GNUTLS compression

[Handi Ajimasta]

Hi all,

I installed gnutls 2.5.5 in Windows XP, and gnutls 2.8.4 in Windows 7
Release Candidate from http://josefsson.org/gnutls4win/ .

I thought that 'DEFLATE' compression algorithm is enabled by default in
all gnutls releases. However, when I force my TLS client to use DEFLATE
algorithm (and not the NULL) by:

int pPriorities[3] = {GNUTLS_COMP_DEFLATE, 0};
gnutls_compression_set_priority(session, pPriorities);

My TLS client is not able to handshake with the server, because the
compression algorithm is not available.

When I did a 'gnutls-cli -l' in command prompt in both Windows XP and
Windows 7, what I saw was: "COMPRESSION: NULL" only, without DEFLATE nor
LZO algorithm.


I successfully installed gnutls in an Ubuntu machine though, and when I
did 'gnutls-cli -l' I could see that it has both DEFLATE algorithm and
NULL there without me configuring anything at all.

My questions are:
1) Is compression available for gnutls in Windows?
2) If it's yes.. how do I enable it?
3) If it's not available.. is there any way that I could enable it?
4) Is there any performance gain from enabling the compression? I
understand that we might save some bandwidth with the compression, but
with increased lag time, is there any noticeable difference?


Thanks in advance for any help given.


Regards,
Handi

Institute for Infocomm Research disclaimer:  "This email is confidential and 
may be privileged. If you are not the intended recipient, please delete it and 
notify us immediately. Please do not copy or use it for any purpose, or 
disclose its contents to any other person. Thank you."