Erste gut funktionierende Version

Die neue Proxy Software ist soweit feritg, als dass diese Version nun mindestens so gut funktionieren dürfte, wie die bestehende

app/CssDocument.php

+<?php
+
+namespace App;
+
+class CssDocument extends Document
+{
+
+    private $styleString;
+
+    public function __construct($password, $base, $styleString)
+    {
+        parent::__construct($password, $base);
+        $this->styleString = $styleString;
+    }
+
+    public function proxifyContent()
+    {
+        # All Resources that I know, that are included within an CSS Stylesheet must have the url() functional quoting
+        # We're gonna replace all URL's that we find within this document
+        # First with Quotation Marks:
+        $this->styleString = preg_replace_callback("/(url\()([\"\']{1})([^\\2]+?)\\2/si", "self::pregReplaceUrl", $this->styleString);
+        # And then the ones without Quotation Marks
+        $this->styleString = preg_replace_callback("/(url\()([^\"\'][^\)]+?)(\))/si", "self::pregReplaceUrlNoQuotes", $this->styleString);
+    }
+
+    private function pregReplaceUrl($matches)
+    {
+        $url = $matches[3];
+        # Relative to Absolute
+        $url = $this->convertRelativeToAbsoluteLink($url);
+        # Proxify Url
+        $url = $this->proxifyUrl($url, false);
+
+        $replacement = $matches[1] . $matches[2] . $url . $matches[2];
+
+        return $replacement;
+    }
+
+    private function pregReplaceUrlNoQuotes($matches)
+    {
+        $url = $matches[2];
+        # Relative to Absolute
+        $url = $this->convertRelativeToAbsoluteLink($url);
+        # Proxify Url
+        $url = $this->proxifyUrl($url, false);
+
+        $replacement = $matches[1] . $url . $matches[3];
+
+        return $replacement;
+    }
+
+    public function getResult()
+    {
+        return $this->styleString;
+    }
+}

app/Document.php

+<?php
+
+namespace App;
+
+use Illuminate\Http\Request;
+use URL;
+
+abstract class Document
+{
+
+    protected $password;
+    protected $baseUrl;
+
+    public function __construct($password, $base)
+    {
+        $this->password = $password;
+        $this->baseUrl  = $base;
+    }
+
+    public function proxifyUrl($url, $topLevel)
+    {
+        // Only convert valid URLs
+        $url = trim($url);
+        if (strpos($url, "http") !== 0 || strpos($url, URL::to('/')) === 0) {
+            return $url;
+        }
+
+        $urlToProxy = base64_encode(str_rot13($url));
+        $urlToProxy = str_replace("/", "<<SLASH>>", $urlToProxy);
+        $urlToProxy = urlencode($urlToProxy);
+
+        if ($topLevel) {
+            $params = \Request::all();
+
+            # Password
+            $pw         = md5(env('PROXY_PASSWORD') . $url);
+            $urlToProxy = base64_encode(str_rot13($url));
+            $urlToProxy = urlencode(str_replace("/", "<<SLASH>>", $urlToProxy));
+
+            # Params
+            $params['password'] = $pw;
+            $params['url']      = $urlToProxy;
+
+            $iframeUrl = action('ProxyController@proxyPage', $params);
+        } else {
+            $params             = \Request::all();
+            $params['password'] = $this->password;
+            $params['url']      = $urlToProxy;
+
+            $iframeUrl = action('ProxyController@proxy', $params);
+
+        }
+
+        return $iframeUrl;
+    }
+
+    protected function convertRelativeToAbsoluteLink($rel)
+    {
+        if (strpos($rel, "//") === 0) {
+            $rel = parse_url($this->baseUrl, PHP_URL_SCHEME) . ":" . $rel;
+        }
+
+        /* return if already absolute URL or empty URL */
+        if (parse_url($rel, PHP_URL_SCHEME) != ''
+            || strlen(trim($rel)) <= 0
+            || preg_match("/^\s*mailto:/si", $rel)) {
+            return ($rel);
+        }
+
+        /* queries and anchors */
+        if ($rel[0] == '#' || $rel[0] == '?') {
+            return ($this->baseUrl . $rel);
+        }
+
+        /* parse base URL and convert to local variables:
+        $scheme, $host, $path */
+        extract(parse_url($this->baseUrl));
+
+        /* remove non-directory element from path */
+        if (isset($path)) {
+            $path = preg_replace('#/[^/]*$#', '', $path);
+        }
+
+        /* destroy path if relative url points to root */
+        if ($rel[0] == '/') {
+            $path = '';
+        }
+
+        /* dirty absolute URL */
+        $abs = '';
+
+        /* do we have a user in our URL? */
+        if (isset($user)) {
+            $abs .= $user;
+
+            /* password too? */
+            if (isset($pass)) {
+                $abs .= ':' . $pass;
+            }
+
+            $abs .= '@';
+        }
+
+        $abs .= $host;
+        /* did somebody sneak in a port? */
+        if (isset($port)) {
+            $abs .= ':' . $port;
+        }
+
+        if (isset($path)) {
+            $abs .= $path;
+        }
+        if (isset($rel)) {
+            $abs .= "/" . ltrim($rel, "/");
+        }
+        /* replace '//' or '/./' or '/foo/../' with '/' */
+        $re = array('#(/\.?/)#', '#/(?!\.\.)[^/]+/\.\./#');
+        for ($n = 1; $n > 0; $abs = preg_replace($re, '/', $abs, -1, $n)) {}
+
+        /* absolute URL is ready! */
+        return ($scheme . '://' . $abs);
+    }
+
+    abstract public function proxifyContent();
+}

app/HtmlDocument.php

+<?php
+
+namespace App;
+
+use DomDocument;
+
+class HtmlDocument extends Document
+{
+
+    private $htmlString;
+
+    public function __construct($password, $baseUrl, $htmlString, $encoding = "UTF-8")
+    {
+        parent::__construct($password, $baseUrl);
+        $this->htmlString = mb_convert_encoding($htmlString, 'HTML-ENTITIES', $encoding);
+    }
+
+    public function getResult()
+    {
+        return $this->htmlString;
+    }
+
+    /**
+     * Function proxifyContent
+     * This method parses the given String and Proxifies all Links/Urls in it so it's targetting this Proxy Server
+     **/
+    public function proxifyContent()
+    {
+        if (trim($this->htmlString) === "") {
+            return;
+        }
+
+        # Let's create a new DOM
+        libxml_use_internal_errors(true);
+        $dom = new DomDocument();
+        $dom->loadHtml($this->htmlString);
+
+        foreach ($dom->getElementsByTagName('base') as $base) {
+            $href = $base->getAttribute('href');
+            # Convert all relative Links to absolute Ones
+            $href          = $this->convertRelativeToAbsoluteLink($href);
+            $this->baseUrl = $href;
+            # Delete Base Tag
+            $base->parentNode->removeChild($base);
+        }
+
+        # First things first. Let's change all a Tags that can define a target Attribute
+        foreach ($dom->getElementsByTagName('a') as $link) {
+            # All Links within a "a" Tag need to target the top level because they change the site on click
+            $this->convertTargetAttribute($link, "_top");
+            # Convert all relative Links to absolute Ones
+            $link->setAttribute("href", $this->convertRelativeToAbsoluteLink($link->getAttribute("href")));
+            # Convert all Links to the proxified Version
+            # All of this Links should target to the top Level
+            $link->setAttribute("href", $this->proxifyUrl($link->getAttribute("href"), true));
+        }
+
+        # All Buttons
+        foreach ($dom->getElementsByTagName('button') as $button) {
+            if ($button->hasAttribute("formtarget")) {
+                $button->setAttribute("formtarget", "_top");
+            }
+            if ($button->hasAttribute("formaction")) {
+                $formaction = $button->getAttribute("formaction");
+                # Rel to abs
+                $formaction = $this->convertRelativeToAbsoluteLink($formaction);
+                # Abs to proxified
+                $formaction = $this->proxifyUrl($formaction, true);
+                # And replace
+                $button->setAttribute("formaction", $formaction);
+            }
+            # Since when are buttons allowed to have a href?
+            # Youtube has such on it's site so we are converting it anyways
+            if ($button->hasAttribute("href")) {
+                $href = $button->getAttribute("href");
+                # Rel to abs
+                $href = $this->convertRelativeToAbsoluteLink($href);
+                # Abs to proxified
+                $href = $this->proxifyUrl($href, true);
+                # And replace
+                $button->setAttribute("href", $href);
+            }
+
+        }
+
+        foreach ($dom->getElementsByTagName('area') as $area) {
+            # All Links within a "a" Tag need to target the top level because they change the site on click
+            $this->convertTargetAttribute($area, "_top");
+        }
+
+        foreach ($dom->getElementsByTagName('form') as $form) {
+            # All Links within a "a" Tag need to target the top level because they change the site on click
+            $this->convertTargetAttribute($form, "_top");
+            # If a Form doesn't define a action It references itself but we need to set the link then
+            $action = $form->getAttribute("action");
+            if ($action === "") {
+                $action = $this->baseUrl;
+            } else {
+                # Otherwise the Link could be relative and we need to change it:
+                # Convert all relative Links to absolute Ones
+                $action = $this->convertRelativeToAbsoluteLink($action);
+            }
+            # And finally Proxify the Url
+            $action = $this->proxifyUrl($action, true);
+            $form->setAttribute("action", $action);
+        }
+
+        # Alle Link Tags
+        foreach ($dom->getElementsByTagName('link') as $link) {
+            # Convert all relative Links to absolute Ones
+            $link->setAttribute("href", $this->convertRelativeToAbsoluteLink($link->getAttribute("href")));
+            # Convert all Links to the proxified Version
+            # All of this Links should NOT target to the top Level
+            $link->setAttribute("href", $this->proxifyUrl($link->getAttribute("href"), false));
+        }
+
+        # All Iframes
+        foreach ($dom->getElementsByTagName('iframe') as $iframe) {
+            # There can be 2 Possible sources
+            # A - The src Attribute defines a Url that the Iframe loads
+            $src = $iframe->getAttribute("src");
+            if ($src !== "") {
+                # Make the Link absolute
+                $src = $this->convertRelativeToAbsoluteLink($src);
+                # Proxify the Link
+                $src = $this->proxifyUrl($src, false);
+                # Replace the old Link
+                $iframe->setAttribute("src", $src);
+            }
+            # B - The srcdoc Attribute defines Html-Code that should be displayed in the frame
+            $srcdoc = $iframe->getAttribute("srcdoc");
+            if ($srcdoc !== "") {
+                # The srcdoc should be a HTML String so we are gonna make a new HTML-Document Element
+                $htmlDoc = new HtmlDocument($this->password, $this->baseUrl, $srcdoc);
+                $htmlDoc->proxifyContent();
+                $srcdoc = $htmlDoc->getResult();
+                # Replace the Old HTML Code
+                $iframe->setAttribute("srcdoc", $srcdoc);
+            }
+        }
+
+        # All Image Tags
+        foreach ($dom->getElementsByTagName('img') as $img) {
+            # Convert all Image src's to Absolute Links
+            $img->setAttribute("src", $this->convertRelativeToAbsoluteLink($img->getAttribute("src")));
+            # Convert all Image Sources to proxified Versions
+            $img->setAttribute("src", $this->proxifyUrl($img->getAttribute("src"), false));
+            # Some Images might contain a srcset (Different Images for different resolutions)
+            # Syntax would be i.e. srcset="medium.jpg 1000w, large.jpg 2000w"
+            $srcset = $img->getAttribute("srcset");
+            if ($srcset !== "") {
+                $images = explode(",", $srcset);
+                foreach ($images as $index => $set) {
+                    $set   = trim($set);
+                    $parts = preg_split("/\s+/si", $set);
+                    # $parts[0] is the Image Path
+                    # It could be relative so convert that one:
+                    $parts[0] = $this->convertRelativeToAbsoluteLink($parts[0]);
+
+                    # And now Proxify it:
+                    $parts[0]       = $this->proxifyUrl($parts[0], false);
+                    $images[$index] = implode(" ", $parts);
+                }
+                $srcset = implode(",", $images);
+                $img->setAttribute("srcset", $srcset);
+            }
+        }
+
+        # Alle Meta Tags
+        foreach ($dom->getElementsByTagName('meta') as $meta) {
+            if ($meta->hasAttribute("href")) {
+                # Convert all relative Links to absolute Ones
+                $meta->setAttribute("href", $this->convertRelativeToAbsoluteLink($meta->getAttribute("href")));
+                # Convert all Links to the proxified Version
+                # All of this Links should NOT target to the top Level
+                $meta->setAttribute("href", $this->proxifyUrl($meta->getAttribute("href"), false));
+            }
+            if ($meta->hasAttribute("http-equiv") && $meta->getAttribute("http-equiv") === "refresh") {
+                # We should refresh the site with a meta tag
+                # But not before profifying the new URL
+                $content = $meta->getAttribute("content");
+                $url     = substr($content, stripos($content, "url=") + 4);
+                # Convert all relative Links to absolute Ones
+                $url = $this->convertRelativeToAbsoluteLink($url);
+
+                # Convert all Links to the proxified Version
+                # All of this Links should NOT target to the top Level
+                $url = $this->proxifyUrl($url, false);
+
+                $content = substr($content, 0, stripos($content, "url=") + 4) . $url;
+
+                $meta->setAttribute("content", $content);
+            }
+        }
+
+        # Alle Script Tags
+        foreach ($dom->getElementsByTagName('script') as $script) {
+            $script->nodeValue = "";
+            $script->setAttribute("src", "");
+            $script->setAttribute("type", "");
+        }
+
+        # Alle Style Blöcke
+        # Werden extra geparsed
+        foreach ($dom->getElementsByTagName('style') as $style) {
+            $styleString = $style->nodeValue;
+            $cssElement  = new CssDocument($this->password, $this->baseUrl, $styleString);
+            $cssElement->proxifyContent();
+            $style->nodeValue = $cssElement->getResult();
+        }
+
+        # Abschließend gehen wir noch einmal alle Tags durch
+        foreach ($dom->getElementsByTagName('*') as $el) {
+            if ($el->getAttribute("style") !== "") {
+                $styleString = $el->getAttribute("style");
+                $cssElement  = new CssDocument($this->password, $this->baseUrl, $styleString);
+                $cssElement->proxifyContent();
+                $el->setAttribute("style", $cssElement->getResult());
+            }
+            # We Will Remove all Javascript Event attributes
+            # To keep things simple we're gonna remove all Attributes which names start with "on"
+            foreach ($el->attributes as $attr) {
+                if (stripos($attr->name, "on") === 0) {
+                    $el->removeAttribute($attr->name);
+                }
+            }
+        }
+
+        $this->htmlString = $dom->saveHtml();
+
+        # Remove all now empty script Tags
+        $this->htmlString = preg_replace("/<\s*[\/]{0,1}\s*script[^>]*?>/si", "", $this->htmlString);
+
+        libxml_use_internal_errors(false);
+    }
+
+/**
+ * This function changes the current Target Attribute on the link to given new target Attribute
+ */
+    private function convertTargetAttribute($link, $newTarget)
+    {
+        $link->setAttribute("target", $newTarget);
+    }
+}

resources/views/ProxyPage.blade.php

 <html>
 	<head>
+		<meta charset="utf-8" />
 		<link href="/css/bootstrap.min.css" rel="stylesheet" type="text/css" />
 		<link href="/css/style.css" rel="stylesheet" type="text/css" />
 	</head>
@@ -18,16 +19,6 @@
 					</div>
 					<div id="proxy-options" class="col-xs-2">
 						<ul class="list-unstyled">
-						@if(!$scriptsEnabled)
-						<li><a href="{{$scriptUrl}}" class="btn btn-warning btn-xs">Skripte blockiert</a></li>
-						@else
-						<li><a href="{{$scriptUrl}}" class="btn btn-info btn-xs">Skripte zugelassen</a></li>
-						@endif
-						@if(!$cookiesEnabled)
-						<li><a href="{{$cookieUrl}}" class="btn btn-warning btn-xs">Cookies gesperrt</a></li>
-						@else
-						<li><a href="{{$cookieUrl}}" class="btn btn-info btn-xs">Cookies zugelassen</a></li>
-						@endif
 						<li><a href="{!!$targetUrl!!}" class="btn btn-danger btn-xs">Proxy ausschalten</a></li>
 						</ul>
 					</div>