certificatelock.php
<?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/>.

/**
 * Lock and unlock the Private Key and Certificate files
 *
 * @package    auth_saml2
 * @author     Nicholas Hoobin <nicholashoobin@catalyst-au.net>
 * @copyright  Catalyst IT
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

require_once(dirname(__FILE__) . '/../../config.php');
require_once($CFG->libdir . '/adminlib.php');

require_login();
require_capability('moodle/site:config', context_system::instance());
$PAGE->set_url("$CFG->wwwroot/auth/saml2/certificatelock.php");
$PAGE->set_course($SITE);


require('setup.php');

$form = new \auth_saml2\form\lockcertificate();

$settingspage = new moodle_url('/admin/settings.php?section=authsettingsaml2');

if ($data = $form->get_data()) {

    if ($form->is_submitted()) {

        $certfiles = [$saml2auth->certpem, $saml2auth->certcrt];
        if (isset($data->unlockcertsbutton)) {
            // Change the permissions in order to regenerate if unlocked.
            foreach ($certfiles as $certfile) {
                chmod($certfile, $CFG->filepermissions);
            }
            // Store the unlocked state in config.
            set_config('certs_locked', '0', 'auth_saml2');
        } else {
            foreach ($certfiles as $certfile) {
                chmod($certfile, $CFG->filepermissions & 0440);
            }
            // Store the locked state in config.
            set_config('certs_locked', '1', 'auth_saml2');
        }

        redirect($settingspage);
    }
} else if ($form->is_cancelled()) {
    redirect($settingspage);
}

echo $OUTPUT->header();
echo $OUTPUT->heading(get_string('certificatelock', 'auth_saml2'));
echo $form->display();
echo $OUTPUT->footer();
