Hacker News Reader

Comment by imkac | Hacker News Reader

The difference between GrapheneOS and iOS is that it is 100% open source, replicable, able to self-sign, and only <1% of the part has dynamic code loading, which is incredibly low compared to any major OS.

View on HN

You are still having to trust a pile of binary blobs even if you built and self signed every release yourself, which I used to do, but at 240gb of source code it is not practical for most individuals even if you do trust all those dozens of blobs from random vendors, which I do not.

This one is not really a fault of GrapheneOS, and more a reality that Android is not actually an open platform and never will be. I require a lot more control of a device I need to be able to trust than anything in the android ecosystem can offer anymore.

Replicant was the right approach but sadly never got the resources to pursue it at the required scale to support new devices.

It's not replicable or open source since your build won't pass attestation

Not passing attestation for certain services has no bearing on software being open source or supporting reproducible builds.

It proves that you haven't built an equivalent binary.

Software doesn't stop being open source because the releases are signed to be able to verify those. Any OS can be installed on the supported device. The verified boot key hash shown at boot will be different for an unofficial build and so will a query to the hardware asking it to provide it. Auditor and AttestationServer are open source. Those work fine with unofficial builds and forks of GrapheneOS after making builds of those with the correct key.

If you can't build the binary from the source, the binary isn't open source.

It's ludicrous to claim software with signed releases isn't open source. Having private keys used to generate the signatures for APKs, updates and the vbmeta image doesn't somehow make it not open source. Every APK is signed and the software isn't somehow not open source because the signature requires the private keys. There are standard tools to compare APKs with different signing keys to ensure the build is reproducible and the same thing exists for the OS as a whole which contains many signed APKs and a signed vbmeta image with verified boot metadata.

The signatures enable the update client to verify the releases and the firmware to verify the OS with the public key flashed by the user as part of installing the OS. Signed updates and verified boot fully work with any build of GrapheneOS following our build instructions. Auditor and AttestationServer also work once they're rebuilt with the new verified boot hash included.

GrapheneOS is open source with reproducible builds. Android key attestation isn't specific to GrapheneOS and is OS independent. It mainly exists to check that a key was generated in a hardware keystore. There's no pass or fail based on having an official or unofficial build of GrapheneOS. The hardware can sign public key certificates with metadata on device security including verified boot state (green, yellow or orange), verified boot key hash, verified boot hash (hash of the core OS) and patch levels. That's not nefarious and is useful to end users. Our Auditor app uses it to help users protect their devices. GrapheneOS doesn't use it to require people to use an official build for any purpose. Some banks have regulations requiring them to verify the hardware, OS and app which means they need to specifically allow each non-Google-certified OS. There are only around 3 banking apps are known to permit GrapheneOS that way and without it they'd ban using any non-Google-certified OS.

Reply on news.ycombinator.com