[RFC PATCH] P2P: Use PSK instead of passphrase for persistent GO fast boot

Jouni Malinen j at w1.fi
Tue Dec 25 07:24:13 EST 2012


On Tue, Nov 27, 2012 at 08:46:52PM +0900, Masashi Honma wrote:
> As I mentioned in previous post [1], pbkdf2_sha1() is a bottleneck for
> persistent GO initialization. So I will propose saving a psk instead of a
> passphrase for persistent GO to skip re-calculation in pbkdf2_sha1().

Thanks.

> As you know, this change breaks Wi-Fi spec. Because [2] says "A P2P Group Owner
> shall maintain a WPA2-PSK pass-phrase for delivery to Legacy Clients." at 3.2.1
> P2P Group ID section. This change breaks interop for legacy STA (STA doesn't
> have WPS).
> So I used CONFIG_P2P_STRICT macro for user who want to conform with [2].

While this would not comply with the requirements, it does not really
break interoperability completely, i.e., this is only preventing manual
configuration using the passphrase. It would still be possible to
configure legacy STAs using the PSK even though it would not be exactly
convenient to write that long string manually.

CONFIG_P2P_STRICT is mainly used to validate incoming messages, so I
don't think it is necessary to add that validation step here for local
behavior that is fully in control of the device.

> How do you think about this patch ?

I applied it with a rewritten commit log and that CONFIG_P2P_STRICT part
removed.

-- 
Jouni Malinen                                            PGP id EFC895FA


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