Search Linux Wireless

Re: brcmfmac: how to setup SAE on RPi // Re: [PATCH] wifi: brcmsmac: advertise MFP_CAPABLE to enable WPA3

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On June 21, 2024 2:24:19 PM KeithG <ys3al35l@xxxxxxxxx> wrote:

On Fri, Jun 21, 2024 at 4:09 AM Arend van Spriel
<arend.vanspriel@xxxxxxxxxxxx> wrote:

+ Jouni

On 6/20/2024 8:25 PM, KeithG wrote:
1718907734.308740: wlan0: WPA: AP group 0x10 network profile group
0x18; available group 0x10
1718907734.308748: wlan0: WPA: using GTK CCMP
1718907734.308758: wlan0: WPA: AP pairwise 0x10 network profile
pairwise 0x10; available pairwise 0x10
1718907734.308767: wlan0: WPA: using PTK CCMP
1718907734.308772: wlan0: WPA: AP key_mgmt 0x400 network profile
key_mgmt 0x400; available key_mgmt 0x0


I suspect the message above indicates the problem as there is no
available key_mgmt to select so looked it up in the code and here it is:

sel = ie.key_mgmt & ssid->key_mgmt;
#ifdef CONFIG_SAE
if ((!(wpa_s->drv_flags & WPA_DRIVER_FLAGS_SAE) &&
!(wpa_s->drv_flags2 & WPA_DRIVER_FLAGS2_SAE_OFFLOAD_STA)) ||
wpas_is_sae_avoided(wpa_s, ssid, &ie))
sel &= ~(WPA_KEY_MGMT_SAE | WPA_KEY_MGMT_SAE_EXT_KEY |
         WPA_KEY_MGMT_FT_SAE |
WPA_KEY_MGMT_FT_SAE_EXT_KEY);
#endif /* CONFIG_SAE */
#ifdef CONFIG_IEEE80211R
if (!(wpa_s->drv_flags & (WPA_DRIVER_FLAGS_SME |
                  WPA_DRIVER_FLAGS_UPDATE_FT_IES)))
sel &= ~WPA_KEY_MGMT_FT;
#endif /* CONFIG_IEEE80211R */
wpa_dbg(wpa_s, MSG_DEBUG,
"WPA: AP key_mgmt 0x%x network profile key_mgmt 0x%x;
available key_mgmt 0x%x",
ie.key_mgmt, ssid->key_mgmt, sel);

So 0x400 matches the expectation:

#define WPA_KEY_MGMT_SAE BIT(10)

You already confirmed that the driver reports SAE and SAE offload
support. So it seems wpas_is_sae_avoided() must return true. That will
check whether the AP and network profile are setup to MFP. This seems to
be the fact as your hostapd.conf and wpa_supplicant.conf both have
ieee80211w=2 defined. This function can only return true when
is enabled in configuration file:

# sae_check_mfp: Require PMF support to select SAE key_mgmt
# 0 = Do not check PMF for SAE (default)
# 1 = Limit SAE when PMF is not enabled
#
# When enabled SAE will not be selected if PMF will not be used
# for the connection.
# Scenarios where this check will limit SAE:
#  1) ieee80211w=0 is set for the network
#  2) The AP does not have PMF enabled.
#  3) ieee80211w is unset, pmf=1 is enabled globally, and
#     the device does not support the BIP cipher.
# Consider the configuration of global parameterss sae_check_mfp=1,
pmf=1 and a
# network configured with ieee80211w unset and key_mgmt=SAE WPA-PSK.
# In the example WPA-PSK will be used if the device does not support
# the BIP cipher or the AP has PMF disabled.
# Limiting SAE with this check can avoid failing to associate to an AP
# that is configured with sae_requires_mfp=1 if the device does
# not support PMF due to lack of the BIP cipher.

The default is not to check it and you wpa_supplicant.conf does not
specify it.

# cat /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
ctrl_interface=DIR=/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="deskSAE"
sae_password="secret123"
proto=RSN
key_mgmt=SAE
pairwise=CCMP
ieee80211w=2
}

$ cat /etc/hostapd/hostapd.conf
# interface and driver
interface=ap0
driver=nl80211

# WIFI-Config
ssid=deskSAE
channel=1
hw_mode=g

wpa=2
wpa_key_mgmt=SAE
wpa_pairwise=CCMP
sae_password=secret123
sae_groups=19
ieee80211w=2
sae_pwe=0

Regards,
Arend


1718907734.308779: wlan0: WPA: Failed to select authenticated key
management type
1718907734.308787: wlan0: WPA: Failed to set WPA key management and
encryption suites

Arend,

I find the wpa_supplicant docs really hard to understand. I have read
through your response a few times and am still a bit confused. Does
this have to do with a pure wpa3 versus a wpa2/3 AP?

Correct. If I am not mistaken MFP aka PMF aka 802.11w is mandatory for WPA3.

I have tried editing my hostapd.conf and my wpa_supplicant.conf and
still cannot get a connection, so I must be doing something wrong.
I commented the ieee80211w line on both and it would not connect.
I tried changing the wpa_key_mgmt on both ends to be 'SAE WPA_PSK' and
it still would not connect.

What *should* the configurations be in the hostapd.conf and
wpa_supplicant.conf to negotiate this as a pure wpa3 setup? What
should it be to be a wpa2/3 setup? My phone worked fine to connect
with the original hostapd setup, but I have no idea what it is doing

As I mentioned in my previous email both config files listed above look okay to me (might be wrong though). The problem seems to be with wpas_is_sae_avoided(). For it to return true the config should have:

sae_check_mfp=1

But you don't have that and default is 0 so it should check for MFP. This is where my trail ends. To learn more I would add additional debug prints. Are you comfortable rebuilding wpa_supplicant from source?

Regards,
Arend


Attachment: smime.p7s
Description: S/MIME Cryptographic Signature


[Index of Archives]     [Linux Host AP]     [ATH6KL]     [Linux Wireless Personal Area Network]     [Linux Bluetooth]     [Wireless Regulations]     [Linux Netdev]     [Kernel Newbies]     [Linux Kernel]     [IDE]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite Hiking]     [MIPS Linux]     [ARM Linux]     [Linux RAID]

  Powered by Linux