A Practical Example of Testing a Web API for a Cybersecurity Solution

Web APIs serve as powerful tools that simplify the coding process and allow developers to access information from external sources to enhance the applications they create. An excellent illustration of a web API is a travel service app, which utilizes an API to retrieve data from hotels, tour planners, airlines, and other relevant companies.

By leveraging APIs, developers gain access to a vast array of data that would otherwise be inaccessible. API providers also benefit by making their information available to developers, usually for a fee. Ultimately, APIs serve the interests of consumers who require data from external or third-party sources for their interactive and user-friendly apps.

Importance of API Security

Web APIs form the backbone of an organization's database. While publicly available APIs offer numerous benefits, they also pose risks to the providers. APIs act as tools and interfaces that enable third-party entities to access data through endpoints, which essentially represent servers along with their database access.

Practical Example of Testing a Web API for a Cybersecurity Solution

At Apriorit, we frequently employ a seven-step strategy for testing web APIs. This approach has been developed and continuously refined based on our experience with numerous projects.

The foundation of this testing algorithm was established during our work on a cybersecurity project that we have successfully maintained for the past decade. Let's delve into a practical example of testing a web API for complex software that monitors client systems, collects artifacts, and performs analysis.

The Software's Primary components currently include:

1. An agent installed on client machines.
2. A proxy server responsible for gathering data from the agents.
3. A server housing the application database.
4. A web API.
5. An application for data configuration and analysis.

When assessing the functionality of your API, you can apply the following testing types:

1. Validation Testing
2. Functional Testing
3. Load Testing
4. Runtime/Error Detection
5. UI Testing
6. Security Testing
7. Fuzz Testing

Validation Testing: Validation testing is typically conducted towards the end of the development process and serves as one of the most important tests. It is performed after verifying the constituent parts and functions of the API.

Functional Testing: Functional testing focuses on testing specific functions within the codebase. While still a broad methodology, it narrows down the scope compared to validation testing.

Load Testing: Load testing validates whether the API can handle massive and/or sustained loads. This involves progressively increasing user requests, ranging from 1,000 to 10,000 and 100,000, to assess how the API handles different load levels and measure the failure rate.

Runtime Error Detection: Runtime error detection specifically examines the operation of the API. It analyzes the results of utilizing the API codebase, monitors the system for execution errors and memory leakage, and tests the API's error handling capabilities.

Unit Testing: Unit testing involves writing tests that automatically run with every application build. These tests are closely tied to the codebase and should pass when executing a build of the application.

Security Testing: Security testing is crucial but often inadequately budgeted. It is essential to ensure that proper security testing occurs based on a comprehensive risk analysis.

Fuzz Testing: Before validating the application, it is important to conduct fuzz testing on all API endpoints. Fuzzing involves sending random data to these endpoints and carefully inspecting the results. The server should not crash or exhibit any abnormal behavior in response to this unexpected traffic.

API Testing Tips

Here are some tips for best practices in API testing to ensure more professional tests and achieve better results:

1. Understand API requirements: Familiarize yourself with the API's purpose and workflow to prepare a comprehensive validation approach that aligns with specific data or other APIs.
2. Determine API output status: Identify the required status code responses and consider them as pass or fail according to the globally recognized five classes standard.
3. Begin with small functional APIs: Start with smaller inputs, such as the login API, to gain a better understanding of the API environment and ensure its functionality.
4. Test a single API at a time: Test one API at a time to avoid a backlog of error messages, unless specific cases require a series of API testing.

Benefits of API Testing

API testing offers several benefits that contribute to improved test coverage, system security, and more efficient development.

Some of the advantages of performing API testing include:

1. Quicker release cycles
2. Enhanced test coverage
3. Reduced maintenance efforts
4. Lower testing costs
5. Improved understanding through a universal language