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sssd

Support level: Community

What is sssd​

From https://sssd.io/

note

SSSD is an acronym for System Security Services Daemon. It is the client component of centralized identity management solutions such as FreeIPA, 389 Directory Server, Microsoft Active Directory, OpenLDAP and other directory servers. The client serves and caches the information stored in the remote directory server and provides identity, authentication and authorization services to the host machine.

Note that authentik supports only user and group objects. As a consequence, it cannot be used to provide automount or sudo configuration nor can it provide netgroups or services to nss. Kerberos is also not supported.

Preperation​

The following placeholders will be used:

  • authentik.company is the FQDN of the authentik install.
  • ldap.baseDN is the Base DN you configure in the LDAP provider.
  • ldap.domain is (typically) an FQDN for your domain. Usually it is just the components of your base DN. For example, if ldap.baseDN is dc=ldap,dc=goauthentik,dc=io then the domain might be ldap.goauthentik.io.
  • ldap.searchGroup is the "Search Group" that can can see all users and groups in authentik.
  • sssd.serviceAccount is a service account created in authentik
  • sssd.serviceAccountToken is the service account token generated by authentik.

Create an LDAP Provider if you don't already have one setup. This guide assumes you will be running with TLS and that you've correctly setup certificates both in authentik and on the host running sssd. See the ldap provider docs for setting up SSL on the authentik side.

Remember the Base DN you have configured for the provider as you'll need it in the sssd configuration.

Create a new service account for all of your hosts to use to connect to LDAP and perform searches. Make sure this service account is added to ldap.searchGroup.

Deployment​

Create an outpost deployment for the provider you've created above, as described here. Deploy this Outpost either on the same host or a different host that your host(s) running sssd can access.

The outpost will connect to authentik and configure itself.

Client Configuration​

First, install the necessary sssd packages on your host. Very likely the package is just sssd.

note

This guide well help you configure the sssd.conf for LDAP only. You will likely need to perform other tasks for a usable setup like setting up automounted or autocreated home directories that are beyond the scope of this guide. See the "additional resources" section for some help.

Create a file at /etc/sssd/sssd.conf with contents similar to the following:

[nss]
filter_groups = root
filter_users = root
reconnection_retries = 3

[sssd]
config_file_version = 2
reconnection_retries = 3
sbus_timeout = 30
domains = ${ldap.domain}
services = nss, pam, ssh

[pam]
reconnection_retries = 3

[domain/${ldap.domain}]
cache_credentials = True
id_provider = ldap
chpass_provider = ldap
auth_provider = ldap
access_provider = ldap
ldap_uri = ldaps://${authentik.company}:636

ldap_schema = rfc2307bis
ldap_search_base = ${ldap.baseDN}
ldap_user_search_base = ou=users,${ldap.baseDN}
ldap_group_search_base = ${ldap.baseDN}

ldap_user_object_class = user
ldap_user_name = cn
ldap_group_object_class = group
ldap_group_name = cn

# Optionally, filter logins to only a specific group
#ldap_access_order = filter
#ldap_access_filter = memberOf=cn=authentik Admins,ou=groups,${ldap.baseDN}

ldap_default_bind_dn = cn=${sssd.serviceAccount},ou=users,${ldap.baseDN}
ldap_default_authtok = ${sssd.serviceAccountToken}

You should now be able to start sssd; however, the system may not yet be setup to use it. Depending on your platform, you may need to use authconfig or pam-auth-update to configure your system. See the additional resources section for details.

note

You can store SSH authorized keys in LDAP by adding the sshPublicKey attribute to any user with their public key as the value.

Additional Resources​

The setup of sssd may vary based on Linux distribution and version, here are some resources that can help you get this setup:

note

authentik is providing a simple LDAP server, not an Active Directory domain. Be sure you're looking at the correct sections in these guides.