Re: [PATCH] [RFC v2] mac80211: Scale down to non-HT association with TKIP/WEP as pairwise cipher

[Johannes Berg <johannes@sipsolutions.net>]

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On Mon, 2008-12-22 at 12:01 +0530, Vasanthakumar Thiagarajan wrote:
> As TKIP is not updated to new security needs which arise when
> TKIP is used to encrypt A-MPDU aggregated data frames, IEEE802.11n
> does not allow any cipher other than CCMP (Which has new extensions
> defined) as pairwise cipher between HT peers.
> 
> When such configuration (TKIP/WEP in HT) is forced, we still
> associate in non-HT mode (11a/b/g).

> --- a/net/mac80211/wext.c
> +++ b/net/mac80211/wext.c
> @@ -873,12 +873,22 @@ static int ieee80211_ioctl_siwauth(struct net_device *dev,
>  
>  	switch (data->flags & IW_AUTH_INDEX) {
>  	case IW_AUTH_WPA_VERSION:
> -	case IW_AUTH_CIPHER_PAIRWISE:
>  	case IW_AUTH_CIPHER_GROUP:
>  	case IW_AUTH_WPA_ENABLED:
>  	case IW_AUTH_RX_UNENCRYPTED_EAPOL:
>  	case IW_AUTH_KEY_MGMT:
>  		break;
> +	case IW_AUTH_CIPHER_PAIRWISE:
> +		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
> +			if (data->value & (IW_AUTH_CIPHER_WEP40 |
> +			    IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
> +				sdata->u.sta.flags |=
> +					IEEE80211_STA_TKIP_WEP_USED;
> +			else
> +				sdata->u.sta.flags &=
> +					~IEEE80211_STA_TKIP_WEP_USED;
> +		}
> +		break;

I still think you might need to put something into cfg.c. Can't we check
the key algorithm for the pairwise key associated with the AP's sta_info
directly in _send_assoc?

johannes

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