Re: [PATCH 00/11] Basic SAE support for AP mode

[James Prestwood <prestwoj@gmail.com>]

Hi John,

On 4/28/24 5:04 PM, John Brandt wrote:
>
>
> On 4/24/24 05:07, James Prestwood wrote:
>>
>> On 4/22/24 6:52 AM, James Prestwood wrote:
>>> Hi John,
>>>
>>> On 4/21/24 5:50 AM, John Brandt wrote:
>>>> This set of patches adds basic SAE support for IWD in AP mode. It has
>>>> been tested by connecting to IWD AP using wpa_supplicant. Note that 
>>>> this
>>>> does not yet correspond to WPA3, since WPA3 would also require the
>>>> support of Management Frame Protection.
>>>>
>>>> Normal client functionality has also been confirmed to still work. 
>>>> After
>>>> applying these patches it remains possible for IWD client to 
>>>> connect to
>>>> WPA3/SAE network.
>>>>
>>>> Remaining TODOs are to include better sanity-checking of received
>>>> frames.
>>>
>>> I took a quick pass and I'm impressed you took the initiative to 
>>> implement this. I do need to take a closer look from the spec side 
>>> of things but overall it looks good.
>>>
>>> Assuming we are compliant with the spec my only concern merging this 
>>> would be the TODOs. You do mention this is experimental and certain 
>>> checks are not done, but you'd be surprised at the number of people 
>>> using IWD in AP mode. The minute we merge this we're going to have 
>>> people using it, which in its current form would be insecure. I 
>>> think we first need to get the frame verification implemented as 
>>> well as MFP. But anyways, this is a good start and I'll give it a 
>>> full review when I have some time, hopefully this week.
>>>
>>> Thanks,
>>>
>>> James
>>
>> Reviewed. I also forgot to mention the CI we have showed test-sae 
>> failed after your patches, so that will need to be addressed as well. 
>> I keep getting reminded I need to also email the patch submitter.
>>
>> Thanks,
>>
>> James
>
> Thanks, I've mostly incorporated the feedback, and also added extra 
> frame checks. I can post the v2 version later this week.
>
> I'm unsure whether I'll also have the time to experiment with MFP. 
> Maybe it's possible to already add SAE support without yet mentioning 
> WPA3 for the AP mode?

MFP may be sort of automatic, it is for station mode. All IWD does is 
some minimal validation since it has an explicit profile setting to 
enable/disable/require MFP. It also checks the cipher support related to 
MFP. But I think for AP mode all you'd need to do is ensure that 
connecting stations are capable of MFP when connecting via WPA3. And set 
the proper bits in the RSNE.

Thanks,

James

>
>>>
>>>>
>>>> John Brandt (11):
>>>>    ap: ability to advertise PSK and SAE
>>>>    ap: accept PSK/SAE in auth depending on config
>>>>    sae: add function sae_set_group
>>>>    sae: refactor and add function sae_calculate_keys
>>>>    sae: make sae_process_commit callable in AP mode
>>>>    sae: verify offered group in AP mode
>>>>    sae: support reception of Confirm frame by AP
>>>>    ap: add support to handle SAE authentication
>>>>    ap: enable start of 4-way HS after SAE
>>>>    eapol: support PTK derivation with SHA256
>>>>    eapol: encrypt key data for AKM-defined ciphers
>>>>
>>>>   src/ap.c    | 135 +++++++++++++++++++++++++++++++++-------
>>>>   src/eapol.c |  58 ++++++++++++-----
>>>>   src/sae.c   | 175 
>>>> +++++++++++++++++++++++++++++++++-------------------
>>>>   3 files changed, 265 insertions(+), 103 deletions(-)
>>>>