certbot-dns-netcup 2.0.0

netcup DNS Authenticator plugin for Certbot

netcup 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 netcup CCP API via nc_dnsapi.

Note: This plugin requires certbot ≥ v2.7.

If you need support for older certbot versions, check version 1.4.X and below.

Installation

Since this package acts as a plugin for certbot, the installation method can vary depending on how certbot is installed.

pip

If certbot is installed normally as a python package, the plugin can be installed using:

pip install certbot-dns-netcup

snap

If certbot is installed as a snap, you’ll have to install this plugin as follows:

sudo snap install certbot-dns-netcup

Furthermore, the following seems to be required in order to connect the plugin to certbot:

sudo snap set certbot trust-plugin-with-root=ok
sudo snap connect certbot:plugin certbot-dns-netcup

docker

Using docker, you can pull an image that contains both certbot and a matching version of the plugin:

docker pull coldfix/certbot-dns-netcup

Usage

To acquire a single certificate for both example.com and *.example.com, waiting 1200 seconds (20min) for DNS propagation:

certbot certonly \\
  --authenticator dns-netcup \\
  --dns-netcup-credentials ~/.secrets/certbot/netcup.ini \\
  --dns-netcup-propagation-seconds 1200 \\
  --keep-until-expiring --non-interactive --expand \
  --server https://acme-v02.api.letsencrypt.org/directory \
  -d 'example.com' \\
  -d '*.example.com'

The parameters and the format of the credentials file are described below.

Named Arguments

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

--authenticator dns-netcup	select the authenticator plugin (Required)
--dns-netcup-credentials FILE	netcup credentials INI file. (Required)
--dns-netcup-propagation-seconds NUM	waiting time for DNS to propagate before asking the ACME server to verify the DNS record. (Default: 900, Recommended: >= 600)
--dns-netcup-login-retries NUM	Number of login retry attempts in case the netcup API client session times out. (Default: 3, Recommended: >= 1)
--dns-netcup-zone-name DOMAIN	Zone name to operate on (often TLD). Will be determined using brute-force requests if not specified.

NOTE: You may need to set an unexpectedly high propagation time (≥ 900 seconds) to give the netcup DNS time to propagate the entries! This may be annoying when calling certbot manually but should not be a problem in automated setups. In exceptional cases, 20 minutes may be required. See #28.

Credentials

Use of this plugin requires a configuration file containing netcup API credentials, obtained from your netcup account page. See also the CCP API documentation.

An example credentials.ini file:

dns_netcup_customer_id  = 123456
dns_netcup_api_key      = 0123456789abcdef0123456789abcdef01234567
dns_netcup_api_password = abcdef0123456789abcdef01234567abcdef0123

The path to this file can be provided interactively or using the --dns-netcup-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 netcup 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).

Docker

You can pull the latest version of the docker image directly from Docker Hub as follows:

docker pull coldfix/certbot-dns-netcup

Alternatively, the docker image can be built from a local checkout and the included Dockerfile as follows:

docker build -t coldfix/certbot-dns-netcup .

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 \
  coldfix/certbot-dns-netcup certbot certonly \
    --authenticator dns-netcup \
    --dns-netcup-propagation-seconds 900 \
    --dns-netcup-credentials /var/lib/letsencrypt/netcup_credentials.ini \
    --keep-until-expiring --non-interactive --expand \
    --server https://acme-v02.api.letsencrypt.org/directory \
    --agree-tos --email "[e-mail]" \
    -d example.com -d '*.example.com'

You may want to change the volumes /var/lib/letsencrypt and /etc/letsencrypt to local directories where the certificates and configuration should be stored.