Encoding (was Re: API tweak request)

On Mon, 2 Nov 2009, John Engelhart wrote:

> Which reminds me: Just what is the encoding for the strings that
> ares_expand_name() and ares_expand_string() return? I haven't dug that deep
> in to the DNS RFC's at this point to dig out the official answer. Anyone
> know off the top of their head? Or any pointers for dealing with
> "non-ASCIIish" stuff in DNS replies?

DNS is purely ASCII.

When speaking "non-ASCII", as in IDN (International Domain Names) the names
are then encoded into an ascii form (punycode - RFC3492) before the lookup is
made. In c-ares land we assume the ASCII form only, and any encoding to
punycode would be done outside.

libidn (http://www.gnu.org/software/libidn/) is a free software library that
provides such encoding.

-- 
  / daniel.haxx.se