This is an API break since 1.16-rc1.
The functions like _nm_utils_wireguard_decode_key() are internal API
and not accessible to a libnm user. Maybe this should be public API,
but for now it is not.
That makes it cumbersome for a client to validate the setting. The client
could only reimplement the validation (bad) or go ahead and set invalid
value.
When setting an invalid value, the user can afterwards detect it via
nm_wireguard_peer_is_valid(), but at that point, it's not clear which
exact property is invalid.
First I wanted to keep the API conservative and not promissing too much.
For example, not promising to do any validation when setting the key.
However, libnm indeed validates the key at the time of setting it
instead of doing lazy validation later. This makes sense, so we can
keep this promise and just expose the validation result to the caller.
Another downside of this is that the API just got more complicated.
But it not provides a validation API, that we previously did not have.
When setting any secrets via D-Bus' Update2 call, then
it assumes that all settings are reset. That means, when
we modify any secrets in the client, we need to first load
them all.
Anyway, load always all secrets, then we can also print them
in the get output.
Honor WG_HIDE_KEYS like `wg` does.
Use the script to test how GObject introspection with libnm's WireGuard
support works.
Also, since support for WireGuard peers is not yet implemented in nmcli
(or other clients), this script is rather useful.
