Re: Dnsdir last call review of draft-ietf-httpbis-alias-proxy-status-05

> On Oct 16, 2023, at 10:50 AM, Rory Hewitt <rory.hewitt@gmail.com> wrote:
> 
> Hopefully not too late to bring this up, and it's really just a nit...
> 
> At the end of Section 2.1 in https://www.ietf.org/archive/id/draft-ietf-httpbis-alias-proxy-status-05.html, there is this:
> 
> It is also possible for a DNS name to include a period character (".") within a label, instead of as a label separator. In this case, the period character MUST be first escaped as "\.". Since the "\" character itself will be percent-encoded, the name "dot\.label.example.com <http://label.example.com/>" would be encoded within a next-hop-aliases parameter as follows:
> 
> Proxy-Status: proxy.example.net <http://proxy.example.net/>; next-hop="2001:db8::1";
>     next-hop-aliases="dot%5C.label.example.com <http://5c.label.example.com/>,service1.example.com <http://service1.example.com/>"
> Upon parsing this name, "dot%5C.label" MUST be treated as a single label.
> 
> Similarly the "\" character in a label MUST be escaped as "\\". Other uses of "\" MUST NOT appear in the label after percent-decoding.
> 
>  <https://www.ietf.org/archive/id/draft-ietf-httpbis-alias-proxy-status-05.html#section-2.1-4>
>  <https://www.ietf.org/archive/id/draft-ietf-httpbis-alias-proxy-status-05.html#section-2.1-5>
>  <https://www.ietf.org/archive/id/draft-ietf-httpbis-alias-proxy-status-05.html#section-2.1-6>
> Can that last line be expounded on and clarified? Will a "\" character in a label be 'eventually' encoded as "\\" or "%5C%5C" or some combination of them?
> 

> Rory
> 

Yes, we could give an example to show the encoded “%5C%5C”. I’ve filed https://github.com/httpwg/http-extensions/issues/2665.

Thanks,
Tommy