Customize hostname check to allow also wildcard certificates

[imsoulfly]

Hello everyone,

I already wrote one solution that I took over from the mint library to activate validation of wildcard certificates with the now stricter Erlang TLS handling in the issue here: #797

But I actually was able to find a better solution of using the wildcard hostname verification directly from the
public_key Erlang module that does to knowledge exactly the same.

Disclaimer: I did manual testing of this but wasn't really able to come up with how to actually test this. Speaking of having a proper test setup that provides a server with wildcard certificate for its domain. If you know a way let me know. For now I can only deliver this 😄

Have a nice day!

[imsoulfly]

Ok I already see that I should provide a fallback for older Erlang versions.

[ericmj]

Can you take a look at this @voltone since you created the original PR for mint?

[imsoulfly]

Hi @voltone, just had time to apply your change requests. Hope that fits and I understood you correctly with regards to the reuse of the VerifyHostname implementation? I now added the a slightly changed match_fun/2 function directly in that module which just makes use of the already existing function for matching the hostnames.

[voltone]

Yes, I think that cleans things up nicely. Thanks!

[ericmj]

Thank you @imsoulfly and @voltone! 💜