From 9c66d72779c0e8f9e346c1159e3991bfc39b8720 Mon Sep 17 00:00:00 2001
From: Adrian Hutchinson <adrian.hutchinson@mheducation.com>
Date: Mon, 17 Feb 2020 09:25:14 -0800
Subject: [PATCH] MDL-67988 mod_lti: remove padding from JWS base64url encoding

---
 mod/lti/certs.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mod/lti/certs.php b/mod/lti/certs.php
index 4618aa1167b..7afbbe68440 100644
--- a/mod/lti/certs.php
+++ b/mod/lti/certs.php
@@ -37,8 +37,8 @@ $jwk = array();
 $jwk['kty'] = 'RSA';
 $jwk['alg'] = 'RS256';
 $jwk['kid'] = get_config('mod_lti', 'kid');
-$jwk['e'] = strtr(base64_encode($details['rsa']['e']), '+/', '-_');
-$jwk['n'] = strtr(base64_encode($details['rsa']['n']), '+/', '-_');
+$jwk['e'] = rtrim(strtr(base64_encode($details['rsa']['e']), '+/', '-_'), '=');
+$jwk['n'] = rtrim(strtr(base64_encode($details['rsa']['n']), '+/', '-_'), '=');
 $jwk['use'] = 'sig';
 
 $jwks['keys'][] = $jwk;