Provision TLS *Cer*tificates for your *LAN*, using the ACME DNS challenge.
LAN-Cer: Certificates For Your LAN
lancer is a tool which will quickly and simply provision certificates for any
number of hosts in a domain, using Let's Encrypt, assuming that you have an
API-controlled DNS service.
You have too many computers. Too many (all) of them have to talk to the Internet. And, as we all know, any computer on the internet needs a TLS certificate and the lock icon that comes with it if you want to be able to talk to it.
- Maybe you need to test some web APIs that don't work without HTTPS, so you need a development certificate for localhost.
- Maybe you have an OpenWRT router and you need to administer it via its web interface; you don't want every compromised IoT device or bored teenager on your WiFi to be able to read your administrator password.
The Bad Old Days
Previously the way you'd address problems like this would be to:
- ⚠️😡⚠️ use a garbage self-signed root and click through annoying warnings all the time
- 🔒️🗑️🔒️ add a garbage self-signed root to your trust store
- 🔥😱🔥 turn off certificate validation entirely in your software
These are all bad in similar ways: they decrease your security and they require fiddly, machine-specific configuration that has to be repeated on every new machine that needs to talk to such endpoints.
Let's Encrypt is 99% of the solution here. And, for public-facing internet
services, it's almost trivially easy to use; many web servers provide built-in
support for it. But you don't want to use production certificates for your
main website on your development box: you want to put an entry in
under a dedicated test domain name, and you shouldn't have to figure out how to
route inbound public traffic to a web server on that host name in order to
respond to a challenge.
Luckily, Let's Encrypt offers DNS-01 validation, so all you need to do is update a DNS record. Lancer uses this challenge.
What You Need
Your DNS needs to be hosted on a platform that supports
DNS and CloudFlare are two that I have tested with), or Gandi's' V5 API which
Lancer has specific support for. You will need an API key.
How To Use It
pip install lancer
- Create empty files for the certificates you want to provision:
touch certificates-for-mydomain.com/myhost1.lan.mydomain.com.pem certificates-for-mydomain.com/myhost2.lan.mydomain.com.pem.
Upon first run, lancer will ask you 4 questions:
- what driver do you want to use? this should be the libcloud driver name, or 'gandi' for the Gandi V5 API.
- what is your username?
- what is the DNS zone that you will be provisioning certificates under?
(usually this is the registrable part of the
domain name; if you want certificates for
lan.somecompany.comthen your zone is usually
- what is your API key? This will be prompted for and stored with Secretly, which uses Keyring to securely store secrets; this may mean that in certain unattended configurations you might need keyrings.alt to store your API key in a configuration file rather than something like Keychain or GnomeKeyring.
It will store the answers to the first three questions in
certificates-for-mydomain.com/lancer.json and the secrets depending upon your
keyring configuration, so you shouldn't need to answer them again (although you
may need to click through a security confirmation on subsequent attempts to
allow access to your API key).
lancer to log that it has successfully provisioned your
certificates, and copy your now-no-longer-empty
.pem files (which will each
contain a certificate, chain certificates, and a private key) to wherever you
need them on your LAN. You can kill it with
^C or you can just leave it
running in the background and let it auto-renew every 90 days or so.
If you don't leave it running, to renew your certificates when they've expired,
lancer certificates-for-mydomain.com again, and any expired or
.pem files in that directory will be renewed and replaced.
You can add new certificates at any time by creating new, empty
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Hashes for lancer-0.4.0-py2.py3-none-any.whl