Interface Android Keystore from NDK

[Jimenez Maxime]

Introduction

I am currently working on a solution that would use Android Keystore new features (since Marshmallow , API level 23). My app use both Java and C++ (NDK) and I have some critical operation that needs to be perform from native code.

I am able to use properly the new Keystore from Java.

Unfortunately, the Android C++ sources are not documented and I have tried to look into it.

Question

I would like to perform operation from both Java and C++. The only dynamic library that I could use and interface is the IKeystoreService and with its associated library /system/lib/libkeystore_binder.so.

I have been able to include headers and the library and compile it. But since the only connection point I can use is a Binder between Java and C++ IKeystoreService(s), I can't find which data I am supposed to use in order to achieve a simple AES encryption (for example).

Would anyone have any insight ?

Thanks