Do I need to create an xsrf middleware in asp net core


ASP.NET is a popular programming used for building web applications. One common question that developers often come across is whether they need to create an XSRF (Cross-Site Request Forgery) middleware in ASP.NET Core. In this article, we will explore this question and examples to help you understand the concept better.

Understanding XSRF

XSRF is a type of security that allows an attacker to trick a user into performing unwanted actions on a website in which they are authenticated. This can lead to serious consequences, such as unauthorized changes to user data or even financial loss.

ASP.NET Core Middleware

Middleware in ASP.NET Core is a component that sits between the web server and the application. It processes requests and responses, allowing you to add custom logic to handle various aspects of the application's behavior.

Do I Need to Create an XSRF Middleware?

ASP.NET Core provides built-in protection XSRF attacks through the use of anti-forgery tokens. These tokens are automatically generated and validated by the framework, making it difficult for attackers to forge requests.

However, in some cases, you may need to create a custom XSRF middleware to add additional security measures or to integrate with existing security systems. This could be necessary if you have specific requirements or if you are with legacy code that does not support the built-in protection.

Example: Creating an XSRF Middleware

Let's consider an example where you want to create a custom XSRF middleware in ASP.NET Core. This middleware will add an XSRF token to each outgoing response and validate it on incoming requests.

public  XsrfMiddleware
    private readonly RequestDelegate _next;

    public XsrfMiddleware(RequestDelegate next)
        _next = next;

    public async Task Invoke( context)
        // Generate and add XSRF token to the response
        string xsrfToken = GenerateXsrfToken();
        context.Response..Add("X-XSRF-Token", xsrfToken);

        // Validate XSRF token on incoming requests
        if (context.Request.Method == "POST" || context.Request.Method == "PUT")
            string requestToken = context.Request.Headers["X-XSRF-Token"];
            if (requestToken != xsrfToken)
                context.Response.StatusCode = 403; // Forbidden

        await _next(context);

    private string GenerateXsrfToken()
        // Generate a unique token using a secure algorithm
        // This can be stored in a session or a cookie for validation
        return Guid.NewGuid().ToString();

In this example, we create a custom middleware called XsrfMiddleware. It generates an XSRF token using a secure algorithm and adds it to the response headers. On incoming requests, it validates the XSRF token and returns a 403 Forbidden status code if the token is invalid.

To use this middleware in your ASP.NET Core application, you need to add it to the middleware pipeline in the Startup class:

public void (IApplicationBuilder app, IWebHostEnvironment env)
    // Other middleware configurations


    // Other middleware configurations

By adding the XsrfMiddleware to the pipeline, it will be executed for every request, allowing you to protect your application against XSRF attacks.


While ASP.NET Core provides built-in protection against XSRF attacks, there may be cases where you need to create a custom XSRF middleware to add additional security measures or integrate with existing systems. By understanding the concept of XSRF and how middleware works in ASP.NET Core, you can make informed decisions on whether to create an XSRF middleware for your application.

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