From 2937aa56cb9cac5c650f59443375a355ab047f66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Mudr=C3=A1k?= <david@moodle.com>
Date: Thu, 23 Mar 2017 13:10:53 +0100
Subject: [PATCH] MDL-58374 lti: Log the error message of a failed message
 verification

Previously the exception message (which holds the actual explanation of
what went wrong) was thrown away so the user had no way to debug.
---
 mod/lti/servicelib.php | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mod/lti/servicelib.php b/mod/lti/servicelib.php
index 88ebdb1c49a..0dae3d0c6f6 100644
--- a/mod/lti/servicelib.php
+++ b/mod/lti/servicelib.php
@@ -250,6 +250,7 @@ function lti_verify_message($key, $sharedsecrets, $body, $headers = null) {
             // TODO: Switch to core oauthlib once implemented - MDL-30149.
             lti\handle_oauth_body_post($key, $secret, $body, $headers);
         } catch (Exception $e) {
+            debugging('LTI message verification failed: '.$e->getMessage());
             $signaturefailed = true;
         }