- dovecot - dovecot.org

Re: Best mail encryption solution for per-user
by Aki Tuomi 23 May '18

23 May '18

On 23.05.2018 10:15, mail(a)sjemm.net wrote: > May 23, 2018 8:31 AM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >> On 23.05.2018 09:13, mail(a)sjemm.net wrote: >> >>> May 20, 2018 8:01 PM, mail(a)sjemm.net wrote: >>>> May 20, 2018 2:47 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 19 May 2018 at 16:40 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 10:01 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 21:44 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 4:43 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 17:38 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 4:05 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 16:43 mail(a)sjemm.net wrote: >>> >>> Hi Tai74 and Aki, >>> I followed your conversation with interest on how to setup per user encryption in dovecot. >>> I have setup my dovecot with the following in a conf file: >>> >>> ============== >>> >>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>> mail_plugins = $mail_plugins mail_crypt >>> plugin { >>> >>> mail_crypt_curve = secp521r1 >>> >>> mail_crypt_save_version = 2 >>> >>> } >>> >>> ============== >>> >>> This works nice, all emails are being encrypted and every user/folder has keys. >>> But as I understood from your conversation these keys are not protected. And I want them to be >>> protected by the users password used by imap. >>> >>> Those passwords are stored in a mysql DB file. ( I used a guide from workaround [dot] org to set up >>> the DB and postfix/dovecot) >>> >>> but how would i set it so, that the users password from the DB is used to encrypt the keys? >>> >>> should i use mail_crypt_private_password = ? >>> how do i point it to the mysql db then? >>> im unsure about this >>> >>> Do you have any hints on this? >>> >>> Kind regards, >>> Zjemm >>> >>> The passwords in your MySQL database are, hopefully, not in plaintext. If you want to secure your >>> user's keys using user's login password, you must have a TOOL that manages this. >>> >>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>> a good option. >>> >>> You can change the key password using 'doveadm mailbox cryptokey', this needs to be done every time >>> user changes his password. >>> >>> Also note that if you go down this road, and the user forgets his password, you will not be able to >>> recover the emails without backup copy of the private key. >>> >>> Aki >>> >>> Hi Aki >>> >>> I used the following command: >>> dovecot pw -s SHA256-CRYPT >>> >>> the output on the chosen password looks like: {SHA256-CRYPT}$5$Rokc06a7In4SF3bO$OQpGQWqg........ >>> >>> This output is used to store in the password fields in the database. So no plain text passwords no >>> :) >>> >>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>> password as private password. >>> >>> can you explain this a bit more for me? >>> >>> for now i have in the 10-auth.conf file the following: >>> ============== >>> passdb { >>> driver = sql >>> >>> # Path for SQL configuration file, see example-config/dovecot-sql.conf.ext >>> args = /etc/dovecot/dovecot-sql.conf.ext >>> } >>> >>> and: >>> >>> userdb { >>> driver = static >>> args = uid=vmail gid=vmail home=/var/vmail/%d/%n >>> } >>> ============== >>> >>> then i have in dovecot-sql.conf.ext >>> ============== >>> driver = mysql >>> connect = host=x.x.x.x dbname=mailserver user=mailuser password=mailpasswordexample >>> default_pass_scheme = SHA256-CRYPT >>> password_query = SELECT email as user, password FROM virtual_users WHERE email='%u'; >>> ============== >>> Where do i need to set : mail_crypt_private_password = %w ? >>> >>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>> a good option. >>> >>> the passwords are allready hashed in the DB using: dovecot pw -s SHA256-CRYPT to genereate the has. >>> so this step isnt nesesary anymore am i right? >>> >>> Thank you for your quick response, very helpfull >>> >>> Zjemm >>> >>> You misunderstood a bit. The idea is to use the *plaintext* password as the password for the >>> private key. Otherwise anyone could just decrypt it by looking at your database where the hashed >>> password is.. >>> >>> So: >>> >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u' >>> >>> Aki >>> >>> Hi Aki, >>> >>> Thank you very much for your help, i realy appreciate that. >>> >>> Ok so if i understand it correctly i'll have to use: >>> >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u' >>> >>> in my dovecot-sql.conf.ext file >>> >>> This query selects the user, the password, and %w >>> >>> if i run a little query myself: >>> MariaDB [mailserver]> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password >>> FROM virtual_users; >>> +------------------+----------------------------------+------------------------------------+ >>> | user | password | userdb_mail_crypt_private_password | >>> +------------------+----------------------------------+------------------------------------+ >>> | john(a)example.org | {SHA256-CRYPT}$5$M/GWzmtjsLroRWI | %w | >>> +------------------+----------------------------------+------------------------------------+ >>> >>> %w is a dovecot variable, and stands for the plaintext password, but the password is not stored as >>> plaintext in the DB, %w get filled with the actual plaintext password by dovecot upon the user that >>> is typing in the password when authenticating. >>> >>> is this correct? >>> >>> yes. >>> >>> so then i have the username the hashed password en the plaintext password as a result of the query. >>> >>> yes >>> >>> now userdb_mail_crypt_private_password = the plaintext password >>> do i need to reference it somewhere? or is userdb_mail_crypt_private_password autmatically used by >>> the dovecot mail_crypt plugin to encrypt the keys? or should it be mail_crypt_private_password? >>> >>> It gets injected into the mail process as 'mail_crypt_private_password', as if it was set in plugin >>> {} section. >>> >>> if i have this setup working i'm going to write a blog post on this topic to share this knowledge >>> >>> Thanks again and have a great weekend. >>> >>> Zjemm >>> >>> Aki >>> >>> Hi Aki, >>> >>> Cool i'm testing it right now. >>> I have set up a new mailserver (life is great with lxc containers :) ) >>> >>> postfix and dovecot are working like normal >>> >>> next i enable mail_crypt >>> >>> i did create a file: /etc/dovecot/conf.d/10-mailcrypt.conf >>> ========================== >>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>> >>> mail_plugins = $mail_plugins mail_crypt >>> >>> plugin { >>> mail_crypt_curve = secp521r1 >>> mail_crypt_save_version = 2 >>> } >>> ========================== >>> >>> and then i changed the file: /etc/dovecot/dovecot-sql.conf.ext >>> >>> so the query is now the new query: >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u'; >>> >>> then i restarted dovecot and postfix and send a test email to the one and only testuser that is in >>> there. >>> >>> when i open the mailbox with the tool mutt, i can see the new email, and when openening the email >>> the mutt client drops the connection. >>> >>> in the log i can see: >>> >>> May 19 13:34:48 mailserver1.example.local dovecot[600]: imap-login: Login: user=<john(a)example.org>, >>> method=PLAIN, rip=::1, lip=::1, mpid=713, TLS, session=<E3PnIY9sNM4AAAAAAAAAAAAAAAAAAAAB> >>> May 19 13:34:49 mailserver1.example.local dovecot[600]: imap(john(a)example.org): Error: read() >>> failed: >>> read(/var/vmail/example.org/john/Maildir/cur/1526736378.M161472P641.mailser…, >>> =571:2,) failed: Private key not available: Cannot decrypt key >>> bfc5bb25b1bf64290eea6dc14b516c6a0a25b64551b6e4f0f8677ba7274887cb: error:03070068:bignum >>> routines:BN_mpi2bn:encoding error (FETCH BODY[] for mailbox INBOX UID 8) >>> >>> i think i missed a step, but witch one? >>> >>> the userpassword hasnt been changed (that would be the next step in the testing process) >>> >>> should i've use doveadm first to encrypt the key with that userpassword? i thought it would do that >>> on the fly, because the initial keys where only just created when enabling the mail_crypt plugin >>> >>> please let me know your thougts >>> Zjemm >>> I noticed you replied directly to me, and not to the list, too... fixed that for you. >>> >>> mail_crypt_private_password is used when key is created, but if you have created it before using >>> password, you'll need to encrypt it before turning the setting on. >>> >>> Aki >>>> Hi, Ok i'm sorry about that, thank you for fixing that. i'm a bit new to mailing lists :) >>>> >>>> are you a dovecot devoloper? or a enthusiastic user? >>>> >>>> anyway, i managed to get it working now with all your help :) >>>> >>>> to start fresh i did a: >>>> rm -rf /var/vmail/example.org >>>> >>>> so all email is gone, and i assume all dovecot keys are gone that way. >>>> >>>> Then i tried to set a password first: >>>> >>>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>>> result: Changed password for 0 key(s) >>>> >>>> (summersun = the password for this user) >>>> >>>> but then it says there are 0 keys, so then i send the test user an email and try to open the >>>> mailbox, i'll get: >>>> >>>> imap(john(a)example.org): Error: read() failed: >>>> read(/var/vmail/example.org/john/Maildir/cur/1526827992.M149712P883.mailser…, >>>> =561:2,) failed: Private key not available: Cannot decrypt key >>>> 71849013a70b0c631c06112077e7c2fe39b0b2737b4933b219793841209d4e7f: error:03070068:bignum >>>> routines:BN_mpi2bn:encoding error >>>> >>>> but hey, now the key's are created, so i tried to set the password again: >>>> >>>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>>> result: dcrypt_key_load_private(787701bd677dd69a26842547a3926cbaa625b0b5a91751f06678c3e9708343d9) >>>> failed: password missing >>>> ========= >>>> >>>> Lets start over again, i did a new: >>>> rm -rf /var/vmail/example.org >>>> >>>> i disabled the mail_crypt_private_password in the sql query and send an email to the test user. >>>> now again new keys are generated. >>>> >>>> then i did set the password via doveadm: >>>> >>>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>>> result: Changed password for 1 key(s) >>>> >>>> i enabled the mail_crypt_private_password again in the sql query part and now it works :) >>>> >>>> YESSS!!! >>>> >>>> if i now change the password for the user, i cannot read the email anymore. that is what should >>>> happen. >>>> so now i changed the password for this user also with doveadm: >>>> - doveadm mailbox cryptokey password -u john(a)example.org -n qwerty -o summersun >>>> >>>> and now i'm able to read the emails again. so it all works now as expected. >>>> >>>> i have now only one thing remaining. >>>> >>>> when i want to add a new user, i have to somehow: >>>> - create the new user in the mysql DB >>>> - start with dovecot not using mail_crypt_private_password (so disabled) >>>> - send an initial email to let the users mailbox be created and generate the keys >>>> - set the users password with doveadm >>>> - restart dovecot again with mail_crypt_private_password (so enabled) >>>> >>>> but this would be disruptive to existing users, and i would have to script the whole thing as a >>>> "add-new-user" script to make it usable i guess. >>>> >>>> do you know of a more easy way of acomplishing this? >>>> could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? >>>> >>>> or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that >>>> column with %w for users that allready exist, and empty for new users. >>>> when being empty, it might not set the mail_crypt_private_password for new users >>>> >>>> or is this the wrong way of thinking? >>>> >>>> let me know your thoughts on this. >>>> >>>> And last but not least, i really want to thank you for all your help. It is a really nice >>>> experience. >>>> Bless you! >>>> >>>> Zjemm >>> Hi Aki, >>> >>> You did fix the posting on the mail archive, i can see our conversation on there, all but the last >>> email i send to you. >>> Maybe you did not received the last email? >>> >>> would you be willing to take a look at my last question in the email See below: >>> Thank you very much. >>> >>> ================================ >>> i have now only one thing remaining. >>> >>> when i want to add a new user, i have to somehow: >>> - create the new user in the mysql DB >>> - start with dovecot not using mail_crypt_private_password (so disabled) >>> - send an initial email to let the users mailbox be created and generate the keys >>> - set the users password with doveadm >>> - restart dovecot again with mail_crypt_private_password (so enabled) >>> >>> but this would be disruptive to existing users, and i would have to script the whole thing as a >>> "add-new-user" script to make it usable i guess. >>> >>> do you know of a more easy way of acomplishing this? >>> could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? >>> >>> or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that >>> column with %w for users that allready exist, and empty for new users. >>> when being empty, it might not set the mail_crypt_private_password for new users >>> >>> or is this the wrong way of thinking? >>> >>> let me know your thoughts on this. >>> >>> And last but not least, i really want to thank you for all your help. It is a really nice >>> experience. >>> Bless you! >>> >>> Zjemm >> If you have mail_crypt_private_password set *when* keys are generated, >> dovecot should use that password to encrypt the user key. >> >> Aki > > Hi Aki, > > well, if there is a new email user setup in the mysql DB, and no email has been send to that new user. at that point there are no keys. > > So trying to set a password on those key's wont work. see: > root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey password -u john2(a)example.org -n qwerty > result: Changed password for 0 key(s) > > the keys need to be generated first. And that only happens when sending a mail to that new user. Also, at the point of creating the keys, the mail_crypt_private_password should be disabled otherwise the keys are generated and also encrypted with no user password, and then im unable to set a new pasword for that key > > > How can i set the password before the keys are generated? > or can i manually generate key's and then set the password? > > so at this point i have to do the following: You can use doveadm mailbox cryptokey generate -u user -U to generate a user key. Aki >>> - create the new user in the mysql DB >>> - start with dovecot not using mail_crypt_private_password (so disabled) >>> - send an initial email to let the users mailbox be created and generate the keys >>> - set the users password with doveadm >>> - restart dovecot again with mail_crypt_private_password (so enabled) > can i somehow enable the mail_crypt_private_password per user? > because this mysql query always returns: %w > and thus allways sets: userdb_mail_crypt_private_password > SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM virtual_users;

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Re: Best mail encryption solution for per-user
by Aki Tuomi 23 May '18

23 May '18

On 23.05.2018 09:13, mail(a)sjemm.net wrote: > May 20, 2018 8:01 PM, mail(a)sjemm.net wrote: >> May 20, 2018 2:47 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >> >>>> On 19 May 2018 at 16:40 mail(a)sjemm.net wrote: >>>> >>>> May 18, 2018 10:01 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>>> On 18 May 2018 at 21:44 mail(a)sjemm.net wrote: >>>> >>>> May 18, 2018 4:43 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>>> On 18 May 2018 at 17:38 mail(a)sjemm.net wrote: >>>> >>>> May 18, 2018 4:05 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>>> On 18 May 2018 at 16:43 mail(a)sjemm.net wrote: >>>> >>>> Hi Tai74 and Aki, >>>> I followed your conversation with interest on how to setup per user encryption in dovecot. >>>> I have setup my dovecot with the following in a conf file: >>>> >>>> ============== >>>> >>>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>>> mail_plugins = $mail_plugins mail_crypt >>>> plugin { >>>> >>>> mail_crypt_curve = secp521r1 >>>> >>>> mail_crypt_save_version = 2 >>>> >>>> } >>>> >>>> ============== >>>> >>>> This works nice, all emails are being encrypted and every user/folder has keys. >>>> But as I understood from your conversation these keys are not protected. And I want them to be >>>> protected by the users password used by imap. >>>> >>>> Those passwords are stored in a mysql DB file. ( I used a guide from workaround [dot] org to set up >>>> the DB and postfix/dovecot) >>>> >>>> but how would i set it so, that the users password from the DB is used to encrypt the keys? >>>> >>>> should i use mail_crypt_private_password = ? >>>> how do i point it to the mysql db then? >>>> im unsure about this >>>> >>>> Do you have any hints on this? >>>> >>>> Kind regards, >>>> Zjemm >>>> >>>> The passwords in your MySQL database are, hopefully, not in plaintext. If you want to secure your >>>> user's keys using user's login password, you must have a TOOL that manages this. >>>> >>>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>>> a good option. >>>> >>>> You can change the key password using 'doveadm mailbox cryptokey', this needs to be done every time >>>> user changes his password. >>>> >>>> Also note that if you go down this road, and the user forgets his password, you will not be able to >>>> recover the emails without backup copy of the private key. >>>> >>>> Aki >>>> >>>> Hi Aki >>>> >>>> I used the following command: >>>> dovecot pw -s SHA256-CRYPT >>>> >>>> the output on the chosen password looks like: {SHA256-CRYPT}$5$Rokc06a7In4SF3bO$OQpGQWqg........ >>>> >>>> This output is used to store in the password fields in the database. So no plain text passwords no >>>> :) >>>> >>>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>>> password as private password. >>>> >>>> can you explain this a bit more for me? >>>> >>>> for now i have in the 10-auth.conf file the following: >>>> ============== >>>> passdb { >>>> driver = sql >>>> >>>> # Path for SQL configuration file, see example-config/dovecot-sql.conf.ext >>>> args = /etc/dovecot/dovecot-sql.conf.ext >>>> } >>>> >>>> and: >>>> >>>> userdb { >>>> driver = static >>>> args = uid=vmail gid=vmail home=/var/vmail/%d/%n >>>> } >>>> ============== >>>> >>>> then i have in dovecot-sql.conf.ext >>>> ============== >>>> driver = mysql >>>> connect = host=x.x.x.x dbname=mailserver user=mailuser password=mailpasswordexample >>>> default_pass_scheme = SHA256-CRYPT >>>> password_query = SELECT email as user, password FROM virtual_users WHERE email='%u'; >>>> ============== >>>> Where do i need to set : mail_crypt_private_password = %w ? >>>> >>>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>>> a good option. >>>> >>>> the passwords are allready hashed in the DB using: dovecot pw -s SHA256-CRYPT to genereate the has. >>>> so this step isnt nesesary anymore am i right? >>>> >>>> Thank you for your quick response, very helpfull >>>> >>>> Zjemm >>>> >>>> You misunderstood a bit. The idea is to use the *plaintext* password as the password for the >>>> private key. Otherwise anyone could just decrypt it by looking at your database where the hashed >>>> password is.. >>>> >>>> So: >>>> >>>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>>> virtual_users WHERE email='%u' >>>> >>>> Aki >>>> >>>> Hi Aki, >>>> >>>> Thank you very much for your help, i realy appreciate that. >>>> >>>> Ok so if i understand it correctly i'll have to use: >>>> >>>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>>> virtual_users WHERE email='%u' >>>> >>>> in my dovecot-sql.conf.ext file >>>> >>>> This query selects the user, the password, and %w >>>> >>>> if i run a little query myself: >>>> MariaDB [mailserver]> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password >>>> FROM virtual_users; >>>> +------------------+----------------------------------+------------------------------------+ >>>> | user | password | userdb_mail_crypt_private_password | >>>> +------------------+----------------------------------+------------------------------------+ >>>> | john(a)example.org | {SHA256-CRYPT}$5$M/GWzmtjsLroRWI | %w | >>>> +------------------+----------------------------------+------------------------------------+ >>>> >>>> %w is a dovecot variable, and stands for the plaintext password, but the password is not stored as >>>> plaintext in the DB, %w get filled with the actual plaintext password by dovecot upon the user that >>>> is typing in the password when authenticating. >>>> >>>> is this correct? >>>> >>>> yes. >>>> >>>> so then i have the username the hashed password en the plaintext password as a result of the query. >>>> >>>> yes >>>> >>>> now userdb_mail_crypt_private_password = the plaintext password >>>> do i need to reference it somewhere? or is userdb_mail_crypt_private_password autmatically used by >>>> the dovecot mail_crypt plugin to encrypt the keys? or should it be mail_crypt_private_password? >>>> >>>> It gets injected into the mail process as 'mail_crypt_private_password', as if it was set in plugin >>>> {} section. >>>> >>>> if i have this setup working i'm going to write a blog post on this topic to share this knowledge >>>> >>>> Thanks again and have a great weekend. >>>> >>>> Zjemm >>>> >>>> Aki >>>> >>>> Hi Aki, >>>> >>>> Cool i'm testing it right now. >>>> I have set up a new mailserver (life is great with lxc containers :) ) >>>> >>>> postfix and dovecot are working like normal >>>> >>>> next i enable mail_crypt >>>> >>>> i did create a file: /etc/dovecot/conf.d/10-mailcrypt.conf >>>> ========================== >>>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>>> >>>> mail_plugins = $mail_plugins mail_crypt >>>> >>>> plugin { >>>> mail_crypt_curve = secp521r1 >>>> mail_crypt_save_version = 2 >>>> } >>>> ========================== >>>> >>>> and then i changed the file: /etc/dovecot/dovecot-sql.conf.ext >>>> >>>> so the query is now the new query: >>>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>>> virtual_users WHERE email='%u'; >>>> >>>> then i restarted dovecot and postfix and send a test email to the one and only testuser that is in >>>> there. >>>> >>>> when i open the mailbox with the tool mutt, i can see the new email, and when openening the email >>>> the mutt client drops the connection. >>>> >>>> in the log i can see: >>>> >>>> May 19 13:34:48 mailserver1.example.local dovecot[600]: imap-login: Login: user=<john(a)example.org>, >>>> method=PLAIN, rip=::1, lip=::1, mpid=713, TLS, session=<E3PnIY9sNM4AAAAAAAAAAAAAAAAAAAAB> >>>> May 19 13:34:49 mailserver1.example.local dovecot[600]: imap(john(a)example.org): Error: read() >>>> failed: >>>> read(/var/vmail/example.org/john/Maildir/cur/1526736378.M161472P641.mailser…, >>>> =571:2,) failed: Private key not available: Cannot decrypt key >>>> bfc5bb25b1bf64290eea6dc14b516c6a0a25b64551b6e4f0f8677ba7274887cb: error:03070068:bignum >>>> routines:BN_mpi2bn:encoding error (FETCH BODY[] for mailbox INBOX UID 8) >>>> >>>> i think i missed a step, but witch one? >>>> >>>> the userpassword hasnt been changed (that would be the next step in the testing process) >>>> >>>> should i've use doveadm first to encrypt the key with that userpassword? i thought it would do that >>>> on the fly, because the initial keys where only just created when enabling the mail_crypt plugin >>>> >>>> please let me know your thougts >>>> Zjemm >>> I noticed you replied directly to me, and not to the list, too... fixed that for you. >>> >>> mail_crypt_private_password is used when key is created, but if you have created it before using >>> password, you'll need to encrypt it before turning the setting on. >>> >>> Aki >> Hi, Ok i'm sorry about that, thank you for fixing that. i'm a bit new to mailing lists :) >> >> are you a dovecot devoloper? or a enthusiastic user? >> >> anyway, i managed to get it working now with all your help :) >> >> to start fresh i did a: >> rm -rf /var/vmail/example.org >> >> so all email is gone, and i assume all dovecot keys are gone that way. >> >> Then i tried to set a password first: >> >> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >> result: Changed password for 0 key(s) >> >> (summersun = the password for this user) >> >> but then it says there are 0 keys, so then i send the test user an email and try to open the >> mailbox, i'll get: >> >> imap(john(a)example.org): Error: read() failed: >> read(/var/vmail/example.org/john/Maildir/cur/1526827992.M149712P883.mailser…, >> =561:2,) failed: Private key not available: Cannot decrypt key >> 71849013a70b0c631c06112077e7c2fe39b0b2737b4933b219793841209d4e7f: error:03070068:bignum >> routines:BN_mpi2bn:encoding error >> >> but hey, now the key's are created, so i tried to set the password again: >> >> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >> result: dcrypt_key_load_private(787701bd677dd69a26842547a3926cbaa625b0b5a91751f06678c3e9708343d9) >> failed: password missing >> ========= >> >> Lets start over again, i did a new: >> rm -rf /var/vmail/example.org >> >> i disabled the mail_crypt_private_password in the sql query and send an email to the test user. >> now again new keys are generated. >> >> then i did set the password via doveadm: >> >> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >> result: Changed password for 1 key(s) >> >> i enabled the mail_crypt_private_password again in the sql query part and now it works :) >> >> YESSS!!! >> >> if i now change the password for the user, i cannot read the email anymore. that is what should >> happen. >> so now i changed the password for this user also with doveadm: >> - doveadm mailbox cryptokey password -u john(a)example.org -n qwerty -o summersun >> >> and now i'm able to read the emails again. so it all works now as expected. >> >> i have now only one thing remaining. >> >> when i want to add a new user, i have to somehow: >> - create the new user in the mysql DB >> - start with dovecot not using mail_crypt_private_password (so disabled) >> - send an initial email to let the users mailbox be created and generate the keys >> - set the users password with doveadm >> - restart dovecot again with mail_crypt_private_password (so enabled) >> >> but this would be disruptive to existing users, and i would have to script the whole thing as a >> "add-new-user" script to make it usable i guess. >> >> do you know of a more easy way of acomplishing this? >> could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? >> >> or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that >> column with %w for users that allready exist, and empty for new users. >> when being empty, it might not set the mail_crypt_private_password for new users >> >> or is this the wrong way of thinking? >> >> let me know your thoughts on this. >> >> And last but not least, i really want to thank you for all your help. It is a really nice >> experience. >> Bless you! >> >> Zjemm > Hi Aki, > > You did fix the posting on the mail archive, i can see our conversation on there, all but the last email i send to you. > Maybe you did not received the last email? > > would you be willing to take a look at my last question in the email See below: > Thank you very much. > > ================================ > i have now only one thing remaining. > > when i want to add a new user, i have to somehow: > - create the new user in the mysql DB > - start with dovecot not using mail_crypt_private_password (so disabled) > - send an initial email to let the users mailbox be created and generate the keys > - set the users password with doveadm > - restart dovecot again with mail_crypt_private_password (so enabled) > > but this would be disruptive to existing users, and i would have to script the whole thing as a "add-new-user" script to make it usable i guess. > > do you know of a more easy way of acomplishing this? > could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? > > or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that column with %w for users that allready exist, and empty for new users. > when being empty, it might not set the mail_crypt_private_password for new users > > or is this the wrong way of thinking? > > let me know your thoughts on this. > > And last but not least, i really want to thank you for all your help. It is a really nice experience. > Bless you! > > Zjemm If you have mail_crypt_private_password set *when* keys are generated, dovecot should use that password to encrypt the user key. Aki

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Cannot delete folder
by Yves Goergen 22 May '18

22 May '18

Hi there, I cannot delete IMAP folders in new mailboxes. When trying to delete a folder in Thunderbird I get the error message "renaming not supported across conflicting directory permissions". Looking up the error on the web led me to checking the mailbox directory's permissions. They're inconsistent in new mailboxes. While every single directory in an old mailbox has "drwx--S---", some of the directories in a new mailbox have "drwxr-sr-x" instead. I'm not sure what that means. The folders with the later permissions are "Drafts", "Sent" and "Trash". Folders with the first permissions are "Junk", "Archives" and "Archives.2018". All folders were created by Thunderbird automatically. Now I wanted to delete "Archives.2018". What's the issue here? Why do folders created by the same MUA in the same event on the same mail server have different permissions and why can't I delete one of them (which would probably move it into the trash folder first)? Dovecot version is 2.2.22 on Ubuntu 16.04, Thunderbird is 52.6.0 on Windows 10. -Yves

7 19

(no subject)
by Rebel Mee 21 May '18

21 May '18

0b4a77c09cb4c18c49177e4ad76e0b62e3ec5ae0

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(no subject)
by Rebel Mee 21 May '18

21 May '18

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Dovecot blacklist?
by Marc Perkel 21 May '18

21 May '18

Just wondering if there is an easy way to have dovecot do a blacklist lookup as a negative authentication so that if the IP is on a blacklist then authentification fails even if they get the password right. If this works I have a blacklist everyone can use.

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SSL error after upgrading to 2.31
by Marc Perkel 21 May '18

21 May '18

After upgrading to 2.31 I'm getting this error. Not sure what I'm doing wrong. No (No signatures could be verified because the chain contains only one certificate and it is not self signed.) ssl = yes ssl_cert = </etc/exim/certs/ctyme.com.crt ssl_key = </etc/exim/certs/ctyme.com.key ssl_ca = </etc/exim/certs/ca.crt local mail.ctyme.com { protocol imap { ssl_cert = </etc/exim/certs/ctyme.com.crt ssl_key = </etc/exim/certs/ctyme.com.key ssl_ca = </etc/exim/certs/ca.crt } protocol pop3 { ssl_cert = </etc/exim/certs/ctyme.com.crt ssl_key = </etc/exim/certs/ctyme.com.key ssl_ca = </etc/exim/certs/ca.crt } } local mail.junkemailfilter.com { protocol imap { ssl_cert = </etc/exim/certs/junkemailfilter.com.crt ssl_key = </etc/exim/certs/junkemailfilter.com.key ssl_ca = </etc/exim/certs/ca.crt } protocol pop3 { ssl_cert = </etc/exim/certs/junkemailfilter.com.crt ssl_key = </etc/exim/certs/junkemailfilter.com.key ssl_ca = </etc/exim/certs/ca.crt } }

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install dovecot 2.2.35 debian jessie
by Webert de Souza Lima 21 May '18

21 May '18

Hi, I can't figure how to install latest stable dovecot version 2.2.35 in Debian Jessie If I follow this guide <https://repo.dovecot.org/>, it ends up installing 2.3 If I follow this guide <https://wiki.dovecot.org/PrebuiltBinaries#preview>, it ends up installing either 2.2.13 if I use "stable" or 2.2.36 alpha if I use "jessie" I see that 2.2.35 seems to be missing here too: http://xi.dovecot.fi/debian/pool/jessie-auto/dovecot-2.2/ Thanks. Regards, Webert Lima DevOps Engineer at MAV Tecnologia *Belo Horizonte - Brasil* *IRC NICK - WebertRLZ*

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Dovecot fts script with solr
by André Rodier 21 May '18

21 May '18

Hello again, I have created a parser script, a little bit more advanced than the one provided with Dovecot. The main feature is probably to index documents inside zip/rar/tgz archives... I am using Ansible, swaks and doveadm to run automatic tests for each supported content. For specific reasons, I am not yet able to add Apache Tika to the distribution. However, I already made some tests with it. For now, I want to talk about the indexing script. I also have noticed a few weird behaviours. I will mention them at the end, albeit I am not 100% sure where they are coming from. I realised last week that using QEMU snapshots was not working as expected, so I am now more careful with this feature. For the developers or users who would be interested and the Dovecot team members to understand my questions, here how the tests are working: To run my tests, I have a set of files in various formats, with a UUID inside. They are office files, text files, or even archives with a text file inside... The first test I am running is the script alone. I check that the script can convert the file to text, and then I use grep to check the UUID is present. This works *perfectly* for all the content, except ppt, but it's minor. The second test is full: - I use swaks to send the email with an attachment and the appropriate mime type. - I then refresh the index using doveadm rescan. - I check that fts search returns a line, with doveadm fts search. - I then expunge the mailbox to be sure that the next test is valid. For the second test, it works almost all the time, except in the following situations: - When the attachment is an email (mime type message/rfc822) - RTF (could be a bug in my script) - Text file in UTF16 (Even if this file is converted to UTF8) *Questions:* 1 - Is there any limitation or special case for the mime message/rfc822 2 - Is the mime type received coming from the email headers? 3 - When the script is called without arguments, what is the purpose of the extension at the end of each supported mime types? 4 - Can I return a wildcard in the supported mime types, for instance "text/* *" ? 5 - I would like to handle attachments of types application/octet-stream. I have added "application/octet-stream *", but I am not sure if dovecot will pass the attachments with these mime type or not. *Notes:* 1 - I used netcat to monitor the solr server. I realise that sometimes, the data sent to the solr server only contains the headers of the email, not the text returned by the parser. Especially with rfc822 messages. I will do more tests. 2 - I just finished to write the script, it's not yet refactored, but at list it is well documented. I will do a full security audit later. I am actually testing an associated AppArmor profile. 3 - I will do more intensive test on the script on bigger mail boxes with more attachments. 4 - I may rewrite the script in Python 5 - Suggestions welcome. I initially attached the current version of the script, but the email is probably pending for review...In this case, the last development version is on Github: https://github.com/progmaticltd/homebox/blob/dev/install/playbooks/roles/do… The configuration of supported mime types is a simple file, accessible on github as well: https://github.com/progmaticltd/homebox/blob/dev/install/playbooks/roles/do… Thanks for your advices or suggestions.

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Re: Best mail encryption solution for per-user
by Aki Tuomi 20 May '18

20 May '18

> On 19 May 2018 at 16:40 mail(a)sjemm.net wrote: > > > May 18, 2018 10:01 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: > >> On 18 May 2018 at 21:44 mail(a)sjemm.net wrote: > >> > >> May 18, 2018 4:43 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: > >> On 18 May 2018 at 17:38 mail(a)sjemm.net wrote: > >> > >> May 18, 2018 4:05 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: > >> On 18 May 2018 at 16:43 mail(a)sjemm.net wrote: > >> > >> Hi Tai74 and Aki, > >> I followed your conversation with interest on how to setup per user encryption in dovecot. > >> I have setup my dovecot with the following in a conf file: > >> > >> ============== > >> > >> mail_attribute_dict = file:%h/Maildir/dovecot-attributes > >> mail_plugins = $mail_plugins mail_crypt > >> plugin { > >> > >> mail_crypt_curve = secp521r1 > >> > >> mail_crypt_save_version = 2 > >> > >> } > >> > >> ============== > >> > >> This works nice, all emails are being encrypted and every user/folder has keys. > >> But as I understood from your conversation these keys are not protected. And I want them to be > >> protected by the users password used by imap. > >> > >> Those passwords are stored in a mysql DB file. ( I used a guide from workaround [dot] org to set up > >> the DB and postfix/dovecot) > >> > >> but how would i set it so, that the users password from the DB is used to encrypt the keys? > >> > >> should i use mail_crypt_private_password = ? > >> how do i point it to the mysql db then? > >> im unsure about this > >> > >> Do you have any hints on this? > >> > >> Kind regards, > >> Zjemm > >> > >> The passwords in your MySQL database are, hopefully, not in plaintext. If you want to secure your > >> user's keys using user's login password, you must have a TOOL that manages this. > >> > >> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login > >> password as private password. You might want to run it thru some hash, so %{sha1:password} might be > >> a good option. > >> > >> You can change the key password using 'doveadm mailbox cryptokey', this needs to be done every time > >> user changes his password. > >> > >> Also note that if you go down this road, and the user forgets his password, you will not be able to > >> recover the emails without backup copy of the private key. > >> > >> Aki > >> > >> Hi Aki > >> > >> I used the following command: > >> dovecot pw -s SHA256-CRYPT > >> > >> the output on the chosen password looks like: {SHA256-CRYPT}$5$Rokc06a7In4SF3bO$OQpGQWqg........ > >> > >> This output is used to store in the password fields in the database. So no plain text passwords no > >> :) > >> > >> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login > >> password as private password. > >> > >> can you explain this a bit more for me? > >> > >> for now i have in the 10-auth.conf file the following: > >> ============== > >> passdb { > >> driver = sql > >> > >> # Path for SQL configuration file, see example-config/dovecot-sql.conf.ext > >> args = /etc/dovecot/dovecot-sql.conf.ext > >> } > >> > >> and: > >> > >> userdb { > >> driver = static > >> args = uid=vmail gid=vmail home=/var/vmail/%d/%n > >> } > >> ============== > >> > >> then i have in dovecot-sql.conf.ext > >> ============== > >> driver = mysql > >> connect = host=x.x.x.x dbname=mailserver user=mailuser password=mailpasswordexample > >> default_pass_scheme = SHA256-CRYPT > >> password_query = SELECT email as user, password FROM virtual_users WHERE email='%u'; > >> ============== > >> Where do i need to set : mail_crypt_private_password = %w ? > >> > >> password as private password. You might want to run it thru some hash, so %{sha1:password} might be > >> a good option. > >> > >> the passwords are allready hashed in the DB using: dovecot pw -s SHA256-CRYPT to genereate the has. > >> so this step isnt nesesary anymore am i right? > >> > >> Thank you for your quick response, very helpfull > >> > >> Zjemm > >> > >> You misunderstood a bit. The idea is to use the *plaintext* password as the password for the > >> private key. Otherwise anyone could just decrypt it by looking at your database where the hashed > >> password is.. > >> > >> So: > >> > >> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM > >> virtual_users WHERE email='%u' > >> > >> Aki > >> > >> Hi Aki, > >> > >> Thank you very much for your help, i realy appreciate that. > >> > >> Ok so if i understand it correctly i'll have to use: > >> > >> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM > >> virtual_users WHERE email='%u' > >> > >> in my dovecot-sql.conf.ext file > >> > >> This query selects the user, the password, and %w > >> > >> if i run a little query myself: > >> MariaDB [mailserver]> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password > >> FROM virtual_users; > >> +------------------+----------------------------------+------------------------------------+ > >> | user | password | userdb_mail_crypt_private_password | > >> +------------------+----------------------------------+------------------------------------+ > >> | john(a)example.org | {SHA256-CRYPT}$5$M/GWzmtjsLroRWI | %w | > >> +------------------+----------------------------------+------------------------------------+ > >> > >> %w is a dovecot variable, and stands for the plaintext password, but the password is not stored as > >> plaintext in the DB, %w get filled with the actual plaintext password by dovecot upon the user that > >> is typing in the password when authenticating. > >> > >> is this correct? > > > > yes. > > > >> so then i have the username the hashed password en the plaintext password as a result of the query. > > > > yes > > > >> now userdb_mail_crypt_private_password = the plaintext password > >> do i need to reference it somewhere? or is userdb_mail_crypt_private_password autmatically used by > >> the dovecot mail_crypt plugin to encrypt the keys? or should it be mail_crypt_private_password? > > > > It gets injected into the mail process as 'mail_crypt_private_password', as if it was set in plugin > > {} section. > > > >> if i have this setup working i'm going to write a blog post on this topic to share this knowledge > >> > >> Thanks again and have a great weekend. > >> > >> Zjemm > > > > Aki > > Hi Aki, > > Cool i'm testing it right now. > I have set up a new mailserver (life is great with lxc containers :) ) > > postfix and dovecot are working like normal > > next i enable mail_crypt > > i did create a file: /etc/dovecot/conf.d/10-mailcrypt.conf > ========================== > mail_attribute_dict = file:%h/Maildir/dovecot-attributes > > mail_plugins = $mail_plugins mail_crypt > > plugin { > mail_crypt_curve = secp521r1 > mail_crypt_save_version = 2 > } > ========================== > > and then i changed the file: /etc/dovecot/dovecot-sql.conf.ext > > so the query is now the new query: > password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM virtual_users WHERE email='%u'; > > then i restarted dovecot and postfix and send a test email to the one and only testuser that is in there. > > when i open the mailbox with the tool mutt, i can see the new email, and when openening the email the mutt client drops the connection. > > in the log i can see: > > May 19 13:34:48 mailserver1.example.local dovecot[600]: imap-login: Login: user=<john(a)example.org>, method=PLAIN, rip=::1, lip=::1, mpid=713, TLS, session=<E3PnIY9sNM4AAAAAAAAAAAAAAAAAAAAB> > May 19 13:34:49 mailserver1.example.local dovecot[600]: imap(john(a)example.org): Error: read() failed: read(/var/vmail/example.org/john/Maildir/cur/1526736378.M161472P641.mailser… failed: Private key not available: Cannot decrypt key bfc5bb25b1bf64290eea6dc14b516c6a0a25b64551b6e4f0f8677ba7274887cb: error:03070068:bignum routines:BN_mpi2bn:encoding error (FETCH BODY[] for mailbox INBOX UID 8) > > > i think i missed a step, but witch one? > > the userpassword hasnt been changed (that would be the next step in the testing process) > > should i've use doveadm first to encrypt the key with that userpassword? i thought it would do that on the fly, because the initial keys where only just created when enabling the mail_crypt plugin > > please let me know your thougts > Zjemm I noticed you replied directly to me, and not to the list, too... fixed that for you. mail_crypt_private_password is used when key is created, but if you have created it before using password, you'll need to encrypt it before turning the setting on. Aki

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