WDS/4addr setup on master: wpa_supplicant doesn't like double quote in PSK

[Borromini]

In preparation for the upcoming 22.xx branch, I bumped my production APs to master. I have a WDS setup running that worked fine (barring interference from the neighbours of course ) on 21.02. As long as the WDS client stayed on 21.02, even with the master AP on a master build it would work fine. However, once I move the WDS client to a master build as well, it ceases to connect. logread isn't very verbose. I did see this though on the client:

# logread -e wlan0
Sun Feb 27 23:56:02 2022 daemon.err wpa_supplicant[1344]: Failed to read or parse configuration '/var/run/wpa_supplicant-wlan0.conf'.
Sun Feb 27 23:56:02 2022 kern.info kernel: [ 3768.911286] br-lan: port 5(wlan0) entered blocking state
Sun Feb 27 23:56:02 2022 kern.info kernel: [ 3768.922026] br-lan: port 5(wlan0) entered disabled state
Sun Feb 27 23:56:02 2022 kern.info kernel: [ 3768.933236] device wlan0 entered promiscuous mode

/var/run/wpa_supplicant-wlan0.conf looks OK though:

country=IT
network={
	scan_ssid=1
	ssid="Zeus 802.11n backhaul"
	key_mgmt=SAE
	psk="$key"
	proto=RSN
	ieee80211w=2
	beacon_int=100
}

/etc/config/wireless on the WDS client:

config wifi-device 'radio0'
	option type 'mac80211'
	option channel '6'
	option band '2g'
	option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
	option country 'IT'
	option htmode 'HT40'
	option txpower '12'
	option cell_density '0'
	option disabled '0'

config wifi-iface 'wds_radio0'
	option device 'radio0'
	option network 'lan'
	option ssid 'Zeus 802.11n backhaul'
	option mode 'sta'
	option wds '1'
	option encryption 'sae'
	option key '$key'
	option ieee80211w '2'

/etc/config/wireless on the WDS master:

config wifi-device 'radio0'
	option type 'mac80211'
	option channel '6'
	option hwmode '11g'
	option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
	option htmode 'HT40'
	option country 'IT'
	option cell_density '0'
	option disabled '0'

config wifi-iface 'wds_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'Zeus 802.11n backhaul'
	option encryption 'sae'
	option isolate '1'
	option wpa_disable_eapol_key_retries '1'
	option wds '1'
	option hidden '1'
	option key '$key'
	option ieee80211w '2'

Anyone know what's going wrong here?

[Borromini]

Well we can chalk this off to wpa_supplicant being more picky about characters in the PSK it seems. Looks like a regression to me. Running wpa_supplicant manually, this error popped up:

Line 8: Invalid passphrase length 4 (expected: 8..63) 'bla bla bla'.
Line 8: failed to parse psk 'bla bla bla'.

Once I replaced the double quote " in the PSK with another character the WDS started functioning again.

[aparcar]

Are you sure this previously worked? I wonder if they changed the handling of spaces and quotes within the last versions. If so we should extend their testing setup.

[Borromini]

It did. All I needed to break it was to migrate from 21.02 HEAD to master while keeping the WDS encryption key. It seems it's really wpa_supplicant that breaks (so the WDS 'client'), since the WDS master came up just fine.