Re: [PATCH 5/8] STA: Support Extended Key ID

On Sun, Mar 15, 2020 at 08:04:23PM +0100, Alexander Wetzel wrote:
> Support Extended Key ID in wpa_supplicant according to
> IEEE 802.11-2016 for infrastructure (AP) associations.
> 
> Extended Key ID allows to rekey pairwise keys without the otherwise
> unavoidable MPDU losses on a busy link. The standard is fully backward
> compatible, allowing STAs to also connect to APs not supporting it.
> 
> The standard is not covering how to use it with extensions like FILS or
> FT and wpa_supplicant sticks to the save settings by default but allows
> the user to enable non-standard Extended Key ID support for FT and FILS.
> 
> BASIC Extended Key ID support does nothing not clearly covered by the
> standard and force it to be off for compatibility when needed.
> FT0, FILS0 and FILS_CUSTOM are not standardized extensions to also allow
> Extended Key ID support to be used with FT and/or FILS.
> 
> FT0, FILS0 and FILS_CUSTOM are not standardized extensions allowing to
> use Extended Key ID also with FT and/or FILS.
> FILS0 and FILS_CUSTOM are both detecting when the AP is using the other
> mode and switch over to it.

I'd like to get a version of this that includes only the fully
standardized parts, i.e., use of Extended Key ID when going through
4-way handshake.

As far as wpa_supplicant configuration for this is concerned, is there
real need for provide per-network profile configuration? I'm thinking of
simply adding a global ext_key_id parameter with 0/1 values that applies
to all cases. This would default to 0 (disabled) for now and then could
be changed to 1 once there has been some interoperability testing of the
functionality between vendors.

-- 
Jouni Malinen                                            PGP id EFC895FA