> > > > Hi, > > > > I'm not a WPA expert and security expert, > > > > Could you explain why the patch sent by Alexander Wetzel break the > security properties of this code? > > > > The Alexander's patch is in attachment. > > > > Thanks for your help. > > It simply disables the replay attack detection :) You could receive the > same (encrypted) packet twice and not throw away the second one. > The author of the patch never said that this patch is a "fix", it is rather > a debug step to understand what happens. > > PTK rekeying is a problem from the spec point of view. In Intel, we did > inquiries and in the end we understood that what we should really do > whenever we get to a situation where we need to rekey the PTK is to > disconnect and reconnect. Only weird configuration allow to change the PTK > more frequently than after X packet (don't remember what X is bu something > like 2^32 which is big enough to hold the connection for days...). > > IIRC, Intel devices don't have problems in Tx while we rekey because we > give the key material along with the packet itself, so that we can't get to > a situation where we have old PN and new key. The Atheros devices separate > the key material and the Tx packet (which is a perfectly valid design > decision), but this introduce the possibility to use the old PN with a new > key meaning that the recipient could decrypt the packet after the new key > has been installed, but it would also update the PN to be high and discard > all the next packets that will come with a new (low) PN. > So essentially, this is a bug in the TX'ing side. Fixing it requires to hit > the performance which is not something people are willing to do, when the > bug is really in the spec. > That's what I remember, but I may be wrong. > Thanks for your answer. Do you know if we can have the same issue with ATH10K chipset? -- 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
