With that said, given that (1) pre-certificates in the log are big and (2) lifetimes are shortening and so there will be a lot of duplicates, it seems like it would be good for someone to make a feed that was just new domain names.

Merklemap offers that: https://www.merklemap.com/documentation/live-tail

The Web Archive also uses the Certificate Transparency logs, some websites that aren't linked anywhere end up in the Wayback Machine this way: https://archive.org/details/certificate-transparency?tab=abo...

Certificate transparency log is a Google project. They don’t need to scrape it. They host all the data. It’s one of those projects where Google hosts it because it thinks it genuinely improves the internet, by reducing certificate authority abuse.

What's the yawn for?

What reason?

For those that never looked at the CT logs: https://crt.sh/?q=ycombinator.com

(the site may occasionally fail to load)

"... for exacty this reason."

Needs clarification. What reason

Correct, that's what I did with caddy, which is now periodically renewing my wildcard certificate through a DNS-01 challenge.

Yep, but this comes with a tradeoff: all of your services now have a valid key/cert for your whole domain, significantly increasing the blast radius if one service is compromised.

Unfortunately they are a bit extra bothersome to automate (depending on your DNS provider/setup) because of the DNS CNAME-method validation requirement.

The ostensible purpose of the certificate transparency logs is to allow validation of a certificate you're looking at - I browse to https://poormathskills.com and want to figure out the details of when its cert was issued.

The (presumably) unintended, unexpected purpose of the logs is to provide public notification of a website coming online for scrapers, search engines, and script kiddies to attack it: I could register https://verylongrandomdomainnameyoucantguess7184058382940052... and unwisely expect it to be unguessable, but as it turns out OpenAI is going to scrape it seconds after the certificate is issued.

There's an extension to static-ct-api, currently implemented by Sunlight logs, that provides a feed of just SANs and CNs: https://github.com/FiloSottile/sunlight/blob/main/names-tile...

For example:

  curl https://tuscolo2026h1.skylight.geomys.org/tile/names/000 | gunzip

(It doesn't deduplicate if the same domain name appears in multiple certificates, but it's still a substantial reduction in bandwidth compared to serving the entire (pre)certificate.)

>The logical next step is for smaller AI players to present themselves as the largest players in the space.

We think we're so different from animals https://en.wikipedia.org/wiki/Mimicry

Right. Crawler user agent strings in general tend to include all sorts of legacy stuff for compatibility.

This actually is a well-behaved crawler user agent because it identifies itself at the end.

> Some search engines provide a list of their scraper IP ranges

Common Crawl's CCBot has published IP ranges. We aren't a search engine (although there are search engines using our data) and we like to describe our crawler as a crawler, not a "scraper".

Yes, it is very common to change your useragent for web scraping. Mainly because there are websites which will block you just based on that alone

If I give my content away for free, it can’t be stolen.

The point of putting up a public web site is so the public can view it (including OpenAI/google/etc).

If I don’t want people viewing it, then I don’t make it public.

Saying that things are stolen when they aren’t clouds the issue.

Because it's hardly news in its context.

Presumably this is well-known among people that already know about this.

P.S. In the hopes of making this more than just a sarcastic comment, the question of "How do people bootstrap knowledge?" is kind of interesting. [1]

> To tackle a hard problem, it is often wise to reuse and recombine existing knowledge. Such an ability to bootstrap enables us to grow rich mental concepts despite limited cognitive resources. Here we present a computational model of conceptual bootstrapping. This model uses a dynamic conceptual repertoire that can cache and later reuse elements of earlier insights in principled ways, modelling learning as a series of compositional generalizations. This model predicts systematically different learned concepts when the same evidence is processed in different orders, without any extra assumptions about previous beliefs or background knowledge. Across four behavioural experiments (total n = 570), we demonstrate strong curriculum-order and conceptual garden-pathing effects that closely resemble our model predictions and differ from those of alternative accounts. Taken together, this work offers a computational account of how past experiences shape future conceptual discoveries and showcases the importance of curriculum design in human inductive concept inferences.

[1]: https://www.nature.com/articles/s41562-023-01719-1

It would be funny if your content disappeared when it was stolen.

The CT log tells you about new websites as soon as they come online. Good if you're intending to scrape the web.

These exist for apex domains; the real use-case is subdomains.

In this case it is actually OpenAI, the IP (74.7.175.182) is in one of their published ranges (74.7.175.128/25).

https://openai.com/searchbot.json

I don't know if imitating a major crawler is really worth it, it may work against very naive filters, but it's easy to definitively check whether you're faking so it's just handing ammo to more advanced filters which do check.

  $ curl -I https://www.cloudflare.com
  HTTP/2 200

  $ curl -I -H "User-Agent: Googlebot" https://www.cloudflare.com
  HTTP/2 403

It is an _incredible_ stretch to frame certificate transparency logs as "content" in the creative sense.

The whole purpose of this data is to be consumed by 3rd-parties.

It implies that this is boring and not article/post-worthy (which I agree with).

Certificate transparency logs are intended to be consumed by others. That is indeed what is happening. Not interesting.

Shameless plug :)

https://www.merklemap.com/search?query=ycombinator.com&page=...

Entries are indexed by subdomain instead of by certificate (click an entry to see all certificates for that subdomain).

Also, you can search for any substring (that was quite the journey to implement so it's fast enough across almost 5B entries):

https://www.merklemap.com/search?query=ycombi&page=0

s/exacty/exactly

"I minted a new TLS cert and it seems that OpenAI is scraping CT logs for what I assume are things to scrape from, based on the near instant response from this:"

The reason presented by the blog post is "for what I assume are things to scrape from"

Putting aside the "assume" part (see below^1), is this also the reason that the other "systems" are "scraping" CT logs

After OpenAI "scrapes" then what does OpenAI do with the data (readers can guess)

But what about all the other "systems", i.e., parties that may use CT logs. If the logs are public then that's potentially a lot of different parties

Imagine in an age before the internet, telephone subscriber X sets up a new telephone line, the number is listed in a local telephone directory ("the phone book") and X immediately receives a phone call from telephone subscriber Z^2

X then writes an op-ed that suggests Z is using the phone book "for who to call"

This is only interesting if X explains why Z was calling or if the reader can guess why Z was calling

Anyone can use the phone book, anyone can use ICANN DNS, anyone can use CT logs, etc.

Why does someone use these public resources. Online commenter: "To look up names and numbers"

Correct. But that alone is not very interesting. Why are they looking up the names and numbers

1.

We can make assumptions about why someone is using a public resource, i.e., what they will use the data for. But that's all they are: assumptions

With the telephone, X could ask "Why are you calling?"

With the internet, that's not possible.^3 This leads to speculation and assumptions. Online commenters love to speculate, and often to make conclusions without evidence

No one knows _everything_ that OpenAI does with the data it collects except OpenAi employees. The public only knows about what OpenAi chooses to share

Similarly no one knows what OpenAI will do with the data in the future

One could speculate that it's naive to think that, in the longterm, data collected by "AI" companies will only be used for "AI"

2. The telephone service also had the notion of "unlisted numbers", but that's another tangent for discussion

3. Hence for example people who do port scans of the IPv4 address space will try to prevent the public from accessing them by restricting access to "researchers", etc. Getting access always involves contacting the people with the scans and explaining what the requester will do with the data. In other words, removing speculation

the ip address the this comes from is a OpenAI search bot range:

> "ipv4Prefix": "74.7.175.128/25"

from https://openai.com/searchbot.json

… the UA is malformed, even.

Makes me want to reconfigure my servers to just drop such traffic. If you can't be arsed to send a well-formed UA, I have doubts that you'll obey other conventions like robots.txt.

May I know does Caddy automatically update with apt if you built custom Caddy binaries for the DNS provider plugin?

Also, may I know which DNS provider you went with? The GitHub issues pages with some of the DNS provider plugins seems to suggest some are more frequently maintained, while some less so.

If you are using a non-standard DNS provider that doesn’t have integration with certbot or cert-manager or whatever you are using, it is pretty easy to set up an acme-dns server to handle it

https://github.com/joohoi/acme-dns

Knowing what DNS names are actually used.

EDIT: that's the flip side of supporting HTTPS that's not well-known among developers - by acquiring a legitimate certificate for your service to enable HTTPS, you also announce to the entire world, through a public log, that your service exists.

Considering how it must be getting hammered what with the "AI" nonsense, it's interesting how crt.sh continues to remain usable, particularly the (limited) direct PostgresSQL db access

To me, this is evidence that SQL databases with high traffic can be made directly accessible on the public internet

crt.sh seems to be more accessible at certain times of the day. I can remember when it had no such accessibility issues

I agree with your analysis but try to not agree with your conclusion, purely for my own metal hygiene: I believe one can retrain the pattern matching of one’s brain for happier outcomes. If I let my brain judge this as a “failure“ (judgment “it is wrong“), I will either get sad about it (judgment “… and I can’t change it“) or angry (… and I can do something about it“). In cases such as this I prefer to accept it as is, so I try to rewrite my brain rule to consider it a necessary part of life (judgment “true/good/correct“).

Not a problem if you have the cert on a shared load balancer, not on the services directly.

also you can use https://github.com/krtab/agnos if you don't have any api access

Yep, but next year they intend to launch an alternative DNS challenge which doesn't require changing DNS records with every renewal. Instead you'll create a persistent TXT record containing a public key, and then any ACME client which has the private key can keep requesting new certs forever.

https://letsencrypt.org/2025/12/02/from-90-to-45#making-auto...

Is it technically possible to obtain a wildcard cert from LetsEncrypt, but then use OpenSSL / X.509 tooling to derive a restricted cert/key to be deployed on servers, which only works for specific domains under the wildcard?

So do Google, Microsoft/Bing, Yandex, etc. How else would they make sure their search/chatbot/q&a products are up to date?

Sure, but the subdomains will be duplicated for the same reasons.

Yet they provide the user agents and IP address ranges which they scrape from, and say they respect robots.txt

I run a web server and so see a lot of scrapers, but OpenAI is one of the ones that appear to respect limits that you set. A lot of (if not most) others don't even have that ethics standard so I'd not say that "OpenAI scrapes everything they can access. Everything" without qualification, as that doesn't seem to be true, at least not until someone puts a file behind a robots deny page and finds that chatgpt (or another of openai's products) has knowledge of it

Of course it doesn't exist if you keep handing it away.

People are just raging and want an outlet. They aren’t thinking logically.

It’s been going on forever (remember how companies were reading files off your computer aka cookies in 1999?)

This seems like a total non-issue and expect that any public files are scraped by OpenAI and tons others. If I don’t want something scraped, I don’t make it public.

When I set up a wildcard cert for my homelab services it was easy to have Cloudflare give me an API token to do the DNS validation for LE.

Unintended: agreed. Unexpected: plenty of us called out this inevitability when the CT proposal was circulated.

The main thing isn't validating the cert you're looking at, per se, it's to validate the activities of the issuers. Mainly that they aren't issuing certificates they aren't supposed to (i.e. you can monitor the logs for your domain to check some random CA you've never done business hasn't issued a cert for it). This is mainly enforced by any violations (i.e. any certificates found that don't show up in the logs) being grounds for being removed from browser's trusted list.

It is not usable.

It's the only website I know of where queries can just randomly fail for no reason, and they don't even have an automatic retry mechanism. Even the worst enterprise nightmares I've seen weren't this user unfriendly.

This is what we do for development containers/hosts - put them behind *.dev.example.com, allows us to hide most testing instances using a shared load balancer. And with a single wildcard CNAME, No info is leaked in CT logs or DNS. Said LB is firewalled, but why pay for extra traffic that's just going to be blocked?

Ah, in case it didn't come across clearly, my conclusion isn't to blame the individuals. My assessment is to seek out better communication patterns, which is partly about "technology" and partly about culture (expectations). People could indeed learn not to act this way with a bit of subtle nudging, feedback, and mechanism design.

I'm also pretty content accepting the unpleasant parts of reality without spin or optimism. Sometimes the better choice is still crappy, after all ;) I think Oliver Burkeman makes a fun and thoughtful case in "The Antidote: Happiness for People Who Can't Stand Positive Thinking" https://www.goodreads.com/book/show/13721709-the-antidote

Oh, sweet! I didn't know about this. I have no need of wildcard certs, but this will greatly simplify the process of issuing certificates for internal services behind my local firewall. No need to maintain an acme-dns server; just configure the ACME client, set the DNS record and you're done? Very nice.

I hadn't heard of Agnos before, interesting alternative to ACME-DNS.

Looking at the README, is the idea that the certificates get generated on the DNS server itself? Not by the ACME client on each machine that needs a certificate? That seems like a confusing design choice to me. How do you get the certificate back to the web server that actually needs it? Or is the idea that you'd have a single server which acts as both the DNS server and the web server?

Great to hear, one less API keys needed for the DNS records.

No

I don't really see how this is a flip-side. If you're putting something on the web, presumably you want it to be accessed by others, so this is actually a benefit.

If you didn't want others to access your service, maybe consider putting it in a private space.

Thanks for looking it up!

I don't have a statistic here, but I'm always surprised how many websites I come across that do limited user-agent and origin/referrer checks, but don't maintain any kind of active IP based tracking. If you're trying to build a site-specific scraper and are getting blocked, mimicking headers is an easy and often sufficient step.

I don't see issue with OAI scraping public logs.

But what GP probably meant is that OAI definitely uses this log to get a list of new websites in order to scrap then later. This is a pretty standard way to use CT logs - you get a list of domains to scrap instead of relying solely on hyperlinks.

matt3210 clearly means that the content of the website (revealed by the CT log) is what is being stolen, not the data in the CT log

I think their point is that the people registering certs may not intend their sites to be immediately scraped, but now OpenAI is bypassing e.g. google indexing or web spidering, and using your cert provider's CT entries to find you immediately for scraping.

> Certificate transparency logs are intended to be consumed by others. That is indeed what is happening. Not interesting

Oh, I read this as indicating OpenAI may make a move into the security space.

> It implies that this is boring and not article/post-worthy (which I agree with).

It's certainly news to me, and presumably some others, that this exists.

Not 100% related but not 100% not-related either: I've got a script that generates variations of the domain names I use the most... All the most common typos/mispelling, all the "1337" variations, all the Levenhstein edit distance of 1, quite some of the 2, etc.

For example for "lillybank.com", I'll generate:

    llllybank.com
    liliybank.com
    ...

and countless others.

Hundreds of thousands of entries. They then are null-routed from my unbound DNS resolver.

My browsers are forced into "corporate" settings where they cannot use DoH/DoT: it's all, between my browsers and my unbound resolver, in the clear.

All DNS UDP traffic that contains any Unicode domain name is blocked by the firewall. No DNS over TCP is allowed (and, no, I don't care).

I also block entire countries' TLD as well as entire countries' IP blocks.

Been running a setup like that (and many killfiles, and DNS resolvers known to block all known porn and know malware sites etc.) since years now already. The Internet keeps working fine.

There's no evidence the barrage of residentially-proxied bot accesses hitting every public website have anything to do with OpenAI, but then again, there's also no evidence they don't.

Thank you!!! Needed exactly this at work.

The first page of results doesn't include ycombinator.com. I get `app.baby-ycombinator.com`, `ycombinator.comchat.com`, everything in between.

Substring doesn't seem like what I'd want in a subdomain search.

Any insights you can share on how you made search so fast? What kind of resources does it take to implement it?

There’s usages of https that don’t overlap with "the (public) web".

If you can't tell the difference between active tracking and inspecting request headers, then it's worth committing a bit of time to ponder. Particularly the costs associated with IP tracking at scale.

Even if it's just for their internal security initiatives it would make sense given how massive they are. Threat hunting via cert monitoring is very effective.

Yeah, this is the unspoken part about HTTPS: you enable it, you also announce to the entire world you're serving stuff from specific DNS names :).

(Which is why I hate it that it's so hard to test things locally without having to get a domain and a certificate. I don't want to buy domain names and announce them publicly for the sake of some random script that needs to offer a HTTP endpoint.)

Modern security is introducing a lot of unexpected couplings into software systems, including coupling to political, social and physical reality, which is surprising if you think in terms of programs you write, which most likely shouldn't have any such relationships.

My favorite example of such unexpected coupling, whose failures are still regularly experienced by users, is wall clock time. If your program touches anything related to certificates, even indirectly, suddenly it's coupled to actual real clock and your users better make sure their system time is in synch with the rest of the world, or else things will stop working.

Glad it was helpful!

> Substring doesn't seem like what I'd want in a subdomain search.

Well, if you want only subdomains search for *.ycombinator.com.

https://www.merklemap.com/search?query=*.ycombinator.com&pag...

Which part is news?

If certificate transparency is new to you, I feel like there are significantly more interesting articles and conversations that could/should have been submitted instead of "A public log intended for consumption exists, and a company is consuming that log". This post would do literally nothing to enlighten you about CT logs.

If the fact that OpenAI is scraping certificate transparency logs is new and interesting to you, I'd love to know why it is interesting. Perhaps I'm missing something.

Way more interesting reads for people unfamiliar with what certificate transparency is, in my opinion, than this "OpenAI read my CT log" post:

https://googlechrome.github.io/CertificateTransparency/log_s...

https://certificate.transparency.dev/

Most of merklemap is stored on ZeroFS [0] and thus allows to scale IO ressources quite crazily :)

[0] https://github.com/Barre/ZeroFS

All of the internal stuff at $employer uses a private CA. I suspect this is fairly universal at places that aren't super tiny.

But it isn’t. Guy posted the fact they sent bot for scraping.

That’s not the intended use for CT logs.

You do know that /etc/hosts is a file you can edit, right? You hopefully also know that you can create your own certificate authority or self signed certificates and add them to your CA store.

> I feel like there are significantly more interesting articles

if this is the article that introduces someone to the concept of certificate transparency, then there's nothing wrong with that. graciously, you followed through with links to what you consider more interesting. that is not something a lot of commenters do and just leave it as a snarky comment for someone being one of the lucky 10000 for the day.

> Watch Ubuntu boot from ZeroFS

Love it

How does ZeroFS handle consistency with writes?

Problem is a lack of solutions that work at places that are tiny, such as a small company, or a household. This is yet another area of the computing ecosystem that forgets there are other use cases for computers than commerce.

> You do know that /etc/hosts is a file you can edit, right?

Yes. What does it have to do with HTTPS?

> You hopefully also know that you can create your own certificate authority or self signed certificates and add them to your CA store.

Sorta, kinda. Does it actually work with third-party apps? Does it work with mobile systems? If not, then it's not a valid solution, because it doesn't allow me to run my stuff in my own networks without interfacing with the global Internet and social and political systems backing its cryptographic infrastructure.

If you use 9P or NBD it handles fsync as expected. With NFS, it's time based.

https://github.com/Barre/ZeroFS#9p-recommended-for-better-pe...

Oh awesome! I was searching for consistency, but I guess durability is the word used for filesystems. Thanks!