In any application, business logic is a fundamental component of functionality. Because it is so critical, having complete, consistent code is essential for a usable and secure application. Failing to audit code or find bugs before release is a recipe for crashes and unhappy customers.
To address this problem, some developers use formal verification to ensure code quality and to protect business logic. By using automated tools and implementing frameworks like the CI/CD pipeline, developers are able to address flaws early, saving themselves and your organization time and resources over the software development life cycle.
Understanding Formal Verification in Software Security
Formal verification is a method, typically mathematical, of confirming that a software design is sound. Often, developers will use mathematical proof of correctness to verify a design and check to see whether business logic is correct.
This is a useful tool, especially as software becomes more complex. Business logic, or the way an application functions and makes decisions, is a fundamental component of all software. However, business logic is only as good as the programming behind it. By implementing formal verification, your development team can ensure that there are no inputs that will break the application.
Some advantages of formal verification include:
- Effective bug checks. Verification tools can be used to detect potential issues in the code based on business logic and potential uses of the software. If an issue is detected, your team will be alerted so that the code can be tweaked before release.
- Speedy bug identification. Other methods of bug detection may be as effective as formal verification, but in some cases, formal verification works faster.
- Early vulnerability identification. Including verification enables your development team to discover issues in the code and business logic early in the process of development. This reduces overall costs and saves time in development.
- Improved security. Because formal verification ensures that there is no risk of failure, the application’s risk of attacks through code vulnerabilities and design flaws is reduced. This greatly benefits the overall security posture of the application and your organization.
These benefits are especially important for software and applications that are critical for a system’s function. There are also many things that require bulletproof software. For example, if you are building software that will fly a plane or help with medical care, failure would be detrimental. In these cases, formal verification is an important way to ensure consistent uptime.
However, formal verification also has some limitations. If your teams are going to use it, they must either be well-versed in the mathematics used or must purchase a tool. Not all teams have this level of expertise, and verification solutions will sometimes have bugs themselves. A faulty tool will yield unreliable results.
Additionally, user error and insufficient specifications can limit the ability of formal verification to assess the software design. So, while implementing formal verification will help secure your software and protect against unauthorized access, it must be implemented correctly and thoroughly for best results.
Applying Formal Verification to Business Logic
Business logic determines how an application will behave when it receives various inputs. To ensure that there are no internal contradictions or invalid pathways that could prevent proper functioning, it’s important to test the code during development. Modeling complex business rules is both difficult and time-consuming, however, which is where formal verification can make a big difference.
Although some organizations have the expertise available to complete formal verification without tools, most will use tools or solutions. Typically, these solutions support modeling and simulation, which helps ensure that all eventualities are accounted for. This also helps with verifying the consistency and completeness of logic.
Ideally, all of your code should follow syntax rules and style conventions. Checking the consistency of your code is an important part of eliminating bugs as even the smallest inconsistency can lead to problems downstream. Formal verification also confirms that every true statement in your code is, in fact, provably true. This ensures that there are no contradictions in your code that could lead to the application breaking.
Inconsistencies in your code can create both minor glitches and major incidents. While sound business logic is important for your organizational continuity and application functionality, there are broader concerns as well. Your organization has to prioritize the customer experience to stay competitive, and one way to do that is to ensure that all information is consistent and the application always runs smoothly.
Integrating Formal Verification into the Development Process
Integrating formal verification can slow down your organization’s development process. So, it’s important to balance formal verification tools, solutions, or methods with agile development practices. One way to do this is automation. Implementing tools that check your software as your team develops it can save you a lot of time and resources over time.
Prompt error detection makes it much easier to correct a problem (as opposed to checking for problems after the code is fully written). Tools like Selenium and Cyprus are sometimes used for verification. Additionally, there are a few different frameworks that can be used during development to guide testing. Continuous Integration/Continuous Deployment (CI/CD) is one of these.
CI/CD is a popular choice because it encourages developers to shift left. By auditing code as they write it and addressing concerns right away, developers can limit the security flaws in the finished product and ultimately reduce time spent fixing them.
Although formal verification is not a perfect solution to all security and development issues, implementing it early in the software development lifecycle can prevent expensive bugs that are difficult to fix and create security vulnerabilities. Business logic and software designs are both becoming more complex to handle increasing demand for features, so it’s important to use a tool that can navigate these complexities.
