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Hauke Mehrtens
2db148c062
WPA3 Specification v3.5 §13 defines the Transition Disable element sent
inside message 3 of the 4-way handshake. An AP that is no longer
offering a transition mode for its SSID sets the matching bit so that
compliant STAs permanently stop falling back to WPA-PSK / WPA-EAP /
open for that SSID, hardening against downgrade attacks and against
operator mistakes where a transition-mode BSS is briefly brought up on
an SSID that previously ran WPA3-only.
Expose this as a UCI list 'transition_disable' with three classes of
entries:
* The existing OpenWrt encryption tokens 'sae' (bit 0x01), 'sae-pk'
(0x02), 'wpa3' (0x04) and 'owe' (0x08) OR into the bitmap. SAE-PK
itself is not yet wired through wifi-scripts; the token only lets
an operator who configured SAE-PK out of band also hand the
matching bit to hostapd.
* 'on' derives the bitmap from the AP's auth_type ('sae' -> 0x01,
'eap2'/'eap192' -> 0x04, pure 'owe' -> 0x08) and overrides any
other explicit tokens in the same list. Transition BSSes
(psk-sae, eap-eap2, owe with owe_transition set) produce no
bits even under 'on' because they are by definition still in
transition.
* 'off' unconditionally suppresses the element regardless of any
other entries. Operators who need to revert a WPA3-only SSID back
to a transition mode can set this proactively, giving compliant
STAs time to forget the permanent bit before the mode change.
Leave the list unset by default. Advertising Transition Disable is a
one-way door -- once a compliant STA has seen the permanent bit for an
SSID it will refuse to associate to a transition-mode BSS of the same
name ever again -- so it must be opted in to per SSID, never flipped
on by a firmware bump. This also matches the WPA3 and Wi-Fi Enhanced
Open Deployment and Implementation Guide v1.1 Table 4 requirement that
Transition Disable be MAND disabled by default on APs.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Link: https://github.com/openwrt/openwrt/pull/23009
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>