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6th August 2011, 09:37 PM |#1  
Mgamerz's Avatar
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The Fingerprint Scanner SDK (originally posted at for Android has been released by Authentec. Currently there is only one device(Motorola Atrix) with a fingerprint scanner, but if you release your application with support for the fingerprint scanner (once you get the hang of it it is really not hard to use at all) then users of phones with fingerprint scanners will most likely be happier with your application.
Google has stated that Google Wallet will use fingerprints to unlock the payment system, so clearly more capable devices are on the way (source: Including fingerprint scanner capability in your application will also future-proof it as AuthenTec will have the same framework in place in other phones that will use their fingerprint scanner (Authentec is a leader in biometric security systems for lots of devices).

MotoDEV Article Guide:

Read and Download the (simple) SDK at their site:
Example of SDK Usage (pulled from the SDK)
At the time of this writing, it is my understanding that before you release the application you need to have them review it to meet their security specifications... They don't want you using this fingerprint scanner library and making their work look bad. It's a fair deal to me. I'm not sure if this is how they want it though - maybe that is just for Advanced SDK or maybe I'm just wrong (taken from their site) It appears right now that there is a mismatch between the developers and the makers of the authentec site... apparently there is no requirement for using the fingerprint scanner, so develop away!

I have an Atrix and the fingerprint scanner is amazing, once you use it you will never go back to patterns or pins. As such this guide was written by a user of the Atrix - future devices might not use the exact methodology but it should be nearly identical.

I have the Advanced SDK but I have not used any of the advanced functions yet. After using the code (And getting it to finally work) I have found some things that are not documented or are documented incorrectly in the SDK docs and I have come here to post items that will save you great time. If you find others I hope to hear about them so I can add it to the list - I'll even credit you (maybe with a post number so you can score some thanks points!)

The swipe fingerprint screen won't show up - but I'm getting a result (mine was always 14)
  • AM2 (Authentec fingerprint framework - there are a lot of unsubscribed terms in the documentation so just go with me here) requires Internet Permission (perhaps to verify the key for the advanced SDK, it might not be done locally - without a key advanced SDK functions will not load). If you don't, all uses of the tsm.jar will not work. Not listed at all in documentation

AM2ClientLibraryLoaded() doesn't work with the code they provide!?
  • You must Instantiate Authentec.AM2ClientLibraryLoaded() - SDK Docs shows as static but it is not used in the example program they give.

It goes into verification but does not show anything and locks up the fingerprint sensor.
  • Do not change the 'screen' in the examples of sScreen... I thought that was the title of the window that would appear, but apparently those strings are built into it... it would work better as static fields passed as integers. For values look at the next answer.

What can I use for sScreen (viaGfxScreen(string))?
  • The documentation says nothing of this but these are different types of verification screens. There is fingerprint scanning only and then there is the unlock style one where you also get the PIN. I'm guessing a modifed version of this is how the lock screen works.
    "lap-verify" is fingerprint and PIN
    "get-app-secret" is fingerprint only - hit and miss right now... will update when I get it perfected

Why does it lock up?
  • Only 1 app at a time can access the fingerprint scanner. Motoblur seems to access it occasionally and I think that's why it died on the Atrix's Froyo 1.8.3. It seems mostly fixed but as you develop you will most likely lock it up as you debug. Having a wrong sScreen variable will kill your FP scanner. If it locks in your app you will lose the ability to unlock the device with the FP scanner.
    Use DDMS to kill com.authentec.TrueSuiteMobile and the lock will work again. This might work on 1.8.3 but I'm not sure it works that way. If the application exits with the home button, it seems to also lock it up. I'm looking into a way to avoid this..

I can't register my application, it's failing with code 6 - (System Error)
  • I encountered this one myself when using my Api key for com.mgamerzproductions.gibbertalk - I changed it to com.mgamerzproductions.gibbertalk.testing and it no longer worked. They did tell me this in the email that it is only for one package - so make sure you choose wisely, or bribe the people giving out the API keys to give you another one. I wish it was more specific (API_KEY_NOT_AUTHENTIC or something)

I'm still having problems. What can I do?
  • You can use these tags for debugging in logcat:
    • AMJNI (AuthenTec Mobile - permissions - server)
    • TrueMobileSuite (some gfx log info - swipe fingerprint screen)
    • AndroidRuntime (will tell you crash related things, as debugging for errors will produce too much to read at once)

Any other things would be greatly appreciated for all of use Developers so speak up if you have something I don't have listed and I'll add it.

If you want to use the encrypted storage provided by the framework you'll need to apply for the Advanced SDK. You have to give them a description of your app, and it has to be security related (obviously that's the whole point of the fingerprint scanner and they don't want you to abuse it).

If you like the guide, and you are on MotoDev, I wouldn't mind a kudos in the contest http://community.developer.motorola....-in/td-p/17206
Last edited by Mgamerz; 11th August 2011 at 06:18 AM. Reason: Shameless self promotion (in small text of course)
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