I’m trying to implement CSRF Token authentication on my system. Below is my config.phpI’m trying to implement CSRF Token authentication on my system. Below is my config.php

$config['csrf_protection'] = TRUE;
$config['csrf_token_name'] = 'tokenizer';
$config['csrf_cookie_name'] = 'Qwerty&(*Asdsfdgf8564!@#)';
$config['csrf_expire'] = 3600;
$config['csrf_regenerate'] = FALSE;
$config['csrf_exclude_uris'] = array();

And my form implementation :

<form class="login_form" id="login_form">
                                <?php
                                $csrf = array(
                                    'name' => $this->security->get_csrf_token_name(),
                                    'hash' => $this->security->get_csrf_hash()
                                );
                                ?>

                                <input type="text" name="<?= $csrf['name']; ?>" value="<?= $csrf['hash']; ?>" />

                                <h1>Login Form</h1>
                                <div class="input-icons">
                                    <input type="text" class="form-control" id="username" placeholder="Email/Phone No" name="username" required="" />
                                    <span class="fa fa-user"></span>
                                </div>

                                <div class="input-icons">
                                    <input type="password" class="form-control password" id="password" name="password" placeholder="Password" required="" />
                                    <span class="fa fa-lock"></span>
                                </div>


                                <div>   
                                    <button class="btn" type="submit" >Login</button> 
                                    </br>

                                    <label class="psw"> <a href="#">Forgot Password?</a></label>

                                </div>



                                <div class="separator">

                                    <div>
                                        <img src="<?php echo base_url(); ?>assets/login/images/moh.png" width="31%" height="40" >
                                        <img src="<?php echo base_url(); ?>assets/login/images/nascop_logo.png" width="31%" height="40" >
                                        <img src="<?php echo base_url(); ?>assets/login/images/logo_3.png" width="31%" height="40" >

                                        <br/>
                                        <p>©2016 . Powered by mHEALTH Kenya . Privacy and Terms</p>
                                    </div>
                                </div>
                            </form>

Through jquery , I submit the above form as a POST request in the following manner :

 $('.login_form').submit(function (event) {

                        $(".loader").show();
                        dataString = $(".login_form").serialize();
                        $(".btn").prop('disabled', true);
                        $.ajax({
                            type: "POST",
                            url: "<?php echo base_url(); ?>login/check_auth",
                            data: dataString,
                            success: function (data) {

                                $(".loader").hide();
                                if (data == "Login Success") {
                                    swal({
                                        title: "Login Success!",
                                        text: "You will be redirected to your Home page in a few.",
                                        imageUrl: '<?php echo base_url(); ?>assets/images/thumbs-up.jpg'
                                    });

                                    setTimeout(function () {
                                        window.location.href = "<?php echo base_url(); ?>";

                                    }, 3000);



                                } else if (data == "User does not exist") {
                                    $(".btn").prop('disabled', false);
                                    swal("Oops", "User does not exist...", "info");
                                } else if (data == "Wrong Password") {
                                    $(".btn").prop('disabled', false);
                                    swal("Error", "Wrong password", "warning");
                                } else if (data == "Pass Exp") {
                                    $(".btn").prop('disabled', false);
                                    swal({
                                        title: "Password Expired!",
                                        text: "Your password has expired please reset before accessing the  system."
                                    });

                                    setTimeout(function () {
                                        window.location.href = "<?php echo base_url(); ?>";

                                    }, 3000);
                                }

                            }

                        });
                        event.preventDefault();
                        return false;
                    });

Without the activation of the CSRF Token , the page works very well but with the activation, I get a 403 Forbidden error. so help me