From 1983718149b5daadf193babf3ac408eb501330a5 Mon Sep 17 00:00:00 2001
From: Dmitri Pisarev <dimaip@gmail.com>
Date: Tue, 22 Jan 2019 11:09:26 +0300
Subject: [PATCH 1/2] MDL-63770 core: Fix a false-positive in
 `reverseproxyabused` check

A `reverseproxyabused` error is wrongly triggered when external port number doesn't equal internal.
---
 lib/setuplib.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/setuplib.php b/lib/setuplib.php
index da146429b41..64dba6498fd 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -899,7 +899,7 @@ function initialise_fullme() {
 
     // hopefully this will stop all those "clever" admins trying to set up moodle
     // with two different addresses in intranet and Internet
-    if (!empty($CFG->reverseproxy) && $rurl['host'] === $wwwroot['host']) {
+    if (!empty($CFG->reverseproxy) && $rurl['host'] === $wwwroot['host'] && (empty($wwwroot['port']) || $rurl['port'] === $wwwroot['port'])) {
         print_error('reverseproxyabused', 'error');
     }
 

From 7910fa322acade7210aa55e577f81509d3cd8faa Mon Sep 17 00:00:00 2001
From: Matteo Scaramuccia <moodle@matteoscaramuccia.com>
Date: Sun, 3 May 2020 23:46:18 +0200
Subject: [PATCH 2/2] MDL-63770 core: 'port' should be an integer like in
 parse_url()

Plus trivial comment cleanup.
---
 lib/setuplib.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/setuplib.php b/lib/setuplib.php
index 64dba6498fd..2af28136af9 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -897,8 +897,9 @@ function initialise_fullme() {
         $_SERVER['SERVER_PORT'] = 443; // Assume default ssl port for the proxy.
     }
 
-    // hopefully this will stop all those "clever" admins trying to set up moodle
-    // with two different addresses in intranet and Internet
+    // Hopefully this will stop all those "clever" admins trying to set up moodle
+    // with two different addresses in intranet and Internet.
+    // Port forwarding is still allowed!
     if (!empty($CFG->reverseproxy) && $rurl['host'] === $wwwroot['host'] && (empty($wwwroot['port']) || $rurl['port'] === $wwwroot['port'])) {
         print_error('reverseproxyabused', 'error');
     }
@@ -950,7 +951,7 @@ function setup_get_remote_url() {
     } else {
         $rurl['host'] = null;
     }
-    $rurl['port'] = $_SERVER['SERVER_PORT'];
+    $rurl['port'] = (int)$_SERVER['SERVER_PORT'];
     $rurl['path'] = $_SERVER['SCRIPT_NAME']; // Script path without slash arguments
     $rurl['scheme'] = (empty($_SERVER['HTTPS']) or $_SERVER['HTTPS'] === 'off' or $_SERVER['HTTPS'] === 'Off' or $_SERVER['HTTPS'] === 'OFF') ? 'http' : 'https';