Alexander Chekalin
2018-Sep-17 10:59 UTC
Proxy secured incoming POP3/IMAP4 to unsecure backend?
Hi, I try to set up dovecot as a proxy server, to proxy requests to several dovecot-based backend servers. I wand external clients who connects to this proxy Dovecot to use TLS (this is easy to set up) while want to have unsecured (plain IMAP/POP) connections to backends. You see, links to backends are over LAN so no TLS needed, and these backends are poor old machines (with old Docecots like 2.0.6) this is why I don't want to use TLS to acces backends. But as I did the test setup I can see proxy Dovecot uses TLS to connect to backends. Is there any way I can specify this aspect of Dovecot proxy? Please advice! Yours, Alexander -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://dovecot.org/pipermail/dovecot/attachments/20180917/b233e80d/attachment.html>
On 17.09.2018 13:59, Alexander Chekalin wrote:> Hi, > > I try to set up dovecot as a proxy server, to proxy requests to > several dovecot-based backend servers. I wand external clients who > connects to this proxy Dovecot to use TLS (this is easy to set up) > while want to have unsecured (plain IMAP/POP) connections to backends. > > You see, links to backends are over LAN so no TLS needed, and these > backends are poor old machines (with old Docecots like 2.0.6) this is > why I don't want to use TLS to acces backends. > > But as I did the test setup I can see proxy Dovecot uses TLS to > connect to backends. Is there any way I can specify this aspect of > Dovecot proxy? > > Please advice! > > Yours, > ? AlexanderDovecot does not use TLS/SSL when connecting to a backend server by default, you are probably specifying this in your proxy config or password database. Aki
> On Sep 17, 2018, at 6:59 AM, Alexander Chekalin <alexander.chekalin at gmail.com> wrote: > > Hi, > > I try to set up dovecot as a proxy server, to proxy requests to several dovecot-based backend servers. I wand external clients who connects to this proxy Dovecot to use TLS (this is easy to set up) while want to have unsecured (plain IMAP/POP) connections to backends. > > You see, links to backends are over LAN so no TLS needed, and these backends are poor old machines (with old Docecots like 2.0.6) this is why I don't want to use TLS to acces backends.A better security practice would be to also use TLS to the backend. You want a defense in depth rather than a "crunchy shell around a soft, chewy center." Jim
Alexander Chekalin
2018-Sep-17 13:35 UTC
Proxy secured incoming POP3/IMAP4 to unsecure backend?
Thank you! Ok, so I can omit ssl=no and startssl=no, and this results in default settings for ssl which is 'off'? Or the defaults are 'on' anyway? Can I somehow specify ports on remote hosts that proxy will use to connect to? Like (just image): 'proxy host_imap=10.1.1.1:143 host_pop=10.1.1.1:110' or somehow? On Mon, Sep 17, 2018 at 4:33 PM Aki Tuomi <aki.tuomi at dovecot.fi> wrote:> Due to certain design issues, the ssl=no is actually same as ssl=yes, same > goes for starttls=no. So there is no support actually for "ssl=no" at this > moment. > > Aki > > > On 17 September 2018 at 15:32 Alexander Chekalin < > alexander.chekalin at gmail.com> wrote: > > > > > > Surely. > > > > Here it is: > > > > # doveadm auth user at domain.com > > Password: > > passdb: chekalin_krg at ascon.ru auth succeeded > > extra fields: > > user=user at domain.com > > proxy > > host=10.10.14.131 > > ssl=no > > startssl=no > > source_ip=10.10.14.2 > > proxy > > proxy > > pass=password > > > > Two "proxy" are from two "proxy" and "proxy=yes" settings passed from > > passdb. > > > > On Mon, Sep 17, 2018 at 3:03 PM Aki Tuomi <aki.tuomi at dovecot.fi> wrote: > > > > > Can you provide output of > > > > > > doveadm auth test some-user > > > Aki > > > > > > On 17.09.2018 14:58, Alexander Chekalin wrote: > > > > > > Dear Aki, > > > > > > we keep our users in LDAP so I when I even return 'proxy > host=backend_ip > > > tls=no' it won't use non-TLS connection. The same is when I remove > 'tls=no' > > > part. May there be any extra things I need to pass when I use LDAP? > > > > > > On Mon, Sep 17, 2018 at 2:07 PM Aki Tuomi <aki.tuomi at dovecot.fi> > wrote: > > > > > >> > > >> > > >> On 17.09.2018 13:59, Alexander Chekalin wrote: > > >> > Hi, > > >> > > > >> > I try to set up dovecot as a proxy server, to proxy requests to > > >> > several dovecot-based backend servers. I wand external clients who > > >> > connects to this proxy Dovecot to use TLS (this is easy to set up) > > >> > while want to have unsecured (plain IMAP/POP) connections to > backends. > > >> > > > >> > You see, links to backends are over LAN so no TLS needed, and these > > >> > backends are poor old machines (with old Docecots like 2.0.6) this > is > > >> > why I don't want to use TLS to acces backends. > > >> > > > >> > But as I did the test setup I can see proxy Dovecot uses TLS to > > >> > connect to backends. Is there any way I can specify this aspect of > > >> > Dovecot proxy? > > >> > > > >> > Please advice! > > >> > > > >> > Yours, > > >> > Alexander > > >> > > >> Dovecot does not use TLS/SSL when connecting to a backend server by > > >> default, you are probably specifying this in your proxy config or > > >> password database. > > >> > > >> Aki > > >> > > > > > > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <https://dovecot.org/pipermail/dovecot/attachments/20180917/1facefd0/attachment.html>
The port is determined with port=nnn setting. You can't return per-protocol port like that, you need to look at the protocol requested by user and return port based on that, or you can omit port to default into "standard port". not using ssl/starttls is default.> On 17 September 2018 at 16:35 Alexander Chekalin <alexander.chekalin at gmail.com> wrote: > > > Thank you! > > Ok, so I can omit ssl=no and startssl=no, and this results in default > settings for ssl which is 'off'? Or the defaults are 'on' anyway? > > Can I somehow specify ports on remote hosts that proxy will use to connect > to? Like (just image): 'proxy host_imap=10.1.1.1:143 host_pop=10.1.1.1:110' > or somehow? > > > > > On Mon, Sep 17, 2018 at 4:33 PM Aki Tuomi <aki.tuomi at dovecot.fi> wrote: > > > Due to certain design issues, the ssl=no is actually same as ssl=yes, same > > goes for starttls=no. So there is no support actually for "ssl=no" at this > > moment. > > > > Aki > > > > > On 17 September 2018 at 15:32 Alexander Chekalin < > > alexander.chekalin at gmail.com> wrote: > > > > > > > > > Surely. > > > > > > Here it is: > > > > > > # doveadm auth user at domain.com > > > Password: > > > passdb: chekalin_krg at ascon.ru auth succeeded > > > extra fields: > > > user=user at domain.com > > > proxy > > > host=10.10.14.131 > > > ssl=no > > > startssl=no > > > source_ip=10.10.14.2 > > > proxy > > > proxy > > > pass=password > > > > > > Two "proxy" are from two "proxy" and "proxy=yes" settings passed from > > > passdb. > > > > > > On Mon, Sep 17, 2018 at 3:03 PM Aki Tuomi <aki.tuomi at dovecot.fi> wrote: > > > > > > > Can you provide output of > > > > > > > > doveadm auth test some-user > > > > Aki > > > > > > > > On 17.09.2018 14:58, Alexander Chekalin wrote: > > > > > > > > Dear Aki, > > > > > > > > we keep our users in LDAP so I when I even return 'proxy > > host=backend_ip > > > > tls=no' it won't use non-TLS connection. The same is when I remove > > 'tls=no' > > > > part. May there be any extra things I need to pass when I use LDAP? > > > > > > > > On Mon, Sep 17, 2018 at 2:07 PM Aki Tuomi <aki.tuomi at dovecot.fi> > > wrote: > > > > > > > >> > > > >> > > > >> On 17.09.2018 13:59, Alexander Chekalin wrote: > > > >> > Hi, > > > >> > > > > >> > I try to set up dovecot as a proxy server, to proxy requests to > > > >> > several dovecot-based backend servers. I wand external clients who > > > >> > connects to this proxy Dovecot to use TLS (this is easy to set up) > > > >> > while want to have unsecured (plain IMAP/POP) connections to > > backends. > > > >> > > > > >> > You see, links to backends are over LAN so no TLS needed, and these > > > >> > backends are poor old machines (with old Docecots like 2.0.6) this > > is > > > >> > why I don't want to use TLS to acces backends. > > > >> > > > > >> > But as I did the test setup I can see proxy Dovecot uses TLS to > > > >> > connect to backends. Is there any way I can specify this aspect of > > > >> > Dovecot proxy? > > > >> > > > > >> > Please advice! > > > >> > > > > >> > Yours, > > > >> > Alexander > > > >> > > > >> Dovecot does not use TLS/SSL when connecting to a backend server by > > > >> default, you are probably specifying this in your proxy config or > > > >> password database. > > > >> > > > >> Aki > > > >> > > > > > > > > > >