From fd7d05e8624b9a8293496ace80ed437ccd02f88d Mon Sep 17 00:00:00 2001
From: rugk <rugk+git@posteo.de>
Date: Fri, 16 Apr 2021 22:03:02 +0200
Subject: [PATCH] Add base URL as default CSP restriction

This follows an [HTTP Observatory recommendation](https://observatory.mozilla.org/analyze/privatebin.net):
> Restricts use of the <base> tag by using base-uri 'none', base-uri 'self', or specific origins.

Given we don't use that anywhere, this safe should be safe. (not tested practically though)
---
 cfg/conf.sample.php   | 2 +-
 lib/Configuration.php | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/cfg/conf.sample.php b/cfg/conf.sample.php
index e958c88d..570503ce 100644
--- a/cfg/conf.sample.php
+++ b/cfg/conf.sample.php
@@ -87,7 +87,7 @@ languageselection = false
 ;   async functions and display an error if not and for Chrome to enable
 ;   webassembly support (used for zlib compression). You can remove it if Chrome
 ;   doesn't need to be supported and old browsers don't need to be warned.
-; cspheader = "default-src 'none'; manifest-src 'self'; connect-src * blob:; script-src 'self' 'unsafe-eval' resource:; style-src 'self'; font-src 'self'; img-src 'self' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads"
+; cspheader = "default-src 'none'; base-uri 'self'; manifest-src 'self'; connect-src * blob:; script-src 'self' 'unsafe-eval' resource:; style-src 'self'; font-src 'self'; img-src 'self' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads"
 
 ; stay compatible with PrivateBin Alpha 0.19, less secure
 ; if enabled will use base64.js version 1.7 instead of 2.1.9 and sha1 instead of
diff --git a/lib/Configuration.php b/lib/Configuration.php
index 2a326caf..741ab7c9 100644
--- a/lib/Configuration.php
+++ b/lib/Configuration.php
@@ -55,7 +55,7 @@ class Configuration
             'urlshortener'             => '',
             'qrcode'                   => true,
             'icon'                     => 'identicon',
-            'cspheader'                => 'default-src \'none\'; manifest-src \'self\'; connect-src * blob:; script-src \'self\' \'unsafe-eval\' resource:; style-src \'self\'; font-src \'self\'; img-src \'self\' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads',
+            'cspheader'                => 'default-src \'none\'; base-uri \'self\'; manifest-src \'self\'; connect-src * blob:; script-src \'self\' \'unsafe-eval\' resource:; style-src \'self\'; font-src \'self\'; img-src \'self\' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads',
             'zerobincompatibility'     => false,
             'httpwarning'              => true,
             'compression'              => 'zlib',
@@ -265,3 +265,4 @@ class Configuration
         return $this->_configuration[$section];
     }
 }
+