Android Fingerprint Raw Data

Question

Does Android's fingerprint sensor implementation support direct access of raw fingerprint data i.e. the actual pattern on the finger? I don't mean the stored secure fingerprint that is used for unlocking the device and making payments, but just getting raw data on demand when a finger is scanned. If not, why not?

Answer 1

The Android API's do not allow direct access of raw fingerprint data. Fingerprint data will not leave the TEE (Trusted Execution Environment).

Google included the following piece of text about this in the CCD (Compatibility Document)

https://source.android.com/security/authentication/fingerprint-hal

Thus, raw images and processed fingerprint features must not be passed in untrusted memory. All such biometric data needs to be secured within sensor hardware or trusted memory. (Memory inside the TEE is considered as trusted memory; memory outside the TEE is considered untrusted.)

There is a different solution however: Don't use the fingerprint-scanner, but the camera.