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Ask HN: Is Let's Encrypt the new swiss crypto ag?

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Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#11

Post by infogulch »

Coxa wrote: post #5
infogulch wrote: post #4

Are you familiar with how certificates and CAs work in general? You don't receive a certificate from the CA, they just sign and attest that the one you made is owned by you. The ways CAs go bad is not breaking any crypto but by signing a certificate that you don't own. This vulnerability is well known and LE takes industry-leading steps to mitigate it via the certificate transparency program which is a permanent audi…

From my understanding of the certificate transparency program does not mitigate the threat of them simply not disclosing a certificate they signed. Ultimately this still gives them MitM capabilities as long as they control the traffic or am I mistaken?

Yes, this property (CAs are capable of creating and signing near-arbitrary certs) is inherent in the concept of Certificate Authorities in general, and the log doesn't automatically fix that because nothing can. But auditors regularly check served certificates against these logs and report unlogged certificates automatically. This can be verified in your browser with things like OCSP stapling.

You may find this useful: http://www.certificate-transparency.org/how-ct-works

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#12

Post by seanhunter »

drummer wrote: post #9

I suppose it would be trivial for them to issue compromised certificates or record the private key in a targetted attack for a specific domain without anyone noticing.

Would be trivial except for the fact that they don't issue certificates.

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#15

Post by advisedwang »

drummer wrote: post #9

I suppose it would be trivial for them to issue compromised certificates or record the private key in a targetted attack for a specific domain without anyone noticing.

During normal certificate issuance, they do not generate or see the private key, so they can't compromise the certs they sign for you.

Like any other CA, they do have the technical ability to sign arbitrary other certs, so could issue a cert for MITM. As some other comments show, certificate transparency is starting to reduce this risk.

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#16

Post by throwaway3neu94 »

Coxa wrote: post #14
tree3 wrote: post #13

Why are you specifically targeting LE with this post? Why not other CAs?

Because I want to use LE and not other CAs.

That's misguided (I'm assuming you're the server admin).

Whether you use any specific CA, like LE, or not, has no security impact.

It's about what your users trust and you don't control that.

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#17

Post by throwaway3neu94 »

infogulch wrote: post #4

Are you familiar with how certificates and CAs work in general? You don't receive a certificate from the CA, they just sign and attest that the one you made is owned by you. The ways CAs go bad is not breaking any crypto but by signing a certificate that you don't own. This vulnerability is well known and LE takes industry-leading steps to mitigate it via the certificate transparency program which is a permanent audi…

Actually some (popular) CA's can generate the cert on their side and let users download it. Not allowing this insecure practice is one more point in which LE is ahead of the curve.

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#19

Post by jeffrallen »

advisedwang wrote: post #15
drummer wrote: post #9

I suppose it would be trivial for them to issue compromised certificates or record the private key in a targetted attack for a specific domain without anyone noticing.

During normal certificate issuance, they do not generate or see the private key, so they can't compromise the certs they sign for you. Like any other CA, they do have the technical ability to sign arbitrary other certs, so could issue a cert for MITM. As some other comments show, certificate transparency is starting to reduce this risk.

LE does not see the private key but certbot does. Who audits certbot?

Re: Ask HN: Is Let's Encrypt the new swiss crypto ag?

#20

Post by JohnFen »

smoyer wrote: post #6
45ure wrote: post #3

Earlier quoted context omitted.

The 'law' is more of an observation and generally applies to headlines. I feel you are being overly dismissive, as a question is being asked is in a dedicated section. There have been instances of CA's, most notably Symantec, which have turned out to be bad apples. There is a constant stream of news dispelling myths surrounding seemingly reputable firms regarding encryption/privacy. Whether these incidences are relat…

I'm not arguing against having the discussion ... my point is that trust in any certificate is reliant on its chain-of-trust and so if Let's Encrypt has this problem, you can't trust other certificates either. But the implication in the head-line is that the NSA/CIA are controlling Let's Encrypt. If that's true, then we've got a real problem ... on the other hand, I think other CAs have shown that, through incompeten…

> if Let's Encrypt has this problem, you can't trust other certificates either.

To be perfectly honest, I don't really trust the other certs, either. I mean, I pretty much have to, and having a mainstream CA sign a cert does provide a bit of reassurance -- but only a bit. I don't really consider CA signing to mean that the cert is "trustworthy", because I don't really trust those CAs, so if they're the anchor for a chain of trust, then the chain of trust is weak.

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