From 65b49f5be684e30d372273bd1bcb6834812961e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADctor=20D=C3=A9niz?= <victor@moodle.com>
Date: Fri, 14 Jan 2022 11:01:19 +0000
Subject: [PATCH] MDL-73582 registration: Add endpoint to provide version to
 linkchecker

---
 admin/registration/check.php | 48 ++++++++++++++++++++++++++++++++++++
 lib/moodlelib.php            |  5 ++++
 2 files changed, 53 insertions(+)
 create mode 100644 admin/registration/check.php

diff --git a/admin/registration/check.php b/admin/registration/check.php
new file mode 100644
index 00000000000..7b92c410747
--- /dev/null
+++ b/admin/registration/check.php
@@ -0,0 +1,48 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Endpoint to get the Moodle version
+ *
+ * Moodle linkchecker will check this endpoint when it cannot get the Moodle version otherwise.
+ *
+ * @package    core
+ * @copyright  2022 Victor Deniz <victor@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+require_once(__DIR__ . '/../../config.php');
+require_once($CFG->libdir . '/filelib.php');
+
+// Get public key.
+$key = download_file_content(HUB_STATSPUBLICKEY);
+// Check $key is a valid public key.
+$publickey = openssl_pkey_get_public($key);
+if ($publickey !== false) {
+    $publickeystr = openssl_pkey_get_details($publickey)['key'];
+} else {
+    die('Error getting a valid public key');
+}
+
+// Encrypt data.
+$message = $CFG->release;
+$success = openssl_public_encrypt(utf8_encode($message), $encrypteddata, $publickeystr);
+
+if ($success) {
+    echo base64_encode($encrypteddata);
+} else {
+    die ('Error encrypting the data');
+}
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index cc6bd768b78..4d366223dc6 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -495,6 +495,11 @@ define('HOMEPAGE_USER', 2);
  */
 defined('HUB_MOODLEORGHUBURL') || define('HUB_MOODLEORGHUBURL', 'https://stats.moodle.org');
 
+/**
+ * URL of the statistic server public key.
+ */
+defined('HUB_STATSPUBLICKEY') || define('HUB_STATSPUBLICKEY', 'https://moodle.org/static/statspubkey.pem');
+
 /**
  * Moodle mobile app service name
  */