[Dovecot] compressed IMAP traffic

[Patrick Domack]

The command I used was:

gnutls-cli --protocols NORMAL:+COMP-DEFLATE --insecure -p 993

I have tried the --comp option, but it always fails for me (ubuntu 8.04)

gnutls-cli (GnuTLS) 2.0.4

Redhat is 5.3
Freebsd is 6.3


Quoting Leonardo Rodrigues <leolistas at solutti.com.br>:

> Timo Sirainen escreveu:
>>
>> And DEFLATE gives the exact same error? LZO isn't supported by OpenSSL.
>>
>>
>    yes ... error from DEFLATE and LZO are exactly the same on
> gnutls-cli output and maillog on the CentOS 5.3 box.
>
>> Well, not the same server but looks like this one works too:
>>
>> gnutls-cli --priority NORMAL:+COMP-DEFLATE -p 993 secure.emailsrvr.com
>>
>> And just for fun I tried imap.gmail.com, that didn't support
>> compression.
>>
>
>    i had tried imap.gmail.com too :)
>
>    interesting findings ..... from CentOS 5.3, i cant get any
> compression method to work:
>
> [root at correio dovecot]# gnutls-cli --insecure -p 993 -p 993
> secure.emailsrvr.com --comp LZO DEFLATE NULL [ ......]
> - Version: TLS 1.0
> - Key Exchange: DHE RSA
> - Cipher: AES 256 CBC
> - MAC: SHA
> - Compression: NULL
>
>    but from a Fedora 8 box:
>
> [root at correio ~]# gnutls-cli --insecure -p 993 -p 993
> secure.emailsrvr.com --comp LZO DEFLATE NULL
> [ ......]
> - Version: TLS 1.0
> - Key Exchange: DHE RSA
> - Cipher: AES 256 CBC
> - MAC: SHA
> - Compression: DEFLATE
>
>
>    and Fedora 8 OpenSSL is even older than CentOS 5.3 one:
>
> CentOS 5.3:
> [root at correio dovecot]# rpm -qi openssl
> Name        : openssl                      Relocations: (not relocatable)
> Version     : 0.9.8e                            Vendor: CentOS
> Release     : 12.el5                        Build Date: Fri 04 Sep 2009
> 09:33:56 AM BRT
>
> Fedora 8:
> [root at correio ~]# rpm -qi openssl
> Name        : openssl                      Relocations: (not relocatable)
> Version     : 0.9.8b                            Vendor: Fedora Project
> Release     : 17.fc8                        Build Date: Mon 15 Oct 2007
> 07:56:22 PM BRST
>
>    probably there's some build option on CentOS that is disabling
> compression. If 0.9.8b on Fedora8 built in October/2007 can do it, so
> 0.9.8e on CentOS 5.3 built on September/2009 should be able to do it
> too ....... oh boy, i really hate those weirds compilation options from
> Redhat  .... :\
>
> -- 
>
>
> 	Atenciosamente / Sincerily,
> 	Leonardo Rodrigues
> 	Solutti Tecnologia
> 	http://www.solutti.com.br
>
> 	Minha armadilha de SPAM, NÃO mandem email
> 	gertrudes at solutti.com.br
> 	My SPAMTRAP, do not email it