move the CSRF Function to global function for easy access

system/autoload/Csrf.php

@@ -0,0 +1,30 @@
+<?php
+
+/**
+ *  PHP Mikrotik Billing (https://github.com/hotspotbilling/phpnuxbill/)
+ *  by https://t.me/ibnux
+ **/
+
+
+class Csrf {
+    public static function generateToken($length = 16) {
+        return bin2hex(random_bytes($length));
+    }
+
+    public static function validateToken($token, $storedToken) {
+        return hash_equals($token, $storedToken);
+    }
+
+    public static function check($token) {
+        if (isset($_SESSION['csrf_token']) && isset($token)) {
+            return self::validateToken($token, $_SESSION['csrf_token']);
+        }
+        return false;
+    }
+
+    public static function generateAndStoreToken() {
+        $token = self::generateToken();
+        $_SESSION['csrf_token'] = $token;
+        return $token;
+    }
+}