Chapter 6. Configuring custom SSL/TLS certificates
You can manually configure the undercloud to use SSL/TLS for communication over public endpoints. When you manually configure undercloud endpoints with SSL/TLS, you are creating secure endpoints as a proof-of-concept. Red Hat recommends using a certificate authority solution.
When you use a certificate authority (CA) solution, you have production ready solutions such as a certificate renewals, certificate revocation lists (CRLs), and industry accepted cryptography. For information on using Red Hat Identity Manager (IdM) as a CA, see Implementing TLS-e with Ansible.
If you want to use a SSL certificate with your own certificate authority, you must complete the following configuration steps.
6.1. Initializing the signing host Copy linkLink copied to clipboard!
The signing host is the host that generates and signs new certificates with a certificate authority. If you have never created SSL certificates on the chosen signing host, you might need to initialize the host so that it can sign new certificates.
Procedure
The
/etc/pki/CA/index.txtfile contains records of all signed certificates. Ensure that the filesystem path andindex.txtfile are present:sudo mkdir -p /etc/pki/CA sudo touch /etc/pki/CA/index.txt
$ sudo mkdir -p /etc/pki/CA $ sudo touch /etc/pki/CA/index.txtCopy to Clipboard Copied! Toggle word wrap Toggle overflow The
/etc/pki/CA/serialfile identifies the next serial number to use for the next certificate to sign. Check if this file exists. If the file does not exist, create a new file with a new starting value:echo '1000' | sudo tee /etc/pki/CA/serial
$ echo '1000' | sudo tee /etc/pki/CA/serialCopy to Clipboard Copied! Toggle word wrap Toggle overflow
6.2. Creating a certificate authority Copy linkLink copied to clipboard!
Normally you sign your SSL/TLS certificates with an external certificate authority. In some situations, you might want to use your own certificate authority. For example, you might want to have an internal-only certificate authority.
Procedure
Generate a key and certificate pair to act as the certificate authority:
openssl genrsa -out ca.key.pem 4096 openssl req -key ca.key.pem -new -x509 -days 7300 -extensions v3_ca -out ca.crt.pem
$ openssl genrsa -out ca.key.pem 4096 $ openssl req -key ca.key.pem -new -x509 -days 7300 -extensions v3_ca -out ca.crt.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow -
The
openssl reqcommand requests certain details about your authority. Enter these details at the prompt. These commands create a certificate authority file calledca.crt.pem. Set the certificate location as the value for the
PublicTLSCAFileparameter in theenable-tls.yamlfile. When you set the certificate location as the value for thePublicTLSCAFileparameter, you ensure that the CA certificate path is added to theclouds.yamlauthentication file.parameter_defaults: PublicTLSCAFile: /etc/pki/ca-trust/source/anchors/cacert.pemparameter_defaults: PublicTLSCAFile: /etc/pki/ca-trust/source/anchors/cacert.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow
6.3. Adding the certificate authority to clients Copy linkLink copied to clipboard!
For any external clients aiming to communicate using SSL/TLS, copy the certificate authority file to each client that requires access to your Red Hat OpenStack Platform environment.
Procedure
Copy the certificate authority to the client system:
sudo cp ca.crt.pem /etc/pki/ca-trust/source/anchors/
$ sudo cp ca.crt.pem /etc/pki/ca-trust/source/anchors/Copy to Clipboard Copied! Toggle word wrap Toggle overflow After you copy the certificate authority file to each client, run the following command on each client to add the certificate to the certificate authority trust bundle:
sudo update-ca-trust extract
$ sudo update-ca-trust extractCopy to Clipboard Copied! Toggle word wrap Toggle overflow
6.4. Creating an SSL/TLS key Copy linkLink copied to clipboard!
Enabling SSL/TLS on an OpenStack environment requires an SSL/TLS key to generate your certificates.
Procedure
Run the following command to generate the SSL/TLS key (
server.key.pem):openssl genrsa -out server.key.pem 2048
$ openssl genrsa -out server.key.pem 2048Copy to Clipboard Copied! Toggle word wrap Toggle overflow
6.5. Creating an SSL/TLS certificate signing request Copy linkLink copied to clipboard!
Complete the following steps to create a certificate signing request.
Procedure
Copy the default OpenSSL configuration file:
cp /etc/pki/tls/openssl.cnf .
$ cp /etc/pki/tls/openssl.cnf .Copy to Clipboard Copied! Toggle word wrap Toggle overflow Edit the new
openssl.cnffile and configure the SSL parameters that you want to use for director. An example of the types of parameters to modify include:Copy to Clipboard Copied! Toggle word wrap Toggle overflow Set the
commonName_defaultto one of the following entries:-
If you are using an IP address to access director over SSL/TLS, use the
undercloud_public_hostparameter in theundercloud.conffile. - If you are using a fully qualified domain name to access director over SSL/TLS, use the domain name.
Edit the
alt_namessection to include the following entries:-
IP- A list of IP addresses that clients use to access director over SSL. -
DNS- A list of domain names that clients use to access director over SSL. Also include the Public API IP address as a DNS entry at the end of thealt_namessection.
NoteFor more information about
openssl.cnf, run theman openssl.cnfcommand.-
If you are using an IP address to access director over SSL/TLS, use the
Run the following command to generate a certificate signing request (
server.csr.pem):openssl req -config openssl.cnf -key server.key.pem -new -out server.csr.pem
$ openssl req -config openssl.cnf -key server.key.pem -new -out server.csr.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow Ensure that you include your OpenStack SSL/TLS key with the
-keyoption.
This command generates a server.csr.pem file, which is the certificate signing request. Use this file to create your OpenStack SSL/TLS certificate.
6.6. Creating the SSL/TLS certificate Copy linkLink copied to clipboard!
To generate the SSL/TLS certificate for your OpenStack environment, the following files must be present:
openssl.cnf- The customized configuration file that specifies the v3 extensions.
server.csr.pem- The certificate signing request to generate and sign the certificate with a certificate authority.
ca.crt.pem- The certificate authority, which signs the certificate.
ca.key.pem- The certificate authority private key.
Procedure
Create the
newcertsdirectory if it does not already exist:sudo mkdir -p /etc/pki/CA/newcerts
sudo mkdir -p /etc/pki/CA/newcertsCopy to Clipboard Copied! Toggle word wrap Toggle overflow Run the following command to create a certificate for your undercloud or overcloud:
sudo openssl ca -config openssl.cnf -extensions v3_req -days 3650 -in server.csr.pem -out server.crt.pem -cert ca.crt.pem -keyfile ca.key.pem
$ sudo openssl ca -config openssl.cnf -extensions v3_req -days 3650 -in server.csr.pem -out server.crt.pem -cert ca.crt.pem -keyfile ca.key.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow This command uses the following options:
-config-
Use a custom configuration file, which is the
openssl.cnffile with v3 extensions. -extensions v3_req- Enabled v3 extensions.
-days- Defines how long in days until the certificate expires.
-in- The certificate signing request.
-out- The resulting signed certificate.
-cert- The certificate authority file.
-keyfile- The certificate authority private key.
This command creates a new certificate named server.crt.pem. Use this certificate in conjunction with your OpenStack SSL/TLS key
6.7. Adding the certificate to the undercloud Copy linkLink copied to clipboard!
Complete the following steps to add your OpenStack SSL/TLS certificate to the undercloud trust bundle.
Procedure
Run the following command to combine the certificate and key:
cat server.crt.pem server.key.pem > undercloud.pem
$ cat server.crt.pem server.key.pem > undercloud.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow This command creates a
undercloud.pemfile.Copy the
undercloud.pemfile to a location within your/etc/pkidirectory and set the necessary SELinux context so that HAProxy can read it:sudo mkdir /etc/pki/undercloud-certs sudo cp ~/undercloud.pem /etc/pki/undercloud-certs/. sudo semanage fcontext -a -t etc_t "/etc/pki/undercloud-certs(/.*)?" sudo restorecon -R /etc/pki/undercloud-certs
$ sudo mkdir /etc/pki/undercloud-certs $ sudo cp ~/undercloud.pem /etc/pki/undercloud-certs/. $ sudo semanage fcontext -a -t etc_t "/etc/pki/undercloud-certs(/.*)?" $ sudo restorecon -R /etc/pki/undercloud-certsCopy to Clipboard Copied! Toggle word wrap Toggle overflow Add the
undercloud.pemfile location to theundercloud_service_certificateoption in theundercloud.conffile:undercloud_service_certificate = /etc/pki/undercloud-certs/undercloud.pem
undercloud_service_certificate = /etc/pki/undercloud-certs/undercloud.pemCopy to Clipboard Copied! Toggle word wrap Toggle overflow Do not set or enable the
generate_service_certificateandcertificate_generation_caparameters. Director uses these parameters to automatically generate a certificate instead of using theundercloud.pemcertificate you created manually.Add the certificate authority that signed the certificate to the list of trusted Certificate Authorities on the undercloud so that different services within the undercloud have access to the certificate authority:
sudo cp ca.crt.pem /etc/pki/ca-trust/source/anchors/ sudo update-ca-trust extract
$ sudo cp ca.crt.pem /etc/pki/ca-trust/source/anchors/ $ sudo update-ca-trust extractCopy to Clipboard Copied! Toggle word wrap Toggle overflow To verify the certificate authority was added to the undercloud, use
opensslto check the trust bundle:openssl crl2pkcs7 -nocrl -certfile /etc/pki/tls/certs/ca-bundle.crt | openssl pkcs7 -print_certs -text | grep <CN of the CA issuer> -A 10 -B 10
$ openssl crl2pkcs7 -nocrl -certfile /etc/pki/tls/certs/ca-bundle.crt | openssl pkcs7 -print_certs -text | grep <CN of the CA issuer> -A 10 -B 10Copy to Clipboard Copied! Toggle word wrap Toggle overflow Replace
<CN of the CA issuer>with the common name of the issuer of the CA. This command outputs the main certificate details, including the validity dates.