Banish OEM self-signed certs forever and roll your own private LetsEncrypt

https://arstechnica.com/information-technology/2024/03/banish-oem-self-signed-certs-forever-and-roll-your-own-private-letsencrypt/

by thunderbong • 2 years ago

37 33 2 years ago

arstechnica.com

luma2• 2 years ago

Replace self-signed certs with a self-signed CA? Now you're just moved the problem, and you'll still have challenges with modern mobile OSes.

If you're going through all the effort to instrument everything with certbot, why not just use LE and get a real cert?

Arch-TK4• 2 years ago

People don't want their internal infrastructure to end up in CT logs.

_factor• 2 years ago

Can confirm. Stood up a test site with SSL on a subdomain recently. Within 2hrs of let's encrypt registration, I was getting hits on file from around the globe with no index defined yet.

niij• 2 years ago

Let's Encrypt supports wildcard certificates now.

mavhc• 2 years ago

Make a LE wildcard cert

noirscape4• 2 years ago

DNS-01 + a wildcard SSL cert takes care of that unless you need third level domain names.

I think the last time I issued non-wildcard SSL certs for my domains was when I was still making the mistake of self-hosting email and the entire setup was a rickety mess.

vbezhenar• 2 years ago

Why CT logs include plaintext domain? Isn't hashing it would be enough?

jasode2• 2 years ago

Replace self-signed certs with a self-signed CA? [...], why not just use LE and get a real cert?

I went back and forth between self-signed CA vs LetsEncrypt.

I liked the self-signed CA root because you can create end-entity certificates for internal ip addresses such as 192.168.1.13 instead of domain names. (No domain name purchase and no public DNS records pointing to 192.168.1.13 required.) The public SSL services like Let'sEncrypt and ZeroSSL can't issue certs for RFC1918 ip addresses -- for obvious reasons.

On the other hand, I didn't want to import my custom CA root certificate into all 8+ devices around the house. (desktops+laptops+phones+tablets+etc.) So, Let'sEncrypt won in my case on that basis.

luma2• 2 years ago

If you're going to the effort to run a CA, why not also run DNS? I say this as a guy who runs an internal CA and eventually just implemented LE due to all the problems with trusting internal CAs and getting that to work across all devices.

globular-toast3• 2 years ago

This could be an interesting learning opportunity. But for the love of god, I hope nobody copies this parrot-fashion just to get rid of the browser warnings. There is no reason to use HTTPS on your LAN. Save yourself the effort and just don't do it.

Arch-TK4• 2 years ago

ZTA is fun to experiment with in your home LAN. And to be fair, most people's networks could benefit from it. That being said, the recommendation in this post is not for proper ZTA.

gregfagan• 2 years ago

Unless you’re building a web app that requires a secure context.

https://developer.mozilla.org/en-US/docs/Web/Security/Secure...

Already__Taken• 2 years ago

yeh secure by default isn't harder than dealing with every edge case and quirk.

globular-toast3• 2 years ago

Browsers support *.localhost as a secure context.

jasode2• 2 years ago

There is no reason to use HTTPS on your LAN. Save yourself the effort and just don't do it.

SSL https is definitely a hassle which seems like overkill with private home networks but there can be reasons for it.

For example, self-hosted Bitwarden/Vaultwarden password manager doesn't work without https:// SSL.

The client UI for managing passwords running in web browsers depend on the Chrome/Firefox cryptography APIs and those don't work for non-encrypted http:// :

Access to the WebCrypto API is restricted to secure origins (which is to say https:// pages). -- from https://www.chromium.org/blink/webcrypto/#:~:text=Access%20t....

noirscape4• 2 years ago

To be more exact, it's far easier to just shell out the cash for a domain name (or get a free subdomain from somewhere) and then just map the DNS on that domain to your internal infrastructure. That way you can just use letsencrypt certs without any hassle.

If you don't want to expose network details, use something like Tailscale to get unique internal IPs and map those. (Don't use Tailscale's own MagicDNS, that one logs individual certificates for machines into CT rather than giving you a wildcard cert for your tailnet).

globular-toast3• 2 years ago

Then you'll need a server running locally and the firewall rules to expose that to the internet and either a static IP address or some dynamic DNS client running.

No, I think it's far easier to just not do it.

Zagitta• 2 years ago

Orrr just buy a domain and get a wildcard LE cert? All of the benefits, none of the hassle, and no subdomain leaking.

8organicbits3• 2 years ago

If the buying a domain part is outside your budget, consider gelocalcert (I work on this) or one of the other free subdomain providers [2].

[1] https://www.getlocalcert.net/

[2] https://free.wdh.gg/#/?id=domains

throw0101b3• 2 years ago

Orrr just buy a domain and get a wildcard LE cert?

If you have dozens (or more) of locations that need a cert, then on a yearly basis you have to run around updating things.

lazyweb• 2 years ago

I am running my own private CA as well, powered by Hashicorp Vault, Ansible and Jenkins.

The Vault initialization and configuration is more or less manual (just a bunch of commands, I have them in my notes). From there I am using an ansible role based on the hasi_vault module [1] which is run by a Jenkins job every night, logging into each target system, renewing certs if needed and reloading services.

Has been working very well for about a year now. Of course, there's a little more technical context needed - my CA needs to be present on all systems interacting with it, and my CI needs to be able to log into each target system (SSH keypair + sudo user). This ties into the rest of my infrastructure, which is managed by Terraform and Ansible.

I might write up a small blog post about this if I find the time.

[1] https://docs.ansible.com/ansible/latest/collections/communit...

8organicbits3• 2 years ago

I believe these instructions give you a CA root that can sign certificates for the entire web (a man-in-the-middle CA). I'd be hard pressed to trust such a CA if it was created by anyone other than myself (or my employer, for work owned devices).

Best practice is to use name constraints to prevent the trust root from impersonating, for example, google.com if your LAN only uses .corp or similar.

WirelessGigabit• 2 years ago

The work to maintain this eventually became too much for me. Everything I did had to have the custom certificates installed, otherwise it would yell at me.

Then there are systems on which installing certificates is hard, like your niece's iPhone. Oh, just use Overseerr to request that movie. What you you mean? Certificate error? Oh, let me fix it.

I get a wildcard from ZeroSSL (after they bought acme.sh) and a couple of non-wildcard ones.

One thing to remember that a wildcard for .domain.com doesn't work for .foo.domain.com. You have to get a second-level *.foo.domain.com wildcard.

Banish OEM self-signed certs forever and roll your own private LetsEncrypt

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