Retries after secrets reject in 4-way handshake

[Alfonso Sanchez-Beato <alfonso sanchez-beato canonical com>]

Hi,

We have found a problem by which a buggy access point rejects a valid passphrase in the 4-Way Handshake phase. This happens just after the AP has rebooted - a few seconds later the AP accepts the passphrase again.

The problem is that NetworkManager drops the passphrase after the failure to connect ( see https://github.com/NetworkManager/NetworkManager/blob/master/src/devices/wifi/nm-device-wifi.c#L1969 ), and then it tries to call an agent to get another passphrase. In this set-up, we do not have that agent, and then the connection stays there and there are no more connection retries.

It does not look like NM has currently a way to force retries in this case, although I would be happy to be proven wrong.

So, I have thought of some possible ways to solve this and would appreciate your feedback on what would be the best approach and what would be acceptable to be merged:

1. Do some retries before calling the agent
2. Do not drop the secret if there is no agent registered
3. Have a new property for the connection that forbids dropping secrets

Thoughts?

Thanks,
Alfonso