Hi Jouni, > From: Jouni Malinen [mailto:j@xxxxx] > Sent: Friday, July 22, 2016 10:25 PM > To: Amitkumar Karwar > Cc: Kalle Valo; linux-wireless@xxxxxxxxxxxxxxx; Cathy Luo; Nishant > Sarmukadam > Subject: Re: [PATCH 5/9] mwifiex: cfg80211 set_default_mgmt_key handler > > On Fri, Jul 22, 2016 at 03:59:47PM +0000, Amitkumar Karwar wrote: > > I am trying to understand the problem you mentioned during IGTK > rekeying. Today I ran tests with two stations connecting an AP. MFP is > enabled on all of them. > > > > On hostapd side, my observation is add_key() is always called followed > by set_default_mgmt_key(). set_default_mgmt_key() sets the key added by > add_key() as default key. > > > > We are ignoring set_default_mgmt_key() and updating Tx key index > during add_key() itself. > > > > Your concerns is we should not update Tx key index during add_key(). > Reason is IGTK rekeying is not yet completed with all stations. Right? > > Correct. set_default_mgmt_key() does not have much effect for the very > first IGTK configuration, but whenever doing IGTK rekeying, hostapd > behaves just like it does with GTK rekeying. In other words, a different > Key ID is selected (alternating between 4 and 5), a random new IGTK is > generated, the new IGTK is configured to the local driver (but the old > IGTK is still supposed to be used for TX), each associated STA is > notified of the new IGTK, the new IGTK is taken into use once the group > key handshake has completed with each associated STA. It is that last > operation that needs set_default_mgmt_key() to allow this rekeying to > work correctly. If you update the TX Key ID on add_key(), you'll risk > sending out frames that some of the associated STAs do not yet have a > key to validate. > Got it. We will implement set_default_mgmt_key() and check if any firmware changes required. Regards, Amitkumar -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
