certbot-dns-infoblox

Infoblox DNS Authenticator plugin for Certbot

This plugin automates the process of completing a dns-01 challenge by creating, and subsequently removing, TXT records using the Infoblox Remote API.

In order to get a certificate from Let’s Encrypt, you have to demonstrate control over the domain name. Usually, this is done using HTTP where you upload a specific file to your website. Using DNS / Infoblox as a backend, you are no longer required to run a webserver, and can furthermore prove ownership of domain names only accessible internally, and even of wildcard DNS names as, e.g., *.example.com.

Note that all certificates issued by Certificate Authorities as, e.g., Let's Encrypt are added to a distributed database called the certificate transparency logs (searchable at e.g. crt.sh). In particular when issuing internal certificates, you should be careful about revealing names of internal servers, etc.

Installation

pip install certbot-dns-infoblox

Named Arguments

To start using DNS authentication for Infoblox, pass the following arguments on certbot's command line:

If you are using certbot >= 1.0, you can skip the certbot-dns-infoblox: in the above arguments.

Credentials

An example credentials.ini file:

#
# Sample Infoblox INI file
# Default location /etc/letsencrypt/infoblox.ini
#
dns_infoblox_hostname="infoblox.example.net"
dns_infoblox_username="my-wapi-user"
dns_infoblox_password="5f4dcc3b5aa765d61d8327deb882cf99"
dns_infoblox_view=""

The path to this file can be provided interactively or using the --dns-infoblox-credentials command-line argument. Certbot records the path to this file for use during renewal, but does not store the file's contents.

CAUTION: You should protect these API credentials as you would the password to your infoblox account. Users who can read this file can use these credentials to issue arbitrary API calls on your behalf. Users who can cause Certbot to run using these credentials can complete a dns-01 challenge to acquire new certificates or revoke existing certificates for associated domains, even if those domains aren't being managed by this server.

Certbot will emit a warning if it detects that the credentials file can be accessed by other users on your system. The warning reads "Unsafe permissions on credentials configuration file", followed by the path to the credentials file. This warning will be emitted each time Certbot uses the credentials file, including for renewal, and cannot be silenced except by addressing the issue (e.g., by using a command like chmod 600 to restrict access to the file).

Examples

To acquire a single certificate for both example.com and *.example.com, waiting 100 seconds for DNS propagation:

certbot certonly \
--authenticator dns-infoblox \
--dns-infoblox-credentials /etc/letsencrypt/.secrets/domain.tld.ini \
--dns-infoblox-propagation-seconds 100 \
--agree-tos \
--rsa-key-size 4096 \
-d 'example.com' \
-d '*.example.com'

Notes

This is based on the work in certbot-dns-ipsconfig and the infoblox-client python package.