#141 SEB 2.4.1 and Moodle 3.9.2+, browser keys could not be validated

[José Luis Ramírez]

Hello.

For reasons that are out of my control, I need to use SEB 2.4.1 for its Windows 7 compatibility. I configured one quiz with SEB turned on (manual settings; everything as default). My test machine has Windows 10 and SEB 2.4.1.

When opening the quiz config file, the quiz page shows this error:

The config key or browser keys could not be validated. Please ensure you are using the Safe Exam Browser with correct configuration file

Basically the same as this post:
https://moodle.org/mod/forum/discuss.php?d=410539

When using SEB 3.0.1, I can access the quiz with no problems.

Moodle was fleshly installed, with minimal customization, no other plugins installed.

Thanks!

[Daniel Schneider]

SEB 3.0.1 should also be compatible with Windows 7. We will try to reproduce the issue with SEB 2.4.1 and Moodle 3.9.2. I guess this only happens with 3.9.2, as it was tested and working with 3.9.0 (and I think 3.9.1).

[Daniel Schneider]

Other users reported the issue also happening with Moodle 3.9 (as long as they got the version right).

Can you provide us with a testing access to a Moodle quiz (you could create some simple placeholder quiz) where this happens? If we cannot reproduce the issue, then we cannot solve it.

[José Luis Ramírez]

Hi, Daniel.

We're between server changes right now. Maybe I can setup a new server for you later.

I made a test quiz in the Moodle Sandbox and it behaved the same way. The quiz will be removed in an hour, so maybe you can create one for testing purposes if it's removed by the time you see this.

https://sandbox.moodledemo.net/mod/quiz/view.php?id=4

Username: student
Password: sandbox

It fails with SEB 2.4.1.

[Daniel Schneider]

Try to temporarily switch off anti-malware software which is scanning internet traffic. Or are you using some special network/internet system configuration, for example a proxy?

When Moodle is checking the Config Key (or Browser Exam Key) send by a SEB client, then the URL of each HTTP request is used on both sides hashed with those keys. If some network configuration or maybe a anti-malware feature would modify the URL in HTTP requests and the URL would't be identical on the Moodle server and the SEB clients, then that would cause such an error you're discribing.

[José Luis Ramírez]

I did some tests on a new Windows 10 laptop with only chrome and office installed. No proxy configuration, nor any other networking software. Used regular home wifi and cellular data connectivity on a simple one question quiz I setup in the Moodle sandbox page.

1. On home wifi, Windows firewall on and SEB 2.4.1: failed.

2. On home wifi, Windows firewall off and SEB 2.4.1: failed.

3. On cellular data, Windows firewall off and SEB 2.4.1: failed.

4. On home wifi, Windows firewall on and SEB 3.0.1: success.

5. On home wifi, Windows firewall off and SEB 3.0.1: success.

6. On cellular data, Windows firewall off and SEB 3.0.1: success.

The failed attemps showed the key could not be validated error message.

The successful attemps let me enter the quiz.

[Daniel Schneider]

I still couldn't reproduce the issue here, with the Moodle 3.9.2 sandbox and SEB 2.4.1, in my case it works as expected. I couldn't use manual settings though, as I have only a virtual machine here for testing and therefore have to upload my own config with allowVirtualMachine = true. Could you try it with "upload my own config" as well?

[José Luis Ramírez]

Thanks, Daniel.

Sadly, it didn't work with "upload my own config." Still the same error.

I'll keep testing things and see if I can resolve it.

Cheers!

[Daniel Schneider]

Really weird that it works for me, are you sure you're not using some anti-malware software which is scanning internet traffic?

[José Luis Ramírez]

[Daniel Schneider]

The test you have online is using a config file with a wrong key in it, that is most likely creating the issue with the config key:

<key>allowWlan</key>
<false />
<key>allowWLAN</key>
<false />

The allowWLAN key is wrong, only allowWlan should be used.

This doesn't explain though why "Yes – configure manually" would not work, because there only the correct allowWlan key would be included in the config.

[Daniel Schneider]

Btw. the reason this wrong key is in the config file is that we shortly had an SEB version which was using this wrong key. Config files created with that version will just keep the wrong key inside and add the correct one. I don't follow that recommendation myself, but from time to time it would be good to reset SEB settings to default settings and then set the according settings freshly. Then you're sure you have clean settings.