Using both starttls and ssl in passdb on proxy results in timeouts

[Filias Heidt]

Hi List,

I have a dovecot which proxies to different backends depending on an entry in a mysql-database. The mysql-query sets ‚ssl‘ to ‚any-cert‘ and this works fine. But this causes me a problem: sieve-backends only support STARTTLS and if I set ‚ssl‘ to ‚any-cert‘ (or yes), it will attempt a TLS-connection to the sieve-backends, which fails. 

My attempt was to alter the query to include %{real_lport} and return ‚ssl=no‘ and ‚starttls=any-cert‘ if the port matches the sieve-port. It works as expected in that it returns the correct values and proxies to the correct backend. 

However it seems that TLS is no longer working and I get timeouts from the backends.

Debug: client passdb out: OK	1	user=someuser at example.com	proxy	proxy_nopipelining=y	host=backend1.example.com	nodelay=y	nologin	starttls=no	ssl=any-cert	hostip=so.me.i.p	pass=<hidden>

results in:
Sep 17 11:08:47 imapproxy1 dovecot: imap-login: Error: proxy(someuser at example.com): Login for so.me.i.p:993 timed out in state=/none (after 30 secs, local=lo.cal.i.p:60524): user=<someuser at example.com>, method=PLAIN, rip=re.mo.te.ip, lip=lo.cal.i.p, TLS, session=<OySXgw12auwgARYIAAYABwAAAAAAAwAU>

My query looks like this:
password_query = SELECT host from proxy_domain, NULL as password, 'y' as nopassword, 'y' as proxy, NULL as destuser, 'y' as proxy_nopipelining, 'y' as nodelay, 'y' as nologin, IF(%{real_lport}=4190, 'any-cert', 'no') as 'starttls', IF(%{real_lport}<>4190, 'any-cert', 'no') as 'ssl‘;

As soon as I remove the starttls-part and the passdb only returns ssl=any-cert (without starttls=no) it works flawlessly.

Is it possible that I am attacking the problem the wrong way? Or is it not possible to set both starttls and ssl to some values in passdb and enable/disable them as needed? 

Thanks for any input :)

Cheers,
Filias