Question

Is there some way to retrieve information about the apk signature at runtime?

For example I have the same App signed with 2 different signatures: app-1.apk and app-2.apk and I’d like to be able of differentiate both apk in run time. Is that possible?

My goal is to implement a licensing system using a external server and based on the version code of the application and the signature.

Answer 1

You can access apk signature using PackageManager.
PackageInfo flag defined in Package Manager return information about the signatures included in the package.

Signature[] sigs = context.getPackageManager().getPackageInfo(context.getPackageName(),PackageManager.GET_SIGNATURES).signatures;    
for (Signature sig : sigs)
{
    Log.i("App", "Signature : " + sig.hashCode());
}

http://developer.android.com/reference/android/content/pm/PackageManager.html