Only create cookie when needed

top.inc.php

@@ -14,9 +14,17 @@ require "inc/reg.inc.php";
 require "inc/pages.inc.php";
 
 // Session initialisation (with cookies)
+if (
+    isset($_COOKIE['niver']) // Resume session
+  OR
+    (SERVICE === "auth"
+    AND PAGE === "login"
+    AND isset($_POST['username']))
+  ) {
   session_start([
     'name' => 'niver',
     'sid_length' => 64,
+    'sid_bits_per_character' => 6,
     'cookie_secure' => true,
     'cookie_httponly' => true,
     'cookie_samesite' => 'Strict',
@@ -27,6 +35,7 @@ session_start([
     'use_cookies' => true,
     'use_only_cookies' => true,
   ]);
+}
 
 // Redirect to the login page if not logged in
 if (SERVICE != "auth" AND !isset($_SESSION['username'])) {