When you upload your .apk to Google Play you are issued with a Base64-encoded RSA public key as your License key. How does one access this same key programmatically in their Android app code?
Secondly, does this key remain constant, or does it change every time you upload an update for a given app (generated presumably from the .apk binary)?
If so, is there any other uniquely-identifying information you can get programmatically from an app that will remain constant regardless of updates. Something that identifies a particular app definitively?
Trivial example, if a library is proprietary but you want to configure it to only work with a pre-determined set of Android apps. You could do this by verifying against some programmatically accessible unique information about the app in which it is being used at runtime.
Many thanks for your help
You are confusing the keys used for license verification and in-app billing with those you use to sign your apps. You can get the signing key with this. The license key is not used by most apps, and if you need it, you have to embed it in the app. Generally, an app is uniquely identified by the package name and signing certificate (or its hash value).