+
+/**
+ * Retrieve the initial IP forwarded by the reverse proxy.
+ *
+ * Inspired from: https://github.com/zendframework/zend-http/blob/master/src/PhpEnvironment/RemoteAddress.php
+ *
+ * @param array $server $_SERVER array which contains HTTP headers.
+ * @param array $trustedIps List of trusted IP from the configuration.
+ *
+ * @return string|bool The forwarded IP, or false if none could be extracted.
+ */
+function getIpAddressFromProxy($server, $trustedIps)
+{
+ $forwardedIpHeader = 'HTTP_X_FORWARDED_FOR';
+ if (empty($server[$forwardedIpHeader])) {
+ return false;
+ }
+
+ $ips = preg_split('/\s*,\s*/', $server[$forwardedIpHeader]);
+ $ips = array_diff($ips, $trustedIps);
+ if (empty($ips)) {
+ return false;
+ }
+
+ return array_pop($ips);
+}
+
+/**
+ * Returns true if Shaarli's currently browsed in HTTPS.
+ * Supports reverse proxies (if the headers are correctly set).
+ *
+ * @param array $server $_SERVER.
+ *
+ * @return bool true if HTTPS, false otherwise.
+ */
+function is_https($server)
+{
+
+ if (isset($server['HTTP_X_FORWARDED_PORT'])) {
+ // Keep forwarded port
+ if (strpos($server['HTTP_X_FORWARDED_PORT'], ',') !== false) {
+ $ports = explode(',', $server['HTTP_X_FORWARDED_PORT']);
+ $port = trim($ports[0]);
+ } else {
+ $port = $server['HTTP_X_FORWARDED_PORT'];
+ }
+
+ if ($port == '443') {
+ return true;
+ }
+ }
+
+ return ! empty($server['HTTPS']);
+}