.. Copyright 2018 Rackspace, US Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ======================================= Octavia Certificate Configuration Guide ======================================= This document is intended for Octavia administrators setting up certificate authorities for the two-way TLS authentication used in Octavia for command and control of :term:`Amphora`. This guide does not apply to the configuration of `TERMINATED_TLS` listeners on load balancers. See the `Load Balancing Cookbook`_ for instructions on creating `TERMINATED_TLS` listeners. .. _Load Balancing Cookbook: ../../user/guides/basic-cookbook.html#deploy-a-tls-terminated-https-load-balancer Two-way TLS Authentication in Octavia ===================================== The Octavia controller processes communicate with the Amphora over a TLS connection much like an HTTPS connection to a website. However, Octavia validates that both sides are trusted by doing a two-way TLS authentication. .. note:: This is a simplification of the full TLS handshake process. See the `TLS 1.3 RFC 8446 `_ for the full handshake. Phase One --------- When a controller process, such as the Octavia worker process, connects to an Amphora, the Amphora will present its `server` certificate to the controller. The controller will then validate it against the `server` Certificate Authority (CA) certificate stored on the controller. If the presented certificate is validated against the `server` CA certificate, the connection goes into phase two of the two-way TLS authentication. Phase Two --------- Once phase one is complete, the controller will present its `client` certificate to the Amphora. The Amphora will then validate the certificate against the `client` CA certificate stored inside the Amphora. If this certificate is successfully validated, the rest of the TLS handshake will continue to establish the secure communication channel between the controller and the Amphora. Certificate Lifecycles ---------------------- The `server` certificates are uniquely generated for each amphora by the controller using the `server` certificate authority certificates and keys. These `server` certificates are automatically rotated by the Octavia housekeeping controller process as they near expiration. The `client` certificates are used for the Octavia controller processes. These are managed by the operator and due to their use on the control plane of the cloud, typically have a long lifetime. See the `Operator Maintenance Guide `_ for more information about the certificate lifecycles. Creating the Certificate Authorities ==================================== As discussed above, this configuration uses two certificate authorities; one for the `server` certificates, and one for the `client` certificates. .. note:: Technically Octavia can be run using just one certificate authority by using it to issue certificates for both roles. However, this weakens the security as a `server` certificate from an amphora could be used to impersonate a controller. We recommend you use two certificate authorities for all deployments outside of testing. For this document we are going to setup simple OpenSSL based certificate authorities. However, any standards compliant certificate authority software can be used to create the required certificates. 1. Create a working directory for the certificate authorities. Make sure to set the proper permissions on this directory such that others cannot access the private keys, random bits, etc. being generated here. .. code-block:: bash $ mkdir certs $ chmod 700 certs $ cd certs 2. Create the OpenSSL configuration file. This can be shared between the two certificate authorities. .. code-block:: bash $ vi openssl.cnf .. literalinclude:: sample-configs/openssl.cnf :language: ini 3. Make any locally required configuration changes to the openssl.cnf. Some settings to consider are: * The default certificate lifetime is 10 years. * The default bit length is 2048. 4. Make directories for the two certificate authorities. .. code-block:: bash $ mkdir client_ca $ mkdir server_ca 5. Starting with the `server` certificate authority, prepare the CA. .. code-block:: bash $ cd server_ca $ mkdir certs crl newcerts private $ chmod 700 private $ touch index.txt $ echo 1000 > serial 6. Create the `server` CA key. * You will need to specify a passphrase to protect the key file. .. code-block:: bash $ openssl genpkey -algorithm RSA -out private/ca.key.pem -aes-128-cbc -pkeyopt rsa_keygen_bits:4096 $ chmod 400 private/ca.key.pem 7. Create the `server` CA certificate. * You will need to specify the passphrase used in step 6. * You will also be asked to provide details for the certificate. These are up to you and should be appropriate for your organization. * You may want to mention this is the `server` CA in the common name field. * Since this is the CA certificate, you might want to give it a very long lifetime, such as twenty years shown in this example command. .. code-block:: bash $ openssl req -config ../openssl.cnf -key private/ca.key.pem -new -x509 -days 7300 -sha256 -extensions v3_ca -out certs/ca.cert.pem 8. Moving to the `client` certificate authority, prepare the CA. .. code-block:: bash $ cd ../client_ca $ mkdir certs crl csr newcerts private $ chmod 700 private $ touch index.txt $ echo 1000 > serial 9. Create the `client` CA key. * You will need to specify a passphrase to protect the key file. .. code-block:: bash $ openssl genpkey -algorithm RSA -out private/ca.key.pem -aes-128-cbc -pkeyopt rsa_keygen_bits:4096 $ chmod 400 private/ca.key.pem 10. Create the `client` CA certificate. * You will need to specify the passphrase used in step 9. * You will also be asked to provide details for the certificate. These are up to you and should be appropriate for your organization. * You may want to mention this is the `client` CA in the common name field. * Since this is the CA certificate, you might want to give it a very long lifetime, such as twenty years shown in this example command. .. code-block:: bash $ openssl req -config ../openssl.cnf -key private/ca.key.pem -new -x509 -days 7300 -sha256 -extensions v3_ca -out certs/ca.cert.pem 11. Create a key for the `client` certificate to use. * You can create one certificate and key to be used by all of the controllers or you can create a unique certificate and key for each controller. * You will need to specify a passphrase to protect the key file. .. code-block:: bash $ openssl genpkey -algorithm RSA -out private/ca.key.pem -aes-128-cbc -pkeyopt rsa_keygen_bits:2048 12. Create the certificate request for the `client` certificate used on the controllers. * You will need to specify the passphrase used in step 11. * You will also be asked to provide details for the certificate. These are up to you and should be appropriate for your organization. * You must fill in the common name field. * You may want to mention this is the `client` certificate in the common name field, or the individual controller information. .. code-block:: bash $ openssl req -config ../openssl.cnf -new -sha256 -key private/client.key.pem -out csr/client.csr.pem 13. Sign the `client` certificate request. * You will need to specify the CA passphrase used in step 9. * Since this certificate is used on the control plane, you might want to give it a very long lifetime, such as twenty years shown in this example command. .. code-block:: bash $ openssl ca -config ../openssl.cnf -extensions usr_cert -days 7300 -notext -md sha256 -in csr/client.csr.pem -out certs/client.cert.pem 14. Create a concatenated `client` certificate and key file. * You will need to specify the CA passphrase used in step 11. .. code-block:: bash $ openssl rsa -in private/client.key.pem -out private/client.cert-and-key.pem $ cat certs/client.cert.pem >> private/client.cert-and-key.pem Configuring Octavia =================== In this section we will configure Octavia to use the certificates and keys created during the `Creating the Certificate Authorities`_ section. 1. Copy the required files over to your Octavia controllers. * Only the Octavia worker, health manager, and housekeeping processes will need access to these files. * The first command should return you to the "certs" directory created in step 1 of the `Creating the Certificate Authorities`_ section. * These commands assume you are running the octavia processes under the "octavia" user. * Note, some of these steps should be run with "sudo" and are indicated by the "#" prefix. .. code-block:: bash $ cd .. # mkdir /etc/octavia/certs # chmod 700 /etc/octavia/certs # cp server_ca/private/ca.key.pem /etc/octavia/certs/server_ca.key.pem # chmod 700 /etc/octavia/certs/server_ca.key.pem # cp server_ca/certs/ca.cert.pem /etc/octavia/certs/server_ca.cert.pem # cp client_ca/certs/ca.cert.pem /etc/octavia/certs/client_ca.cert.pem # cp client_ca/private/client.cert-and-key.pem /etc/octavia/certs/client.cert-and-key.pem # chmod 700 /etc/octavia/certs/client.cert-and-key.pem # chown -R octavia.octavia /etc/octavia/certs 2. Configure the [certificates] section of the octavia.conf file. * Only the Octavia worker, health manager, and housekeeping processes will need these settings. * The "" should be replaced with the passphrase that was used in step 6 of the `Creating the Certificate Authorities`_ section. .. code-block:: ini [certificates] cert_generator = local_cert_generator ca_certificate = /etc/octavia/certs/server_ca.cert.pem ca_private_key = /etc/octavia/certs/server_ca.key.pem ca_private_key_passphrase = 3. Configure the [controller_worker] section of the octavia.conf file. * Only the Octavia worker, health manager, and housekeeping processes will need these settings. .. code-block:: ini [controller_worker] client_ca = /etc/octavia/certs/client_ca.cert.pem 4. Configure the [haproxy_amphora] section of the octavia.conf file. * Only the Octavia worker, health manager, and housekeeping processes will need these settings. .. code-block:: ini [haproxy_amphora] client_cert = /etc/octavia/certs/client.cert-and-key.pem server_ca = /etc/octavia/certs/server_ca.cert.pem 5. Start the controller processes. .. code-block:: bash # systemctl start octavia-worker # systemctl start octavia-healthmanager # systemctl start octavia-housekeeping