August 2020 - dovecot

using %d as a variable in the ldap search base
by Luke Schierer 01 Sep '20

01 Sep '20

Hi, I'm trying to configure dovecot to use LDAP authentication directly, and I'm having a bit of trouble. I have a somewhat unusual setup, in that I have an LDAP directory that has 3 OUs each of which have their own set of users, some of which overlap. As I was trying to figure things out, I was setting the search base in my /etc/dovecot/dovecot-ldap.conf.ext file which is referenced by /etc/dovecot/conf.d/auth-ldap.conf.ext file to base = ou=%d,dc=thecrazyguys,dc=net however, the resulting searches against the directory endup just dropping the %d, resulting in ou=,dc=thecrazyguys,dc=net which is invalid. On a whim, I tried a search base of base = dc=%d,dc=thecrazyguys,dc=net and found that it did correctly substitute in the variable, which would be correct, except that my ldap tree is set up with OUs and not an extra DC segment. for whatever reason, it will do variable substitution for dc=%d, but not for ou=%d. this is certainly not documented, and seems like wrong behavior, since having an ou in a search base is valid. I'm including configuration information below. Please let me know if I've missed including information that is required. Thanks! Luke luke@schierer@littera001:/etc/dovecot$ lsb_release -rd Description: Ubuntu 18.04.5 LTS Release: 18.04 luke@schierer@littera001:/etc/dovecot$ luke@schierer@littera001:/etc/dovecot$ dpkg -l | grep -i dovecot ii dovecot-core 1:2.2.33.2-1ubuntu4.6 amd64 ii dovecot-imapd 1:2.2.33.2-1ubuntu4.6 amd64 ii dovecot-ldap 1:2.2.33.2-1ubuntu4.6 amd64 ii dovecot-pop3d 1:2.2.33.2-1ubuntu4.6 amd64 luke@schierer@littera001:/etc/dovecot$ root@littera001:/etc/dovecot# dovecot -n # 2.2.33.2 (d6601f4ec): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.21 (92477967) # OS: Linux 4.15.0-112-generic x86_64 Ubuntu 18.04.5 LTS auth_verbose = yes first_valid_uid = 1001 imap_hibernate_timeout = 100 secs lock_method = dotlock mail_cache_min_mail_count = 15 mail_fsync = always mail_location = maildir:~/Maildir:LAYOUT=fs:INDEX=MEMORY mail_nfs_index = yes mail_nfs_storage = yes mail_privileged_group = mail mailbox_list_index = yes maildir_broken_filename_sizes = yes maildir_very_dirty_syncs = yes mbox_min_index_size = 10 B mmap_disable = yes namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = separator = / } passdb { args = /etc/dovecot/dovecot-ldap.conf.ext driver = ldap } protocols = " imap pop3" ssl_cert = </etc/dovecot/dovecot.pem ssl_key = # hidden, use -P to show it userdb { args = /etc/dovecot/dovecot-ldap.conf.ext driver = ldap } protocol imap { mail_max_userip_connections = 20 } root@littera001:/etc/dovecot# root@littera001:/etc/dovecot# cat /etc/dovecot/dovecot-ldap.conf.ext | grep -v ^# | uniq | more hosts = censor001.plerumque.thecrazyguys.net tls = yes tls_require_cert = allow debug_level = 4 auth_bind = yes base = ou=%d,dc=thecrazyguys,dc=net scope = subtree user_attrs = homeDirectory=home,uidNumber=uid,gidNumber=gid user_filter = (&(objectClass=posixAccount)(uid=%n)) blocking = no root@littera001:/etc/dovecot#

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Re: replicator: Panic: data stack: Out of memory
by Thomas Tsiakalakis 01 Sep '20

01 Sep '20

So nobody has any idea why this could happen? Let me know if I should provide more Information Thanks Thomas Tsiakalakis Team Applikationsbetrieb GDV Dienstleistungs-GmbH Tel: +49(40)33449-4318 Fax: E-Mail: Thomas.Tsiakalakis(a)gdv-dl.de<mailto:Thomas.Tsiakalakis@gdv-dl.de> GDV Dienstleistungs-GmbH Glockengießerwall 1 D-20095 Hamburg www.gdv-dl.de<http://www.gdv-dl.de> Niederlassungen: Wilhelmstraße 43 / 43 G 10117 Berlin Frankenstraße 18 20097 Hamburg Sitz und Registergericht: Hamburg HRB 145291 USt.-IdNr : DE 205183123 Geschäftsführer: Dr. Jens Bartenwerfer Fred di Giuseppe Chiachiarella Aufsichtsratsvorsitzender: Werner Schmidt ------------------------------------------------------------------ Diese E-Mail und alle Anhänge enthalten vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese E-Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe der E-Mail ist nicht gestattet. This e-mail and any attached files may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Von: Thomas Tsiakalakis Gesendet: Dienstag, 23. Juni 2020 11:25 An: dovecot(a)dovecot.org Betreff: AW: replicator: Panic: data stack: Out of memory I managed to convince the System that I really want a core dump Von: Thomas Tsiakalakis Gesendet: Donnerstag, 18. Juni 2020 16:26 An: 'dovecot(a)dovecot.org' <dovecot(a)dovecot.org> Betreff: replicator: Panic: data stack: Out of memory Hi, I have set up 2 SLES 15 Hosts with dovecot and replication. Everything seems to work fine but every time a message is delivered, I get an out of memory error in the logs. The Replication itself seems to work fine though. I increased default_vsz_limit to 512M but the only thing that changed was that dovecot was trying to allocate 1073741864 bytes instead of 268435496 As I said, I’m running SLES 15 SP1 and Dovecot 2.3.10 (0da0eff44) (both Hosts have the same version) Each Host currently has 8GB of Memory. # free -h total used free shared buff/cache available Mem: 7.8Gi 278Mi 7.3Gi 47Mi 183Mi 7.2Gi Swap: 4.0Gi 0B 4.0Gi # journalctl -f Jun 18 15:55:48 mail1 postfix/pickup[3457]: 18533C009C8: uid=0 from=<root> Jun 18 15:55:48 mail1 postfix/cleanup[3669]: 18533C009C8: message-id=<20200618135548.18533C009C8@mail1> Jun 18 15:55:48 mail1 postfix/qmgr[3458]: 18533C009C8: from=<root@mail1>, size=431, nrcpt=1 (queue active) Jun 18 15:55:48 mail1 dovecot[1833]: lmtp(3673): Connect from local Jun 18 15:55:48 mail1 dovecot[1833]: replicator: Panic: data stack: Out of memory when allocating 268435496 bytes Jun 18 15:55:48 mail1 dovecot[1833]: replicator: Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0(backtrace_append+0x42) [0x7f8346d6d262] -> /usr/lib64/dovecot/libdovecot.so.0(backtrace_get+0x1e) [0x7f8346d6d37e] -> /usr/lib64/dovecot/libdovecot.so.0(+0xebcee) [0x7f8346d77cee] -> /usr/lib64/dovecot/libdovecot.so.0(+0xebd91) [0x7f8346d77d91] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7f8346cd1f8b] -> /usr/lib64/dovecot/libdovecot.so.0(t_pop_last_unsafe+0) [0x7f8346d73660] -> /usr/lib64/dovecot/libdovecot.so.0(+0xe7a50) [0x7f8346d73a50] -> /usr/lib64/dovecot/libdovecot.so.0(+0x10eb58) [0x7f8346d9ab58] -> /usr/lib64/dovecot/libdovecot.so.0(+0xe3ac5) [0x7f8346d6fac5] -> /usr/lib64/dovecot/libdovecot.so.0(buffer_write+0xf2) [0x7f8346d6fdb2] -> dovecot/replicator(replicator_queue_push+0xde) [0x5648989a5cde] -> dovecot/replicator(+0x5464) [0x5648989a5464] -> dovecot/replicator(+0x4a0b) [0x5648989a4a0b] -> dovecot/replicator(+0x4c02) [0x5648989a4c02] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_call_io+0x69) [0x7f8346d90c99] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x134) [0x7f8346d92574] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run+0x4c) [0x7f8346d90d9c] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f8346d90fc8] -> /usr/lib64/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f8346d01873] -> dovecot/replicator(main+0x1a0) [0x5648989a3cb0] -> /lib64/libc.so.6(__libc_start_main+0xea) [0x7f83468f534a] -> dovecot/replicator(_start+0x2a) [0x5648989a3d5a] Jun 18 15:55:48 mail1 dovecot[1833]: lmtp(test(a)example.com)<3673><q5sLCGRy615ZDgAATn/NZw>: Warning: replication(test(a)example.com): Sync failure: Jun 18 15:55:48 mail1 dovecot[1833]: lmtp(test(a)example.com)<3673><q5sLCGRy615ZDgAATn/NZw>: Warning: replication(test(a)example.com): Remote sent invalid input: - Jun 18 15:55:48 mail1 dovecot[1833]: lmtp(test(a)example.com)<3673><q5sLCGRy615ZDgAATn/NZw>: msgid=<20200618135548.18533C009C8@mail1>: saved mail to INBOX Jun 18 15:55:48 mail1 dovecot[1833]: lmtp(3673): Disconnect from local: Client has quit the connection (state=READY) Jun 18 15:55:48 mail1 postfix/lmtp[3672]: 18533C009C8: to=<test(a)example.com>, orig_to=<test(a)domain.com>, relay=mail1[private/dovecot-lmtp], delay=0.17, delays=0.02/0.01/0.02/0.13, dsn=2.0.0, status=sent (250 2.0.0 <test(a)example.com> q5sLCGRy615ZDgAATn/NZw Saved) Jun 18 15:55:48 mail1 postfix/qmgr[3458]: 18533C009C8: removed Jun 18 15:55:48 mail1 dovecot[1833]: replicator: Fatal: master: service(replicator): child 2948 killed with signal 6 (core not dumped - https://dovecot.org/bugreport.html#coredumps - set /proc/sys/fs/suid_dumpable to 2)

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how fetch zlibed mails with doveadm
by rudolf＠padaru.de 31 Aug '20

31 Aug '20

Hey there, i need some help with an administrativ dovecot question. I run a dovecot 2.2.33 ubuntu server with mdbox and "zlib_save = gz zlib_save_level = 6". Now i want to fetch the mailheader from some mails via doveadm fetch -u <user> hdr uid <uid>. The only thing what i receive is some binary stuff. Is there a way, i can tell the dovemadm fetch command, that he should deflate the output for me? Yours sincerely Pascal Rudolf

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zlib errors after upgrading from 2.3.10.1 to 2.3.11.3
by Robert Nowotny 31 Aug '20

31 Aug '20

I get ZLIB Errors after dovecot upgrade from 2.3.10.1 to 2.3.11.3 Thunderbird reports some error when try to save/open a bigger attachment. Aug 21 15:27:34 lxc-imap dovecot: imap(acsida)<63870><jZk...>: Error: Mailbox Sent: UID=40826: read(zlib(/home/vmail/virtualmailboxes/acsida/storage/m.2409)) failed: read(/home/vmail/virtualmailboxes/acsida/storage/m.2409) failed: Broken pipe (FETCH BODY[]) Aug 21 15:27:34 lxc-imap dovecot: imap(acsida)<63871><9A0...>: Error: Mailbox Sent: UID=40826: read(zlib(/home/vmail/virtualmailboxes/acsida/storage/m.2409)) failed: read(/home/vmail/virtualmailboxes/acsida/storage/m.2409) failed: Broken pipe (FETCH BODY[]) Aug 21 15:30:11 lxc-imap dovecot: imap(cpotzinger)<63889><Ig6...>: Error: Mailbox Sent: UID=29495: read(zlib(/home/vmail/virtualmailboxes/cpotzinger/storage/m.4703)) failed: read(/home/vmail/virtualmailboxes/cpotzinger/storage/m.4703) failed: Broken pipe (FETCH BODY[]) Aug 21 15:30:17 lxc-imap dovecot: imap(cpotzinger)<64169><GXe...>: Error: Mailbox Sent: UID=29495: read(zlib(/home/vmail/virtualmailboxes/cpotzinger/storage/m.4703)) failed: read(/home/vmail/virtualmailboxes/cpotzinger/storage/m.4703) failed: Broken pipe (FETCH BODY[]) Aug anything I can tweak or do ? Robert

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PBKDF2 password hashing as in ASP.NET Core
by Yves Goergen 30 Aug '20

30 Aug '20

Hello, I'm setting up a new server and, again, seek for a decently secure (from a security specialist's POV) way to store and verify user passwords in a database. Additionally now, GDPR requires me to use a solid state-of-the-art solution. My OS is Ubuntu 20.04, Dovecot version 2.3.7, database backend with PostgreSQL 12. Obviously, storing the plaintext password is a terrible idea. SHA-based methods aren't suitable either. bcrypt has been recommended often [1]. PBKDF2 was preferred over bcrypt even more [2]. I'm managing all database contents with an ASP.NET Core application that implements the management user frontend. It's a bit hard to find bcrypt support for .NET (there are a few NuGet packages of unknown quality [3]). .NET does however implement, use and recommend PBKDF2 for its own user management. If this is by far the best way to go, I'm already covered on that side. Now the problem is, once again*, how I can use this in applications to make them as secure. I need a solution for Dovecot and Exim. Exim seems to be able to ask Dovecot (IMAP) for user authentication, so I might try that and only need to solve the problem in Dovecot alone. Dovecot documentation says that PBKDF2 is somewhat possible [4]. It requires the hash in the format "$1$salt$rounds$hash". I guess that "salt", "rounds" and "hash" are the parameters here. But what is their format? The .NET implementation [5] describes its format as "{ 0x01, prf (UInt32), iter count (UInt32), salt length (UInt32), salt, subkey }" with big-edian integers. The result is base64-encoded. Prf is an enum value, describing the HMAC SHA-256. Subkey is the hash value part. I might find a way to convert .NET's format into what Dovecot understands. The hmac is SHA-256, the rounds is 10000. But I wasn't able to get it working. My test password is: simplepassword The .NET hash: AQAAAAEAACcQAAAAEG0Anzb9vKOqsAKxLyhXedCTJoHrP381hKiKBHuPHhMdkjqW8Bks8RFOQZLssJ2grQ== The converted hash for Dovecot: $1$bQCfNv28o6qwArEvKFd50A==$10000$kyaB6z9/NYSoigR7jx4THZI6lvAZLPERTkGS7LCdoK0= I've also found the source code in Dovecot that should verify the hash [6]. It gives some more hints about the expected format that are sadly missing from the documentation, making it almost useless. I also tried with the "{PBKDF2}" prefix, with the base64 padding "=" removed and with the hash part converted from base64 to hex. Nothing works. The source mentions "SHA1" somewhere. Is that all it can accept? No up-to-date SHA-256? So what have I done wrong here? Why can't I authenticate? The Dovecot log isn't helpful, it doesn't even mention the user name I tried to log in with from Thunderbird, most of the time (it's unpredictable). What is the correct usage of Dovecot's PBKDF2 feature? Is it functional at all? There's a test case for it [7] but that's not helpful to me. If Dovecot's PBKDF2 support is not functional or not compatible with ASP.NET Core's parameters, what options do I have? Can I build my own authentication service that Dovecot can communicate with, to fill the gap of missing crypto support? Yves *) During my research today, I find myself finding my own questions from 6 years ago when I did this the last time. The situation hasn't changed much since then. Secure password hashing is still impossible or complicated in server applications like Exim or Dovecot. [1] https://codahale.com/how-to-safely-store-a-password/ (linked from the Dovecot documentation) [2] https://www.reddit.com/r/node/comments/4u1jcn/is_bcrypt_the_best_possible_p… [3] https://nugetmusthaves.com/Tag/bcrypt [4] https://doc.dovecot.org/configuration_manual/authentication/password_scheme… [5] https://github.com/dotnet/AspNetCore/blob/master/src/Identity/Extensions.Co… [6] https://github.com/dovecot/core/blob/81b5b188c478ec36bea8bda8fcad1e5f32ac61… [7] https://github.com/dovecot/core/blob/ff5305136ae747867b6f6af9a1737188ae7b3b…

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moving /var/vmail/vmail1 Maildir tree to another partition?
by Voytek Eymont 30 Aug '20

30 Aug '20

I have a small Postfix/Dovecot/MariaDB on Centos 7 with a dozen virtual domains, I'm running out of space in /var but got space can I simply move the entire /var/vmail/vmail1 tree elsewhere ? like say /vmail/vmail1 is it as simple as shutting Dovecot/Postfix, move tree, edit conf and re start ? or am I missing something ..? or is the a better way of doing this ? # grep 'var/vmail' *.conf dovecot.conf: sieve_global_dir = /var/vmail/sieve dovecot.conf: sieve_global_path = /var/vmail/sieve/dovecot.sieve dovecot.conf:# location = maildir:/var/vmail/public/:CONTROL=~/Maildir/public:INDEX=~/Maildir/public # cd ../postfix # grep 'var/vmail' *.cf main.cf:virtual_mailbox_base = /var/vmail # dovecot --version 2.3.11.3 (502c39af9)

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Rsync the dovecot repo
by Marc Roos 30 Aug '20

30 Aug '20

Is it possible to rsync some repo that has centos7 2.3.11? http://repo.dovecot.org/ce-2.3-latest/centos/7/RPMS/x86_64/2.3.11.3-3_ce/

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Imaptest stalls when removing msgs argument
by Marc Roos 30 Aug '20

30 Aug '20

I have had this imaptest[1] stall. I compared this command with what you have on the website and I was a bit surprised that what is on the website is working. What I have noticed is that if you remove this msgs argument, the imaptest stalls. I am not sure if this is according to design, but one might expect that specifying a secs, makes specifying msgs redundant? [1] imaptest - append=100,0 logout=0 host=xx.local port=143 user=xxx pass=xxx seed=100 secs=240 clients=1 mbox=64kb.mbox box=inbox/test. [2] https://doc.dovecot.org/admin_manual/sample_tests/ Using: dovecot-imaptest-2.3.10-2.x86_64

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lazy_expunge and fts_autoindex
by Gregory Heytings 29 Aug '20

29 Aug '20

Hi list, I have both lazy_expunge and fts_autoindex activated (with fts-xapian), as follows: plugin { lazy_expunge = EXPUNGED/ } plugin { fts = xapian fts_xapian = partial=2 full=20 attachments=1 verbose=0 fts_autoindex = yes fts_enforced = yes fts_autoindex_exclude = EXPUNGED fts_autoindex_exclude2 = EXPUNGED/* } However, I still see "indexer-worker...: Info: Indexed 1 messages in EXPUNGED/..." in the dovecot log each time I expunge an email. I tried various other settings for "fts_autoindex_exclude" (EXPUNGED alone, EXPUNGED + EXPUNGED/ + EXPUNGED/*, ...), but none of them seem to work. Thanks for your help, Gregory

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Expuning & Purging doesn't fully remove emails?
by Zelic Bojan 27 Aug '20

27 Aug '20

Hello, I'm facing an issue where deleted emails keep re-appearing after my mailbox index gets recreated. I'm running version 2.2.36 of dovecot, but I tested the same scenario under 2.3.10. I'm also using mdbox, autoexpunge, and using dovecot replication. I've had several instances now where some expunged emails show up again in a mailbox. I noticed this error: doveadm: Error: Corrupted dbox file /var/mail/virtual/mailbox(a)domain.com/mdbox/storage/m.3228 (around offset=1988744): msg header has bad magic value which caused the index to get rebuilt... however several times now, the indexes got rebuilt even though there doesnt seem like there was any error... so im not sure why that is. lmtp(13910): Warning: fscking index file /var/mail/virtual/mailbox(a)domain/mdbox/storage/dovecot.map.index lmtp(13910): Warning: fscking index file /var/mail/virtual/mailbox(a)domain/mdbox/storage/dovecot.map.index lmtp(13910): Warning: mdbox /var/mail/virtual/mailbox@domain/mdbox/storage: rebuilding indexes I'm not sure why these mails keep coming back though... or if there's anything that I can do to limit the number of emails that get restored. I want to make sure expunged & purged emails stay expunged & purged. If I run a purge and then force index recreation... why would expunged emails come back? Shouldn't I expect them all to be deleted & purged? Does expunge not expunge all emails? (In production, I'm running autoexpunge but this test below shows what happens when I attempt to expunge everything) doveadm search -u email@domain all | wc -l # output 22096 doveadm expunge -u email@domain mailbox '*' all doveadm search -u email@domain all | wc -l # output: 0 doveadm purge -u email@domain doveadm dump /var/mail/virtual/email@domain/mdbox/storage/ | grep -c 'ref.*\b0\b' # output: 0 doveadm force-resync -u email@domain Inbox # output: # doveadm(email@domain): Warning: fscking index file /var/mail/virtual/email(a)domain/mdbox/storage/dovecot.map.index # doveadm(email@domain): Warning: mdbox /var/mail/virtual/email@domain/mdbox/storage: rebuilding indexes # doveadm(email@domain): Warning: fscking index file /var/mail/virtual/email(a)domain/mdbox/storage/dovecot.map.index doveadm search -u email@domain all | wc -l # output: 843 I would expect the output to be 0. Theoretically I deleted all emails and purged all emails. Nothing should be left on the disk? However... I can see there are still m.* files in mdbox/storage for the mailbox. Overall, I'm not sure why the index got recreated... but I'm trying to limit the impact of mailbox corruption so that deleted emails do not come back if the index is somehow recreated again. If I were to re-run expunge, purge, and force-resync a 2nd time... it does get emptied out, but I'm not looking to run force-resync intentially since it causes dataloss with mdbox, and re-running only expunge & purge doesn't seem to do anything. Bojan Zelic Sr. IT Infrastructure Engineer

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