Use API key authentication to restrict and manage access to your ASP.NET Core Web APIs effectively.
In ASP.NET Core 7, there are several robust options for securing your APIs, such as JWT tokens, ASP.NET Core Identity, bearer tokens, OpenID Connect, and OAuth 2.0 identity providers. Another common security approach is API key authentication, which helps authenticate applications or services accessing your APIs. Unlike user-based authentication, API keys do not identify individual users but validate the requesting application.
API keys are unique tokens that applications pass with API requests, typically in the request header, query string, or a cookie. The keys allow control over which applications can access the API, help track usage, and even manage access to specific API methods. While API keys offer an effective way to authenticate applications, they are not sufficient for secure authorization. This means API key authentication should be combined with user authentication methods when fine-grained security is required.
API key authentication is particularly useful when you’re dealing with internal services or partners needing limited access to your API, as it simplifies validation without requiring complex user authentication systems.
Setting Up API Key Authentication in ASP.NET Core 7
Let’s walk through how to implement API key authentication. You will need Visual Studio 2022 installed on your system. If you don’t have it yet, it can be downloaded from the official website.
Step 1: Creating an ASP.NET Core Web API Project
Begin by setting up an ASP.NET Core 7 Web API project in Visual Studio 2022. Follow these steps:
- Launch Visual Studio 2022 and select “Create new project.”
- Choose “ASP.NET Core Web API” from the list of templates.
- Click Next and provide a name and directory for your project.
- In the next screen, leave the “Use controllers” option checked (since we won’t use minimal APIs), and set the “Authentication Type” to “None.”
- Uncheck features such as “Enable Open API Support,” “Configure for HTTPS,” and “Enable Docker,” as they are not needed for this implementation.
Once this basic project setup is complete, you will use it to implement API key authentication.
Step 2: Configuring API Key Authentication
The next step involves writing custom middleware or a filter to check if the incoming request contains a valid API key. This API key would be stored securely in your configuration settings or database, and the application would compare the incoming request’s key against the stored key.
Step 3: Securing Endpoints with API Keys
API key authentication should be applied only to specific endpoints or areas of your API, depending on the service needs. You can also extend the logic to include rate-limiting based on API keys to further control how much access a particular client has to the API.
Step 4: Testing the Implementation
Finally, once your API key validation logic is in place, test your API by simulating requests with and without the valid API key. Make sure to test from different client applications or tools like Postman, verifying that unauthorized requests are blocked.
With this setup, you can effectively manage API access for various applications and services, ensuring they are authenticated before using your API. However, remember that API keys should not be treated as the sole security mechanism, especially when handling sensitive data or complex authorization scenarios.