Consider allowing for authenticaion

[mdavids]

Maybe something like:

./dog -H @https://doh:[email protected]/dns-query example.nl

Albeit this method is deprecated as per RFC3986, par. 3.2.1, so perhaps "-u doh -p BeGentle" would be the better approach.

[ogham]

I did consider this, but didn't think there'd be any DoH servers that required authentication. Of course, over time, I guess there would be.

My preference would actually be to embed the credentials in the URL, even though doing that is deprecated, as you say. Providing a username and password is only appropriate for the HTTPS transport, where you have to pass a URL anyway, and they'll be by far the less-used option compared to not providing any, so I'd rather avoid adding two whole new top-level command-line arguments for this case. At some point, dog will switch to the url crate for URL parsing, so we'll essentially get this functionality "for free" in a way.

(I suppose we'd also have to handle HTTP 401 with a friendlier error message when implementing this).