802.11r and FT-EAP

Yury Shvedov yshvedov at arccn.ru
Mon Sep 28 03:46:51 EDT 2015

Thank you for your help!

On 09/03/2015 09:57 PM, Jouni Malinen wrote:
> On Tue, Sep 01, 2015 at 04:22:32PM +0300, Yury Shvedov wrote:
>> I'm working with 802.11r and trying to test my scheme using
>> mac80211_hwsim. I configured hostapd and wpa supplicant to use
>> FT-PSK first. It works fine. But when I try to use radius with FT
>> (FT-EAP), the 4-way handshake failed. Surfing the code and debug
>> logs I found out that the reason is in xxkey field of
>> wpa_state_machine (it is empty and ft can't derive ptk). The xxkey
>> sets by wpa_auth when eapKeyData is 64 bytes long (2 * PMK_LEN). But
>> eapKeyData fills up only by radius MS-MPPE-Send-Key and
>> MS-MPPE-Recv-Key both 16 bytes long.
>> How I have to configure hostapd, wpa_supplicant and radius to get
>> another 32 bytes of key in xxkey field?
> By using an EAP method that derives sufficient key material.
>> Configuration files in attachment. Thank you!
> Those use eap=MSCHAPV2, i.e., EAP-MSCHAPv2 as the EAP method (this is
> _without_ PEAP or TTLS and TLS tunnel). That is not advisable for any
> use today from security view point. In addition to that, EAP-MSCHAPV2
> does not derive sufficiently long keys to allow FT key hierarchy to be
> formed. If you were to replace that with MSCHAPv2 within PEAP or TTLS
> Phase 2, this would work.

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