From e4b0f5b3ed3deb89f1194eaa27c7a236f0b4ff00 Mon Sep 17 00:00:00 2001
From: Jerome Jutteau <mojo@couak.net>
Date: Wed, 20 May 2015 11:52:34 +0200
Subject: [PATCH] add support for http_X_forwarded_for header, refs #36

Signed-off-by: Jerome Jutteau <mojo@couak.net>
---
 lib/functions.php | 59 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 13 deletions(-)

diff --git a/lib/functions.php b/lib/functions.php
index 0f42e21..2c799f2 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -1108,31 +1108,64 @@ function jirafeau_challenge_upload_ip ($cfg, $ip)
     return false;
 }
 
+/** Tell if we have some HTTP headers generated by a proxy */
+function has_http_forwarded()
+{
+    if (!empty ($_SERVER['HTTP_X_FORWARDED_FOR']))
+        return true;
+    if (!empty ($_SERVER['http_X_forwarded_for']))
+        return true;
+    return false;
+}
+
+/**
+ * Generate IP list from HTTP headers generated by a proxy
+ * return  array of IP strings
+ */
+function get_ip_list_http_forwarded()
+{
+    $ip_list = array();
+    if (!empty ($_SERVER['HTTP_X_FORWARDED_FOR']))
+    {
+        $l = explode (',', $_SERVER['HTTP_X_FORWARDED_FOR']);
+        foreach ($l as $ip)
+            array_push ($ip_list, preg_replace ('/\s+/', '', $ip));
+    }
+    if (!empty ($_SERVER['http_X_forwarded_for']))
+    {
+        $l = explode (',', $_SERVER['http_X_forwarded_for']);
+        foreach ($l as $ip)
+        {
+            // Separate IP from port
+            $ip = explode (':', $ip)[0];
+            array_push ($ip_list, preg_replace ('/\s+/', '', $ip));
+        }
+    }
+    return $ip_list;
+}
+
 /**
  * Get the ip address of the client from REMOTE_ADDR
  * or from HTTP_X_FORWARDED_FOR if behind a proxy
  * @returns an the client ip address
  */
 function get_ip_address($cfg) {
-    if (count ($cfg['proxy_ip']) == 0 ||
-        empty ($_SERVER['HTTP_X_FORWARDED_FOR']))
-        return $_SERVER['REMOTE_ADDR'];
+    $remote = $_SERVER['REMOTE_ADDR'];
+    if (count ($cfg['proxy_ip']) == 0 || !has_http_forwarded ())
+        return $remote;
 
-    $iplist = explode (',', $_SERVER['HTTP_X_FORWARDED_FOR']);
-    if (count ($iplist) == 0)
-        return $_SERVER['REMOTE_ADDR'];
+    $ip_list = get_ip_list_http_forwarded ();
+    if (count ($ip_list) == 0)
+        return $remote;
 
     foreach ($cfg['proxy_ip'] as $proxy_ip)
     {
-        if ($_SERVER['REMOTE_ADDR'] != $proxy_ip)
+        if ($remote != $proxy_ip)
             continue;
-
-        // Take the last IP (the one which has been set by our proxy).
-        $ip = end($iplist);
-        $ip = preg_replace ('/\s+/', '', $ip);
-        return $ip;
+        // Take the last IP (the one which has been set by the defined proxy).
+        return end ($ip_list);
     }
-    return $_SERVER['REMOTE_ADDR'];
+    return $remote;
 }
 
 /**
-- 
2.34.1