When building your API, the most crucial step is to protect the application from malicious attacks and unauthorized access. I will recap some of the tips to manage your application more securely. Please keep to cure this situation, we can only try as much as possible.
Use SSL/TLS
When deploying your application always remember to keep your API secret and use the domain. Secure the domain of your application using SSL and Always use trusted SSL certificates. By using the SSL feature your data will be encrypted in transit between the client and server. Using SSL will trigger your URL into the HTTP.
Authentication & Autorization
Before deploying your application to the public, always create the authentication method in your API. it will help you protect all of your resources from unauthenticated users. Here is some method you can use including:
OAuth2
JWT Token
Sessions
The next step after implementing authentication is to handle and give restrict access to specific resources and actions and it's called Authorization. The easy way to manage the authorization in API is by adding the role to your user, then in each endpoint add a middleware to check if the user gives access to doing that action.
Validate Input
When creating the API endpoint always remember to validate the input, including your parameters, and the body. if you're using type programming language like typescript, go, or rust you will automatically check the input using the class or object. However, when using dynamic programming like javascript you just need the checker for your input like Zod.
By validating your input, you can avoid SQL Injection, XSS, and other vulnerabilities.
Implement Content Type
To doing checking the Content-Type in your API is using the Content-Type and Accept headers. Content-Type headers have specified the type of data access to the server. While the Accept is specified the type of data sent from the server to the client. So all requests that do not match the specific type will be rejected to prevent the attack.
Use Rate Limit
A huge amount of requests at the same time will make your application lack, unresponsive, and also affect the cost of your server. If you are unlucky will get the DOS and DDOS, Brute force attacks that make your server down and fail. To protect can add the rate limiting technique.
A rate limit can give limited access to the user in the same IP address to do some actions and requests at the same time.
Use Pagination
In case you need to get billion data at the same time, the best way to get the data is using pagination. By using pagination we can limit the request from the user. If not, when your user requests a huge amount of data then this will make your server crash and even down.
Keep Updated
Always update your application and the dependencies to the latest version. You need to ensure that the dependencies do not have a vulnerable issue.