dovecot - Jun 2017 - Auth Policy Server

I've made a preliminary auth policy server in Perl - and it sort of 
works (mostly) - but I've got some questions on "proper"
implementation.

It appears the communication is HTTP based - is the intent to talk to a 
"proper" webserver, or is a simple dedicated daemon appropriate (which
is what I made)?

Should connections be maintained, or terminated after each response 
(which is my current setup)?

If my implementation is correct, I may have found a bug, as I have some 
log entries like:

Jun 30 08:24:20 bubba dovecot: imap-login: Warning: Auth connection 
closed with 1 pending requests (max 31 secs, pid=10253, EOF)
Jun 30 08:24:20 bubba dovecot: auth: Fatal: master: service(auth): child 
31631 killed with signal 11 (core dumped)

Guidance would be appreciated.

-- 
Daniel

> On June 30, 2017 at 9:49 PM Daniel Miller <dmiller at amfes.com>
wrote:
> 
> 
> I've made a preliminary auth policy server in Perl - and it sort of 
> works (mostly) - but I've got some questions on "proper"
implementation.
> 
> It appears the communication is HTTP based - is the intent to talk to a 
> "proper" webserver, or is a simple dedicated daemon appropriate
(which
> is what I made)?
> 
> Should connections be maintained, or terminated after each response 
> (which is my current setup)?
> 
> If my implementation is correct, I may have found a bug, as I have some 
> log entries like:
> 
> Jun 30 08:24:20 bubba dovecot: imap-login: Warning: Auth connection 
> closed with 1 pending requests (max 31 secs, pid=10253, EOF)
> Jun 30 08:24:20 bubba dovecot: auth: Fatal: master: service(auth): child 
> 31631 killed with signal 11 (core dumped)
> 
> Guidance would be appreciated.
> 
> -- 
> Daniel
Hi!

First of all, which version are you running, and can you get a bt full backtrace
of the crash?

Secondly, the endpoint does not need to be a proper web server, you can compare
with https://github.com/PowerDNS/weakforced which is another implementation of
auth policy server.

Aki

On 6/30/2017 12:05 PM, Aki Tuomi wrote:
>> On June 30, 2017 at 9:49 PM Daniel Miller <dmiller at amfes.com>
wrote:
>>
>>
>> I've made a preliminary auth policy server in Perl - and it sort of
>> works (mostly) - but I've got some questions on "proper"
implementation.
>>
>>
> Hi!
>
> First of all, which version are you running, and can you get a bt full
backtrace of the crash?
>
> Secondly, the endpoint does not need to be a proper web server, you can
compare with https://github.com/PowerDNS/weakforced which is another
implementation of auth policy server.
>
> Aki
That link helped a lot - among other things forcing me to read.  I 
actually broke my policy server trying to "improve" it - I implemented
a
30-second auth delay on valid logins!  Setting that back to 0 seems to 
do the trick...

I running Dovecot 2.2.28.  For the bt - I'll be happy to if still 
desired, but you'll have to give me instructions as I don't know how.

As I continue tweaking this, if there's any interest I'll see about 
sharing this.  For my own needs I wanted a GeoIP based policy.  My 
thinking, skewed as it is, is that while SMTP needs to be relatively 
open - as I have friends & business contacts in other countries - the 
only people who access my IMAP server are somewhere in my country.  
Therefore, simply restricting login attempts to only be from IP's in my 
country will block the majority of botnets (at least, that's what I 
think I'm seeing from my logs).

Daniel