Dovecot can't connect to openldap over starttls [REQUEST OF OPENLDAP]

[Aki Tuomi]

Did you do some succesful lookup with something there? I can see few failed attempts and one that seems to have worked just fine.

As pointed out earlier, are you using security frameworks like SELinux or AppArmor? Also, can you provide namei -l /etc/ssl/certs/LetsEncrypt.pem

The failed attempts are really short, indicating a VERY early problem with SSL handshake.

Aki

> On March 20, 2017 at 9:24 PM info at gwarband.de wrote:
> 
> 
> I have a new pcap from beginning to the end with openldap "TLS 
> negoiation failed"
> 
> https://gwarband.de/openldap/tracefile.dump
> 
> The sourceports are 45376 and 45377
> 
> Tobias
> 
> Am 2017-03-20 19:59, schrieb Aki Tuomi:
> > Well, those actually *reduce* the possible algorithms that can be
> > used, so uncommenting those can make things worse.
> > 
> > Anyways, your pcap seems incomplete, can you try again?
> > 
> > Aki
> > 
> >> On March 20, 2017 at 8:14 PM info at gwarband.de wrote:
> >> 
> >> 
> >> I have also tested with 2.2.28 and this version has the same issue.
> >> 
> >> The finding of compatible ciphers is not the problem because I have
> >> uncommented the ldap entrys:
> >> TLSCipherSuite
> >> SECURE128:-ARCFOUR-128:-CAMELLIA-128-CBC:-3DES-CBC:-CAMELLIA-128-GCM
> >> TLSProtocolMin          3.1
> >> 
> >> Maybe you have further ideas.
> >> 
> >> Am 2017-03-20 17:42, schrieb Aki Tuomi:
> >>>> On March 20, 2017 at 5:28 PM info at gwarband.de wrote:
> >>>> 
> >>>> 
> >>>> Can sombody say something about this request?
> >>>> 
> >>>> This is an email from the openldap-technical mailinglist from
> >>>> openldap.
> >>>> 
> >>>> Systemdetails are mention in the other email.
> >>>> 
> >>>> -------- Originalnachricht --------
> >>>> Betreff: Re: Dovecot can't connect to openldap over starttls
> >>>> Datum: 2017-03-20 16:18
> >>>> Absender: Dan White <dwhite at cafedemocracy.org>
> >>>> Empfänger: info at gwarband.de
> >>>> Kopie: openldap-technical at openldap.org
> >>>> 
> >>>> On 03/20/17 16:06 +0100, info at gwarband.de wrote:
> >>>>>> Debug Dovecot's implementation of ldap_start_tls_s().
> >>>>> I don't have any idea how to set a higher debug level to dovecot. 
> >>>>> In
> >>>>> my opinion I have the highest. So I can't deliver a greater log.
> >>>> 
> >>>> I recommend consulting Dovecot's advice on how to run a debugger, 
> >>>> or
> >>>> dig
> >>>> into the code which calls libldap.
> >>> 
> >>> Hi!
> >>> I just ran a quick test, and following things are needed:
> >>> 
> >>> uris = ldap://ldap.host.com
> >>> tls = yes
> >>> tls_ca_cert_file = /path/to/cert-bundle.crt
> >>> 
> >>> this has been tested with 2.2.28, and works just fine. Not sure why
> >>> you are having issues.
> >>> 
> >>> Of course this could be anything between not finding compatible
> >>> ciphers to the LDAP server actually expecting client certificate, 
> >>> what
> >>> with the logs not actually being too verbose unfortunately. There
> >>> isn't too much to "debug" in Dovecot's TLS implementation, it's not
> >>> doing anything fancy asides from calling the ldap_start_tls_s.
> >>> 
> >>> I am not sure what debugging you could try further.
> >>> 
> >>> Aki