From: "John W. Linville" <linville@tuxdriver.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-wireless@vger.kernel.org
Subject: Re: [PATCH v3] mac80211: remove wep dependency
Date: Tue, 20 Jul 2010 14:56:44 -0400 [thread overview]
Message-ID: <20100720185643.GB3468@tuxdriver.com> (raw)
In-Reply-To: <1279623588.3706.17.camel@jlt3.sipsolutions.net>
On Tue, Jul 20, 2010 at 12:59:48PM +0200, Johannes Berg wrote:
> On Wed, 2010-07-07 at 15:07 -0400, John W. Linville wrote:
> > The current mac80211 code assumes that WEP is always available. If WEP
> > fails to initialize, ieee80211_register_hw will always fail.
> >
> > In some cases (e.g. FIPS certification), the cryptography used by WEP is
> > unavailable. However, in such cases there is no good reason why CCMP
> > encryption (or even no link level encryption) cannot be used. So, this
> > patch removes mac80211's assumption that WEP (and TKIP) will always be
> > available for use.
> >
> > Signed-off-by: John W. Linville <linville@tuxdriver.com>
> > ---
> > v3 -> actually post changed patch...
> > v2 -> make it safe to call ieee80211_wep_free even if ieee80211_wep_init
> > had failed
>
> I think this is missing a change like this:
>
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -1228,6 +1228,10 @@ static int ieee80211_scan(struct wiphy *wiphy,
> static int ieee80211_auth(struct wiphy *wiphy, struct net_device *dev,
> struct cfg80211_auth_request *req)
> {
> + if (req->auth_type == NL80211_AUTHTYPE_SHARED_KEY &&
> + IS_ERR(sdata->local->wep_tx_tfm))
> + return -EINVAL;
> +
> return ieee80211_mgd_auth(IEEE80211_DEV_TO_SUB_IF(dev), req);
> }
>
>
> since otherwise you could end up trying to encrypt the auth frame with
> the uninitialised WEP TFM?
Yes, I think that makes sense. The check in ieee80211_wep_encrypt_data
will make it safe either way, but that will trigger a warning
in ieee80211_send_auth and leave us unable to return an error to
the ieee80211_auth caller. Also, it will send the auth request
unencrypted...
Care to send that as a "real" patch? :-)
John
--
John W. Linville Someday the world will need a hero, and you
linville@tuxdriver.com might be all we have. Be ready.
next prev parent reply other threads:[~2010-07-20 19:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-06 20:19 [PATCH] mac80211: remove wep dependency John W. Linville
2010-07-07 18:44 ` [PATCH v2] " John W. Linville
2010-07-07 19:07 ` [PATCH v3] " John W. Linville
2010-07-20 10:59 ` Johannes Berg
2010-07-20 18:56 ` John W. Linville [this message]
2010-07-21 8:09 ` [PATCH] mac80211: refuse shared key auth when WEP is unavailable Johannes Berg
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