p11_get_session
ret = p11_get_session(NULL, p11rsa->p, p11rsa->slot, NULL, &session);
ret = p11_get_session(NULL, p11rsa->p, p11rsa->slot, NULL, &session);
ret = p11_get_session(context, p, slot, lock, &session);
static int p11_get_session(hx509_context,