Register an existing key in a secure element.
Minimal implementation that doesn't call any driver method and just
lets the application declare whatever it wants.
Allow the application to choose the slot number in a secure element,
rather than always letting the driver choose.
With this commit, any application may request any slot. In an
implementation with isolation, it's up to the service to filter key
creation requests and apply policies to limit which applications can
request which slot.
Run all functions that take a key handle as input with a key that is
in a secure element. All calls are expected to error out one way or
another (not permitted by policy, invalid key type, method not
implemented in the secure element, ...). The goal of this test is to
ensure that nothing bad happens (e.g. invalid pointer dereference).
Run with various key types and algorithms to get good coverage.
