Message-ID: <1ba2fa240803191356h5f1b132bkd0ca6f718e76a0e1@mail.gmail.com> (sfid-20080319_205733_595381_919A873F)
Date: Wed, 19 Mar 2008 22:56:53 +0200
From: "Tomas Winkler" <tomasw@gmail.com>
To: "Jouni Malinen" <j@w1.fi>
Subject: Re: [ipw3945-devel] [PATCH 1/5] mac80211: allows driver to request a Phase 2 key
Cc: "Emmanuel Grumbach" <egrumbach@gmail.com>,
	"Johannes Berg" <johannes@sipsolutions.net>,
	"Emmanuel Grumbach" <emmanuel.grumbach@intel.com>,
	linux-wireless@vger.kernel.org, ipw3945-devel@lists.sourceforge.net
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On Wed, Mar 19, 2008 at 10:10 PM, Jouni Malinen <j@w1.fi> wrote:
> On Wed, Mar 19, 2008 at 08:41:22PM +0200, Tomas Winkler wrote:
>
>  > So how do you call WEP key that is used for both unicast and broadcast
>  > i.e the old WEP key.
>
>  The IEEE 802.11 name for this would be "default key". IEEE 802.1X (or
>  well, RFC 3580 is the authoritative specification for this) calls it
>  "broadcast (default key)". Please note that this is not really a key
>  that is always used both for unicast and broadcast. If there is a
>  key-mapping key (unicast/individual) for the matching
>  transmitter/receiver addresses, that key will be used instead. The "old
>  WEP key" way of using only statically configured default keys just does
>  not set the key-mapping key and because of that, the default key ends up
>  being used for all frames (or well, one of the possible four default
>  keys).
>
>
>  > What mac80211 currently does it's attach it to broadcast address. If
>  > there is a group key re keying you don't know whether also unicast key
>  > have to be overridden or not since you don't know if this is a
>  > 'static/global; key or  dynamic group key
>
>  I haven't looked at what the current implementation does, but as far as
>  WEXT and SIOCSIWENCODEEXT is concerned, IW_ENCODE_EXT_GROUP_KEY flag
>  should be used to select which key is being configured. There is no
>  difference between "static/global" and "dynamic group" keys. The only
>  difference is between default and key-mapping (individual) keys.
>
>  Sure, the terminology here can be quite confusing, but as far as I can
>  tell, that IW_ENCODE_EXT_GROUP_KEY flag is all that is needed to
>  distinguish which key is being configured and configuring a single key
>  should not automatically change another one (even if the key index is
>  same which could, at least in theory, happen with key index 0 that can
>  be used both with default and key-mapping keys).
>

Just trying to translate it to configuration flow: To determine if the
key is old-WEP would be
Use group key as default key for all traffic unless and key-mapping key was set
Is that correct?

I will check how difficult is to do that implementation wise

Thanks
Tomas

>
>  --
>  Jouni Malinen                                            PGP id EFC895FA
>