openwrt/package/network
Hauke Mehrtens 68165c85c8 wifi-scripts: ucode: default BIP cipher from wpa_pairwise
The WPA3 and Wi-Fi Enhanced Open Deployment and Implementation Guide
v1.1 (Tables 4, 5, 6) requires the group-management cipher (BIP) to
match the mode and strength of the pairwise cipher: GCM-mode pairwise
ciphers pair with BIP-GMAC integrity, CCM-mode pairwise ciphers with
BIP-CMAC integrity.  The ucode pipeline hard-coded group_mgmt_cipher
to AES-128-CMAC (BIP-CMAC-128) regardless of the pairwise cipher,
except for the eap192 special case that already forced BIP-GMAC-256.
An EHT WPA3-Personal BSS therefore emitted wpa_pairwise=GCMP-256
alongside group_mgmt_cipher=AES-128-CMAC -- the integrity cipher two
steps weaker than the data cipher and a spec violation on EHT.

hostapd has a single group_mgmt_cipher knob, so the selected BIP has
to be compatible with every pairwise cipher in wpa_pairwise.  Picking
from the first token would mis-select on mixed lists -- e.g.
wpa_pairwise=\"GCMP-256 CCMP\" would yield BIP-GMAC-256, which a
CCMP-only STA cannot negotiate.

Walk the wpa_pairwise tokens and pick the BIP that matches the
weakest cipher present:

  CCMP / TKIP -> AES-128-CMAC (BIP-CMAC-128)
  CCMP-256    -> BIP-CMAC-256
  GCMP        -> BIP-GMAC-128
  GCMP-256    -> BIP-GMAC-256

Token matching uses fnmatch wildcards against a copy of wpa_pairwise
that is padded with leading and trailing spaces, so each token is
space-bounded regardless of its position in the list.

The RSN override pairwise lists are not consulted: in the only
caller that sets them (WPA3-Personal Compatibility Mode), Tables 6
and 7 require BIP-CMAC-128 across RSNE/RSNOE/RSNO2E even when the
override lists advertise GCMP-256, so wpa_pairwise=CCMP already
yields the correct BIP.

An explicit ieee80211w_mgmt_cipher UCI value still wins over the
derived default.

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>
2026-05-02 20:34:22 +02:00
..
config wifi-scripts: ucode: default BIP cipher from wpa_pairwise 2026-05-02 20:34:22 +02:00
ipv6 6rd: add CPPFLAGS 2026-02-17 22:16:58 +01:00
services dropbear: require busybox pidof applet 2026-04-29 10:12:18 +02:00
utils xdp-tools: fix musl build issues 2026-04-20 08:53:33 +02:00