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OPNsense

Support level: Community

What is OPNsense​

OPNsense is a free and Open-Source FreeBSD-based firewall and routing software. It is licensed under an Open Source Initiative approved license.

-- https://opnsense.org/

note

This is based on authentik 2024.2.2 and OPNsense 24.1.3_1-amd64 installed using https://docs.opnsense.org/manual/install.html. Instructions may differ between versions.

Preparation​

The following placeholders will be used:

  • authentik.company is the FQDN of authentik.
  • opnsense is the name of the authentik Service account we'll create.
  • DC=ldap,DC=goauthentik,DC=io is the Base DN of the LDAP Provider (default)

Step 1​

In authentik, go and 'Create Service account' (under Directory/Users) for OPNsense to use as the LDAP Binder, leaving 'Create group' ticked as we'll need that group for the provider. In this example, we'll use opnsense-user as the Service account's username

note

Take note of the password for this user as you'll need to give it to OPNsense in Step 4.

Step 2​

In authentik, create an LDAP Provider (under Applications/Providers) with these settings:

note

Only settings that have been modified from default have been listed.

Protocol Settings

  • Name: LDAP
  • Search group: opnsense
  • Certificate: authentik Self-signed certificate

Step 3​

In authentik, create an application (under Applications/Applications) which uses this provider. Optionally apply access restrictions to the application using policy bindings.

note

Only settings that have been modified from default have been listed.

  • Name: LDAP
  • Slug: ldap
  • Provider: LDAP

Step 4​

In authentik, create an outpost (under Applications/Outposts) of type LDAP that uses the LDAP Application you created in Step 2.

note

Only settings that have been modified from default have been listed.

  • Name: LDAP
  • Type: LDAP

Step 5​

Add your authentik LDAP server to OPNsense by going to your OPNsense Web UI and clicking the + under System/Access/Servers.

Change the following fields

  • Descriptive name: authentik
  • Hostname or IP address: authentik.company
  • Transport: SSL - Encrypted
  • Bind credentials
    • User DN: CN=opnsense-user,OU=users,DC=ldap,DC=goauthentik,DC=io
    • Password: whatever-you-set
    • Base DN: DC=ldap,DC=goauthentik,DC=io
  • Authentication containers: OU=users,DC=ldap,DC=goauthentik,DC=io;OU=groups,DC=ldap,DC=goauthentik,DC=io
  • Extended Query: &(objectClass=user)

Step 6​

In OPNsense, go to System/Settings/Administration and under Authentication at the bottom of that page, add authentik to the Server list

Step 7​

You can now either import users, or synchronize from Authentik LDAP. See https://docs.opnsense.org/manual/how-tos/user-ldap.html for more.

Notes​

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Secure LDAP more by creating a group for your DN Bind users and restricting the Search group of the LDAP Provider to them.