Per-protocol ssl_protocols settings

[Felix Zandanel]

I performed a quick test and it seems that the "ssl_protocols" setting is per-IP only and shared among all listeners defined for that address.  As you want this setting to be active for one specific "inet_listener" only (with port 10995 in your case), dovecot would have to permit the "ssl_protocols" directive in that scope, which it doesn’t.

As a workaround I suggest using a special, unused loopback address to which you can apply the distinct SSL settings. You could use iptables/NAT to forward all incoming traffic originating from your external IP on port 10995 to 127.0.0.2:10995 for example. Then configure the POP3 service with an "inet_listener" for 127.0.0.2:10995 and use the "local" directive to set up the SSL protocols without touching global settings:

local 127.0.0.2 {
   ssl_protocols = !SSLv2
}

Regards,
Felix Zandanel


> Am 09.02.2015 um 11:33 schrieb Gionatan Danti <g.danti at assyoma.it>:
> 
> Sorry for the bump...
> 
> Anyone know if it is possible to have multiple protocols instances with different ssl_protocols settings?
> 
> Regards.
> 
> On 07/02/15 00:03, Gionatan Danti wrote:
>> Hi all,
>> anyone with some ideas?
>> 
>> Thanks.
>> 
>> Il 2015-02-02 23:08 Gionatan Danti ha scritto:
>>> Hi all,
>>> I have a question regarding the "ssl_protocols" parameter.
>>> 
>>> I understand that editing the 10-ssl.conf file I can set the
>>> ssl_protocols variable as required.
>>> At the same time, I can edit a single protocol file (eg: 20-pop3.conf)
>>> to set the ssl_protocols for a specific protocol/listener.
>>> 
>>> I wander if (and how) I can create a different listener for another
>>> POP3 instance, for example listening on port 10995, and using another
>>> ssl_protocol setting.
>>> 
>>> In short, I would like to create a different, firewalled pop3s service
>>> enabling the SSLv3 stack, while disabling it at system-wide settings.
>>> 
>>> I am able to successfully create a new listener for port 10995, but I
>>> don't understand how to associate the ssl_protocols value to the new
>>> listener. Simply putting the ssl_protocols value into the listener
>>> section give me a configuration error.
>>> 
>>> Thank you all.
>> 
> 
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> Danti Gionatan
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