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6-Day and IP Address Certificates Are Generally Available

366 points13 hoursletsencrypt.org
ivanr13 hours ago

As already noted on this thread, you can't use certbot today to get an IP address certificate. You can use lego [1], but figuring out the exact command line took me some effort yesterday. Here's what worked for me:

    lego --domains 206.189.27.68 --accept-tos --http --disable-cn run --profile shortlived
[1] https://go-acme.github.io/lego/
Svoka12 hours ago

I wonder if the support made it to Caddy yet

(seems to be WIP https://github.com/caddyserver/caddy/issues/7399)

mholt12 hours ago

It works, but as another comment mentioned there may be quirks with IP certs, specifically IPv6, that I hope will be fixed by v2.11.

jsheard12 hours ago

IPv4 certs are already working fine for me in Caddy, but I think there's some kinks to work out with IPv6.

rsync10 hours ago

IP address certificates are particularly interesting for iOS users who want to run their own DoH servers.

A properly configured DoH server (perhaps running unbound) with a properly constructed configuration profile which included a DoH FQDN with a proper certificate would not work in iOS.

The reason, it turns out, is that iOS insisted that both the FQDN and the IP have proper certificates.

This is why the configuration profiles from big organizations like dns4eu and nextdns would work properly when, for instance, installed on an iphone ... but your own personal DoH server (and profile) would not.

hypeatei9 hours ago

OpenSSL is quite particular about the IP address being included in the SAN field of the cert when making a TLS connection, fwiw. iOS engineers may not have explicitly added this requirement and it might just be a side effect of using a crypto library.

fuomag99 hours ago

I use DoH behind a reverse proxy with my own domain daily without any kind of issue

midtake10 hours ago

Why 6 day and not 8?

- 8 is a lucky number and a power of 2

- 8 lets me refresh weekly and have a fixed day of the week to check whether there was some API 429 timeout

- 6 is the value of every digit in the number of the beast

- I just don't like 6!

halifaxbeard9 hours ago

> 8 lets me refresh weekly and have a fixed day of the week to check whether there was some API 429 timeout

There’s your answer.

6 days means on a long enough enough timeframe the load will end up evenly distributed across a week.

8 days would result in things getting hammered on specific days of the week.

PunchyHamster9 hours ago

> 6 days means on a long enough enough timeframe the load will end up evenly distributed across a week.

people will put */5 in cron and result will be same, because that's obvious, easy and nice number.

phantom7847 hours ago

I'd have it renew Monday and Thursday to avoid weekend outages.

bayindirh8 hours ago

ACME doesn't renew certificates when there's enough time, so it'll always renew around 6 days, even if you check more aggressively.

Currently ACME sets its cron job to 12 days on 90 day certificates.

akerl_3 hours ago

Which ACME client are you referring to?

nojs3 hours ago

I thought people generally run it daily? It’s a no-op if it doesn’t need renewal.

blibble9 hours ago

so now people that want humans around will now renew twice in a week instead of once?

6thbit9 hours ago

Worry not, cause it's not 6 days (144 hours), it is 6-ish days: 160 hours

And 160 is the sum of the first 11 primes, as well as the sum of the cubes of the first three primes!

nine_k8 hours ago

Mr Ramanujan, I presume?

themafia31 minutes ago

Every K-Paxian knows this.

abdullahkhalids6 hours ago

I was hoping Wolfram|Alpha would spit out the above, but on just entering 160 [1], we get

> A regular 160-gon is constructible with straightedge and compass.

> 160 has a representation as a sum of 2 squares: 160 = 4^2 + 12^2

> 160 is an even number.

> 160 has the representation 160 = 2^7 + 32.

> 160 divides 31^2 - 1.

> 160 = aa_15 repeats a single digit in base 15.

[1] https://www.wolframalpha.com/input?i=160

bayindirh10 hours ago

Because it allows to you to work for six days, and rest on the seventh. Like God did.

encrypted_bird21 minutes ago

Not my god. My god meant to go into work but got wasted and eventually passed out in the bathtub, fully clothed and holding a bowl of riceroni.

kibwen9 hours ago

² By the seventh day God had finished the work He had been doing; so on the seventh day He rested from all His work. ³ Then the on-call tech, Lucifer, the Son of Dawn, was awoken at midnight because God did not renew the heavens' and the earths' HTTPS certificate. ⁴ Thusly Lucifer drafted his resignation in a great fury.

encrypted_bird25 minutes ago

I just got home from a stressful day in retail (oh who am I kidding; every day is stress in retail) and this gave me a chuckle I really needed. Thank you.

JoBrad8 hours ago

Is this the TLS version of the Bible?

MobiusHorizons8 hours ago

I’m pretty sure that has been hidden from our eyes

mindcrime8 hours ago

Gilfoyle?

GTP7 hours ago

This made my day :D

batisteo9 hours ago

I don't think He worked after the 6th day. Went on doing other pet projects

raegis1 hour ago

Six is the smallest perfect number. Perfection is key here.

hamdingers9 hours ago

It's actually 6 and 2/3rds! I'm trying to figure out a rationale for 160 hours and similarly coming up empty, if anyone knows I'd be interested.

200 would be a nice round number that gets you to 8 1/3 days, so it comes with the benefits of weekly rotation.

mcpherrinm6 hours ago

I chose 160 hours.

The CA/B Forum defines a "short-lived" certificate as 7 days, which has some reduced requirements on revocation that we want. That time, in turn, was chosen based on previous requirements on OCSP responses.

We chose a value that's under the maximum, which we do in general, to make sure we have some wiggle room. https://bugzilla.mozilla.org/show_bug.cgi?id=1715455 is one example of why.

Those are based on a rough idea that responding to any incident (outage, etc) might take a day or two, so (assuming renewal of certificate or OCSP response midway through lifetime) you need at least 2 days for incident response + another day to resign everything, so your lifetime needs to be at least 6 days, and then the requirement is rounded up to another day (to allow the wiggle, as previously mentioned).

Plus, in general, we don't want to align to things like days or weeks or months, or else you can get "resonant frequency" type problems.

We've always struggled with people doing things like renewing on a cronjob at midnight on the 1st monday of the month, which leads to huge traffic surges. I spend more time than I'd like convincing people to update their cronjobs to run at a randomized time.

dtech9 hours ago

It's less than 7 exactly so you cannot set it on a weekly rotation

tensegrist9 hours ago

biweekly rotation?

UqWBcuFx6NV4r2 hours ago

We say pan-weekly these days

saintfire4 hours ago

Or is it semi-weekly?

zja9 hours ago

The are some great points

charcircuit11 hours ago

Next, I hope they focus on issuing certificates for .onion addresses. On the modern web many features and protocols are locked behind HTTPS. The owner of a .onion has a key pair for it, so proving ownership is more trustworthy than even DNS.

throw0101d10 hours ago

'Automated Certificate Management Environment (ACME) Extensions for ".onion" Special-Use Domain Names'

* https://datatracker.ietf.org/doc/html/rfc9799

* https://acmeforonions.org

* https://onionservices.torproject.org/research/appendixes/acm...

londons_explore11 hours ago

But isn't it unnecessary to use https, since tor itself encrypts and verifies the identity of the endpoint?

charcircuit10 hours ago

For example HTTP/2 and HTTP/3 require HTTPS. While technically HTTPS is redundant, .onion sites should avoid requiring browsers to add special casing for them due to their low popularity compared to regular web sites.

tucnak7 hours ago

What are benefits of HTTP/2 and HTTP/3 for Tor hidden service traffic?

charcircuit5 hours ago

Considerably faster page load times due to being able to continue to use the same connection for each request.

rnhmjoj11 hours ago

Yes, but browsers moan if you connect to a website without https, no matter if it's on localhost or an onion service.

creatonez10 hours ago

Tor Browser handles this, it treats `.onion` as a secure context.

tucnak7 hours ago

Well, you're not supposed to use Tor from browsers that don't explicitly support it. Tor Browser, Brave, and I'm sure some others really wouldn't mind HTTP hidden service traffic.

gizmo68610 hours ago

It would give you a certificate chain which may authenticate the onion service as being operated as who it purports to. Of course, depending on context, a certificate that is useful for that purpose might itself be too much if an information leak

huhhuh10 hours ago

DV certificates (that lets encrypt) provides offer no verification of the owner. EV certificates for .onion could be actually useful though, but one generally has to pay for EV cert.

andrewaylett4 hours ago

A certificate that's valid for both a regular domain and an onion domain gives you a degree of confidence of common ownership.

gruez13 hours ago

For people who want IP certificates, keep in mind that certbot doesn't support it yet, with a PR still open to implement it: https://github.com/certbot/certbot/pull/10495

I think acme.sh supports it though.

mcpherrinm12 hours ago

Some ACME clients that I think currently support IP addresses are acme.sh, lego, traefik, acmez, caddy, and cert-manager. Certbot support should hopefully land pretty soon.

sgtcodfish12 hours ago

cert-manager maintainter chiming in to say that yes, cert-manager should support IP address certs - if anyone finds any bugs, we'd love to hear from you!

We also support ACME profiles (required for short lived certs) as of v1.18 which is our oldest currently supported[1] version.

We've got some basic docs[2] available. Profiles are set on a per-issuer basis, so it's easy to have two separate ACME issuers, one issuing longer lived certs and one issuing shorter, allowing for a gradual migration to shorter certs.

[1]: https://cert-manager.io/docs/releases/ [2]: https://cert-manager.io/docs/configuration/acme/#acme-certif...

qwertox12 hours ago

I have now implemented a 2 week renewal interval to test the change to the 45 days, and now they come with a 6-day certificate?

This is no criticism, I like what they do, but how am I supposed to do renewals? If something goes wrong, like the pipeline triggering certbot goes wrong, I won't have time to fix this. So I'd be at a two day renewal with a 4 day "debugging" window.

I'm certain there are some who need this, but it's not me. Also the rationale is a bit odd:

> IP address certificates must be short-lived certificates, a decision we made because IP addresses are more transient than domain names, so validating more frequently is important.

Are IP addresses more transient than a domain within a 45 day window? The static IPs you get when you rent a vps, they're not transient.

cortesoft3 hours ago

> Are IP addresses more transient than a domain within a 45 day window? The static IPs you get when you rent a vps, they're not transient.

They can be as transient as you want. For example, on AWS, you can release an elastic IP any time you want.

So imagine I reserve an elastic IP, then get a 45 day cert for it, then release it immediately. I could repeat this a bunch of times, only renting the IP for a few minutes before releasing it.

I would then have a bunch of 45 day certificates for IP addresses I don't own anymore. Those IP addresses will be assigned to other users, and you could have a cert for someone else's IP.

Of course, there isn't a trivial way to exploit this, but it could still be an issue and defeats the purpose of an IP cert.

kevincox11 hours ago

The short-lived requirement seems pretty reasonable for IP certs as IP addresses are often rented and may bounce between users quickly. For example if you buy a VM on a cloud provider, as soon as you release that VM or IP it may be given to another customer. Now you have a valid certificate for that IP.

6 days actually seems like a long time for this situation!

bigstrat200311 hours ago

The push for shorter and shorter cert lifetimes is a really poor idea, and indicates that the people working on these initiatives have no idea how things are done in the wider world.

akerl_8 hours ago

Which wider world?

These changes are coming from the CAB forum, which includes basically every entity that ships a popular web browser and every entity that ships certificates trusted in those browsers.

There are use cases for certificates that exist outside of that umbrella, but they are by definition niche.

nottorp8 hours ago

>which includes basically every entity that ships a popular web browser and every entity that ships certificates trusted in those browsers.

So no one that actually has to renew these certificates.

Hey! How long does a root certificate from a certificate authority last?

10 to 25 years?

Why don't those last 120 minutes? They're responsible for the "security" of the whole internet aren't they?

codys5 hours ago

> So no one that actually has to renew these certificates.

I believe google, who maintain chrome and are on the CAB, are an entity well known for hosting various websites (iirc, it's their primary source of income), and those websites do use https

cpach7 hours ago

It’s capped to 15 years.

In another comment someone linked to a document from the Chrome team.

Here’s a quote that I found interesting:

“In Chrome Root Program Policy 1.5, we landed changes that set a maximum ‘term-limit’ (i.e., period of inclusion) for root CA certificates included in the Chrome Root Store to 15 years.

While we still prefer a more agile approach, and may again explore this in the future, we encourage CA Owners to explore how they can adopt more frequent root rotation.”

https://googlechrome.github.io/chromerootprogram/moving-forw...

akerl_7 hours ago

It's almost like the threat models for CA and leaf certs are different.

michaelt8 hours ago

About 99.99% of people and organisations are neither CAs nor Browsers. Hence they have no representation in the CAB Forum.

Hardly 'by definition niche' IMHO.

+1
akerl_7 hours ago
alibarber11 hours ago

Well they offer a money-back guarantee. And other providers of SSL certificates exist.

jsheard11 hours ago

For better or worse the push down to 47-day certificates is an industry-wide thing, in a few years no provider will issue certificates for longer than that.

Nobody is being forced to use 6-day certs for domains though, when the time comes Let's Encrypt will default to 47 days just like everyone else.

+1
hungryhobbit9 hours ago
+1
singpolyma310 hours ago
jdsully10 hours ago

At some point it makes sense to just let us use self signed certs. Nobody believes SSL is providing attestation anyways.

woodruffw9 hours ago

What does attestation mean in this context? The point of the Web PKI is to provide consistent cryptographic identity for online resources, not necessarily trustworthy ones.

(The classic problem with self-signed certs being that TOFU doesn’t scale to millions of users, particularly ones who don’t know what a certificate fingerprint is or what it means when it changes.)

vimda10 hours ago

A lot corporate environments load their root cert and MITM you anyway

cpach9 hours ago

Then you might as well get rid of TLS altogether.

+1
jdsully8 hours ago
jofla_net10 hours ago

Rule by the few, us little people don't matter.

Thing is, NOTHING, is stopping anyone from already getting short lived certs and being 'proactive' and rotating through. What it is saying is, well, we own the process so we'll make Chrome not play ball with your site anymore unless you do as we say...

The CA system has cracks, that short lived certs don't fix, so meanwhile we'll make everyone as uncomfortable as possible while we rearrange deck chairs.

awaiting downvotes in earnest.

Sohcahtoa8211 hours ago

It's really security theater, too.

Though if I may put on my tinfoil hat for a moment, I wonder if current algorithms for certificate signing have been broken by some government agency or hacker group and now they're able to generate valid certificates.

But I guess if that were true, then shorter cert lives wouldn't save you.

NoahZuniga11 hours ago

> broken by some government agency or hacker group

Probably not. For browsers to accept this certificate it has to be logged in a certificate transparency log for anyone to see, and no such certificates have been seen to be logged.

woodruffw10 hours ago

One of the ideas behind short-lived certificates is to put certificate lifetimes within the envelope of CRL efficacy, since CRLs themselves don’t scale well and are a significant source of operational challenges for CAs.

This makes sense from a security perspective, insofar as you agree with the baseline position that revocations should always be honored in a timely manner.

vbezhenar10 hours ago

I'm not sure it is about security. For security, CRLs and OCSP were a thing from the beginning. Short-lived certificates allow to cancel CRLs or at least reduce their size, so CA can save some expenses (I guess it's quite a bit of traffic for every client to download CRLs for entire letsencrypt).

wang_li11 hours ago

My browser on my work laptop has 219 root certificates trusted. Some of those may be installed from my employer, but I suspect most of them come from MS as it's Edge on Windows 11. I see in that list things like "Swedish Government Root Authority" "Thailand National Root Certification Authority" "Staat der Nederlanden Root CA" and things like "MULTICERT Root Certification Authority" "ACCVRAUZ1". I don't think there is any reason to believe any certificate. If a government wants a cert for a given DNS they will get it, either because they directly control a trusted root CA, or because they will present a warrant to a company that wants to do business in their jurisdiction and said company will issue the cert.

TLS certs should be treated much more akin to SSH host keys in the known hosts file. Browsers should record the cert the first time they see it and then warn me if it changes before it's expiration date, or some time near the expiration date.

+1
londons_explore11 hours ago
jofla_net10 hours ago

>> TLS certs should be treated much more akin to SSH host keys in the known hosts file. Browsers should record the cert the first time they see it and then warn me if it changes before it's expiration date, or some time near the expiration date.

This is great, and actually constructive!

I use, a hack i put together http://www.jofla.net/php__/CertChecker/ to keep a list (in json) of a bunch of machines (both https and SSH) and the last fingerprints/date it sees. Every time it runs i can see if any server has changed, just is a heads-up for any funny business. Sure its got shortcommings, it doesnt mimmic headers and such but its a start.

It would be great if browsers could all, you know, have some type of distributed protocol, ie DHT where by at least some concensus about whether this cert has been seen by me or enough peers lately.

Having a ton of CAs and the ability to have any link in that chain sing for ANY site is crazy, and until you've seen examples of abuse you assume the foundations are sound.

mholt11 hours ago

It's less about IP address transience, and more about IP address control. Rarely does the operator of a website or service control the IP address. It's to limit the CA's risk.

compumike8 hours ago

> If something goes wrong, like the pipeline triggering certbot goes wrong, I won't have time to fix this. So I'd be at a two day renewal with a 4 day "debugging" window.

I think a pattern like that is reasonable for a 6-day cert:

- renew every 2 days, and have a "4 day debugging window" - renew every 1 day, and have a "5 day debugging window"

Monitoring options: https://letsencrypt.org/docs/monitoring-options/

This makes me wonder if the scripts I published at https://heyoncall.com/blog/barebone-scripts-to-check-ssl-cer... should have the expiry thresholds defined in units of hours, instead of integer days?

Sohcahtoa8211 hours ago

> Are IP addresses more transient than a domain within a 45 day window?

If I don't assign an EIP to my EC2 instance and shut it down, I'm nearly guaranteed to get a different IP when I start it again, even if I start it within seconds of shutdown completing.

It'd be quite a challenge to use this behavior maliciously, though. You'd have to get assigned an IP that someone else was using recently, and the person using that IP would need to have also been using TLS with either an IP address certificate or with certificate verification disabled.

qwertox10 hours ago

Ok, though if you're in that situation, is an IP cert the correct solution?

toast010 hours ago

It's probably not a good solution if you're dealing with clients you control.

Otoh, if you're dealing with browsers, they really like WebPKI certs, and if you're directing load to specific servers in real time, why add DNS and/or a load balancer thing in the middle?

andrewaylett4 hours ago

You should probably be running your renewal pipeline more frequently than that: if you had let your ACME client set itself up on a single server, it would probably run every 12h for a 90-day certificate. The ACME client won't actually give you a new certificate until the old one is old enough to be worth renewing, and you have many more opportunities to notice that the pipeline isn't doing what you expect than if you only run when you expect to receive a new certificate.

PunchyHamster9 hours ago

What worries me more about the push for shorter and shorter cert terms instead of making revoking that works is that if provider fails now you have very little time to switch to new one

jsheard9 hours ago

Some ACME clients can failover to another provider automatically if the primary one doesn't work, so you wouldn't necessarily need manual intervention on short notice as long as you have the foresight to set up a secondary provider.

mcpherrinm6 hours ago

This is a two-sided solution, and one significant reason for shorter certificate lifetimes helps make revocation work better.

cpach9 hours ago

People have tried. Revocation is a very hard problem to solve on this scale.

alibarber11 hours ago

If you are doing this in a commercial context and the 4 day debugging window, or any downtime, would cause you more costs than say, buying a 1 year certificate from a commercial supplier, then that might be your answer there...

mxey10 hours ago

There will be no certificates longer than 45 days by any CA in browsers in a few years.

charcircuit11 hours ago

>I won't have time to fix this

Which should push you to automate the process.

buckle801711 hours ago

He's expressly talking about broken automation.

charcircuit11 hours ago

You can have automation to fix the broken automation.

+1
buckle80179 hours ago
apitman5 hours ago

Very excited about this. IP certs solve an annoying bootstrapping problem for selfhosted/indiehosted software, where the software provides a dashboard for you to configure your domain, but you can't securely access the dashboard until you have a cert.

As a concrete example, I'll probably be able to turn off bootstrap domains for TakingNames[0].

[0]: https://takingnames.io/blog/instant-subdomains

cryptonector11 hours ago

I wonder if transport mode IPsec can be relevant again if we're going to have IP address certificates. Ditto RFC 5660 (which -full disclosure- I authored).

reincarnate0x147 hours ago

Maybe but probably not. Various always-on , SDN, or wide scale site-to-site VPN schemes are deployed widely enough for long enough now that it's expected infrastructure at this point.

Even getting people to use certificates on IPSEC tunnels is a pain. Which reminds me, I think the smallest models of either Palo Alto or Checkpoint still have bizarre authentication failures if the certificate chain is too long, which was always weird to me because the control planes had way more memory than necessary for well over a decade.

cryptonector7 hours ago

You're not thinking creatively enough. I'm only interested in ESP, not IKE. Consider having the TLS handshake negotiate the use of ESP, and when selected the system would plumb ESP for this connection using keys negotiated by TLS (using the exporter). Think ktls/kssl but with ESP. Presto -- no orchestration of IKE credentials, nothing -- it should just work.

The real key is getting ESP HW offload.

reincarnate0x146 hours ago

Oh I agree with it being nice, I'm just imagining more socialization oriented resistance to implementation and both large organizations and hobbyists already have answers that mostly cover the use cases even if not exactly as cleanly. Moving node to node encryption to an accelerated implementation of transport mode would be great, but if you're already using TLS I can see people just sticking in TLS versus hoping both ends had the necessary handshake->ESP path working, plus people are more experienced with existing troubleshooting, etc.

cryptonector5 hours ago

It's still "TLS" as far as the application is concerned, which is why this could work, but yes, there are a few roadblocks, not the least of which is the absence of compelling HW. Another thing is that I/O is faster than compute nowadays, so making it faster may not be helpful :joy:

PunchyHamster9 hours ago

IPSec is terrible, huge, and messy standard that company that made it took 20 years to stop getting CVE every year

cryptonector7 hours ago

But the very nice thing about ESP (over UDP or not) is that it's much simpler to build HW offload than for TLS.

Using the long ago past as FUD here is not useful.

xg1511 hours ago

IP addresses must be accessible from the internet, so still no way to support TLS for LAN devices without manual setup or angering security researchers.

johannes12343219 hours ago

I recently migrated to a wildcard (*.home.example.com) certificate for all my home network. Works okay for many parts. However requires a public DNS server where TXT records can be set via API (lego supports a few DNS providers out of the box, see https://go-acme.github.io/lego/dns/ )

mnahkies8 hours ago

I use a fairly niche provider (https://go-acme.github.io/lego/dns/zonomi/index.html) and it's supported - I'd go further and say they support most providers

cpach11 hours ago

One can also use a private CA for that scenario.

bigfishrunning9 hours ago

Exactly -- how many 192.168.0.1 certs do you think LetsEncrypt wants to issue?

tialaramex8 hours ago

The BRs specifically forbid issuing such a certificate since 2015. So, slightly before they were required to stop using SHA-1, slight after they were forbidden from issuing certificates for nonsense like .com or .ac.uk which obviously shouldn't be available to anybody even if they do insist they somehow "own" these names.

tialaramex5 hours ago

I can't edit it now, but that comment should have said *.com or *.ac.uk -- that is wildcards in which the suffix beyond the wildcard is an entire TLD or an entire "Public Suffix" which the rules say don't belong to anyone as a whole, they're to be shared by unrelated parties and so such a wildcard will never be a reasonable thing to exist.

progbits11 hours ago

I mean if it's not routable how do you want to prove ownership in a way nobody else can? Just make a domain name.

alibarber11 hours ago

Also I don't see the point of what TLS is supposed to solve here? If you and I (and everyone else) can legitimately get a certificate for 10.0.0.1, then what are you proving exactly over using a self-signed cert?

There would be no way of determining that I can connecting to my-organisation's 10.0.0.1 and not bad-org's 10.0.0.1.

londons_explore10 hours ago

Perhaps by providing some identifier in the URL?

ie. https://10.0.0.1(af81afa8394fd7aa)/index.htm

The identifier would be generated by the certificate authority upon your first request for a certificate, and every time you renew you get to keep the same one.

alibarber10 hours ago

I see what you're getting at - but to me this sounds almost exactly like just using DNS, even if the (A/AAAA) record you want to use resolves to an un-routable address: https://letsencrypt.org/docs/challenge-types/#dns-01-challen... - you just create a DNS TXT record instead of them trying to access a server at the address for verification.

Latty10 hours ago

This is assuming NAT, with IPv6 you should be able to have globally unique IPs. (Not unique to IPv6 in theory, of course, but in practice almost no one these days is giving LAN devices public IPv4s).

cpach10 hours ago

A public CA won’t give you a cert for 10.0.0.1

alibarber10 hours ago

Exactly - no one can prove they own it (on purpose because it's reserved for private network use, so no one can own it)

arianvanp9 hours ago

For ipv6 proof of ownership can easily be done with an outbound connection instead. And would work great for provisioning certs for internal only services.

stackghost7 hours ago

>so still no way to support TLS for LAN devices without manual setup or angering security researchers.

Arguably setting up letsencrypt is "manual setup". What you can do is run a split-horizon DNS setup inside your LAN on an internet-routable tld, and then run a CA for internal devices. That gives all your internal hosts their own hostname.sub.domain.tld name with HTTPS.

Frankly: it's not that much more work, and it's easier than remembering IP addresses anyway.

tosti6 hours ago

> run a CA

> easier than remembering IP addresses

idk, the 192.168.0 part has been around since forever. The rest is just a matter of .12 for my laptop, .13 for the one behind the telly, .14 for the pi, etc.

Every time I try to "run a CA", I start splitting hairs.

stackghost5 hours ago

No, what I'm saying is

1. Running a CA is more work than just setting up certbot for IP addresses, but not that much more

And that enables you to

2. Remember only domain names, which is easier than ip addresses.

I guess if you're ipv4 only and small it's not much benefit but if you have a big or bridged network like wonderLAN or the promised LAN it's much better.

cpach7 hours ago

There’s also the DNS-01 challenge that works well for devices on private networks.

iamrobertismo13 hours ago

This is interesting, I am guessing the use case for ip address certs is so your ephemeral services can do TLS communication, but now you don't need to depend on provisioning a record on the name server as well for something that you might be start hundreds or thousands of, that will only last for like an hour or day.

jeroenhd12 hours ago

One thing this can be useful for is encrypted client hello (ECH), the way TLS/HTTPS can be used without disclosing the server name to any listening devices (standard SNI names are transmitted in plaintext).

To use it, you need a valid certificate for the connection to the server which has a hostname that does get broadcast in readable form. For companies like Cloudflare, Azure, and Google, this isn't really an issue, because they can just use the name of their proxies.

For smaller sites, often not hosting more than one or two domains, there is hardly a non-distinct hostname available.

With IP certificates, the outer TLS connection can just use the IP address in its readable SNI field and encrypt the actual hostname for the real connection. You no longer need to be a third party proxying other people's content for ECH to have a useful effect.

agwa11 hours ago

That doesn't work, as neither SNI nor the server_name field of the ECHConfig are allowed to contain IP addresses: https://www.ietf.org/archive/id/draft-ietf-tls-esni-25.html#...

Even if it did work, the privacy value of hiding the SNI is pretty minimal for an IP address that hosts only a couple domains, as there are plenty of databases that let you look up an IP address to determine what domain names point there - e.g. https://bgp.tools/prefix/18.220.0.0/14#dns

jsheard11 hours ago

I don't really see the value in ECH for self-hosted sites regardless. It works for Cloudflare and similar because they have millions of unrelated domains behind their IP addresses, so connecting to their IPs reveals essentially nothing, but if your IP is only used for a handful of related things then it's pretty obvious what's going on even if the SNI is obscured.

buzer11 hours ago

As far as I understand you cannot use IP address as the outer certificate as per https://www.ietf.org/archive/id/draft-ietf-tls-esni-25.txt

> In verifying the client-facing server certificate, the client MUST interpret the public name as a DNS-based reference identity [RFC6125]. Clients that incorporate DNS names and IP addresses into the same syntax (e.g. Section 7.4 of [RFC3986] and [WHATWG-IPV4]) MUST reject names that would be interpreted as IPv4 addresses.

medmunds11 hours ago

The July announcement for IP address certs listed a handful of potential use cases: https://letsencrypt.org/2025/07/01/issuing-our-first-ip-addr...

iamrobertismo8 hours ago

Thanks! This is helpful to read.

axus13 hours ago

No dependency on a registrar sounds nice. More anonymous.

traceroute6612 hours ago

> No dependency on a registrar sounds nice.

Actually the main benefit is no dependency on DNS (booth direct and root).

IP is a simple primitive, i.e. "is it routable or not ?".

saltcured11 hours ago

The popular HTTP validation method has the same drawback whether using DNS or IP certificates? Namely, if you can compromise routes to hijack traffic, you can also hijack the validation requests. Right?

zinekeller2 hours ago

Yes, there have been cases where this has happened (https://notes.valdikss.org.ru/jabber.ru-mitm/), but it's really now into the realm of

1) How to secure routing information: some says RPKI, some argues that's not enough and are experimenting with something like SCION (https://docs.scion.org/en/latest/)

2) Principal-Agent problem: jabber.ru's hijack relied on (presumably) Hetzner being forced to do it by German law agents based on the powers provided under the German Telecommunications Act (TKG)

organsnyder13 hours ago

IP addresses also are assigned by registrars (ARIN in the US and Canada, for instance).

traceroute6612 hours ago

> IP addresses also are assigned by registrars (ARIN in the US and Canada, for instance).

To be pedantic for a moment, ARIN etc. are registries.

The registrar is your ISP, cloud provider etc.

You can get a PI (Provider Independent) allocation for yourself, usually with the assistance of a sponsoring registrar. Which is a nice compromise way of cutting out the middleman without becoming a registrar yourself.

+1
immibis12 hours ago
buckle801712 hours ago

Arguably neither is particularly secure, but you must have an IP so only needing to trust one of them seems better.

iamrobertismo13 hours ago

Yeah actually seems pretty useful to not rely on the name server for something that isn't human facing.

traceroute6612 hours ago

> I am guessing the use case for ip address certs is so your ephemeral services can do TLS communication

There's also this little thing called DNS over TLS and DNS over HTTPS that you might have heard of ? ;)

iamrobertismo8 hours ago

I don't quite understand how this relates?

pdntspa12 hours ago

Maybe you want TLS but getting a proper subdomain for your project requires talking to a bunch of people who move slowly?

iamrobertismo12 hours ago

Very very true, never thought about orgs like that. However, I don't think someone should use this like a bandaid like that. If the idea is that you want to have a domain associated with a service, then organizationally you probably need to have systems in place to make that easier.

pdntspa12 hours ago

Ideally, sure. But in some places you're what you're proposing is like trying to boil the oceans to make a cup of tea

VBA et al succeeded because they enabled workers to move forward on things they would otherwise be blocked on organizationally

Also - not seeing this kind of thing could be considered a gap in your vision. When outsiders accuse SV of living in a high-tech ivory tower, blind to the realities of more common folk, this is the kind of thing they refer to.

iamrobertismo8 hours ago

Bruh, I'm not from SV lol. I just don't work at massive orgs.

jrockway1 hour ago

I have a check in a helm chart somewhere I no longer work that complains if you try to enable TLS and only provide an IP address. That code is now broken. Sad!

razakel11 hours ago

Has anyone actually given a good explanation as to why TLS Client Auth is being removed?

dextercd10 hours ago

It's a requirement from the Chrome root program. This page is probably the best resource on why they want this: https://googlechrome.github.io/chromerootprogram/moving-forw...

0xbadcafebee7 hours ago

I get why Chrome doesn't want it (it doesn't serve Chrome's interests), but that doesn't explain why Let's Encrypt had to remove it. The reason seems to be "you can't be a Chrome CA and not do exactly what Chrome wants, which is... only things Chrome wants to do". In other words, CAs have been entirely captured by Chrome. They're Chrome Authorities.

Am I the only person that thinks this is insane? All web security is now at the whims of Google?

dextercd4 hours ago

All major root store programs (Chrome, Apple, Microsoft, Mozilla) have this power. They set the requirements that CAs must follow to be included in their root store, and for most CAs their certs would be useless if they aren't included in all major ones.

I don't think the root programs take these kind of decisions lightly and I don't see any selfish motives they could have. They need to find a balance between not overcomplicating things for site operators and CAs (they must stay reliable) while also keeping end users secure.

A lot of CAs and site operators would love if nothing ever changed: don't disallow insecure signature/hash algorithms, 5+ year valid certs, renewals done manually, no CT, no MPIC, etc. So someone else needs to push for these improvements.

The changes the root programs push for aren't unreasonable, so I'm not really concerned about the power they have over CAs.

That doesn't mean the changes aren't painful in the short term. For example, the move to 45 day certificates is going to cause some downtime, but of course the root programs/browsers don't benefit from that. They're still doing this because they believe that in the long term it's going to make WebPKI more robust.

There's also the CA/Browser Forum where rule changes are discussed and voted on. I'm not sure how root programs decide on what to make part of their root policy vs. what to try to get voted into the baseline requirements. Perhaps in this case Chrome felt that too many CAs would vote against for self-interested reasons, but that's speculation.

+1
mcpherrinm3 hours ago
singpolyma310 hours ago

Because Google doesn't want anyone using PKI for anything but simple websites

cryptonector11 hours ago

One reason is that the client certificate with id-kp-clientAuth EKU and a dNSName SAN doesn't actually authenticate the client's FQDN. To do that you'd have to do something of a return routability check at the app layer where the server connects to the client by resolving its FQDN to check that it's the same client as on the other connection. I'm not sure how seriously to take that complaint, but it's something.

greyface-5 hours ago

It competes with "Sign in with Google" SSO.

cryptonector11 hours ago

How are IP address certificates useful?

SahAssar11 hours ago

* DoT/DoH

* An outer SNI name when doing ECH perhaps

* Being able to host secure http/mail/etc without being beholden to a domain registrar

12_throw_away9 hours ago

To save others a trip to Kagi: DoT / DoH = DNS over TLS [1] / https [2]

E.g.:

[1] https://developers.cloudflare.com/1.1.1.1/encryption/dns-ove...

[2] https://developers.cloudflare.com/1.1.1.1/encryption/dns-ove...

miladyincontrol10 hours ago

IP addresses arent valid for the SNI used with ECH, even with TLS. On paper I do agree though it would be a decent option should things one day change there.

cryptonector10 hours ago

Oh nice! I hadn't considered DoT/DoH. The ECH angle is interesting. Thanks.

meling12 hours ago

If I can use my DHCP assigned IP, will this allow me to drop having to use self-signed certificates for localhost development?

michaelt12 hours ago

No, they will only give out certificates if you can prove ownership of the IP, which means it being publicly routable.

wongarsu12 hours ago

Finally a reason to adopt IPv6 for your local development

greyface-5 hours ago

Yes, please publish the location of your dev servers in Cert Transparency logs for everyone to see.

inetknght12 hours ago

A lot of publicly routable IP addresses are assigned by DHCP...

meling4 hours ago

Sorry, I wasn’t precise enough. I’m at a university and our IP addresses are publicly routable, I think.

toast010 hours ago

It's just control isn't it, not ownership? I can't prove ownership of the IPs assigned to me, but I can prove control.

einsteinx29 hours ago

Yes that’s correct

wolttam12 hours ago

Browsers consider ‘localhost’ a secure context without needing https

For local /network/ development, maybe, but you’d probably be doing awkward hairpin natting at your router.

treve12 hours ago

it's nice to be able to use https locally if you're doing things with HTTP/2 specifically.

Sohcahtoa8211 hours ago

What's stopping you from creating a "localhost.mydomain.com" DNS record that initially resolves to a public IP so you can get a certificate, then copying the certificate locally, then changing the DNS to 127.0.0.1?

Other than basically being a pain in the ass.

cpach10 hours ago

One can also use the DNS-01 challenge in that scenario.

6thbit9 hours ago

This comment used to say that was in staging only. (Nevermind, i was confused following the links from original article)

iancarroll9 hours ago

That is a very old article that seems to be outdated now.

cedws11 hours ago

I guess IP certs won't really be used for anything important, but isn't there a bigger risk due to BGP hijacking?

toast010 hours ago

No additional risk IMHO. If you can hijack my service IPs, you can establish control over the IPs or the domain names that point to them. (If you can hijack my DNS IPs, you can often do much more... even with DNSSEC, you can keep serving the records that lead to IPs you hijacked)

zamadatix12 hours ago

Does anyone know when Caddy plans on supporting this?

mholt12 hours ago

We've supported it for about a year!

zamadatix11 hours ago

Very nice, thank you guys!

bflesch12 hours ago

This sounds like a very good thing, like a lot of stuff coming from letsencrypt.

But what risks are attached with such a short refresh?

Is there someone at the top of the certificate chain who can refuse to give out further certificates within the blink of an eye?

If yes, would this mean that within 6 days all affected certificates would expire, like a very big Denial of Service attack?

And after 6 days everybody goes back to using HTTP?

Maybe someone with more knowledge about certificate chains can explain it to me.

iso163112 hours ago

With a 6 day lifetime you'd typically renew after 3 days. If Lets Encrypt is down or refuses to issue then you'd have to choose a different provider. Your browser trusts many different "top of the chain" providers.

With a 30 day cert with renewal 10-15 days in advance that gives you breathing room

Personally I think 3 days is far too short unless you have your automation pulling from two different suppliers.

bflesch11 hours ago

Thank you, I missed the part with several "top of the chain" providers. So all of them would need to go down at the same time for things to really stop working.

How many "top of chain" providers is letsencrypt using? Are they a single point of failure in that regard?

I'd imagine that other "top of chain" providers want money for their certificates and that they might have a manual process which is slower than letsencrypt?

mholt10 hours ago

LE has 2 primary production data centers: https://letsencrypt.status.io/

But in general, one of the points of ACME is to eliminate dependence on a single provider, and prevent vendor lock-in. ACME clients should ideally support multiple ACME CAs.

For example, Caddy defaults to both LE and ZeroSSL. Users can additionally configure other CAs like Google Trust Services.

This document discusses several failure modes to consider: https://github.com/https-dev/docs/blob/master/acme-ops.md#if...

cpach11 hours ago

“Are they a single point of failure in that regard?”

It depends. If the ACME client is configured to only use Let’s Encrypt, then the answer is yes. But the client could fall-back to Google’s CA, ZeroSSL, etc. And then there is no single point of failure.

+3
bflesch11 hours ago
rubatuga9 hours ago

Honestly not a big fan of IP address certs in the context of dynamic IP address generation

hojofpodge12 hours ago

Something about a 6 day long IP address based token brings me back to the question of why we are wasting so much time on utterly wrong TOFU authorization?

If you are supposed to have an establishable identity I think there is DNSSEC back to the registrar for a name and (I'm not quite sure what?) back to the AS.for the IP.

ycombinatrix12 hours ago

Domains map one-to-one with registrars, but multiple AS can be using the same IP address.

hojofpodge12 hours ago

Then it would be a grave error to issue an IP cert without active insight into BGP. (Or it doesn't matter which chain you have.. But calling a website from a sampling of locations can't be a more correct answer.)

ycombinatrix8 hours ago

>it would be a grave error to issue an IP cert without active insight into BGP

Why? Even regular certs are handed out via IP address.

MORPHOICES8 hours ago

[dead]

notepad0x9010 hours ago

It's a huge ask, but i'm hoping they'll implement code-signing certs some day, even if they charge for it. It would be nice if appstores then accepted those certs instead of directly requiring developer verification.

duskwuff10 hours ago

1) For better or worse, code signing certificates are expected to come with some degree of organizational verification. No one would trust a domain-validated code signing cert, especially not one which was issued with no human involvement.

2) App stores review apps because they want to verify functionality and compliance with rules, not just as a box-checking exercise. A code signing cert provides no assurances in that regard.

notepad0x907 hours ago

They can just do id verification instead of domain, either in-house or outsource it.

app store review isn't what I was talking about, I meant not having to verify your identity with the appstore, and use your own signing cert which can be used between platforms. Moreover, it would be less costly to develop signed windows apps. It costs several hundred dollars today.

briHass2 hours ago

Azure has a service ('Artifact Signing') which is $10/month for signing Windows executables (not Windows Store apps, which don't need it.)

That's pretty reasonable, considering it is built in to all the major code signing tools on Windows, they perform the identity verification, and the private keys are fully managed by Azure. Code signing certs are required to be on HSMs, so you're most likely going to be paying some cloud CA anyway.

cpach8 hours ago

Would be cool. But since they’re a non-profit, they would need some way to make it scalable.

notepad0x907 hours ago

I see no problem with outsourcing id verification to a trusted partner. Or they could verify payment by charging you $1 to verify you control the payment card, and combine that with address verification by paper-mailing a verification code.