Added config backendForceSecure used to force HTTPS

Refs https://security.googleblog.com/2016/09/moving-towards-more-secure-web.html

config/cms.php

@@ -38,6 +38,19 @@ return [
 
     'backendUri' => 'backend',
 
+    /*
+    |--------------------------------------------------------------------------
+    | Back-end force HTTPS security
+    |--------------------------------------------------------------------------
+    |
+    | Use this setting to force a secure protocol when accessing any back-end
+    | pages, including the authentication pages. If set to null, this setting
+    | is enabled when debug mode (app.debug) is disabled.
+    |
+    */
+
+    'backendForceSecure' => null,
+
     /*
     |--------------------------------------------------------------------------
     | Back-end timezone
@@ -284,8 +297,8 @@ return [
     |--------------------------------------------------------------------------
     |
     | If safe mode is enabled, the PHP code section is disabled in the CMS
-    | for security reasons. If set to null, safe mode is on when debug mode
+    | for security reasons. If set to null, safe mode is enabled when
-    | (app.debug) is disabled.
+    | debug mode (app.debug) is disabled.
     |
     */
 

modules/backend/classes/Controller.php

@@ -9,6 +9,7 @@ use Config;
 use Request;
 use Backend;
 use Session;
+use Redirect;
 use Response;
 use Exception;
 use BackendAuth;
@@ -174,6 +175,13 @@ class Controller extends Extendable
             return Response::make(Lang::get('backend::lang.page.invalid_token.label'), 403);
         }
 
+        /*
+         * Check forced HTTPS protocol.
+         */
+        if (!$this->verifyForceSecure()) {
+            return Redirect::secure(Request::path());
+        }
+
         /*
          * Extensibility
          */
@@ -667,7 +675,7 @@ class Controller extends Extendable
     }
 
     //
-    // CSRF Protection
+    // Security
     //
 
     /**
@@ -693,4 +701,23 @@ class Controller extends Extendable
             $token
         );
     }
+
+    /**
+     * Checks if the back-end should force a secure protocol (HTTPS) enabled by config.
+     * @return bool
+     */
+    protected function verifyForceSecure()
+    {
+        if (Request::secure() || Request::ajax()) {
+            return true;
+        }
+
+        // @todo if year >= 2018 change default from false to null
+        $forceSecure = Config::get('cms.backendForceSecure', false);
+        if ($forceSecure === null) {
+            $forceSecure = !Config::get('app.debug', false);
+        }
+
+        return !$forceSecure;
+    }
 }

modules/system/classes/ErrorHandler.php

@@ -53,13 +53,14 @@ class ErrorHandler extends ErrorHandlerBase
      */
     public function handleCustomError()
     {
-        if (Config::get('app.debug', false))
+        if (Config::get('app.debug', false)) {
             return null;
+        }
 
         $theme = Theme::getActiveTheme();
+        $router = new Router($theme);
 
         // Use the default view if no "/error" URL is found.
-        $router = new Router($theme);
         if (!$router->findByUrl('/error')) {
             return View::make('cms::error');
         }