laravel/app/Http/Filters/CsrfFilter.php

<?php namespace App\Http\Filters;

use Session;
use Illuminate\Http\Request;
use Illuminate\Routing\Route;
use Illuminate\Session\TokenMismatchException;

class CsrfFilter {

	/**
	 * Run the request filter.
	 *
	 * @return mixed
	 */
	public function filter(Route $route, Request $request)
	{
		if (Session::token() != $request->input('_token'))
		{
			throw new TokenMismatchException;
		}
	}

}