diff --git a/app/courses/proxy.php b/app/courses/proxy.php
new file mode 100644
index 0000000000..99d6e5d93c
--- /dev/null
+++ b/app/courses/proxy.php
@@ -0,0 +1,145 @@
+ function returns "px"
+ * 800% => function returns %
+ *
+ * @param string $value
+ * @return string
+ */
+function addPixelOrPercentage($value)
+{
+ $addPixel = strpos($value, 'px');
+ $addPixel = !($addPixel === false);
+ $addCharacter = '';
+ if ($addPixel == false) {
+ $addPercentage = strpos($value, '%');
+ $addPercentage = !($addPercentage === false);
+ if ($addPercentage) {
+ $addCharacter = '%';
+ }
+ } else {
+ $addCharacter = 'px';
+ }
+
+ return $addCharacter;
+}
+
+function get_http_response_code($theURL)
+{
+ $headers = get_headers($theURL);
+
+ return substr($headers[0], 9, 3);
+}
+
+
+$height = isset($_GET['height']) ? (int) $_GET['height'].addPixelOrPercentage($_GET['height']) : '';
+$width = isset($_GET['width']) ? (int) $_GET['width'].addPixelOrPercentage($_GET['width']) : '';
+$vars = isset($_GET['flashvars']) ? htmlentities($_GET['flashvars']) : '';
+$src = isset($_GET['src']) ? htmlentities($_GET['src']) : '';
+$id = isset($_GET['id']) ? htmlentities($_GET['id']) : '';
+$type = isset($_GET['type']) ? $_GET['type'] : 'flash';
+
+// Fixes URL like: https://www.vopspsy.ugent.be/pdfs/download.php?own=mvsteenk&file=caleidoscoop.pdf
+if (strpos($src, 'download.php') !== false) {
+ $src = str_replace('download.php', 'download.php?', $src);
+ $src .= isset($_GET['own']) ? '&own='.htmlentities($_GET['own']) : '';
+ $src .= isset($_GET['file']) ? '&file='.htmlentities($_GET['file']) : '';
+}
+
+$result = get_http_response_code($src);
+$urlToTest = parse_url($src, PHP_URL_HOST);
+$g = stream_context_create (array('ssl' => array('capture_peer_cert' => true)));
+$r = @stream_socket_client("ssl://$urlToTest:443", $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $g);
+$cont = stream_context_get_params($r);
+$convertToSecure = false;
+
+$certinfo = openssl_x509_parse($cont['options']['ssl']['peer_certificate']);
+if (isset($certinfo) && isset($certinfo['subject']) && isset($certinfo['subject']['CN'])) {
+ $certUrl = $certinfo['subject']['CN'];
+ $parsed = parse_url($certUrl);
+
+ // Remove www from URL
+ $parsedUrl = preg_replace('#^(http(s)?://)?w{3}\.#', '$1', $certUrl);
+
+ if ($urlToTest == $certUrl || $parsedUrl == $urlToTest) {
+ $convertToSecure = true;
+ }
+
+ if ($urlToTest != $certUrl) {
+ // url and cert url are different this will show a warning in browsers
+ // use normal "http" version
+ $result = false;
+ }
+}
+
+if ($result == false) {
+ $src = str_replace('https', 'http', $src);
+}
+
+if ($convertToSecure) {
+ $src = str_replace('http', 'https', $src);
+}
+
+$result = '';
+switch ($type) {
+ case 'link':
+ // Check if links comes from a course
+ $srcParts = explode('/', $src);
+ $srcParts = array_filter($srcParts);
+ $srcParts = array_values($srcParts);
+
+ if (isset($srcParts[0], $srcParts[2]) && $srcParts[0] === 'courses' && $srcParts[2] === 'document') {
+ $src = $_configuration['root_web'].$src;
+ }
+
+ if (strpos($src, 'http') === false) {
+ $src = "http://$src";
+ }
+ header('Location: '.$src);
+ exit;
+ break;
+ case 'iframe':
+ $result = '';
+ break;
+ case 'flash':
+ $result = '
+ ';
+}
+
+echo $result;