php-proxy/src/Plugin/ProxifyPlugin.php at 6550a678de860157d4bb4fda6bc988a5f0e8e3e9 · webaddicto/php-proxy · GitHub

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<?php

namespace Proxy\Plugin;

use Proxy\Plugin\AbstractPlugin;
use Proxy\Event\ProxyEvent;
use Proxy\Config;
use Proxy\Html;

class ProxifyPlugin extends AbstractPlugin {

	private $base_url = '';

	private function css_url($matches){

		$url = trim($matches[1]);

		if(stripos($url, 'data:') === 0){
			return $matches[0];
		}

		return str_replace($matches[1], proxify_url($matches[1], $this->base_url), $matches[0]);
	}

	// this.params.logoImg&&(e="background-image: url("+this.params.logoImg+")")
	private function css_import($matches){
		return str_replace($matches[2], proxify_url($matches[2], $this->base_url), $matches[0]);
	}

	// replace src= and href=
	private function html_attr($matches){

		// could be empty?
		$url = trim($matches[2]);

		if(stripos($url, 'data:') === 0 || stripos($url, 'magnet:') === 0 ){
			return $matches[0];
		}

		return str_replace($url, proxify_url($url, $this->base_url), $matches[0]);
	}

	private function form_action($matches){

		// sometimes form action is empty - which means a postback to the current page
		// $matches[1] holds single or double quote - whichever was used by webmaster

		// $matches[2] holds form submit URL - can be empty which in that case should be replaced with current URL
		if(!$matches[2]){
			$matches[2] = $this->base_url;
		}

		$new_action = proxify_url($matches[2], $this->base_url);

		// what is form method?
		$form_post = preg_match('@method=(["\'])post\1@i', $matches[0]) == 1;

		// take entire form string - find real url and replace it with proxified url
		$result = str_replace($matches[2], $new_action, $matches[0]);

		// must be converted to POST otherwise GET form would just start appending name=value pairs to your proxy url
		if(!$form_post){

			// may throw Duplicate Attribute warning but only first method matters
			$result = str_replace("<form", '<form method="POST"', $result);

			// got the idea from Glype - insert this input field to notify proxy later that this form must be converted to GET during http
			$result .= '<input type="hidden" name="convertGET" value="1">';
		}

		return $result;
	}

	public function onBeforeRequest(ProxyEvent $event){

		$request = $event['request'];

		// check if one of the POST pairs is convertGET - if so, convert this request to GET
		if($request->post->has('convertGET')){

			// we don't need this parameter anymore
			$request->post->remove('convertGET');

			// replace all GET parameters with POST data
			$request->get->replace($request->post->all());

			// remove POST data
			$request->post->clear();

			// This is now a GET request
			$request->setMethod('GET');

			$request->prepare();
		}
	}

	private function meta_refresh($matches){
		$url = $matches[2];
		return str_replace($url, proxify_url($url, $this->base_url), $matches[0]);
	}

	// <title>, <base>, <link>, <style>, <meta>, <script>, <noscript>
	private function proxify_head($str){

		// let's replace page titles with something custom
		if(Config::get('replace_title')){
			$str = preg_replace('/<title[^>]*>(.*?)<\/title>/is', '<title>'.Config::get('replace_title').'</title>', $str);
		}


		// base - update base_url contained in href - remove <base> tag entirely
		//$str = preg_replace_callback('/<base[^>]*href=

		// link - replace href with proxified
		// link rel="shortcut icon" - replace or remove

		// meta - only interested in http-equiv - replace url refresh
		// <meta http-equiv="refresh" content="5; url=http://example.com/">
		$str = preg_replace_callback('/content=(["\'])\d+\s*;\s*url=(.*?)\1/is', array($this, 'meta_refresh'), $str);

		return $str;
	}

	// The <body> background attribute is not supported in HTML5. Use CSS instead.
	private function proxify_css($str){

		// The HTML5 standard does not require quotes around attribute values.

		// if {1} is not there then youtube breaks for some reason
		$str = preg_replace_callback('@[^a-z]{1}url\s*\((?:\'|"|)(.*?)(?:\'|"|)\)@im', array($this, 'css_url'), $str);

		// https://developer.mozilla.org/en-US/docs/Web/CSS/@import
		// TODO: what about @import directives that are outside <style>?
		$str = preg_replace_callback('/@import (\'|")(.*?)\1/i', array($this, 'css_import'), $str);

		return $str;
	}

	public function onCompleted(ProxyEvent $event){

		// to be used when proxifying all the relative links
		$this->base_url = $event['request']->getUri();

		$response = $event['response'];
		$content_type = strtolower(trim($response->headers->get('content-type')));

		$str = $response->getContent();

		// DO NOT do any proxification on .js files and text/plain content type
		// Support also resource like Content-Type: text/javascript;charset=UTF-8
		foreach(array('text/javascript', 'application/javascript', 'application/x-javascript', 'text/plain') as $type){
			if(strpos($content_type, $type) === 0){
				return;
			}
		}

		// remove JS from urls
		$js_remove = Config::get('js_remove');
		if(is_array($js_remove)){
			$domain = parse_url($this->base_url, PHP_URL_HOST);

			foreach($js_remove as $pattern){
				if(strpos($domain, $pattern) !== false){
					$str = Html::remove_scripts($str);
				}
			}
		}

		// add html.no-js

		// let's remove all frames?? does not protect against the frames created dynamically via javascript
		$str = preg_replace('@<iframe[^>]*>[^<]*<\\/iframe>@is', '', $str);

		$str = $this->proxify_head($str);
		$str = $this->proxify_css($str);

		// src= and href=
		$str = preg_replace_callback('@(?:src|href)\s*=\s*(["|\'])(.*?)\1@is', array($this, 'html_attr'), $str);

		// form
		$str = preg_replace_callback('@<form[^>]*action=(["\'])(.*?)\1[^>]*>@i', array($this, 'form_action'), $str);

		$response->setContent($str);
	}

}

?>