From 2fb0138721d5eb746919cd87ff93a9b38feee906 Mon Sep 17 00:00:00 2001
From: Tim Hunt <T.J.Hunt@open.ac.uk>
Date: Mon, 2 Nov 2009 16:50:26 +0000
Subject: [PATCH] moodlelib: MDL-20702 New require_sesskey function. Backported
 from head.

---
 lib/moodlelib.php | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index ad5f8d02112..7ff7e42f913 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -1603,6 +1603,16 @@ function confirm_sesskey($sesskey=NULL) {
     return ($USER->sesskey === $sesskey);
 }
 
+/**
+ * Check the session key using {@link confirm_sesskey()},
+ * and cause a fatal error if it does not match.
+ */
+function require_sesskey() {
+    if (!confirm_sesskey()) {
+        print_error('invalidsesskey');
+    }
+}
+
 /**
  * Setup all global $CFG course variables, set locale and also themes
  * This function can be used on pages that do not require login instead of require_login()