From cd16c5e4796204c993d5f8c76d6c9c684cd0705c Mon Sep 17 00:00:00 2001
From: Frank Karlitschek <frank@owncloud.org>
Date: Mon, 11 Jun 2012 12:13:08 +0200
Subject: [PATCH] implement a simple request token session garbage collector

---
 lib/util.php | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 mode change 100644 => 100755 lib/util.php

diff --git a/lib/util.php b/lib/util.php
old mode 100644
new mode 100755
index 7c85db71f5..b6f3cb5df4
--- a/lib/util.php
+++ b/lib/util.php
@@ -358,12 +358,30 @@ class OC_Util {
 	 * Todo: Write howto
 	 */
 	public static function callRegister(){
+		//mamimum time before token exires
+		$maxtime=(60*60);  // 1 hour
+
 		// generate a random token.
 		$token=mt_rand(1000,9000).mt_rand(1000,9000).mt_rand(1000,9000);
 
 		// store the token together with a timestamp in the session.
 		$_SESSION['requesttoken-'.$token]=time();
 
+		// cleanup old tokens garbage collector
+		// only run every 20th time so we donīt waste cpu cycles
+		if(rand(0,20)==0) {  
+			foreach($_SESSION as $key=>$value) {
+				// search all tokens in the session
+				if(substr($key,0,12)=='requesttoken') {
+					if($value+$maxtime<time()){
+						// remove outdated tokens
+						unset($_SESSION[$key]);						
+					}
+				}	
+			}
+		}
+
+
 		// return the token
 		return($token);
 	}