Certain private keys being mangled by wg on FreeBSD

[Jason A. Donenfeld]

On 6/6/21, Christian McDonald <rcmcdonald91 at gmail.com> wrote:
> Would it not be better for wg to just fail outright instead of
> transforming a poorly generated key entered by a user, regardless of
> where the key came from? Especially if that problematic key passes the
> regex validation that was provided in another thread in this email
> list?

No, it would not be better. There is nothing wrong with using those
keys. They're not "poorly generated" or "problematic" or dangerous in
the least. This is only a concern with your UI.

The kernel is doing the correct thing -- clamping keys -- and
displaying an unambiguous identifier to the user: the key that it will
actually be using.

I suspect the best thing to do for your UI would be to hide private
(and preshared) keys, and only show public keys, unless explicitly
exported into a config file. This not only reduces potential confusion
with this issue, but mitigates another potential footgun down the
line. It's also what wg(8)'s show command does by default (while
showconf will export all).