115
Let’s Encrypt Begins Supporting IP Address Certificates
(linuxiac.com)
Can I get a cert for 127.0.0.1 ? /s
How many bits is a /s mask?
i
8
The down votes are from people who work in IT support that have to deal with idiots that play with things they dont understand.
It’s unfortunate they don’t know what /s means
We do, it's just that those users will also often go "nah, I'm just joking!" then do some shit anyways.
How do I setup a reverse proxy for pure TCP? /s
Think that's called NATing
nah, I was once an idiot who didn't understand so idgaf
Yeah, the unfortunate part about internet security is that everyone has to start somewhere. And that means there’s always a newbie making dumb mistakes that they don’t even realize are dumb. It’s not a personal failing, unless they fail to learn from it.
This would actually be useful for local testing of software during development.
If you can get their servers to connect to that IP under your control, you've earned it
That's kind of awesome! I have a bunch of home lab stuff, but have been putting off buying a domain (I was a broke college student when I started my lab and half the point was avoiding recurring costs- plus I already run the DNS, as far as the WAN is concerned, I have whatever domain I want). My loose plan was to stand up a certificate authority and push the root public key out with active directory, but being able to certify things against Let's Encrypt might make things significantly easier.
Setting up a root and a immediate CA is significantly more fun though ;) It's also teaches you more about PKI which is a good skill to have.
but for the love of god and your own benefit, put a name constraint directly on the root cert
I use a domain, but for homelab I eventually switched to my own internal CA.
Instead of having to do service.domain.tld it's nice to do service.lan.
Any good instructions you would recommend for doing this?
use the official home.arpa as specified in RFC 8375
No thanks. I get some people agreed to this, but I'm going to continue to use .lan, like so many others. If they ever register .lan for public use, there will be a lot of people pissed off.
IMO, the only reason not to assign a top-level domain in the RFC is so that some company can make money on it. The authors were from Cisco and Nominum, a DNS company purchased by Akamai, but that doesnt appear to be the reason why. .home and .homenet were proposed, but this is from the mailing list:
- we cannot be sure that using .home is consistent with the existing (ab)use
- ICANN is in receipt of about a dozen applications for ".home", and some of those applicants no doubt have deeper pockets than the IETF does should they decide to litigate
https://mailarchive.ietf.org/arch/msg/homenet/PWl6CANKKAeeMs1kgBP5YPtiCWg/
So, corporate fear.
But home.arpa’s top-level domain is .arpa?
I'm not sure I follow the question. All of the TLD *.arpa is not reserved for private use, only *.home.arpa. So all your internal services are required to be a sub domain.
Sounds like you followed.
Now that I’m moving goalposts, why not use .home.arpa subdomains?
Instead of having to do
service.domain.tldit's nice to doservice.lan.
FYI you can get a numeric xyz domain for 1$ a year
At least for the first year.
Pretty sure it remains $1. But it's specifically only 6-9 digit numeric .xyz domains.
nice
Would this work with a public dynamic DNS?
With dynamic DNS? Yeah it always has, as long as you can host a http server.
With a dynamic IP? It should do, the certs are only valid for 6 days for that reason.
This could go a long way towards fighting online censorship. One less issue when an authoritarian overreach gets your domain seized. Pretty awesome.
Its like self signed certs with the convience of a third party
Maybe kinda, but it's also a third party whose certificates are almost if not entirely universally trusted. Self-signed certs cause software to complain unless you also spread a root certificate to be trusted to any machine that might use one of your self-signed certs.
F I N A L L Y
Now tell me it supports IPv6 and I'll be the happiest man alive
Maybe I'm not understanding it but I can't see what I would use this for due to the 6 day issue period. Bringing a NAS up to copy data for a couple days is the only real use case I find for home users.
Because even if you pay for a static external IP from your ISP, this doesn't support using such for longer than that period right?
Let's Encrypt is meant yo be used with automated certificate renewal using the ACME protocol. There are many clients for this. Both standalone and built into e.g. Caddy, Traefik and other software that does SSL termination.
So this specific concern doesn't really make sense. But that doesn't mean I really see a use case for it either, since it usually makes more sense to access resources via a host name.
I would read layman discussions about why this (by context?) is good.
I never understood why we don't use IP certificates to encrypt the domain with SNI.
What do you mean?
In much simpler terms:
Think of an IP address like a street address. 192 My Street.
There might be multiple businesses at one street address. In real life we address them with things like 1/192 My Street and 2/192 My Street, but there's no direct parallel to that in computer networks. Instead, what we do is more like directing your letter to say "Business A c/o 192 My Street". That's what SNI does.
Because we have to write all of that on the outside of the envelope, everyone gets to see that we're communicating with Business A. But what if one of the businesses at 192 My Street is highly sensitive and we'd rather people didn't know we were communicating with them? @bjoern_tantau@swg-empire.de's proposal is basically like if you put the "Business A" part inside the envelope, so the mailman (and anyone who sees the letter on the way) only see that it's going to 192 My Street. Then the front room at that address could open the envelope and see that the ultimate destination is Business A, and pass it along to them.
There's Encrypted Client Hello, supported by major browsers that does the SNI encryption. It's starting to be fairly widely supported.
Hell yuh.
Couldn't this prove very troublesome in combination with carrier grade nat?
I don't see how? Normal HTTP/TLS validation would still apply so you'd need port forwarding. You can't host anything on the CGNAT IP so you can't pass validation and they won't issue you a cert.
You can totally host something on carrier-grade NAT using techniques like NAT hole punching.
You don't get control of the incoming port that way. For LetsEncrypt to issue a certificate primarily intended for HTTPS, they will check that the HTTP server on that IP is owned by the requesting party. That has to live on port 80, which you can't forward on CGNAT.
this post was submitted on 06 Jul 2025
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