AzuraCast/app/library/DF/Auth/Adapter/Cas.php

<?php
namespace DF\Auth\Adapter;

class Cas implements \Zend_Auth_Adapter_Interface
{
	protected $_options;

    public function __construct($options)
    {
		$this->setOptions($options);
    }
	
	public function setOptions($options)
	{
		$this->_options = $options;
	}
	
    public function authenticate()
    {
        try
        {
			$auth_result = $this->login();
			
			if ($auth_result['success'])
			{
				$result = new \Zend_Auth_Result(
                    \Zend_Auth_Result::SUCCESS,
                    $auth_result,
                    array()
                );
			}
			else
			{
				$result = new \Zend_Auth_Result(
                    \Zend_Auth_Result::FAILURE_UNCATEGORIZED,
                    null,
                    array($auth_result['message'])
                );
			}
        }
        catch( \Exception $e )
        {
            $result = new \Zend_Auth_Result(
                \Zend_Auth_Result::FAILURE,
                null,
                (array)sprintf('%s',
                    $e->getMessage()
                )
            );
        }
        
        return $result;
    }
	
	public function login($destination_url = NULL)
	{
		// Get the CAS ticket if it has been set.
		$ticket = (isset($_REQUEST['ticket'])) ? $_REQUEST['ticket'] : '';
		
		if (is_null($destination_url) || empty($destination_url))
		{
			$destination_url = $this->getServiceUrl();
		}
		
		if (!empty($ticket))
		{
			$validate = (substr($ticket, 0, 2) == 'ST') ? 'serviceValidate' : 'proxyValidate';
			
			$query_string = array(
				'service'		=> $destination_url,
				'ticket'		=> $ticket,
			);
			$file_url = $this->_options['cas_base'].'/'.$validate.'?'.http_build_query($query_string);
			$file = file_get_contents($file_url);

			if (!$file)
			{
				throw new \Exception('Could Not Authenticate: The CAS service did not return a complete response.');
			}
		}
		else
		{
			$query_string = array('service'	=> $destination_url);
			
			if ($this->_options['renew'])
			{
				$query_string['renew'] = 'true';
			}
			
			// Redirect to login page.
			header("Location: ".$this->_options['cas_base'].'/login?'.http_build_query($query_string));
			exit;
		}
		
		$xml_array = \DF\Export::XmlToArray($file);
		$return_value = array();
		
		if (isset($xml_array['cas:serviceResponse']['cas:authenticationSuccess']))
		{
			$attributes = $xml_array['cas:serviceResponse']['cas:authenticationSuccess'][0]['cas:attributes'][0];
			
			$return_value['success'] = TRUE;
			$return_value['uin'] = $attributes['cas:tamuEduPersonUIN'];
			$return_value['netid'] = $attributes['cas:tamuEduPersonNetID'];
		}
		else
		{
			$return_value['success'] = FALSE;
			$return_value['message'] = $xml_array['cas:serviceResponse']['cas:authenticationFailure']['code'];
		}
		
		return $return_value;
	}
	
	public function logout($destination_url = NULL)
	{
		if ($this->_options['full_logout'])
		{
			if (is_null($destination_url))
			{
				$destination_url = $this->getServiceUrl();
			}
			
			$url_params = array(
				'service'		=> $destination_url,
			);
			
			// Redirect to login page.
			header("Location: ".$this->_options['cas_base'].'/logout?'.http_build_query($url_params));
			exit;
		}
	}
	
	private function getServiceUrl()
	{
		return \DF\Url::current(TRUE, FALSE);
	}
}