Certificate System Role

CI Testing

Role for managing TLS/SSL certificate issuance and renewal

Linux system role to issue and renew SSL certificates.

Basic usage:

---
- hosts: webserver

  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign

  roles:
    - rhel-system-roles.certificate

On a RPM-based system this will place the certificate in /etc/pki/tls/certs/mycert.crt and the key in /etc/pki/tls/private/mycert.key.

Variables

Parameter Description Type Required Default

certificate_wait

If the task should wait for the certificate to be issued.

bool

no

yes

certificate_requests

A list of dicts representing each certificate to be issued. See certificate_requests.

list

no

-

certificate_requests

Note: Fields such as common_name, country, state, locality, organization, organizational_unit, email, key_usage, and extended_key_usage that can be included in the certificate request are defined by the RFC 5280.

Note: Be aware that the CA might not honor all the requested fields. For example, even if a request include country: US, the CA might issue the certificate without country in it’s subject.

Note: The fields dns, email and ip are used to define the Subject Alternative Names (SAN).

Parameter Description Type Required Default

name

Name of the certificate. A full path can be used to choose the directory where files will be stored.

str

yes

-

ca

CA that will issue the certificate. See CAs and Providers.

str

yes

-

dns

Domain (or list of domains) to be included in the certificate. Also can provide the default value for common_name.

str or list

no

-

email

Email (or list of emails) to be included in the certificate.

str or list

no

-

ip

IP, or list of IPs, to be included in the certificate. IPs can be IPv4, IPv6 or both. Also can provide the default value for common_name.

str or list

no

-

auto_renew

Indicates if the certificate should be renewed automatically before it expires.

bool

no

yes

owner

User name (or user id) for the certificate and key files.

str

no

User running Ansible

group

Group name (or group id) for the certificate and key files.

str

no

Group running Ansible

key_size

Generate keys with a specific keysize in bits.

int

no

2048 - See key_size

common_name

Common Name requested for the certificate subject.

str

no

See common_name

country

Country code requested for the certificate subject.

str

no

-

state

State requested for the certificate subject.

str

no

-

locality

Locality requested for the certificate subject (usually city).

str

no

-

organization

Organization requested for the certificate subject.

str

no

-

organizational_unit

Organizational unit requested for the certificate subject.

str

no

-

contact_email

Contact email requested for the certificate subject.

str

no

-

key_usage

Allowed Key Usage for the certificate. For valid values see: key_usage.

list

no

See key_usage

extended_key_usage

Extended Key Usage attributes to be present in the certificate request.

list

no

See extended_key_usage

run_before

Command that should run before saving the certificate. See run hooks.

str

no

-

run_after

Command that should run after saving the certificate. See run hooks.

str

no

-

principal

Kerberos principal.

str

no

-

provider

The underlying method used to request and manage the certificate.

str

no

Varies by CA

common_name

If common_name is not set the role will attempt to use the first value of dns or ip, respectively, as the default. If dns and ip are also not set, common_name will not be included in the certificate.

key_size

Recommended minimal-values for a certificate key size, from different organizations, vary across time. In the attempt to provide safe settings, the default minimal-value for key_size will be increased over time.

If you want your certificates to always keep the same key_size when renewed, set this variable to the desired value.

key_usage

Valid values for key_usage are:

  • digitalSignature

  • nonRepudiation

  • keyEncipherment

  • dataEncipherment

  • keyAgreement

  • keyCertSign

  • cRLSign

  • encipherOnly

  • decipherOnly

The defaults for key_usage are:

  • digitalSignature

  • keyEncipherment

extended_key_usage

Any valid oid can be used to set one or more extended_key_usage. In addition to that there is also a list of known aliases that will be recognized by the role:

  • id-kp-serverAuth

  • id-kp-clientAuth

  • id-kp-codeSigning

  • id-kp-emailProtection

  • id-kp-timeStamping

  • id-kp-OCSPSigning

  • id-kp-ipsecEndSystem

  • id-kp-ipsecTunnel

  • id-kp-ipsecUser

If extended_key_usage is not set the role will default to:

  • id-kp-serverAuth

  • id-kp-clientAuth

run hooks

Sometimes you need to execute a command just before a certificate is renewed and another command just after. In order to do that use run_before and run_after.

The value provided to run_before and run_after will be wrapped and stored in shell script files that later will be executed by the provider.

CAs and Providers

CA Providers CA description Requirements

self-sign

certmonger*

Issue self-signed certificates from a local CA.

ipa

certmonger*

Issue certificates using the FreeIPA CA.

Host needs to be enrolled in a FreeIPA server.

* Default provider.

CA represents the CA certificates that will be used to issue and sign the requested certificate. Provider represents the method used to send the certificate request to the CA and then retrieve the signed certificate.

If a user chooses self-sign CA, with certmonger as provider and, later on decide to change the provider to openssl, the CA certificates used in both cases needs to be the same. Please note that openssl is not yet a supported provider and it’s only mentioned here as an example.

Certmonger and SELinux

If SELinux is enforced, the certmonger service is only able to write or edit files in directories where the cert_t context is present.

Additionally to that, if the scripts executed by run_before and run_after parameters need to write or edit files, those scripts also require the cert_t context to be present prior to the role execution.

You can use linux-system-roles/selinux to manage SELinux contexts.

For more information about certmonger and SELinux requirements, see certmonger_selinux(8) man pages.

Examples:

Issuing a self-signed certificate:

Issue a certificate for *.example.com and place it in the standard directory for the distribution.

---
- hosts: webserver

  vars:
    certificate_requests:
      - name: mycert
        dns: *.example.com
        ca: self-sign

  roles:
    - rhel-system-roles.certificate

You can find the directories for each distribution in the following locations:

  • Debian/Ubuntu:

    • Certificates: /etc/ssl/localcerts/certs/

    • Keys: /etc/ssl/localcerts/private/

  • RHEL/CentOS/Fedora:

    • Certificates: /etc/pki/tls/certs/

    • Keys: /etc/pki/tls/private/

Choosing where to place the certificates

Issue a certificate and key and place them in the specified location. The example below creates a certificate file in /another/path/mycert.crt and a key file in /another/path/mycert.key.

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: /another/path/mycert
        dns: *.example.com
        ca: self-sign

  roles:
    - rhel-system-roles.certificate

Issuing certificates with multiple DNS, IP and Email

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns:
          - www.example.com
          - sub1.example.com
          - sub2.example.com
          - sub3.example.com
        ip:
          - 192.0.2.12
          - 198.51.100.65
          - 2001:db8::2:1
        email:
          - sysadmin@example.com
          - support@example.com
        ca: self-sign

  roles:
    - rhel-system-roles.certificate

Setting common subject options

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        common_name: www.example.com
        ca: self-sign
        country: US
        state: NY
        locality: New York
        organization: Red Hat
        organizational_unit: platform
        email: admin@example.com
  roles:
    - rhel-system-roles.certificate

Setting the certificate key size

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        key_size: 4096
  roles:
    - rhel-system-roles.certificate

Setting the "Key Usage" and "Extended Key Usage" (EKU)

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        key_usage:
          - digitalSignature
          - nonRepudiation
          - keyEncipherment
        extended_key_usage:
          - id-kp-clientAuth
          - id-kp-serverAuth
  roles:
    - rhel-system-roles.certificate

Don’t wait for the certificate to be issued

The certificate issuance can take several minutes depending on the CA. Because of that it’s also possible to request the certificate but not actually wait for it.

This configuration affects all certificates: if certificate_wait is set to no the role does not wait for any certificate to be issued.

---
- hosts: webserver
  vars:
    certificate_wait: false
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
  roles:
    - rhel-system-roles.certificate

Setting a principal

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        principal: HTTP/www.example.com@EXAMPLE.COM

  roles:
    - rhel-system-roles.certificate

Choosing to not auto-renew a certificate

By default certificates generated by the role are set for auto-renewal. To disable that behavior set auto_renew: no.

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        auto_renew: no

  roles:
    - rhel-system-roles.certificate

Using FreeIPA to issue a certificate

If your host is enrolled in a FreeIPA server, you also have the option to use it’s CA to issue your certificate. To do that, set ca: ipa.

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        principal: HTTP/www.example.com@EXAMPLE.COM
        ca: ipa

  roles:
    - rhel-system-roles.certificate

Running a command before or after a certificate is issued

Sometimes you need to execute a command just before a certificate is renewed and another command just after. To do so, use run_before and run_after.

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        run_before: systemctl stop webserver.service
        run_after: systemctl start webserver.service

  roles:
    - rhel-system-roles.certificate

Setting the certificate owner and group

If you are using a certificate for a service, for example httpd, you need to set the certificate owner and group that will own the certificate. In the following example the owner and group are both set to httpd.

---
- hosts: webserver
  vars:
    certificate_requests:
      - name: mycert
        dns: www.example.com
        ca: self-sign
        owner: httpd
        group: httpd

  roles:
    - rhel-system-roles.certificate

Note that you can also use UID and GID instead of user and group names.

Compatibility

Currently supports CentOS 7+, RHEL 7+, Fedora. It has been tested with Debian 10.

Dependencies

None.

License

MIT

Author Information

Sergio Oliveira Campos (@seocam)