PowerMock indirectly allows setAccessible on any method

The CS class I'm on staff for is looking into ways to grade Java Android app-based assignments securely. Restricting student code without breaking Robolectric is tricky - we need to allow e.g. reflection when done by Robolectric or the test suites but not when done by student code. Some of our test suites use PowerMock, which of course internally exercises all kinds of permissions. Unfortunately it could be used by student code to override access modifiers and call arbitrary methods: WhiteboxImpl provides the public function getAllMethods, which makes all a class's methods accessible and returns them.

So checking whether trusted frameworks are using the dangerous permissions is insufficient. Fortunately, we make PowerMock a testImplementation dependency, so it's not on the compile classpath for the student sources. While students could access it at runtime via reflection (the problematic method is public), our SecurityManager can check whether PowerMock is being invoked reflectively and deny permission if so.