use public api for session access from server container

lib/util.php

@@ -107,7 +107,7 @@ class OC_Util {
 	 */
 	public static function getVersion() {
 		OC_Util::loadVersion();
-		return $_SESSION['OC_Version'];
+		return \OC::$server->getSession()->get('OC_Version');
 	}
 
 	/**
@@ -116,7 +116,7 @@ class OC_Util {
 	 */
 	public static function getVersionString() {
 		OC_Util::loadVersion();
-		return $_SESSION['OC_VersionString'];
+		return \OC::$server->getSession()->get('OC_VersionString');
 	}
 
 	/**
@@ -127,7 +127,7 @@ class OC_Util {
 	 */
 	public static function getEditionString() {
 		OC_Util::loadVersion();
-		return $_SESSION['OC_Edition'];
+		return \OC::$server->getSession()->get('OC_Edition');
 	}
 
 	/**
@@ -136,7 +136,7 @@ class OC_Util {
 	 */
 	public static function getChannel() {
 		OC_Util::loadVersion();
-		return $_SESSION['OC_Channel'];
+		return \OC::$server->getSession()->get('OC_Channel');
 	}
         
 	/**
@@ -145,20 +145,26 @@ class OC_Util {
 	 */
 	public static function getBuild() {
 		OC_Util::loadVersion();
-		return $_SESSION['OC_Build'];
+		return \OC::$server->getSession()->get('OC_Build');
 	}
 
 	/**
 	 * @description load the version.php into the session as cache
 	 */
 	private static function loadVersion() {
-		if(!isset($_SESSION['OC_Version'])){
-			require('version.php');
-			$_SESSION['OC_Version']=$OC_Version;
-			$_SESSION['OC_VersionString']=$OC_VersionString;
-			$_SESSION['OC_Edition']=$OC_Edition;
-			$_SESSION['OC_Channel']=$OC_Channel;
-			$_SESSION['OC_Build']=$OC_Build;
+		if(!\OC::$server->getSession()->exists('OC_Version')) {
+			require 'version.php';
+			$session = \OC::$server->getSession();
+			/** @var $OC_Version string */
+			$session->set('OC_Version', $OC_Version);
+			/** @var $OC_VersionString string */
+			$session->set('OC_VersionString', $OC_VersionString);
+			/** @var $OC_Edition string */
+			$session->set('OC_Edition', $OC_Edition);
+			/** @var $OC_Channel string */
+			$session->set('OC_Channel', $OC_Channel);
+			/** @var $OC_Build string */
+			$session->set('OC_Build', $OC_Build);
 		}
 	}