[flagged]
Maybe read the actual definition before assuming you're so much smarter than "HN". One doesn't need third parties to have pki, it's a concept, you can roll out your own
I’ve been discussing the practical implementation of PKI as it exists in the real world, specifically in the context of bootloader verification and TLS certificate validation. You know, the actual systems people use every day.
But please, do enlighten me with whatever Wikipedia definition you’ve just skimmed that you think contradicts anything I’ve said. Because here’s the thing: whether you want to pedantically define PKI as “any infrastructure involving public keys” or specifically as “a hierarchical trust model with certificate authorities,” my point stands completely unchanged.
In the context that spawned this entire thread, LineageOS and bootloader signature verification, there is a chain of trust, there are designated trusted authorities, and signatures outside that chain are rejected. That’s PKI. That’s how it works. That’s what I described.
If your objection is that I should have been more precise about distinguishing between “Web PKI” and “PKI generally,” then congratulations on missing the forest for the trees whilst simultaneously contributing absolutely nothing of substance to the discussion.
But sure, I’m the one who needs to read definitions. Perhaps you’d care to actually articulate which part of my explanation was functionally incorrect for the use case being discussed, rather than posting a single snarky sentence that says precisely nothing?
EDIT: your edit is much more nuanced but still misses the point; https://imgur.com/a/n2VwltC
I've explained the same point three different ways now. Not one person has actually demonstrated where the technical argument is wrong, just deflected to TOFU comparisons, philosophical ownership debates, and now tone policing.
If Aachen has an actual technical refutation, I'm all ears. But "read the definition" isn't one, and neither is complaining about snark whilst continuing to avoid the substance.
But you're demonstrably wrong. The purpose of a PKI is to map keys to identities. There's no CA located across the network that gets queried by the Android boot process. Merely a local store of trusted signing keys. AVB has the same general shape as SecureBoot.
The point of secure boot isn't to involve a third party. It's to prevent tampering and possibly also hardware theft.
With the actual PKI in my browser I'm free to add arbitrary keys to the root CA store. With SecureBoot on my laptop I'm free to add arbitrary signing keys.
The issue has nothing to do with PKI or TOFU or whatever else. It's bootloaders that don't permit enrolling your own keys.
No, the purpose is "can I trust this entity". The mapping is the mechanism, not the purpose.
> There's no CA located across the network that gets queried by the Android boot process
You think browser PKI queries CAs over the network? It doesn't. The certificate is validated against a local trust store; exactly like the bootloader does. If it's not signed by a trusted authority in that store, it's rejected. Same mechanism.
> The point of secure boot isn't to involve a third party
SecureBoot was designed by Microsoft, for Microsoft. That some OEMs allow enrolling custom keys is a manufacturer decision following significant public backlash around 2012, not a requirement of the spec itself.
> The issue has nothing to do with PKI [...] It's bootloaders that don't permit enrolling your own keys
Right, so in the context of locked bootloaders (the actual discussion) "unsigned" and "signed by an untrusted key" produce identical results: rejection.
Where exactly am I "demonstrably wrong"?
You compared bootloader validation to TLS verification. The purpose of TLS CAs is to verify that the entity is who they claim to be. Nothing more, nothing less. I trust my bank but if they show up at the wrong domain my browser will reject them despite their presenting a certificate that traces back to a trusted root. It isn't a matter of trust it's a matter of identity.
Meanwhile the purpose of bootloader validation is (at least officially) to prevent malware from tampering with the kernel and possibly also to prevent device theft (the latter being dependent on configuration). Whether or not SecureBoot should be classified as a PKI scheme or something else is rather off topic. The underlying purpose is entirely different from that of TLS.
> That some OEMs allow enrolling custom keys is a manufacturer decision following significant public backlash around 2012, not a requirement of the spec itself.
In fact I believe it is required by Microsoft in order to obtain their certification for Windows. Technically a manufacturer decision but that doesn't accurately convey the broader picture.
Again, where are you going with this? It seems as though you're trying to score imaginary points.
> Where exactly am I "demonstrably wrong"?
Your claimed that the point of SecureBoot is to involve a third party. It is not. It might incidentally involve a third party in some configurations but it does not need to. The actual point of the thing is to prevent low level malware.
Somehow this was controversial.
Besides the "what does pki mean" discussion, as for who "misses the point" here, consider that both sides in a discussion have a chance at having missed the original point of a reply (it's not always only about how the world is / what the signing keys are, but how the world should be / whose keys should control a device). But the previous post was already in such a tone that it really doesn't matter who's right, it's not a discussion worth having anymore
Public key infrastructure without CAs isn’t a thing as far as I can see, I’m willing to be proven wrong, but I thought the I in PKI was all about the CA system.
We have PGP, but that's not PKI, thats peer-based public key cryptography.
Lineage is signed, sure. It needs to be blessed with that root for it to work on that device.
Then you admit you actually understood this the entire time, but my tone put you off elaborating.
So you watched this thread pile on someone for being technically correct, said nothing of substance, and now reveal you knew they were right all along but simply chose not to contribute because you didn't like how they said it.
That's not you taking the high road, mate. That's you admitting you prioritised posturing over clarity, then got smug about it.
Brilliant contribution. Really moved the discourse forward there.