PHP - Algo estoy hacendo mal / me dan una mano

//

// ENC

//

if ($_CONFIG['enc'] == true) { ?>

    <div class="tab-pane <?php if ($getsection === "#enc") echo "active"; ?>" id="enc">

        <div class="row form-group">

            <div class="col-xs-6">

                <label><?php echo getString('key'); ?></label>

                <input type="text" name="key" placeholder="Entre el password" class="form-control">

            </div>

            <div class="col-xs-12">

                 <label><?php echo getString('string'); ?></label>

                <textarea name="string" placeholder="Entre el contenido a codificar" class="form-               control"></textarea>

            </div>

        </div>

    </div>

<?php

elseif ($getsection === "#enc") {

    $key = filter_input(INPUT_POST, "key", FILTER_SANITIZE_STRING);

    $string = filter_input(INPUT_POST, "string", FILTER_SANITIZE_STRING);

   $iv = mcrypt_create_iv(

        mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC),

        MCRYPT_DEV_URANDOM

    );

    $encrypted = base64_encode(

        $iv .

        mcrypt_encrypt(

            MCRYPT_RIJNDAEL_128,

            hash('sha256', $key, true),

            $string,

            MCRYPT_MODE_CBC,

            $iv

        )

    );

    if ($encrypted) {

         $output_data = '$encrypted';

    }

$output_data = $encrypted;