v2.2.20 release candidate released

[Gerhard Wiesinger]

On 06.12.2015 13:10, Timo Sirainen wrote:
> On 05 Dec 2015, at 11:32, Gerhard Wiesinger <lists at wiesinger.com> wrote:
>> Is it possible to configure the secure session caching mechanism?
>> e.g. like in nginx: https://bjornjohansen.no/optimizing-https-nginx
> I remember hearing about various security vulnerabilities in that earlier.. I guess they're fixed now then, unless people find more ways to exploit it. Anyway I'm not sure how useful it would actually even be for most IMAP/POP3 servers, because most clients don't connect all that often. Or I guess it might help some clients that create multiple connections immediately.
>
> Then again, we are planning on adding some HTTP(S)-based services to Dovecot and there it would likely be more useful. So I guess it gets implemented at some point.
>
>

Session tickets are broken by DESIGN as they violate PFS (Perfect 
Forward Secrecy). If you can steal one AES key (all session tickets are 
encrypted for server lifetime with only one key) you can decrypt ALL 
sessions ever made with session tickets for the future. This violates 
PFS (Perfect Forward Secrecy) as only server side "parameters" are 
relevant from now on.

Yes, session caching should reduce server load on multiple connections.

See e.g. https://community.qualys.com/thread/15768

Therefore it would be great if you could implement the secure session 
caching mechanism.

As Gedalya mentioned OCSP would be great, too.

Ciao,
Gerhard