--- loncom/lti/ltiutils.pm	2017/12/30 14:04:00	1.3
+++ loncom/lti/ltiutils.pm	2018/01/04 12:19:25	1.5
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Utility functions for managing LON-CAPA LTI interactions 
 #
-# $Id: ltiutils.pm,v 1.3 2017/12/30 14:04:00 raeburn Exp $
+# $Id: ltiutils.pm,v 1.5 2018/01/04 12:19:25 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -51,7 +51,7 @@ use LONCAPA qw(:DEFAULT :match);
 #
 # When LON-CAPA is operating as a Provider, nonce checking 
 # occurs when a user in course context in another LMS (the 
-# Consumer launches an external tool to access a LON-CAPA URL: 
+# Consumer) launches an external tool to access a LON-CAPA URL: 
 # /adm/lti/ with LON-CAPA symb, map, or deep-link ID appended.
 #
 
@@ -286,7 +286,7 @@ sub verify_lis_item {
             my $expected_sig;
             if ($context eq 'grade') {
                 my $uniqid = $digsymb.':::'.$diguser.':::'.$cdom.'_'.$cnum;
-                $expected_sig = &get_service_id($secret,$uniqid);
+                $expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0]; 
                 if ($expected_sig eq $sigrec) {
                     return 1;
                 } else {
@@ -294,7 +294,7 @@ sub verify_lis_item {
                 }
             } elsif ($context eq 'roster') {
                 my $uniqid = $digsymb.':::'.$cdom.'_'.$cnum;
-                $expected_sig = &get_service_id($secret,$uniqid);
+                $expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0]; 
                 if ($expected_sig eq $sigrec) {
                     return 1;
                 } else {
@@ -314,7 +314,7 @@ sub verify_lis_item {
 # LON-CAPA as LTI Consumer
 #
 # Sign a request used to launch an instance of an external
-# too in a LON-CAPA course, using the key and secret supplied 
+# tool in a LON-CAPA course, using the key and secret supplied 
 # by the Tool Provider.
 #