A simple solution is to force the authentication method using a function that always returns true, using the following code in your config file.
Your Script (for codeigniter):
if(login()){
   set_cookie('ckf_role','admin',2592000*10); // 10 month
}
Top:
        $config['authentication'] = function() {
            return true;
        };
Middle:
    session_start();
    $config['roleSessionVar'] = 'CKFinder_UserRole';
    $_SESSION['CKFinder_UserRole'] = !empty($_COOKIE['ckf_role']) ? strtolower($_COOKIE['ckf_role']) : "guest";
    $config['accessControl'][] = array(
    'role'                => 'guest',
    'resourceType'        => '*',
    'folder'              => '/',
    'FOLDER_VIEW'         => false,
    'FOLDER_CREATE'       => false,
    'FOLDER_RENAME'       => false,
    'FOLDER_DELETE'       => false,
    'FILE_VIEW'           => false,
    'FILE_UPLOAD'         => false,
    'FILE_RENAME'         => false,
    'FILE_DELETE'         => false,
    'IMAGE_RESIZE'        => false,
    'IMAGE_RESIZE_CUSTOM' => false
    );
   $config['accessControl'][] = array(
    'role'                => 'admin',
    'resourceType'        => '*',
    'folder'              => '/',
    'FOLDER_VIEW'         => true,
    'FOLDER_CREATE'       => true,
    'FOLDER_RENAME'       => true,
    'FOLDER_DELETE'       => true,
    'FILE_VIEW'           => true,
    'FILE_UPLOAD'         => true,
    'FILE_RENAME'         => true,
    'FILE_DELETE'         => true,
    'IMAGE_RESIZE'        => true,
    'IMAGE_RESIZE_CUSTOM' => true
    );