Wifi connections with unsupported TLS protocols should be handled better

[Jrelvas]

first time poster, hope im not posting something too catastrophically bad

It’s 2023. TLS 1.0 is considered outdated and no longer allowed by default in the Linux desktop (and rightfully so).

Unfortunately, not every sysadmin is living in the same year as us. Today, I had to connect to my school’s institutional network.

Seems pretty simple right? Just a simple wpa-enterprise connection.

Wrong. For some inexplicable reason, phase 1 auth is still done entirely with TLS 1.0. Windows, Android and iOS are still accepting a TLS version this old, but that’s not the case with Fedora, preventing a connection from being made.

The issue is pretty simple. The authentication fails, but the user interface handles the failure generically; it retries three times, then (sometimes) prompts the user to provide their credentials again. This behaviour is pretty bad because it makes the user think that their credentials are wrong, instead of letting them know what the actual issue is.

It’s possible to identify the issue by checking the system’s logs, but you need to know what you’re looking for. (SSL unsupported protocol)

You can then manually configure NetworkManager to accept TLS 1.0 (just on the offending network) with the nmcli utility.

Although the issue can be fixed, the way you go around it is very user unfriendly, especially when you consider that users on other operating systems are able to connect without making any changes to the configuration.
Some options, including allowed TLS protocols, are not exposed graphically and are generally only editable via nmcli, and, in some cases, editing the connection’s configuration via settings actually resets these flags, requiring another visit to nmcli.

In the short term, I believe that the user should simply be prompted when their connection is using an incompatible TLS protocol. Even if no way to rectify the issue graphically is given, simply being aware of what you’re actually supposed to be looking at would be extremely helpful.

Long-term, the number of network options available graphically in settings should be increased. I believe that a simple “Allow legacy encryption standards (Unsafe)” toggle would suffice, but there’s probably a smarter way to do it in terms of UX.

[mcatanzaro (Michael Catanzaro)]

@Jrelvas

Long-term, the number of network options available graphically in settings should be increased. I believe that a simple “Allow legacy encryption standards (Unsafe)” toggle would suffice, but there’s probably a smarter way to do it in terms of UX.

I don’t think it makes sense to add this UI unless there are really a very large number of networks still using TLS 1.0, which seems unlikely because I’ve never seen anybody complain about this before until now. But I agree the error reporting should be way better.

[mcatanzaro (Michael Catanzaro)]

BTW:

• Fedora requires that all applications use the system crypto policy as the base policy, but it’s possible for applications to append additional policy. That is, if NetworkManager were to decide that supporting TLS 1.0 is still important, it could choose to do so.
• Only Fedora-ecosystem distros use system crypto policy because it’s implemented via downstream patches. Fedora’s policy is generally much stricter than upstream defaults. It’s possible other distros still allow TLS 1.0; not sure.

[Jrelvas]

@mcatanzaro

I don’t think it makes sense to add this UI unless there are really a very large number of networks still using TLS 1.0

Hmm… right. I’d personally try to ensure all networks which are accepted by other operating systems don’t require too much hassle, but well… this is the definition of a edge case; my school’s IT is well below average, even for “public high school” standards.

@mcatanzaro

Fedora requires that all applications use the system crypto policy as the base policy, but it’s possible for applications to append additional policy. That is, if NetworkManager were to decide that supporting TLS 1.0 is still important, it could choose to do so.

That’s correct. Funnily enough, this isn’t the first time I ran into this issue (I just got a rude reminder today, which prompted me to post here). At the time, Fedora 37’s version of NetworkManager did not have any flags for enabling TLS versions, just for disabling… which would’ve forced me to open the can of worms that is crypto policy configuration. Luckily, Fedora 38 Beta had an updated version of NetworkManager, so I picked my poison and lived on the bleeding edge for a few days until the official release.