Laravel 5.4 null csrf_token() when posting to route - php

Question

I'm sending an ajax post request, and with Laravel it seems that is done by creating a post route for it. I've set it up so a csrf token is put in the header automaticaly for every ajax request using ajaxSetup. I'm attempting to then catch that header on the backend and verify the tokens match.
In my web routes (which automatically use the web middleware), this returns as expected:
Route::get('/test', function() {
return csrf_token();
});
However, when I post to a route via AJAX, like either of the below ways:
Attempt 1:
Route::post('/test', 'AjaxController#test');
In the AjaxController construct, followed by an alert in the view:
var_dump(csrf_token().',hi'); die;
Response: ',hi' (csrf_token was null).
Attempt 2:
Route::post('/test', ['test' => csrf_token().',hi', 'uses' => 'AjaxController#test']);
$test = $request->route()->getAction()['test'];
var_dump($test); die;
Response: ',hi' (csrf_token was null).
What I seem to be running into is, with get requests csrf_token() is populated, on my post request, it is not.
Any ideas?

Answer 1

check your route group it must apply the web middleware as
Route::group(['middleware' => 'web'], function () {
Route::get('/test', function() {
return csrf_token();
//or return $request->session()->token();
});
});

Answer 2

Finally figured this out.
CSRF can indeed be checked on an ajax post request. I wanted to make sure someone on their own site isn't hitting my ajax endpoint with any success of doing anything, especially for another user.
However, I ran into a Laravel order of operations issue, with the way Laravel sets up the session. I was trying to call a validation method (within in the same class) in the constructor, where I validated for CSRF and verified the requesting user all in one place. I wanted to do this so that any time someone hits this class, I didn't have to call the verification in each public method in the class, I'd only have to call it once.
However, csrf_token(), and the request session in general, is not available to me yet in my construct. It is, however, available to me in the method within the controller class that is called in the route.
For example, given the following route:
Route::post('/test', 'AjaxController#test');
If I injected Request into the construct and then tried to reference anything in the session (in the construct), or get the value of csrf_token(), it will throw an error, because Laravel hasn't set that stuff up yet. But if I reference either of those things in the test method, it'll be there and available just fine.
A bit of a weird Laravel order of operations issue.

Answer 3

csrf protections are managed by Laravel Forms. It won't be available when dealing with APIs.
You should have a look at how middlewares are used in Laravel
https://laravel.com/docs/5.4/middleware
Think using API middleware for your APIs ;)

Answer 4

If you run this command php artisan make:auth documented here https://laravel.com/docs/5.4/authentication#authentication-quickstart when going to resources/views/layouts/app.blade.php you'll see this:
<meta name="csrf-token" content="{{ csrf_token() }}">
And in app.js
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN':$('meta[name="csrf-token"]').attr('content')
}
});
In 5.3 there was this cool feature which looks as though it has since been removed in 5.4.
<script>
window.Laravel = <?php echo json_encode([
'csrfToken' => csrf_token(),
]); ?>
</script>
So what you need to do is add the csrf field to every request. Do the first 2 code snippets and you'll be fine. The 3rd I believe is probably for Vue.
Answer to your question: no, no, no and no. CSRF tokens I wouldn't believe are generated in POST requests, it's a Cross site Reference token, not an authentication token. If you're looking for something like authentication token refreshing then checkout JWT although the packages for JWT for laravel are a bit unfinished at the moment; with a little work you can get them working.
https://github.com/tymondesigns/jwt-auth 1.0.*#dev is pretty good. You can then use their refresh middleware to generate new tokens on request but this is quite advanced and unless it's for authentication then I wouldn't bother really.
I believe Dingo (another work in progress I believe) https://github.com/dingo/api uses the above package
Anything else let me know!