Joomla-Sermon-Distributor/site/controllers/download.php

<?php
/*--------------------------------------------------------------------------------------------------------|  www.vdm.io  |------/
    __      __       _     _____                 _                                  _     __  __      _   _               _
    \ \    / /      | |   |  __ \               | |                                | |   |  \/  |    | | | |             | |
     \ \  / /_ _ ___| |_  | |  | | _____   _____| | ___  _ __  _ __ ___   ___ _ __ | |_  | \  / | ___| |_| |__   ___   __| |
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       \  / (_| \__ \ |_  | |__| |  __/\ V /  __/ | (_) | |_) | | | | | |  __/ | | | |_  | |  | |  __/ |_| | | | (_) | (_| |
        \/ \__,_|___/\__| |_____/ \___| \_/ \___|_|\___/| .__/|_| |_| |_|\___|_| |_|\__| |_|  |_|\___|\__|_| |_|\___/ \__,_|
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/-------------------------------------------------------------------------------------------------------------------------------/

	@version		1.3.0
	@build			11th January, 2016
	@created		22nd October, 2015
	@package		Sermon Distributor
	@subpackage		download.php
	@author			Llewellyn van der Merwe <https://www.vdm.io/>	
	@copyright		Copyright (C) 2015. All Rights Reserved
	@license		GNU/GPL Version 2 or later - http://www.gnu.org/licenses/gpl-2.0.html 
	
	A sermon distributor that links to Dropbox. 
                                                             
/-----------------------------------------------------------------------------------------------------------------------------*/

// No direct access to this file
defined('_JEXEC') or die('Restricted access');

// import Joomla controllerform library
jimport('joomla.application.component.controller');

/**
 * Sermondistributor Download Controller
 */
class SermondistributorControllerDownload extends JControllerLegacy
{
	
	public function __construct($config)
	{
		parent::__construct($config);
		// load the tasks 
		$this->registerTask('file', 'download');
	}
	
	public function download()
	{
		$jinput 	= JFactory::getApplication()->input;
		// Check Token!
		$token 		= JSession::getFormToken();
		$call_token	= $jinput->get('token', 0, 'ALNUM');
		if($token == $call_token)
                {
			$task = $this->getTask();
			switch($task)
                        {
				case 'file':
					$keys = $jinput->get('key', NULL, 'BASE64');
					$enUrl = $jinput->get('link', NULL, 'BASE64');
					$filename = $jinput->get('filename', NULL, 'CMD');
					if((base64_encode(base64_decode($enUrl, true)) === $enUrl) && (base64_encode(base64_decode($keys, true)) === $keys) && $filename)
					{
						// we must first count this download
						if (SermondistributorHelper::countDownload($keys,$filename))
						{
							// Get local key
							$localkey = SermondistributorHelper::getLocalKey();
							$opener = new FOFEncryptAes($localkey, 256);
							$link = rtrim($opener->decryptString(base64_decode($enUrl)));
							$info = $this->getContentInfo($link);
							// set headers
							if (isset($info['type']) && $info['type'])
							{
								header('Content-Type: '.$info['type']);
							}
							elseif (strpos($filename, '.mp3') !== false)
							{
								header('Content-Type: audio/mpeg');
							}
							else
							{
								header('Content-Type: application/octet-stream');
							}
							header("Content-Transfer-Encoding: Binary"); 
							header("Content-disposition: attachment; filename=\"" . $filename . "\"");
							header('Expires: 0');
							header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
							header('Pragma: public');
							if (isset($info['filesize']) && $info['filesize'])
							{
								header('Content-Length: ' . $info['filesize']);
							}
							ob_clean();
							flush();
							// this is faster but expose the dropbox url
							// header("Location: $link");
							// this is slower but better much more secure
							readfile($link); 
							jexit();
						}
					}
				break;
			}
		}
		return false;
	}
	
	protected function getContentInfo($url)
	{
		// we first try the curl option
		if ($this->_isCurl())
		{
			$ch = curl_init($url);
			curl_setopt($ch, CURLOPT_NOBODY, true);
			curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
			curl_setopt($ch, CURLOPT_HEADER, true);
			curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

			$data = curl_exec($ch);
			curl_close($ch);
		}
		else
		{
			// then we try getheaders (this is slower)
			stream_context_set_default( array('http' => array('method' => 'HEAD')));
			$headers = get_headers($url);
			if (SermondistributorHelper::checkArray($headers))
			{
				$data = implode("\n", $headers);
			}
		}
		// get the Content Length
		if (preg_match('/Content-Length: (\d+)/', $data, $matches))
		{
			// Contains file size in bytes
			$found['filesize'] = (int)$matches[1];

		}
		// get the Content Type
		if (preg_match_all('/Content-Type: (.+)/', $data, $matches))
		{
			foreach ($matches[1] as $match)
			{
				// not the html
				if (strpos( $match, 'text/html') === false)
				{
					$found['type'] =  $match;
					break;
				}
			}

		}
		// return found values
		if (isset($found) && SermondistributorHelper::checkArray($found))
		{
			return $found;
		}
		return false;
	}
	
	protected function _isCurl()
	{
		return function_exists('curl_version');
	}
}