This will get interesting for many CT transparency monitors which for many are already seeing scalability issues.
I am operating https://www.merklemap.com/ and the current scale is already impressive.
Six day and IP address certificate options in 2025
21–30 of 166 posts
Re: Six day and IP address certificate options in 2025
#22Earlier quoted context omitted.
Yes, a forward looking org like Let's Encrypt would have said IPv4 if needed. Here is an example from Cloudflare https://[2606:4700:4700::1111]
Why does the url say one.one.one.one in my browser?
Because your are redirected to one.one.one.one via the location header and 301 status code from the ip address.
http://1.1.1.1 redirects to https://1.1.1.1 which then redirects to https://one.one.one.one
but the TLS cert on https://1.1.1.1 (or https://[2606:4700:4700::1111] on ipv6) is still valid for the ipaddress otherwise your browser would put up a warning during the tls handshake.
Re: Six day and IP address certificate options in 2025
#23> Our six-day certificates will not include OCSP or CRL URLs. If someone else did this, Mozilla would be threatening to remove them from their trusted roots. IP address certs sound like a security nightmare that could be subverted by BGP hijacking. Which is why most CAs don't issue them. Does accessing the ACME challenge from multiple endpoints adequately prevent this type of attack?
> IP address certs sound like a security nightmare that could be subverted by BGP hijacking.
The attack scenario is exactly the same as hostname certificates, which are often validated by HTTP or TLS ACME challenges.
> Does accessing the ACME challenge from multiple endpoints adequately prevent this type of attack?
Yes. You'd essentially have to MitM all traffic towards the IP for it to work, and with more and more networks rolling out BGP origin validation a global BGP hijack becomes harder and harder to pull off.
You'd still be in trouble if you expect your own ISP to be hostile, of course. Don't single-home with an ISP you don't trust, or stick with domain name certs and force DNS challenges.
Re: Six day and IP address certificate options in 2025
#24I don't disagree with anything they say here: https://letsencrypt.org/2025/01/16/6-day-and-ip-certs/#short... But... How often do these types of compromises happen? I can't say I've ever seen or heard of it happening.
Often enough a protocol was made to deal with it. The compromises have mostly been kept quiet though or at least didn’t get much news traction.
Re: Six day and IP address certificate options in 2025
#25I don't disagree with anything they say here: https://letsencrypt.org/2025/01/16/6-day-and-ip-certs/#short... But... How often do these types of compromises happen? I can't say I've ever seen or heard of it happening.
Impossible to say, as most people probably don't even know that their private key is stolen. I've personally seen it only once on a real certificate revocation. Yet another reason to have shorter lifespan.
It's a pretty narrow threat model for Alice to get her cert stolen by Bob, be completely unaware that this has happened, and the means Bob used only works once.
Re: Six day and IP address certificate options in 2025
#26Earlier quoted context omitted.
Why does the url say one.one.one.one in my browser?
Because your are redirected to one.one.one.one via the location header and 301 status code from the ip address. http://1.1.1.1 redirects to https://1.1.1.1 which then redirects to https://one.one.one.one but the TLS cert on https://1.1.1.1 (or https://[2606:4700:4700::1111] on ipv6) is still valid for the ipaddress otherwise your browser would put up a warning during the tls handshake.
Its too bad it does the last redirect.
Re: Six day and IP address certificate options in 2025
#27Note that ACME profiles are new, to the extent that the draft spec is (a) personal (and not prefixed with draft-ietf… ), and (b) currently versioned -00 : * https://datatracker.ietf.org/doc/draft-aaron-acme-profiles/ The ACME spec is: * https://datatracker.ietf.org/doc/html/rfc8555
Yeah... thankfully, it's "pretty simple" for clients to implement. Just add a JSON field to your payload and that's it. (There's a little bit of error checking logic and input validation, like making sure the value is valid, but overall it's not too complex, unlike ARI, which is much more work.)
Re: Six day and IP address certificate options in 2025
#28Six days? I can't even set the cron job to weekly. Maybe that is the point of this though from being on call I really hate thing restarting every day. Caddy, Nginx, HAProxy, and IIS all seem to handle certs without a full restart. MS SQL Server, nope.
Re: Six day and IP address certificate options in 2025
#29I'm very interested in trying this. acme.sh is planning to support certificate profiles, so hopefully that'll be ready when LE's short-lived certificates become available. (Or I'll switch to a different ACME client I suppose)
Caddy/CertMagic/ACMEz already support this in the latest commits. Should be ready in time for the production rollout!
Re: Six day and IP address certificate options in 2025
#30I don't disagree with anything they say here: https://letsencrypt.org/2025/01/16/6-day-and-ip-certs/#short... But... How often do these types of compromises happen? I can't say I've ever seen or heard of it happening.
That's the thing. We don't always know. Hence the need to reduce the attack lifetime.