certbot-dns-ionos

IONOS 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 IONOS Remote API.

Configuration of IONOS

In the System -> Remote Users you have to have a user, with the following rights

• Client Functions
• DNS zone functions
• DNS txt functions

Installation

pip install certbot-dns-ionos

Named Arguments

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

--authenticator dns-ionos	select the authenticator plugin (Required)
--dns-ionos-credentials	ionos Remote User credentials INI file. (Required)
--dns-ionos-propagation-seconds	waiting time for DNS to propagate before asking the ACME server to verify the DNS record. (Default: 10, Recommended: >= 600)

Credentials

An example credentials.ini file:

dns_ionos_prefix = myapikeyprefix
dns_ionos_secret = verysecureapikeysecret
dns_ionos_endpoint = https://api.hosting.ionos.com

The path to this file can be provided interactively or using the --dns-ionos-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 ionos 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 900 seconds for DNS propagation:

certbot certonly \
  --authenticator dns-ionos \
  --dns-ionos-credentials /etc/letsencrypt/.secrets/domain.tld.ini \
  --dns-ionos-propagation-seconds 900 \
  --server https://acme-v02.api.letsencrypt.org/directory \
  --agree-tos \
  --rsa-key-size 4096 \
  -d 'example.com' \
  -d '*.example.com'

Docker

In order to create a docker container with a certbot-dns-ionos installation, create an empty directory with the following Dockerfile:

FROM certbot/certbot
RUN pip install certbot-dns-ionos

Proceed to build the image:

docker build -t certbot/dns-ionos .

Once that's finished, the application can be run as follows:

docker run --rm \
   -v /var/lib/letsencrypt:/var/lib/letsencrypt \
   -v /etc/letsencrypt:/etc/letsencrypt \
   --cap-drop=all \
   certbot/dns-ionos certonly \
   --authenticator dns-ionos \
   --dns-ionos-propagation-seconds 900 \
   --dns-ionos-credentials \
       /etc/letsencrypt/.secrets/domain.tld.ini \
   --no-self-upgrade \
   --keep-until-expiring --non-interactive --expand \
   --server https://acme-v02.api.letsencrypt.org/directory \
   -d example.com -d '*.example.com'

It is suggested to secure the folder as follows:: chown root:root /etc/letsencrypt/.secrets chmod 600 /etc/letsencrypt/.secrets