usually run before other types of tests;
- Reduced development time: white box tests are very efficient in terms of speeding up design and development timelines. In addition, it is very easy to automate these kinds of tests that are much faster to execute as well as reliable;
- Improved code quality: With white box testing, developers can check the written code a second time to be sure of cleanliness and quality. By performing an analysis of individual pieces and modules, they have the ability to eliminate the parts of code that need to be cleaned up, making it easier to edit in the future.
White box testing vs black box testing: the main differences
When it comes to white box testing, it is essential to understand precisely how it differs from the black box testing. The latter is a type of software testing that differs mainly in that it has no knowledge or information about the internal structure of the code or how to implement it.
The term black box refers to the fact that the tester is ignorant about the basics of the code and will simply check the program's external outputs, i.e., verify what the end user is going to experience. Black box testing does not occur with privileged access, but more truthfully simulates an external attack on the software.
These tests are known as behavioral tests in that they analyze the behavior of software in precise situations and are employed to be certain that the system is functioning properly when acting as a whole.
Another distinguishing feature is that black box tests need to less technical knowledge in the programming environment than white box tests, which are more complex and time-consuming and consequently can be performed even by non-developers. Finally, it should be mentioned that black box tests are more difficult to automate than white box tests because they require software automation tools.