Proyectos de Subversion Moodle

<?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/>.

namespace quizaccess_seb;

use quizaccess_seb;

defined('MOODLE_INTERNAL') || die();

require_once(__DIR__ . '/test_helper_trait.php');

/**

 * PHPUnit tests for plugin rule class.

 *

 * @package    quizaccess_seb

 * @author     Andrew Madden <andrewmadden@catalyst-au.net>

 * @copyright  2020 Catalyst IT

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 * @covers \quizaccess_seb

 */

class rule_test extends \advanced_testcase {

    use \quizaccess_seb_test_helper_trait;

    /**

     * Called before every test.

     */

    public function setUp(): void {

        parent::setUp();

        $this->resetAfterTest();

        $this->course = $this->getDataGenerator()->create_course();

    }

    /**

     * Called after every test.

     */

    public function tearDown(): void {

        global $SESSION;

        if (!empty($this->quiz)) {

            unset($SESSION->quizaccess_seb_access);

        }

    }

    /**

     * Helper method to get SEB download link for testing.

     *

     * @return string

     */

    private function get_seb_download_link() {

        return 'https://safeexambrowser.org/download_en.html';

    }

    /**

     * Helper method to get SEB launch link for testing.

     *

     * @return string

     */

    private function get_seb_launch_link() {

        return 'sebs://www.example.com/moodle/mod/quiz/accessrule/seb/config.php';

    }

    /**

     * Helper method to get SEB config download link for testing.

     *

     * @return string

     */

    private function get_seb_config_download_link() {

        return 'https://www.example.com/moodle/mod/quiz/accessrule/seb/config.php';

    }

    /**

     * Provider to return valid form field data when saving settings.

     *

     * @return array

     */

    public function valid_form_data_provider(): array {

        return [

            'valid seb_requiresafeexambrowser' => ['seb_requiresafeexambrowser', '0'],

            'valid seb_linkquitseb0' => ['seb_linkquitseb', 'http://safeexambrowser.org/macosx'],

            'valid seb_linkquitseb1' => ['seb_linkquitseb', 'safeexambrowser.org/macosx'],

            'valid seb_linkquitseb2' => ['seb_linkquitseb', 'www.safeexambrowser.org/macosx'],

            'valid seb_linkquitseb3' => ['seb_linkquitseb', 'any.type.of.url.looking.thing'],

            'valid seb_linkquitseb4' => ['seb_linkquitseb', 'http://any.type.of.url.looking.thing'],

        ];

    }

    /**

     * Provider to return invalid form field data when saving settings.

     *

     * @return array

     */

    public function invalid_form_data_provider(): array {

        return [

            'invalid seb_requiresafeexambrowser' => ['seb_requiresafeexambrowser', 'Uh oh!'],

            'invalid seb_linkquitseb0' => ['seb_linkquitseb', '\0'],

            'invalid seb_linkquitseb1' => ['seb_linkquitseb', 'invalid url'],

            'invalid seb_linkquitseb2' => ['seb_linkquitseb', 'http]://safeexambrowser.org/macosx'],

            'invalid seb_linkquitseb3' => ['seb_linkquitseb', '0'],

            'invalid seb_linkquitseb4' => ['seb_linkquitseb', 'seb://any.type.of.url.looking.thing'],

        ];

    }

    /**

     * Test no errors are found with valid data.

     *

     * @param string $setting

     * @param string $data

     *

     * @dataProvider valid_form_data_provider

     */

    public function test_validate_settings_with_valid_data(string $setting, string $data): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            $setting => $data

        ], [], $form);

        $this->assertEmpty($errors);

    }

    /**

     * Test errors are found with invalid data.

     *

     * @param string $setting

     * @param string $data

     *

     * @dataProvider invalid_form_data_provider

     */

    public function test_validate_settings_with_invalid_data(string $setting, string $data): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form and quiz instance.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            $setting => $data

        ], [], $form);

        $this->assertEquals([$setting => 'Data submitted is invalid'], $errors);

    }

    /**

     * Test settings validation is not run if settings are locked.

     */

    public function test_settings_validation_is_not_run_if_settings_are_locked(): void {

        $user = $this->getDataGenerator()->create_user();

        $this->quiz = $this->create_test_quiz($this->course);

        $this->attempt_quiz($this->quiz, $user);

        $this->setAdminUser();

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form and quiz instance.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid, 'seb_requiresafeexambrowser' => 'Uh oh!'

        ], [], $form);

        $this->assertEmpty($errors);

    }

    /**

     * Test settings validation is not run if settings are conflicting.

     */

    public function test_settings_validation_is_not_run_if_conflicting_permissions(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        $user = $this->getDataGenerator()->create_user();

        $roleid = $this->getDataGenerator()->create_role();

        $context = \context_module::instance($this->quiz->cmid);

        assign_capability('quizaccess/seb:manage_seb_requiresafeexambrowser', CAP_ALLOW, $roleid, $context->id);

        $this->getDataGenerator()->role_assign($roleid, $user->id, $context->id);

        // By default The user won't have permissions to configure manually.

        $this->setUser($user);

        // Validate settings with a dummy form and quiz instance.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'seb_requiresafeexambrowser' => 'Uh oh!'

        ], [], $form);

        $this->assertEmpty($errors);

    }

    /**

     * Test bypassing validation if user don't have permissions to manage seb settings.

     */

    public function test_validate_settings_is_not_run_if_a_user_do_not_have_permissions_to_manage_seb_settings(): void {

        // Set the user who can't change seb settings. So validation should be bypassed.

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form and quiz instance.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid, 'seb_requiresafeexambrowser' => 'Uh oh!'

        ], [], $form);

        $this->assertEmpty($errors);

    }

    /**

     * Test settings are saved to DB.

     */

    public function test_create_settings_with_existing_quiz(): void {

        global $DB;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_NO);

        $this->assertFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $this->quiz->id]));

        $this->quiz->seb_requiresafeexambrowser = settings_provider::USE_SEB_CONFIG_MANUALLY;

        quizaccess_seb::save_settings($this->quiz);

        $this->assertNotFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $this->quiz->id]));

    }

    /**

     * Test settings are not saved to DB if settings are locked.

     */

    public function test_settings_are_not_saved_if_settings_are_locked(): void {

        global $DB;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->attempt_quiz($this->quiz, $user);

        $this->setAdminUser();

        $this->quiz->seb_requiresafeexambrowser = settings_provider::USE_SEB_CONFIG_MANUALLY;

        quizaccess_seb::save_settings($this->quiz);

        $this->assertFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $this->quiz->id]));

    }

    /**

     * Test settings are not saved to DB if conflicting permissions.

     */

    public function test_settings_are_not_saved_if_conflicting_permissions(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $roleid = $this->getDataGenerator()->create_role();

        $context = \context_module::instance($this->quiz->cmid);

        assign_capability('quizaccess/seb:manage_seb_requiresafeexambrowser', CAP_ALLOW, $roleid, $context->id);

        $this->getDataGenerator()->role_assign($roleid, $user->id, $context->id);

        // By default The user won't have permissions to configure manually.

        $this->setUser($user);

        $this->quiz->seb_requiresafeexambrowser = settings_provider::USE_SEB_NO;

        quizaccess_seb::save_settings($this->quiz);

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $this->assertEquals(settings_provider::USE_SEB_CONFIG_MANUALLY, $quizsettings->get('requiresafeexambrowser'));

    }

    /**

     * Test exception thrown if cm could not be found while saving settings.

     */

    public function test_save_settings_throw_an_exception_if_cm_not_found(): void {

        global $DB;

        $this->expectException(\dml_missing_record_exception::class);

        $this->expectExceptionMessage('Can\'t find data record in database.');

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $DB->delete_records('quiz', ['id' => $this->quiz->id]);

        $this->quiz->seb_requiresafeexambrowser = settings_provider::USE_SEB_NO;

        quizaccess_seb::save_settings($this->quiz);

    }

    /**

     * Test nothing happens when deleted is called without settings saved.

     */

    public function test_delete_settings_without_existing_settings(): void {

        global $DB;

        $this->setAdminUser();

        $quiz = new \stdClass();

        $quiz->id = 1;

        quizaccess_seb::delete_settings($quiz);

        $this->assertFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $quiz->id]));

    }

    /**

     * Test settings are deleted from DB.

     */

    public function test_delete_settings_with_existing_settings(): void {

        global $DB;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Using a generator will create the quiz_settings record.

        $this->assertNotFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $this->quiz->id]));

        quizaccess_seb::delete_settings($this->quiz);

        $this->assertFalse($DB->record_exists('quizaccess_seb_quizsettings', ['quizid' => $this->quiz->id]));

    }

    /**

     * A helper method to check invalid config key.

     */

    protected function check_invalid_config_key() {

        // Create an event sink, trigger event and retrieve event.

        $sink = $this->redirectEvents();

        // Check that correct error message is returned.

        $errormsg = $this->make_rule()->prevent_access();

        $this->assertNotEmpty($errormsg);

        $this->assertStringContainsString("The Safe Exam Browser keys could not be validated. "

            . "Check that you're using Safe Exam Browser with the correct configuration file.", $errormsg);

        $this->assertStringContainsString($this->get_seb_download_link(), $errormsg);

        $this->assertStringContainsString($this->get_seb_launch_link(), $errormsg);

        $this->assertStringContainsString($this->get_seb_config_download_link(), $errormsg);

        $events = $sink->get_events();

        $this->assertEquals(1, count($events));

        $event = reset($events);

        // Test that the event data is as expected.

        $this->assertInstanceOf('\quizaccess_seb\event\access_prevented', $event);

        $this->assertEquals('Invalid SEB config key', $event->other['reason']);

    }

    /**

     * Test access prevented if config key is invalid.

     */

    public function test_access_prevented_if_config_key_invalid(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = 'Broken config key';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->check_invalid_config_key();

    }

    /**

     * Test access prevented if config keys is invalid and using uploaded config.

     */

    public function test_access_prevented_if_config_key_invalid_uploaded_config(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_UPLOAD_CONFIG);

        $xml = file_get_contents(__DIR__ . '/fixtures/unencrypted.seb');

        $this->create_module_test_file($xml, $this->quiz->cmid);

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = 'Broken config key';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->check_invalid_config_key();

    }

    /**

     * Test access prevented if config keys is invalid and using template.

     */

    public function test_access_prevented_if_config_key_invalid_uploaded_template(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_TEMPLATE);

        $quizsettings->set('templateid', $this->create_template()->get('id'));

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = 'Broken config key';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->check_invalid_config_key();

    }

    /**

     * Test access not prevented if config key matches header.

     */

    public function test_access_allowed_if_config_key_valid(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access not prevented if config key matches header.

     */

    public function test_access_allowed_if_config_key_valid_uploaded_config(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_TEMPLATE);

        $quizsettings->set('templateid', $this->create_template()->get('id'));

        $quizsettings->save();

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access not prevented if config key matches header.

     */

    public function test_access_allowed_if_config_key_valid_template(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_UPLOAD_CONFIG);

        $xml = file_get_contents(__DIR__ . '/fixtures/unencrypted.seb');

        $this->create_module_test_file($xml, $this->quiz->cmid);

        $quizsettings->save();

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access not prevented if browser exam keys match headers.

     */

    public function test_access_allowed_if_browser_exam_keys_valid(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to require seb and save BEK.

        $browserexamkey = hash('sha256', 'testkey');

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_CLIENT_CONFIG); // Doesn't check config key.

        $quizsettings->set('allowedbrowserexamkeys', $browserexamkey);

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $browserexamkey);

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_REQUESTHASH'] = $expectedhash;

        $_SERVER['HTTP_USER_AGENT'] = 'SEB';

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access not prevented if browser exam keys match headers.

     */

    public function test_access_allowed_if_browser_exam_keys_valid_use_uploaded_file(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $browserexamkey = hash('sha256', 'testkey');

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_UPLOAD_CONFIG);

        $quizsettings->set('allowedbrowserexamkeys', $browserexamkey);

        $xml = file_get_contents(__DIR__ . '/fixtures/unencrypted.seb');

        $this->create_module_test_file($xml, $this->quiz->cmid);

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedbrowserkey = hash('sha256', $FULLME . $browserexamkey);

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_REQUESTHASH'] = $expectedbrowserkey;

        $expectedconfigkey = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedconfigkey;

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    public function test_access_allowed_if_access_state_stored_in_session(): void {

        global $SESSION;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CLIENT_CONFIG);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Check that access is prevented.

        $this->check_invalid_basic_header();

        $SESSION->quizaccess_seb_access = [$this->quiz->cmid => true];

        // Check access is now not prevented.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * A helper method to check invalid browser key.

     *

     * @param bool $downloadseblink Make sure download SEB link is present.

     * @param bool $launchlink Make sure launch SEB link is present.

     * @param bool $downloadconfiglink Make download config link is present.

     */

    protected function check_invalid_browser_exam_key($downloadseblink = true, $launchlink = true, $downloadconfiglink = true) {

        // Create an event sink, trigger event and retrieve event.

        $sink = $this->redirectEvents();

        // Check that correct error message is returned.

        $errormsg = $this->make_rule()->prevent_access();

        $this->assertNotEmpty($errormsg);

        $this->assertStringContainsString("The Safe Exam Browser keys could not be validated. "

            . "Check that you're using Safe Exam Browser with the correct configuration file.", $errormsg);

        if ($downloadseblink) {

            $this->assertStringContainsString($this->get_seb_download_link(), $errormsg);

        } else {

            $this->assertStringNotContainsString($this->get_seb_download_link(), $errormsg);

        }

        if ($launchlink) {

            $this->assertStringContainsString($this->get_seb_launch_link(), $errormsg);

        } else {

            $this->assertStringNotContainsString($this->get_seb_launch_link(), $errormsg);

        }

        if ($downloadconfiglink) {

            $this->assertStringContainsString($this->get_seb_config_download_link(), $errormsg);

        } else {

            $this->assertStringNotContainsString($this->get_seb_config_download_link(), $errormsg);

        }

        $events = $sink->get_events();

        $this->assertEquals(1, count($events));

        $event = reset($events);

        // Test that the event data is as expected.

        $this->assertInstanceOf('\quizaccess_seb\event\access_prevented', $event);

        $this->assertEquals('Invalid SEB browser key', $event->other['reason']);

    }

    /**

     * Test access prevented if browser exam keys do not match headers.

     */

    public function test_access_prevented_if_browser_exam_keys_are_invalid(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to require seb and save BEK.

        $browserexamkey = hash('sha256', 'testkey');

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_CLIENT_CONFIG); // Doesn't check config key.

        $quizsettings->set('allowedbrowserexamkeys', $browserexamkey);

        $quizsettings->save();

        // Set up dummy request.

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_REQUESTHASH'] = 'Broken browser key';

        $_SERVER['HTTP_USER_AGENT'] = 'SEB';

        $this->check_invalid_browser_exam_key(true, false, false);

    }

    /**

     * Test access prevented if browser exam keys do not match headers and using uploaded config.

     */

    public function test_access_prevented_if_browser_exam_keys_are_invalid_use_uploaded_file(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $browserexamkey = hash('sha256', 'testkey');

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_UPLOAD_CONFIG);

        $quizsettings->set('allowedbrowserexamkeys', $browserexamkey);

        $xml = file_get_contents(__DIR__ . '/fixtures/unencrypted.seb');

        $this->create_module_test_file($xml, $this->quiz->cmid);

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        // Set  up broken browser key.

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_REQUESTHASH'] = 'Broken browser key';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $this->check_invalid_browser_exam_key();

    }

    /**

     * Test access not prevented if browser exam keys do not match headers and using template.

     */

    public function test_access_prevented_if_browser_exam_keys_are_invalid_use_template(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb and save BEK.

        $browserexamkey = hash('sha256', 'testkey');

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_TEMPLATE);

        $quizsettings->set('allowedbrowserexamkeys', $browserexamkey);

        $quizsettings->set('templateid', $this->create_template()->get('id'));

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        // Set  up broken browser key.

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_REQUESTHASH'] = 'Broken browser key';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access allowed if using client configuration and SEB user agent header is valid.

     */

    public function test_access_allowed_if_using_client_config_basic_header_is_valid(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_CLIENT_CONFIG); // Doesn't check config key.

        $quizsettings->save();

        // Set up basic dummy request.

        $_SERVER['HTTP_USER_AGENT'] = 'SEB_TEST_SITE';

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access prevented if using client configuration and SEB user agent header is invalid.

     */

    public function test_access_prevented_if_using_client_configuration_and_basic_head_is_invalid(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_CLIENT_CONFIG); // Doesn't check config key.

        $quizsettings->save();

        // Set up basic dummy request.

        $_SERVER['HTTP_USER_AGENT'] = 'WRONG_TEST_SITE';

        // Create an event sink, trigger event and retrieve event.

        $this->check_invalid_basic_header();

    }

    /**

     * A helper method to check invalid basic header.

     */

    protected function check_invalid_basic_header() {

        // Create an event sink, trigger event and retrieve event.

        $sink = $this->redirectEvents();

        // Check that correct error message is returned.

        $this->assertStringContainsString(

            'This quiz has been configured to use the Safe Exam Browser with client configuration.',

            $this->make_rule()->prevent_access()

        );

        $events = $sink->get_events();

        $this->assertEquals(1, count($events));

        $event = reset($events);

        // Test that the event data is as expected.

        $this->assertInstanceOf('\quizaccess_seb\event\access_prevented', $event);

        $this->assertEquals('No Safe Exam Browser is being used.', $event->other['reason']);

    }

    /**

     * Test access allowed if using client configuration and SEB user agent header is invalid and use uploaded file.

     */

    public function test_access_allowed_if_using_client_configuration_and_basic_head_is_invalid_use_uploaded_config(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_UPLOAD_CONFIG); // Doesn't check basic header.

        $xml = file_get_contents(__DIR__ . '/fixtures/unencrypted.seb');

        $this->create_module_test_file($xml, $this->quiz->cmid);

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        $_SERVER['HTTP_USER_AGENT'] = 'WRONG_TEST_SITE';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access allowed if using client configuration and SEB user agent header is invalid and use template.

     */

    public function test_access_allowed_if_using_client_configuration_and_basic_head_is_invalid_use_template(): void {

        global $FULLME;

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        // Set quiz setting to require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_TEMPLATE);

        $quizsettings->set('templateid', $this->create_template()->get('id'));

        $quizsettings->save();

        // Set up dummy request.

        $FULLME = 'https://example.com/moodle/mod/quiz/attempt.php?attemptid=123&page=4';

        $expectedhash = hash('sha256', $FULLME . $quizsettings->get_config_key());

        $_SERVER['HTTP_X_SAFEEXAMBROWSER_CONFIGKEYHASH'] = $expectedhash;

        $_SERVER['HTTP_USER_AGENT'] = 'WRONG_TEST_SITE';

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test access not prevented if SEB not required.

     */

    public function test_access_allowed_if_seb_not_required(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set quiz setting to not require seb.

        $quizsettings = seb_quiz_settings::get_record(['quizid' => $this->quiz->id]);

        $quizsettings->set('requiresafeexambrowser', settings_provider::USE_SEB_NO);

        $quizsettings->save();

        // The rule will not exist as the settings are not configured for SEB usage.

        $this->assertNull($this->make_rule());

    }

    /**

     * Test access not prevented if USER has bypass capability.

     */

    public function test_access_allowed_if_user_has_bypass_capability(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        // Set the bypass SEB check capability to $USER.

        $this->assign_user_capability('quizaccess/seb:bypassseb', \context_module::instance($this->quiz->cmid)->id);

        // Check that correct error message is returned.

        $this->assertFalse($this->make_rule()->prevent_access());

    }

    /**

     * Test that quiz form cannot be saved if using template, but not actually pick one.

     */

    public function test_mod_quiz_form_cannot_be_saved_using_template_and_template_is_not_set(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'seb_requiresafeexambrowser' => settings_provider::USE_SEB_TEMPLATE

        ], [], $form);

        $this->assertContains(get_string('invalidtemplate', 'quizaccess_seb'), $errors);

    }

    /**

     * Test that quiz form cannot be saved if uploaded invalid file.

     */

    public function test_mod_quiz_form_cannot_be_saved_using_uploaded_file_and_file_is_not_valid(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'seb_requiresafeexambrowser' => settings_provider::USE_SEB_UPLOAD_CONFIG,

            'filemanager_sebconfigfile' => 0,

        ], [], $form);

        $this->assertContainsEquals(get_string('filenotpresent', 'quizaccess_seb'), $errors);

    }

    /**

     * Test that quiz form cannot be saved if the global settings are set to require a password and no password is set.

     */

    public function test_mod_quiz_form_cannot_be_saved_if_global_settings_force_quiz_password_and_none_is_set(): void {

        $this->setAdminUser();

        // Set global settings to require quiz password but set password to be empty.

        set_config('quizpasswordrequired', '1', 'quizaccess_seb');

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'seb_requiresafeexambrowser' => settings_provider::USE_SEB_CONFIG_MANUALLY,

        ], [], $form);

        $this->assertContains(get_string('passwordnotset', 'quizaccess_seb'), $errors);

    }

    /**

     * Test that access to quiz is allowed if global setting is set to restrict quiz if no quiz password is set, and global quiz

     * password is set.

     */

    public function test_mod_quiz_form_can_be_saved_if_global_settings_force_quiz_password_and_is_set(): void {

        $this->setAdminUser();

        // Set global settings to require quiz password but set password to be empty.

        set_config('quizpasswordrequired', '1', 'quizaccess_seb');

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'quizpassword' => 'set',

            'seb_requiresafeexambrowser' => settings_provider::USE_SEB_CONFIG_MANUALLY,

        ], [], $form);

        $this->assertNotContains(get_string('passwordnotset', 'quizaccess_seb'), $errors);

    }

    /**

     * Test that quiz form can be saved if the global settings are set to require a password and no seb usage selected.

     */

    public function test_mod_quiz_form_can_be_saved_if_global_settings_force_quiz_password_and_none_no_seb(): void {

        $this->setAdminUser();

        // Set global settings to require quiz password but set password to be empty.

        set_config('quizpasswordrequired', '1', 'quizaccess_seb');

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_NO);

        $form = $this->createMock('mod_quiz_mod_form');

        $form->method('get_context')->willReturn(\context_module::instance($this->quiz->cmid));

        // Validate settings with a dummy form.

        $errors = quizaccess_seb::validate_settings_form_fields([], [

            'instance' => $this->quiz->id,

            'coursemodule' => $this->quiz->cmid,

            'seb_requiresafeexambrowser' => settings_provider::USE_SEB_NO,

        ], [], $form);

        $this->assertNotContains(get_string('passwordnotset', 'quizaccess_seb'), $errors);

    }

    /**

     * Test get_download_seb_button, checks for empty config setting quizaccess_seb/downloadlink.

     */

    public function test_get_download_seb_button(): void {

        $this->setAdminUser();

        $this->quiz = $this->create_test_quiz($this->course, settings_provider::USE_SEB_CONFIG_MANUALLY);

        $user = $this->getDataGenerator()->create_user();

        $this->setUser($user);

        $reflection = new \ReflectionClass('quizaccess_seb');

        $method = $reflection->getMethod('get_download_seb_button');