From eb19d87fdf83f282af3aedbe6d75be17a64379c7 Mon Sep 17 00:00:00 2001
From: Damian <99253504+DamianORourke@users.noreply.github.com>
Date: Tue, 29 Apr 2025 10:19:37 +0100
Subject: [PATCH] Update LTI_Message_Launch.php get_public_key method

I can't say exactly when this started happening but all of my instances of LTI connection via Moodle 4.1.4 failed with PHP Warning:  file_get_contents(https://moodletesting.tiltroleplay.com/mod/lti/certs.php): failed to open stream: HTTP request failed! HTTP/1.1 403 Forbidden.  In case anyone else runs into this issue either edit this method yourself or employ CURL to do same but if in WP environment can't always rely on CURL being enabled or as an option by host.
---
 src/lti/LTI_Message_Launch.php | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/lti/LTI_Message_Launch.php b/src/lti/LTI_Message_Launch.php
index 7a18195d..e0f56eed 100644
--- a/src/lti/LTI_Message_Launch.php
+++ b/src/lti/LTI_Message_Launch.php
@@ -209,7 +209,17 @@ private function get_public_key() {
         $key_set_url = $this->registration->get_key_set_url();
 
         // Download key set
-        $public_key_set = json_decode(file_get_contents($key_set_url), true);
+        // Prevent PHP Warning:  file_get_contents(https://moodletesting.tiltroleplay.com/mod/lti/certs.php): failed to open stream: HTTP request failed! HTTP/1.1 403 Forbidden
+        $options = [
+            'http' => [
+                'method' => 'GET',
+                'header' => "User-Agent: PHP\r\n"
+            ]
+        ];
+
+        $context = stream_context_create($options);
+        
+        $public_key_set = json_decode(file_get_contents($key_set_url,false,$context), true);
 
         if (empty($public_key_set)) {
             // Failed to fetch public keyset from URL.
@@ -369,4 +379,4 @@ private function validate_message() {
 
     }
 }
-?>
\ No newline at end of file
+?>