Chapter 32. Authenticating a RHEL client to the network by using the 802.1X standard with a certificate stored on the file system

Procedure

1. Set the Extensible Authentication Protocol (EAP) to tls and the paths to the client certificate and key file:

   # nmcli connection modify enp1s0 802-1x.eap tls 802-1x.client-cert /etc/pki/tls/certs/client.crt 802-1x.private-key /etc/pki/tls/certs/certs/client.key

   Note that you must set the 802-1x.eap, 802-1x.client-cert, and 802-1x.private-key parameters in a single command.

2. Set the path to the CA certificate:

   # nmcli connection modify enp1s0 802-1x.ca-cert /etc/pki/tls/certs/ca.crt

3. Set the identity of the user used in the certificate:

   # nmcli connection modify enp1s0 802-1x.identity user@example.com

4. Optionally, store the password in the configuration:

   # nmcli connection modify enp1s0 802-1x.private-key-password password

   Important

   By default, NetworkManager stores the password in clear text in the /etc/sysconfig/network-scripts/keys-connection_name file, that is readable only by the root user. However, clear text passwords in a configuration file can be a security risk.

   To increase the security, set the 802-1x.password-flags parameter to 0x1. With this setting, on servers with the GNOME desktop environment or the nm-applet running, NetworkManager retrieves the password from these services. In other cases, NetworkManager prompts for the password.

5. Activate the connection profile:

   # nmcli connection up enp1s0

Procedure

1. Create a YAML file, for example ~/create-ethernet-profile.yml, with the following content:

   ---
   interfaces:
   - name: enp1s0
     type: ethernet
     state: up
     ipv4:
       enabled: true
       address:
       - ip: 192.0.2.1
         prefix-length: 24
       dhcp: false
     ipv6:
       enabled: true
       address:
       - ip: 2001:db8:1::1
         prefix-length: 64
       autoconf: false
       dhcp: false
     802.1x:
       ca-cert: /etc/pki/tls/certs/ca.crt
       client-cert: /etc/pki/tls/certs/client.crt
       eap-methods:
         - tls
       identity: client.example.org
       private-key: /etc/pki/tls/private/client.key
       private-key-password: password
   routes:
     config:
     - destination: 0.0.0.0/0
       next-hop-address: 192.0.2.254
       next-hop-interface: enp1s0
     - destination: ::/0
       next-hop-address: 2001:db8:1::fffe
       next-hop-interface: enp1s0
   dns-resolver:
     config:
       search:
       - example.com
       server:
       - 192.0.2.200
       - 2001:db8:1::ffbb

   These settings define an Ethernet connection profile for the enp1s0 device with the following settings:

   • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
   • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
   • An IPv4 default gateway - 192.0.2.254
   • An IPv6 default gateway - 2001:db8:1::fffe
   • An IPv4 DNS server - 192.0.2.200
   • An IPv6 DNS server - 2001:db8:1::ffbb
   • A DNS search domain - example.com
   • 802.1X network authentication using the TLS EAP protocol

2. Apply the settings to the system:

   # nmstatectl apply ~/create-ethernet-profile.yml

Procedure

1. Create a playbook file, for example ~/playbook.yml, with the following content:

   ---
   - name: Configure an Ethernet connection with 802.1X authentication
     hosts: managed-node-01.example.com
     tasks:
       - name: Copy client key for 802.1X authentication
         ansible.builtin.copy:
           src: "/srv/data/client.key"
           dest: "/etc/pki/tls/private/client.key"
           mode: 0600
   
       - name: Copy client certificate for 802.1X authentication
         ansible.builtin.copy:
           src: "/srv/data/client.crt"
           dest: "/etc/pki/tls/certs/client.crt"
   
       - name: Copy CA certificate for 802.1X authentication
         ansible.builtin.copy:
           src: "/srv/data/ca.crt"
           dest: "/etc/pki/ca-trust/source/anchors/ca.crt"
   
       - name: Configure connection
         ansible.builtin.include_role:
           name: rhel-system-roles.network
         vars:
           network_connections:
             - name: enp1s0
               type: ethernet
               autoconnect: yes
               ip:
                 address:
                   - 192.0.2.1/24
                   - 2001:db8:1::1/64
                 gateway4: 192.0.2.254
                 gateway6: 2001:db8:1::fffe
                 dns:
                   - 192.0.2.200
                   - 2001:db8:1::ffbb
                 dns_search:
                   - example.com
               ieee802_1x:
                 identity: user_name
                 eap: tls
                 private_key: "/etc/pki/tls/private/client.key"
                 private_key_password: "password"
                 client_cert: "/etc/pki/tls/certs/client.crt"
                 ca_cert: "/etc/pki/ca-trust/source/anchors/ca.crt"
                 domain_suffix_match: example.com
               state: up

   These settings define an Ethernet connection profile for the enp1s0 device with the following settings:

   • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
   • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
   • An IPv4 default gateway - 192.0.2.254
   • An IPv6 default gateway - 2001:db8:1::fffe
   • An IPv4 DNS server - 192.0.2.200
   • An IPv6 DNS server - 2001:db8:1::ffbb
   • A DNS search domain - example.com
   • 802.1X network authentication using the TLS Extensible Authentication Protocol (EAP)

2. Validate the playbook syntax:

   $ ansible-playbook --syntax-check ~/playbook.yml

   Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

3. Run the playbook:

   $ ansible-playbook ~/playbook.yml