> Well, since I'm not an SSL layer expert maybe you should first make sure that
> a small application that uses GnuTLS directly still works fine when
> connecting/handshaking with this site? I mean to just first make sure that the
> error is in how libcurl uses GnuTLS and nothing else

You are actually right. I made 2 simple clients one with OpenSSL
another with GnuTLS. While OpenSSL version works fine, GnuTLS fails
right after the handshake. We should investigate the server side. Big
thanks for the tip.

--
Sergey Gerasimenko