October 2013 - dovecot

Re: [Dovecot] Encryption solution for messages at rest
by Douglas Mortensen 30 Oct '13

30 Oct '13

Currently our dovecot servers are on our webhosting linux boxes. We are using the LAMP stack to host websites, and also doing email with postfix & dovecot on these systems. We provide this as a hosting setup for 100+ accounts/websites on a single server (a multi-tenant setup). Each customer has anywhere between 1-100 email accounts which Dovecot services. If a customer has vulnerable PHP code on a website, some of these will allow a remote file upload. I have seen cases where they upload a PHP script that is a sort of web-based console/shell to the server (file-system, etc.). It provides several tools which all run through the uploaded PHP script to try to brute force and do other attacks. I've seen attempts at a root exploit. We've never had a root exploit and any such case of a customer's site being hacked has been easily contained by simple filesystem permissions being correct (and the fact that we have apache setup to run all scripts as the user who is the owner of the script files, which confines the script to that users' permissions). Still nobody loves the idea of bad guys trying to hack on your box. So.... given that type of scenario, if filesystem permissions weren't correct, or some new exploit surfaced that allowed someone bypass or elevate to root, then they could theoretically have access to the entire fileystem including where emails are stored. I hope to never have this sort of thing happen. We patch our systems regularly and have other security measures we follow to prevent this. We also are managing most of the PHP scripts customers use ourselves now and are updating those for the CMS' and other systems proactively. However, it would be nice to know that even if we were breached, the emails on the server were encrypted and would be completely useless to an attacker. This type of encryption is ideal and some regulations prefer (although don't require) it. - Doug Mortensen Network Consultant Impala Networks P: 505.327.7300 -----Original Message----- From: dovecot-bounces(a)dovecot.org [mailto:dovecot-bounces@dovecot.org] On Behalf Of Michael Orlitzky Sent: Monday, October 28, 2013 11:52 AM To: dovecot Subject: Re: [Dovecot] Encryption solution for messages at rest On 10/28/2013 12:02 PM, Douglas Mortensen wrote: > Hi, > > We have clients with various security & compliance requirements. > Although not required, it would be ideal to have messages encrypted at > rest. You can rule out a lot of the crazier options by answering the questions, (a) What attack scenario do you have in mind? (b) How will encryption help?

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[Dovecot] Right values for Antispam plugin
by Michael Neurohr 30 Oct '13

30 Oct '13

Hi! I'm currently configuring the Dovecot Antispam plugin for the use with Dspam. In general it works, but I'm not sure about one special config parameter: antispam_dspam_args At the moment I set it to: antispam_dspam_args = --source=error;--signature=%%s;--user;%u Is that the appropriate value for retraining? I'm not sure if "%%s" is correct to get the signature value. I was not able to find any documentation that describes that value. So I just want to know if my plugin config is correct for retraining. plugin { antispam_backend = dspam antispam_spam = Spam antispam_trash = trash;Trash;Deleted Items;Deleted Messages antispam_signature = X-DSPAM-Signature antispam_signature_missing = move antispam_dspam_binary = /usr/bin/dspam antispam_dspam_args = --source=error;--signature=%%s;--user;%u } Thanks, Michael

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Re: [Dovecot] Encryption solution for messages at rest
by Douglas Mortensen 30 Oct '13

30 Oct '13

So I suppose you're not a fan of the email hosting systems on the planet that bundle many services onto 1 box. Thanks for the feedback. - Doug Mortensen Network Consultant Impala Networks P: 505.327.7300 -----Original Message----- From: dovecot-bounces(a)dovecot.org [mailto:dovecot-bounces@dovecot.org] On Behalf Of Alan Brown Sent: Tuesday, October 29, 2013 10:05 AM To: dovecot Subject: [Dovecot] Encryption solution for messages at rest > Date: Tue, 29 Oct 2013 08:54:04 +0100 > From: Robert Schetterer <rs(a)sys4.de> > To: dovecot(a)dovecot.org > Subject: Re: [Dovecot] Encryption solution for messages at rest > Message-ID: <526F699C.9080402(a)sys4.de> > Content-Type: text/plain; charset=ISO-8859-1 > > > you shouldnt host mail/imap services on the same servers with massive > http hosting, You shouldn't host anything else on a webserver FULLSTOP. Webservers are best treated as "disposable" and should be heavily sandboxed. Any resources they can use should be vetted and ideally set as "read only" Inbound external access should be firewalled down to the webserver ports and OUTBOUND traffic should be firewalled too (If it has no business initiating external connections then block all SYNs), in order to stop it becoming a DDoS zombie. It's foolish (at best) to have mail servers running on a webserver, because if it's compromised it can immediately be used as a spam engine without much further effort. At least if it has to hand mail off to another mailserver you have a chance to run outbound filtering on the emitted mail without worrying about that being compromised too.

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[Dovecot] separate mail_location for system and normal users
by Andrzej A. Filip 30 Oct '13

30 Oct '13

How to configure dovecot to use different default mail_location for system (uid<1_000) and normal users (uid>=1_000)? I want to to use by default * classic mailbox in standard location for system users * maildir in $HOME subdirectory for normal users

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[Dovecot] Disable unsecure POP3 at all (Dovecot 2.1)
by Андрей Кумыков 30 Oct '13

30 Oct '13

Hi to all. Is it possible to disable unsecure POP3 protocol at all in Dovecot 2.1? There was "protocols" option in 1.x version, and there was separate pop3 and pop3s modules. There is no "pop3s" in configuration files in 2.1.

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[Dovecot] Problem with dovecot-lda
by Wolfgang Ganzert 29 Oct '13

29 Oct '13

Hello Ladies and Gentlemen, first of all I have to say that dovecot is really impressive. I seems to be a very goot IMAP server and has in general a good documentation. I'm a beginner regarding the administration so please excuse if my questions sound silly but I want to learn to administrate these sophisticated things. Now here's my configuration: Linux openSuSE 12.1 Postfix 2.8.8 Dovecot 2.0.16 Boundary condition: Postfix as smtp (Postfix is configured as relay server; mail is sent to smtp.web.de if mail is not locally distributed) Dovecot as IMAP server in my private network (192.168....) Situation: I want to store outgoing mail which is send by postfix also in a "SENT" folder in Dovecot. The SENT folder is available and created through the plugin "autocreate". The main.cf file from postfix contains the following mailbox command: mailbox_command = /usr/lib/dovecot/dovecot-lda -f "$SENDER" -a "$RECIPIENT" -m SENT If I send a simple mail from the shell with the following command echo "Hello me" | mail -s "Dovecot test 50, shell nach SENT" $USER the mail is send to my mailbox and stored in the folder "SENT" as unread. Problem: 1. I would expect to have to mails coming in; one in my "SENT" folder because this is copy of the mail and another one which is the incoming folder because the mail was sent to me. But, there is no mail in the incoming folder. 2. If I use a mail client like kmail2 the same thing happens. The mail is distributed to the SENT folder but there's no copy in the incoming folder. 3. If I send a mail to my adress at @web.de with the postfix configuration from above I do not receive the mail at web.de. 4. If I send a mail to my adress at @web.de with a postfix simplified mailbox command NOT containing the mailbox with "-m", then mail is send to web.de and there I receive it in the incoming box. This is the simplified command: mailbox_command = /usr/lib/dovecot/dovecot-lda -f "$SENDER" -a "$RECIPIENT" Summary: All examples from above show that I do not get a COPY of the outgoing mail in my "SENT" folder but it's the REAL mail. Can You please give me some advice what to do? Thank You! Wolfgang P.S.: In /var/log/mail and /var/log/dovecot.log I do not get any errors.

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[Dovecot] Building the Antispam plugin fails
by Michael Neurohr 29 Oct '13

29 Oct '13

Hi! I'm running Dovecot 2.2.5 on a CentOS 6.4 server from the ATRPMs repository. Unfortunately this repo does not provide a packaged version of the Antispam Plugin. So I followed the steps outlined in the Dovecot Wiki [1]. But when running the command ./configure, I get stuck with the following error: checking for dovecot-config in "/usr/local/lib/dovecot"... not found configure: configure: Use --with-dovecot=DIR to provide the path to the dovecot-config file. configure: error: dovecot-config not found So I downloaded the dovecot-devel package and run the configure command again with the following command: ./configure --with-dovecot=/usr/include/dovecot but with the same result. I made sure the the directory "/usr/include/dovecot" does contain the Dovecot header files. What can I do next? Do I really also have to install Dovecot from the sources only to get the Antispam Plugin working? Thanks, Michael [1] http://wiki2.dovecot.org/Plugins/Antispam

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[Dovecot] Encryption solution for messages at rest
by Alan Brown 29 Oct '13

29 Oct '13

> Date: Tue, 29 Oct 2013 08:54:04 +0100 > From: Robert Schetterer <rs(a)sys4.de> > To: dovecot(a)dovecot.org > Subject: Re: [Dovecot] Encryption solution for messages at rest > Message-ID: <526F699C.9080402(a)sys4.de> > Content-Type: text/plain; charset=ISO-8859-1 > > > you shouldnt host mail/imap services on the same servers with massive > http hosting, You shouldn't host anything else on a webserver FULLSTOP. Webservers are best treated as "disposable" and should be heavily sandboxed. Any resources they can use should be vetted and ideally set as "read only" Inbound external access should be firewalled down to the webserver ports and OUTBOUND traffic should be firewalled too (If it has no business initiating external connections then block all SYNs), in order to stop it becoming a DDoS zombie. It's foolish (at best) to have mail servers running on a webserver, because if it's compromised it can immediately be used as a spam engine without much further effort. At least if it has to hand mail off to another mailserver you have a chance to run outbound filtering on the emitted mail without worrying about that being compromised too.

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[Dovecot] recipient_delimiter deux
by LuKreme 29 Oct '13

29 Oct '13

OK, I've been banging my head on why my procmail setup for virtual users is no longer working (difficult to test, since enabling it breaks live user's mail). There are only a few virtual users who have any sort of filters in place anyway (the heavy procmail users are local, not virtual), and they are fairly simple, so I think I can recreate them with sieve. I think I have everything I need for sieve to work, but now what? The first thing I want to do is have sieve process recipient_delimiter into a separate mailbox (creating it, if needed). Googling just for example sieve scripts comes up empty (well, directing to the dovecot wiki which at least on the links that come up, does not have sample scripts). so, foo+bar(a)example.com will go into foo's mailstore in the folder .bar/new/ On 27 Sep 2013, at 00:24 , Steffen Kaiser <skdovecot(a)smail.inf.fh-brs.de> wrote: > Dovecot LDA uses the "-m" option and only lda_mailbox_autocreate and lda_mailbox_autosubscribe, no need for recipient_delimiter to override the default mailbox. Which I still don't understand. recipient_delimiter = + is the default, so I shouldn't need to set it in my confs, I just need to setup a sieve recipe (is that what it is called? script?) that will process these messages, right? What would that look like? I have to setup the SQL users so that LMTP or LDA is used for deliver, but I want that to apply only to the sql users. Something like this, maybe? userdb { args = /etc/dovecot/dovecot-sql.conf.ext default_fields = uid=vpopmail gid=vchkpw mail_location=/usr/local/virtual/%u mail=maildir:/usr/local/virtual/%u sieve=/var/sieve/%u.sieve protocol_lda=$mailplugins sieve driver = sql } I'm sure that protoco_lda isn't the right syntax though. If I set sieve=/var/sieve/%u.sieve as above would users still be able to use sieve-manage to manage their own sieve files? And what MUAs support this? If I left that out, do I put ~/.dovecot.sieve in with the other mailboxes and {cur,new,tmp} and the index files, or will there be issues? If I put a dovecot.sieve file there will it just be seen, processed, and work? (SQL user's $HOME is their maildir) $ doveconf -n # 2.2.5: /usr/local/etc/dovecot/dovecot.conf # OS: FreeBSD 9.1-RELEASE i386 auth_mechanisms = PLAIN LOGIN disable_plaintext_auth = no first_valid_uid = 89 login_log_format_elements = user=<%u> %r %m %c mail_location = maildir:~/Maildir mail_max_userip_connections = 90 managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { auto = subscribe special_use = \Junk } mailbox NotJunk { auto = subscribe } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } protocols = imap sieve service auth { unix_listener /var/spool/postfix/private/auth { mode = 0666 } } service imap-login { inet_listener imaps { port = 993 ssl = yes } } ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem userdb { driver = passwd } userdb { args = /etc/dovecot/dovecot-sql.conf.ext default_fields = uid=vpopmail gid=vchkpw mail_location=/usr/local/virtual/%u mail=maildir:/usr/local/virtual/%u driver = sql } -- 'He's mad, isn't he?' 'No, mad's when you froth at the mouth,' said Gaspode. ' He's insane. That's when you froth at the brain.'

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[Dovecot] pigeonhole sources no more available
by me＠electronico.nc 29 Oct '13

29 Oct '13

Hi all, Please excuse me for this message but I can't find the pigeonhole sources available anymore. This page : http://pigeonhole.dovecot.org/download.html Points to (for latest sources) : http://www.rename-it.nl/dovecot/2.2/dovecot-2.2-pigeonhole-0.4.2.tar.gz And it seems that : www.rename-it.nl is now : http://www.medicalbits.nl So we get 404 error ... Could someone point us the to right URL and, maybe, update pigeonhole.dovecot.org ? Thanks in advance for your time. Nicolas

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