Laravel Ajax CSRF - Javascript

When working with Laravel and Ajax, it is important to address the issue of Cross-Site Request Forgery (CSRF) protection. In essence, CSRF attacks allow malicious users to execute requests on behalf of a victim user without their consent. The easiest way to protect against such attacks is to use Laravel's built-in CSRF protection middleware.

Laravel CSRF Protection

Laravel utilizes double-submit cookie technique to protect applications from CSRF attacks. Once a user logs in, Laravel generates a random token which is added to the user's session and as an input field named _token in all HTML forms generated by the application.

On form submission, Laravel verifies that the token in the input field matches the one stored in the user's session. If they don't match, a TokenMismatchException is thrown.

Ajax Request with CSRF Protection

When sending Ajax request, we can not add the _token field manually to the request headers like a normal form submission. In these cases, we can pass the token as a X-CSRF-TOKEN header instead. Laravel checks this header and matches it with the token stored in the user's session.

Here's an example of how to implement it with jQuery:

$.ajaxSetup({
    headers: {
        'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
    }
});

$.ajax({
    url: '/your-url',
    type: 'POST',
    data: yourData,
    success: function(response) {
        console.log(response);
    },
    error: function(xhr, status, error) {
        console.log(error);
    }
});

In this example, we are adding the X-CSRF-TOKEN header to all Ajax requests using ajaxSetup method. This header is obtained by reading the value of a csrf-token meta tag in the HTML document.

Conclusion

Using Laravel's built-in CSRF protection middleware is an important security measure when working with Ajax requests. By implementing a simple token-based approach, we can protect against malicious users who may try to execute unwanted requests on behalf of a user.