[Dovecot] SSL + compression?

Benjamin R. Haskell dovecot at benizi.com
Fri Jun 20 23:48:22 EEST 2008

On Fri, 20 Jun 2008, Johannes Berg wrote:

>>>> I don't think it does be default. The only what I know is to establish
>>>> a compressed SSH tunnel to your server and then access the server over
>>>> the tunnel. It will compress and give you an extra layer of encryption.
>>> Umm, no. It will not compress. Think about it, encrypted data is
>>> fundamentally not compressible, that's the whole point.
>> [...me...]
> Well, as far as I understood Marc, since he was saying "an extra layer 
> of encryption" I understood him to mean that he wanted to
> encrypt(compress(encrypt(imap stream)))
> by building an ssh-tunnelled imaps (or imap/tls) connection. IOW, 
> dovecot would see an SSL connection too.

Hmm, yes. I took it to mean that the 'encrypt' of

encrypt(compress(imap stream))

was the "extra layer". But, I think your interpretation is more easily 
arrived at, and if it's what Mark meant, you're absolutely right that the 
tunnel won't help.

A compressed SSH tunnel to regular, non-SSL IMAP should work to reduce 
traffic, though.


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