[PATCH] hostapd: fallback to psk when generating r0kh/r1kh

[Eneas U de Queiroz]

The 80211r r0kh and r1kh defaults are generated from the md5sum of
"$mobility_domain/$auth_secret".  auth_secret is only set when using EAP
authentication, but the default key is used for SAE/PSK as well.  In
this case,  auth_secret is empty, and the default value of the key can
be computed from the SSID alone.

Fallback to using $key when auth_secret is empty.  While at it, rename
the variable holding the generated key from 'key' to 'ft_key', to avoid
clobbering the PSK.

Signed-off-by: Eneas U de Queiroz <cotequeiroz at gmail.com>
---

This should be cherry-picked to 21.02 as well.

 package/network/services/hostapd/files/hostapd.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/package/network/services/hostapd/files/hostapd.sh b/package/network/services/hostapd/files/hostapd.sh
index d9d5f34877..e00fc21cd9 100644
--- a/package/network/services/hostapd/files/hostapd.sh
+++ b/package/network/services/hostapd/files/hostapd.sh
@@ -876,10 +876,10 @@ hostapd_set_bss_options() {
 				set_default pmk_r1_push 0
 
 				[ -n "$r0kh" -a -n "$r1kh" ] || {
-					key=`echo -n "$mobility_domain/$auth_secret" | md5sum | awk '{print $1}'`
+					ft_key=`echo -n "$mobility_domain/${auth_secret:-${key}}" | md5sum | awk '{print $1}'`
 
-					set_default r0kh "ff:ff:ff:ff:ff:ff,*,$key"
-					set_default r1kh "00:00:00:00:00:00,00:00:00:00:00:00,$key"
+					set_default r0kh "ff:ff:ff:ff:ff:ff,*,$ft_key"
+					set_default r1kh "00:00:00:00:00:00,00:00:00:00:00:00,$ft_key"
 				}
 
 				[ -n "$r1_key_holder" ] && append bss_conf "r1_key_holder=$r1_key_holder" "$N"