I am developing an app using Xcode 9.2 and Swift 4 to work on iPhones with Touch ID or Face ID capability. There will be a button that will show a fingerprint for iPhones with Touch ID and a friendly face for ones with Face ID. I would like my button to look like the following:
Is there a way to assign an UIButton image to the Apple Touch ID or Face ID built-in set of images?
Touch ID support was included in iOS 7 and Face ID in iOS 11 and I would like the code to work with iOS 7 and above.


We've done this kind of thing before at a prior job. Apple really wants to be sure that you use those kinds of logos appropriately and as I recall we had to get the icons from them. I would start with the Apple trademarks department:
https://www.apple.com/legal/intellectual-property/guidelinesfor3rdparties.html
From there you will probably have to meet with them and assure them that you are using the logos appropriately. For example, if you use the TouchID logo they want to make sure it MEANS TouchID in context. They would then provide the graphics and usage guidelines.