Add management of permission requests

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
Removal of the generation of random keys

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
Commenting and finalizing

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>