我们还可以使用Android M的指纹API做什么？

Question

Since the release of Android 6.0 Marshmallow, Google added fingerprint support to Android. This API is called: Fingerprint Authentication, it can be found here:

https://developer.android.com/about/versions/marshmallow/android-6.0.html#fingerprint-authentication

Now, I was wondering whether we can use the fingerprint scanner for other purposes than authenticating the user. For example: print the scanned fingerprint on the screen. Much like how current users register their fingerprint in the settings, but instead, make the fingerprint in the middle of the screen your own fingerprint.

I am aware of the fact that fingerprint scanners were added for security. I also understand that such an app can be quite dangerous, even if it was meant just for fun.

My question: Can we use the fingerprint scanner (in combination with an API) for other purposes than authentication, and if so, how?

Answer 1

FingeprintManager has only 3 methods:

• authenticate : to authenticate user
• hasEnrolledFingerprints : if there is at least one fingerprint enrolled.
• isHardwareDetected : to check if fingerprint sensor is available

You could also generate an encryption key which is stored securely on the device using the Android Keystore system:

• http://android-developers.blogspot.fr/2015/10/new-in-android-samples-authenticating.html
• http://www.techotopia.com/index.php/An_Android_Fingerprint_Authentication_Tutorial

If you want to get fingerprint (image or template) from sensor it's not possible with Android Fingerprint API. You could use an external fingerprint sensor with specific SDK for this.