This repository contains sample Android key attestation certificate chains in
directories named after the ro.product.model value for the devices where they
were generated.
Each of these is a valid certificate chain up to the key attestation root. The devices are running the stock OS with the bootloader locked and verified boot enforcing integrity, which can be confirmed from the metadata in the initial attestation certificate.
The challenge string is set to sample (UTF-8 encoded) rather than the usual
random challenge. These are collected with the Auditor
app so the app id in the
certificate is app.attestation.auditor and the fingerprint is for the release
signing key. Older samples are marked with an empty LEGACY file in the
directory and use a legacy app id and signing key. The legacy H3113 sample is
even older and predates the sample gathering code in the Auditor app. It was
generated using ad hoc code in a debug build so it has a different key, random
32 byte challenge string and quick expiry date.
The collection of data published here is public domain / CC0 licensed and is crowdsourced.
Contributing
This project and the apps / services using it depend on data submissions being made from a variety of Android devices.
To help out by contributing data, you'll need any Android device launched with Android 8.0 or later. A device upgraded to Android 8.0 from an earlier version isn't enough. Data submitted from devices running an aftermarket OS is okay but we need at least one submission from a device variant where the device has the stock OS and the bootloader locked. It's easy to tell if the device is running the stock OS from the certificate chain so there's no harm in submissions where the OS has been modified.
To submit data, install the Auditor app (which is available free for non-commercial usage on GitHub), press the menu button in the action bar and press 'Submit sample data' which will submit a sample certificate chain and system properties accessible to the app to https://attestation.app/. The system properties will only be published in a heavily filtered form without properties that aren't constant across devices of that model.