Re: [idn] IDN eamples for testing

["James Seng" <jseng@pobox.org.sg>]

> Can you elaborate? How does this break anything? They respond to
> strictly erroneous requests, with erroneous responses. I can't see
> how this could cause failures of other participants of the DNS.

Two wrong dont make it right. Nothing in RFC 1034 & 1035 mention the DNS
should response error with error.

> So, I *could* interpret RFC 2616 as defining how to handle
> specification of charsets, as it is "MIME-like". Therefore, I infer that
> sending
>
> MIME-Version: 1.0
> Host: =?iso-8859-1?q?www=2Ebrav=E5=2Enu?=
>
> is conforming to both RFC 3490 and RFC 2616.

According to RFC 2616, the BNF for Host header is as follows:

    Host = "Host" ":" host [ ":" port ]

And "host" is adopted from RFC 2396,

      host          = hostname | IPv4address
      hostname      = *( domainlabel "." ) toplabel [ "." ]
      domainlabel   = alphanum | alphanum *( alphanum | "-" ) alphanum
      toplabel      = alpha | alpha *( alphanum | "-" ) alphanum

So by this definition, a header like "Host:
=?iso-8859-1?q?www=2Ebrav=E5=2Enu?=" is not conforming to RFC 2616.

-James Seng