--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/program/steps/utils/modcss.inc	Thu Jan 04 15:52:31 2018 -0500
@@ -0,0 +1,83 @@
+<?php
+
+/**
+ +-----------------------------------------------------------------------+
+ | program/steps/utils/modcss.inc                                        |
+ |                                                                       |
+ | This file is part of the Roundcube Webmail client                     |
+ | Copyright (C) 2007-2014, The Roundcube Dev Team                       |
+ |                                                                       |
+ | Licensed under the GNU General Public License version 3 or            |
+ | any later version with exceptions for skins & plugins.                |
+ | See the README file for a full license statement.                     |
+ |                                                                       |
+ | PURPOSE:                                                              |
+ |   Modify CSS source from a URL                                        |
+ |                                                                       |
+ +-----------------------------------------------------------------------+
+ | Author: Thomas Bruederli <roundcube@gmail.com>                        |
+ | Author: Aleksander Machniak <alec@alec.pl>                            |
+ +-----------------------------------------------------------------------+
+*/
+
+$url = preg_replace('![^a-z0-9.-]!i', '', $_GET['_u']);
+
+if ($url === null || !($realurl = $_SESSION['modcssurls'][$url])) {
+    header('HTTP/1.1 403 Forbidden');
+    exit("Unauthorized request");
+}
+
+// don't allow any other connections than http(s)
+if (!preg_match('~^(https?)://~i', $realurl, $matches)) {
+    header('HTTP/1.1 403 Forbidden');
+    exit("Invalid URL");
+}
+
+if (ini_get('allow_url_fopen')) {
+    $scheme  = strtolower($matches[1]);
+    $options = array(
+        $scheme => array(
+            'method' => 'GET',
+            'timeout' => 15,
+        )
+    );
+
+    $context = stream_context_create($options);
+    $source  = @file_get_contents($realurl, false, $context);
+
+    // php.net/manual/en/reserved.variables.httpresponseheader.php
+    $headers = implode("\n", (array) $http_response_header);
+}
+else if (function_exists('curl_init')) {
+    $curl = curl_init($realurl);
+    curl_setopt($curl, CURLOPT_TIMEOUT, 15);
+    curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 15);
+    curl_setopt($curl, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS);
+    curl_setopt($curl, CURLOPT_ENCODING, '');
+    curl_setopt($curl, CURLOPT_HEADER, true);
+    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
+    $data = curl_exec($curl);
+
+    if ($data !== false) {
+        list($headers, $source) = explode("\r\n\r\n", $data, 2);
+    }
+    else {
+        $headers = false;
+        $source  = false;
+    }
+}
+else {
+    header('HTTP/1.1 403 Forbidden');
+    exit("HTTP connections disabled");
+}
+
+$ctype_regexp = '~Content-Type:\s+text/(css|plain)~i';
+
+if ($source !== false && preg_match($ctype_regexp, $headers)) {
+    header('Content-Type: text/css');
+    echo rcube_utils::mod_css_styles($source, preg_replace('/[^a-z0-9]/i', '', $_GET['_c']));
+    exit;
+}
+
+header('HTTP/1.0 404 Not Found');
+exit("Invalid response returned by server");