5 Best Practices for A Secure Code Review

Software development is a strong-growing business and doing a Secure Code Review is important. It has gained extreme relevance and dominance due to increased demand for software, code, and applications, among other related products. And this explains why 57% of IT companies plan to pay significant attention to software development. 

But this industry does not come without its share of challenges. For instance, code vulnerabilities are a common sight and challenge. A considerable chunk of these vulnerabilities  (over 50%) is considered high risk. 

Questions such as: is a Secure Code Review? Is the code appropriately designed? Is the code free from errors? Indeed, coding is a process prone to mistakes. A study has shown that programmers make mistakes at least once in every five lines of code. And the results of these mistakes could be devastating. 

But all is not lost. With a clear and strategic secure code review, vulnerabilities, bugs, and repeated lines, among other code errors, like IMS error messages, will be eliminated. Therefore, a secure code review could help enhance the efficiency and quality of the code. According to Smartbear’s State of the API Report, most developers voted code review as the top way of improving the quality of the code. 

Usually, the Software Development Lifecycle (SDLC) comes with lots of hindrances that could negatively impact the functionality and quality of the product. A secure code review is one of the most fundamental elements of the code review procedure that helps in the identification of missing best practices as early as possible.

Whereas the typical code review focuses on quality, functionality, usability, and maintenance of the code, A secure code review is more concerned with the security aspects of the software, including but not limited to validity, authenticity, integrity, and confidentiality of the code. 

Create A Checklist

Every software of code will have different features, requirements, and functionalities. It means that every code review should be unique depending on these factors. A checklist that contains predetermined rules, guidelines, and questions will need to be created to guide you through the whole review process. A checklist will give you the benefit of a more structured approach in determining the efficacy of the code in fulfilling its intended objectives. The following are some of the issues that the checklist must address;

• Authorization: Has the code implemented efficient authorization controls?
• Code Signing Certificate: Here, issues such as the availability and type of code signing certificate will be addressed. The EV code signing certificate should always be given utmost priority because of its usability and security advantages compare to organization validation code signing cert. EV code signing comes with higher authentication and Microsoft SmartScreenFilter that filters malicious scripts easily. 
• Authentication: Has the code applied adequate authorization controls such as the two-factor authentication?
• Security: Is data encrypted, or does the code expose sensitive data to cyber-attacks?
• Does the error message from the code show any sensitive information? 
• Are there adequate security checks and measures to safeguard the code from SQL injections, malware distributions, and XSS attacks? 

These questions are vital in ensuring the security of your code. Above everything, always remember that one checklist might not apply in all cases. Reviewers should find aspects of a checklist that best apply to their code. 

Use Code Review Metrics

There is no way you are going to correct or edit the quality of a code without measuring it. The best way to measure the quality of a code is by introducing objective metrics. These metrics will help determine the efficacy of your review by analyzing the effect of the change in the process and predicting the time it will take to complete the review project. The following are some of the commonly used code review metrics that you can employ for your review project;

• Inspection Rate: This refers to the time it takes for a security code review team to review a specific code. It is arrived at by dividing the lines of code by the total number of inspection hours. If the inspection rate is too low, then there might be possible vulnerability issues that need to be addressed. 
• Defect Density: This is the number of defects identified in a particular amount of code. The defect density is arrived at by dividing the defect count by the thousands of lines of code. This metric is crucial because it helps in the identification of code components that are more prone to defects. The reviewers can then allocate more time and resources toward such components. Take the case where one web application has more flaws than others. You might want to assign more developers to work on the component in such a case. 
• Defect Rate: This refers to the frequency at which a defect emerges from your review. It is arrived at by dividing the defect count by the number of hours spent on the inspection. This review metric is of significant essence because it helps in the identification of the effectiveness of your review procedures. For instance, if your developers are slow in identifying flaws in the code, you might consider using other testing tools for the review project. 

Supplement Your Review With Automation

A manual security code review might not yield adequate and effective results like those using automation tools. Software and applications usually contain thousands of code lines, which makes it challenging to conduct code reviews manually. Therefore, employing automation tools to help you out would be great. For instance, an app like Workzone will help you plan when and how to push code changes and add reviewers to pull requests. Another excellent automation tool that could help you is the Code Owners for Bitbucket. 

Split the Code Into Sections

Web development involves several folders and files. All these folders carry hundreds of thousands of lines of codes. It might look dense and confusing to review all these lines one after the other. It will take you time to do so. The best strategy is to split the code into sections. Doing so will paint a clear view of the flow of the codes. Splitting the codes into sections for review will help you not feel bored and disinterested. 

Check for Test-Cases and Rebuild the Code

This is the final and one of the most vital steps in a secure code review process. At this point, you have rectified all possible errors and flaws that existed in the code. You now need to go back to your checklist to check whether all the tests and conditions have been satisfied. Upon ascertaining that all the requirements on your checklist have been passed, it is now time to rebuild the code. After that, you can organize for a demo presentation. This is where your team will demonstrate the working of your new software of application and highlight the changes and why the changes were necessary. 

An excellent security code review will help to highlight some of the potential risks and vulnerabilities that might exist in your code, application or software. Identifying, evaluating and mitigating such vulnerabilities is vital for the well-being and proper functionality of the code. This article has explained what a secure code review is and the five best practices developers must adopt when conducting the review.