Friday, October 19, 2007

Dovecot IMAP + Squirrel Mail + retrieve user data + Active Directory + Postfix

Written by Paul Matthews

This is my replacement for M$ exchange server. Dovecot runs as either pop3 or imap, the Perl script draws down the aliases from the Active Directory CN, postfix runs as the SMTP server, Squirrel Mail runs as my mail
client and the Squirrel Mail plug-in draws the needed information down from Active directory automatically every time you login and places it in your squirrel mail preferences and winbind authenticates against active directory to synchronize the usernames/passwords between ADS and the Linux box.

Name: Dovecot
HomePage: http://dovecot.org/
Function: Dovecot is an open source IMAP and POP3 server for Linux/UNIX-like systems, written with security primarily in mind.

Name: Postfix
HomePage: http://www.postfix.org/
Function: Postfix attempts to be fast, easy to administer, and secure, while at the same time being sendmail compatible enough to not upset existing users

Name: Squirrel Mail
Homepage: http://www.squirrelmail.org/
Function: Webmail client, used to check e-mails from anywhere in world, via the internet, like gmail or hotmail



1. Edit the dovecot file dovecot.conf




nano /etc/dovecot.conf



dovecot.conf:
protocols = imap


2. Make the '/home/MYDOMAIN' directory writable by everyone

chmod a+rwx /home/MYDOMAIN

3. Now edit the dovecot.conf file.



/etc/dovecot.conf



dovecot.conf:
auth_userdb = passwd

auth_passdb = pam

default_mail_env = mbox:/home/%D/%u/mail:INBOX=/var/spool/mail/%u


4. Set dovecot to start on boot and then start it

chkconfig dovecot on

/etc/init.d/dovecot start

5. Start the apache webserver next,

/etc/init.d/httpd start

6. Make sure that squirrelmail is working properly go to the web address

http://ip-address-of-the-mail-server/webmail/

(if squirrelmail was installed at the installation of fedora this alias should already be made)

5. Now it's time get winbind to authenticate against Active Directory. stop both winbind and samba services

/etc/init.d/smb stop
/etc/init.d/winbind stop

7. Edit Kerberos files to have the right configuration

/etc/krb5.conf



krb5.conf:
[libdefaults]
default_realm = WINDOWS.SERVER.INT

[realms]
WINDOWS.SERVER.INT = {
kdc = mc1.windows.server.int
default_domain = WINDOWS.SERVER.INT
kpasswd_server = mc1.windows.server.int
admin_server = mc1.windows.server.int
}

[domain_realm]
.windows.server.int = WINDOWS.SERVER.INT


8. Edit Samba files to have the right configuration

/etc/samba/smb.conf



smb.conf:
workgroup = server
security = ads
realm = WINDOWS.SERVER.INT
encrypt passwords = yes

username map = /etc/samba/smbusers

winbind uid = 10000-20000
winbind gid = 10000-20000
winbind use default domain = yes
winbind enum users = yes
winbind enum groups = yes


9. Now it's time to join the domain

net ads join -U administrator -S mc1

10. Now we need to edit the nsswitch.conf file



nano /etc/nsswitch.conf

from:



nsswitch.conf:
passwd: files
shadow: files
group: files


to:



nsswitch.conf:
passwd: files winbind
shadow: files winbind
group: files winbind


11. Now it's time to start both winbind and samba services

/etc/init.d/smb start
/etc/init.d/winbind start

12. Now hopefully all that went well, to test it out lets try this comand

/usr/bin/wbinfo -g

this should display all the groups in your active directory structure.

13. Now it is time to edit dovecot pam module

nano /etc/pam.d/dovecot



Code.conf:
#%PAM-1.0

auth sufficient /lib/security/$ISA/pam_unix.so likeauth nullok
auth required pam_listfile.so onerr=fail file=/etc/postfix/usernames item=user sense=allow
auth sufficient pam_winbind.so

account required /lib/security/$ISA/pam_unix.so
account sufficient /lib/security/$ISA/pam_localuser.so
account sufficient /lib/security/$ISA/pam_succeed_if.so uid < 100 quiet
account required /lib/security/$ISA/pam_permit.so

password requisite /lib/security/$ISA/pam_cracklib.so retry=3
password sufficient /lib/security/$ISA/pam_unix.so nullok use_authtok
password required /lib/security/$ISA/pam_deny.so

session required /lib/security/$ISA/pam_limits.so
session required /lib/security/$ISA/pam_unix.so
auth required /lib/security/$ISA/pam_deny.so


14. Once that is done it's time to setup the aliases in postfix and usernames, download the following scripts.

http://www.opensourcehowto.org/uploads/scripts/getadusername_pl.txt

http://www.opensourcehowto.org/uploads/scripts/getadalias_pl.txt

http://www.opensourcehowto.org/uploads/scripts/getadusernameformap_pl.txt

15. Edit the files to suit your network

16. Now add the following in this file

nano /etc/postfix/sync-db



sync-db:
/etc/postfix/getadalias_pl.txt
/etc/postfix/getadusernameforlocalmap_pl.txt
/etc/postfix/getadusername_pl.txt
/usr/sbin/postalias hash:/etc/postfix/ldap-aliases.cf
/usr/sbin/postmap hash:/etc/postfix/usernames_forlocalmaps


17. Make cron run this script every 10 minutes, or whenever you want it to.

crontab -e

then place the following information into the file

31 * * * * /etc/postfix/sync-db

18. Make the files executable and then run it

chmod ug+rwx /etc/postfix/getadalias_pl.txt
/etc/postfix/getadalias_pl.txt

chmod ug+rwx /etc/postfix/getadusername_pl.txt
/etc/postfix/getadusername_pl.txt

chmod ug+rwx /etc/postfix/getadusernameforlocalmap_pl.txt
/etc/postfix/getadusernameforlocalmap_pl.txt

chmod ug+rwx /etc/postfix/sync-db
/etc/postfix/sync-db

19. Change your postfix main.cf file to look like this



nano /etc/postfix/main.cf


main.cf:
alias_maps = hash:/etc/aliases, hash:/etc/postfix/ldap-aliases.cf

local_recipient_maps = unix:passwd.byname hash:/etc/postfix/usernames_forlocalmaps


20. This requires Net::LDAP to be installed. To install Net::LDAP,

Download it from

http://search.cpan.org/~gbarr/perl-ldap-0.33/lib/Net/LDAP.pod

Install it

21. This script searches your active directory database to returns with the
sAMAccountName and mail attriube, strips out the unnecessary
'@example.com' and then places them in the file that you choose when
editing the script (eg: /etc/postfix/ldap-aliases.cf) in the format of
postfix aliases (aliases: username).

22. Download the 'Retrieve User Data' from the plugins section of the squirrelmail website

http://www.squirrelmail.org/plugin_view.php?id=11

and put the file in the folder

/usr/share/squirrelmail/plugins

23. Unzip the file

gzip -d retrieveuserdata.0.9-1.4.0.tar.gz

tar -xvf retrieveuserdata.0.9-1.4.0.tar

24. The to the folder '/usr/share/squirrelmail/config' and run the program

./conf.pl

23. Choose option 8 'Plugins' and then installed the retrieveuserdata plugin by selecting the number next do it, after it has

been installed choose the save option 's' then quit 'q'

25. Then go back into the plugins folder and into the retrieveuserdata folder

cd /usr/share/squirrelmail/plugins/retrieveuserdata

26. Edit the below part of your 'config.php' file to suit your network settings.



nano config.php




config.php:
$SQRUD_LDAP_FROM_MAIN_CONFIG = 0;
$SQRUD_LDAP_UID = "sAMAccountName";
$SQRUD_LDAP_USERNAME = "displayName";
$SQRUD_LDAP_MAIL = "mail"; // or "mail"
$SQRUD_LDAP_MAIL_ALIASES = "proxyaddresses";
$SQRUD_LDAP_MAIL_ALIAS_PREFIX = "smtp:";
$SQRUD_LDAP_ANONYMOUS_BIND = 0;
// $SQRUD_LDAP_BIND_RDN = "cn=moodleuser,cn=users,dc=fedora,dc=directory,dc=server";
$SQRUD_LDAP_BIND_RDN = "fedora\\SQRUD_UID"; // for Microsoft ADS
$SQRUD_LDAP_SERVER[0] = array(
'host' => 'fedora.directory.server', // hostname, required
'base' => 'dc=fedora,dc=directory,dc=server', // base distinguished name, required
'port' => '389', // port, optional
'charset' => 'utf-8' // charset, optional


27. Now we need to change the way squirrel mail delievers it's mail

/usr/share/squirrelmail/config/conf.pl

Choose:

2. Server Settings

Choose:

3. Sendmail or SMTP : SMTP

Choose

SMTP

Choose:

Return 'R' & then

Choose

4. General Options

Then

10. Allow editing of identity

Make Both false/false

28. Now we need to set postfix as the default MTA for the system

'alternatives --config mta'

then select postfix as your mta

29. Now it's time to set all our severs

chkconfig postfix on

/etc/init.d/potfix start

/etc/init.d/sendmail stop

rpm -qa | grep sendmail

sendmail-8.13.1-2
sendmail-cf-8.13.1-2

rpm -e sendmail-8.13.1-2
rpm -e sendmail-cf-8.13.1-2

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