Integrate Windows AD with Ubuntu using SSSD

558 Nesvin KN February 9, 2024 Tweaks & Configuration 2347

How to integrate Windows AD with Ubuntu 18/20/22 using SSSD?

Ensure that the following ports on the Ubuntu host are open and accessible to the AD domain controllers.

DNS =53, LDAP =389, Kerberos 88 & 464, LDAP Global Catalog 3268 and NTP 123 (UDP)

Verify that the system time on both systems is synchronized. This ensures that Kerberos is able to work correctly.

Refer article to correct server time in Centos, RHEL, Ubuntu, SUSE

1. Login to Ezeelogin Web-GUI > open settings > Ldap

How to find base DN and bind RDN

Add the details of LDAP configurations.

Verify Certificate feature is only available from Ezeelogin version 7.35.0.

Refer article to upgrade Ezeelogin to the latest version.

2. Go to Settings > General > Authentication > change Web Panel Authentication to LDAP

3. Select the LDAP users and click on the button to import users into Ezeelogin

You can confirm the imported LDAP users were listed in the Users tab in Ezeelogin GUI. You will be able to log in to Ezeelogin GUI with windows user credentials.

4. Enable Security Code LDAP option from Settings > General > Authentication, if the user does not want to login to Ezeelogin GUI to set up a security code.

Backend configuration to integrate Windows with Ubuntu

1. Install the required packages.

root@gateway ~]# apt-get install realmd sssd oddjob oddjob-mkhomedir adcli samba-common krb5-user nscd -y

2. Provide Windows IP and Windows domain name in hosts file.

root@gateway ~]# vim /etc/hosts

windows_ip windows_domain_name

3. Provide Windows IP in resolv.conf to resolve and discover the AD domain.

root@gateway ~]# vim /etc/resolv.conf

nameserver windows_ip

4. Check if AD domain discovery is successful. Refer below example with ldapad.com

root@gateway ~]# realm discover ldapad.com

ldapad.com
type: kerberos
realm-name: LDAPAD.COM
domain-name: ldapad.com
configured: kerberos-member
server-software: active-directory
client-software: sssd
required-package: sssd-tools
required-package: sssd
required-package: libnss-sss
required-package: libpam-sss
required-package: adcli
required-package: samba-common-bin
login-formats: %U
login-policy: allow-realm-logins

5. Join Ubuntu in the Active Directory domain. Replace Administrator with Windows admin account.

root@gateway ~]# realm join ldapad.com -U Administrator

Password for Administrator:

6. Confirm joining successfully with the realm list. Refer below example.

root@gateway ~]# realm list

7. After successful joining you will get below sssd.conf and you need to change use_fully_qualified_names to False and shell to ezsh.

root@gateway ~]# vim /etc/sssd/sssd.conf

[sssd]
domains = ldapad.com
config_file_version = 2
services = nss, pam

[domain/ldapad.com]
ad_domain = ldapad.com
krb5_realm = LDAPAD.COM
realmd_tags = manages-system joined-with-adcli
cache_credentials = True
id_provider = ad
krb5_store_password_if_offline = True
default_shell = /bin/bash
ldap_id_mapping = True
use_fully_qualified_names = False
fallback_homedir = /home/%u@%d
access_provider = ad

override_shell = /usr/local/bin/ezsh

8. Enable autocreate home directory on login by adding the following to /etc/pam.d/common-session by the following command

root@gateway ~]# echo "session optional pam_mkhomedir.so skel=/etc/skel umask=077" >> /etc/pam.d/common-session

9. Restart sssd and nscd using the below commands.

root@gateway ~]# systemctl restart sssd nscd

10. Run id username /getent passwd username and see AD user details.

root@gateway ~]# id john
uid=1701601108(john) gid=1701600513(domain users) groups=1701600513(domain users)

root@gateway ~]# getent passwd john
john:*:1701601108:1701600513:john user:/home/[email protected]:/usr/local/bin/ezsh

Use the below command to clear the cache of the user.

root@gateway ~]# sss_cache -u username

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