OpenID sure seems promising, right? But it’s a mountain of work to implement, until now. Finally a company called JanRain has released RPX, a simple solution for OpenID implementations. It can be found here: https://rpxnow.com/
This great service is free for up to 6 providers. I’ve made a CI library for it. When using the library, OpenID authentication becomes as easy as this (in a start controller):
function login()
{
$this->load->library('openidrpx');
// In the view, display an iframe pointing to the "embedurl"
$this->load->view('loginview', array('embedurl', $this->openidrpx->EmbedUrl('start/openidverify'));
}
function openidverify()
{
$this->load->library('openidrpx');
if($token = $this->input->post('token'))
{
$data = $this->openidrpx->AuthInfo($token);
if($id = OpenIDRpx::Identifier($data))
{
// Authorize user!
}
}
}
Forum thread: http://codeigniter.com/forums/viewthread/126012/
NOTE: The library requires PHP5 and CURL to work.