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A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

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Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#181

Post by MattPalmer1086 »

3np wrote: post #166
MattPalmer1086 wrote: post #163

Things like this make me wonder why certificates are not also signed by the certificate owner. Right now, a CA can issue a certificate for any public key and domain they like. A rogue trusted CA can intercept all traffic. If a certificate also included a signature by the owner of the public key signed by the CA (using their private key, signed over the CA signature), then a CA would no longer have this ability. What…

> What am I missing? Infrastructure and processes for key distribution and revocation. Reusing the existing PKI infrastructure used for CA trust roots won't handle it. Perhaps public keys/certs could be distributed over DNS, like for DANE (or maybe even using DANE)? Not saying it can't be done, just to point out how it's not trivial and requires buy-in from incumbents across the ecosystem. https://en.wikipedia.org/wi…

Oh sure, any change to X.509 certs would require a lot of change.

I'm not sure it would make much difference to most of the existing PKI infrastructure though. CAs wouldn't see any difference. For example, currently this is what happens:

1. Owner: generate CSR and send to CA 2. CA: validates owner identity, signs cert and returns cert to owner.

All we would then add is:

3. Owner: signs cert with own private key and uses it.

As far as I can see, the only other changes required would be to clients (so they could reject non owner signed certs), and maybe some revocation stuff.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#182

Post by [deleted] »

rhplus wrote: post #173
MattPalmer1086 wrote: post #163

Things like this make me wonder why certificates are not also signed by the certificate owner. Right now, a CA can issue a certificate for any public key and domain they like. A rogue trusted CA can intercept all traffic. If a certificate also included a signature by the owner of the public key signed by the CA (using their private key, signed over the CA signature), then a CA would no longer have this ability. What…

> What am I missing? The chain of trust for all the certificates in your example is established by trusting the rogue CA root certificate. The CA (or a bad actor who misled the CA through real-world fraud) could be the “owner” of the key pair you’re trusting for the second signature.

[deleted]

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#183

Post by Muromec »

mnau wrote: post #44
awinter-py wrote: post #25

Earlier quoted context omitted.

what's the state's interest in having their CA built into windows?

E.g. identity verification. My state has a "qualified" certificate that can be used to sign contracts and basically everything else you can do in-person. When you can transfer you home with that, there are higher requirements on checking the identity of a person who gets the certificate. That CA is not used for much else and is basically confined to our state. But it has to be in Windows, otherwise no other software…

You don't really need your CA doing eIDAS in the system root. This scheme works as a closed system where you need eIDAS app to produce the artifact and another eIDAS app to verify it, when both have their own non-system root.

Ukraine for example successfully operates their own eIDAS-like scheme where everything is based on DSTU+GOST algos not supported by any operating systems a major libraries, the certs are signed by the government root and it doesn't leak into web pki.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#184

Post by Muromec »

tsimionescu wrote: post #133
mnau wrote: post #44

Earlier quoted context omitted.

E.g. identity verification. My state has a "qualified" certificate that can be used to sign contracts and basically everything else you can do in-person. When you can transfer you home with that, there are higher requirements on checking the identity of a person who gets the certificate. That CA is not used for much else and is basically confined to our state. But it has to be in Windows, otherwise no other software…

Why would you want to mix identity verification with the WebPKI? This makes no sense at all. Just because a CA is trusted for web verification doesn't mean it's trusted for identity verification, machine enrollment, or any other purpose. And vice-versa: a CA for identity verification is not in any way trusted for web verification.

I think the idea was to use client certs for strong authentication on the government web services, which didn't rally took off, except maybe in Estonia.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#185

Post by nordsieck »

tsimionescu wrote: post #136
amluto wrote: post #70

Earlier quoted context omitted.

I’m not talking about a name constraint — that would need to be part of the root certificate. I’m suggesting that MS add a feature to its root store to constrain the usage of the certificates in the store. IIRC Google’s root store has features like this.

The Windows trust store doesn't offer a verification API, I believe it simply lists the trusted certificates so that they can be looked up by verification software. That is, OpenSSL doesn't ask windows "hey, is this certificate with this chain trusted for google.com?" it asks Windows "hey, do you have a cert in the trusted root CAs with this ID? If so give it to me", and then OpenSSL will use that root cert to check…

> Either way, this makes little sense overall. If a CA is trustable, it can be trusted to sign a certificate for any domain. And if it's not trustable, then you can't trust it for any domain.

That's a silly position to take.

When I lived with roommates, I trusted them. But I also locked my bedroom when I went out. Because there's no good reason to rely on trust when you don't have to.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#186

Post by echoangle »

3np wrote: post #178
echoangle wrote: post #167

Earlier quoted context omitted.

Does any employer get a certificate from any of the CAs you listed to MITM their internal networks?

The listed companies are employers. I think they all have self-managed CAs.

Yes, but surely the listed companies don't use their public and globally trusted CAs to MITM their internal networks. I hope they have another internal CA to allow them to MITM their internal Network.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#187

Post by MattPalmer1086 »

rhplus wrote: post #173
MattPalmer1086 wrote: post #163

Things like this make me wonder why certificates are not also signed by the certificate owner. Right now, a CA can issue a certificate for any public key and domain they like. A rogue trusted CA can intercept all traffic. If a certificate also included a signature by the owner of the public key signed by the CA (using their private key, signed over the CA signature), then a CA would no longer have this ability. What…

> What am I missing? The chain of trust for all the certificates in your example is established by trusting the rogue CA root certificate. The CA (or a bad actor who misled the CA through real-world fraud) could be the “owner” of the key pair you’re trusting for the second signature.

Good point.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#188

Post by 8organicbits »

coretx wrote: post #81

Does anyone have a list of state ( associated ) CA's so that I can ditch them all ?

I built a partial list last year [1]. It's challenging to decide which CAs are government operated or controlled: the names don't always make it clear, private companies may operate under government direction, law may require CAs to follow government requests. These were all very clearly government/military organizations running CAs. The Brazilian CA referenced here is number two on the list.

[1] https://alexsci.com/blog/ca-trust/#government-control-of-cas

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#189

Post by tsimionescu »

nordsieck wrote: post #185
tsimionescu wrote: post #136

Earlier quoted context omitted.

The Windows trust store doesn't offer a verification API, I believe it simply lists the trusted certificates so that they can be looked up by verification software. That is, OpenSSL doesn't ask windows "hey, is this certificate with this chain trusted for google.com?" it asks Windows "hey, do you have a cert in the trusted root CAs with this ID? If so give it to me", and then OpenSSL will use that root cert to check…

> Either way, this makes little sense overall. If a CA is trustable, it can be trusted to sign a certificate for any domain. And if it's not trustable, then you can't trust it for any domain. That's a silly position to take. When I lived with roommates, I trusted them. But I also locked my bedroom when I went out. Because there's no good reason to rely on trust when you don't have to.

It is given the design of the PKI and DNS. There's no relation between CA and the TLDs on the certificate being signed.

Re: A Brazilian CA trusted only by Microsoft has issued a certificate for google.com

#190

Post by switch007 »

grayhatter wrote: post #73
foota wrote: post #63

Earlier quoted context omitted.

I think the parent is saying that if they meant to use the cert only internally (e.g., to monitor employees) then that would arguably not be malicious.

> (e.g., to monitor employees) then that would arguably not be malicious. If only there was a way to monitor company equipment without issuing a cert for a public 3rd party.

AI screen monitoring right
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