Currently the interface is not useful. When we need to vary the
implementation for testing purposes we can introduce a local interface
for the service/chore that needs it, rather than using the large api.
Unfortunately, this requires adding a cleanup callback for tests, there
might be a better solution to this problem.
Change-Id: I079fe4dbe297b0ae08c10081a1cea4dfbc277682
Currently the tool verifies:
* validity of plain_offset
* whether plain_size is smaller than encrypted_size
Change-Id: I9ec4fb5ead3356a196392c26ca377fcdb367138e