[PATCH 20/21] tests: Add MBSSID test verifying beacon loss if MIC is incorrect

[Benjamin Berg]

From: Benjamin Berg <benjamin.berg at intel.com>

This adds a test where the BIGTK is corrupted on the AP side, causing
all beacons to be lost. Then reverse the checks to verify the expected
failures.

Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
Reviewed-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
 tests/hwsim/test_he_mbssid.py | 46 +++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 10 deletions(-)

diff --git a/tests/hwsim/test_he_mbssid.py b/tests/hwsim/test_he_mbssid.py
index befe7d1caa..422a39cd7c 100644
--- a/tests/hwsim/test_he_mbssid.py
+++ b/tests/hwsim/test_he_mbssid.py
@@ -433,6 +433,11 @@ def test_mbssid_nontx_beacon_prot_non_tx_then_tx(dev, apdev, params):
     """HE AP MBSSID beacon protection (only non-TX) with Association on non-Tx BSS followed by Tx BSS"""
     run_mbssid_beacon_prot(dev, apdev, params, True, False)
 
+def test_he_ap_mbssid_beacon_prot_invalid_bigtk(dev, apdev, params):
+    """HE AP MBSSID beacon protection with invalid BIGTK on AP (Tx BSS then non-Tx BSS)"""
+    run_mbssid_beacon_prot(dev, apdev, params, False, invalidate_bigtk=True)
+
+
 def get_mac80211_bigtks(dev):
     phy = dev.get_driver_status_field("phyname")
     keys = f"/sys/kernel/debug/ieee80211/{phy}/keys"
@@ -463,7 +468,7 @@ def get_mac80211_bigtks(dev):
 
     return res
 
-def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True):
+def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True, invalidate_bigtk=False):
     check_sae_capab(dev[0])
     check_sae_capab(dev[1])
     f, fname, ifname = mbssid_create_cfg_file(apdev, params)
@@ -486,6 +491,7 @@ def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True
         dev[1].set("sae_groups", "")
         hapd, pid = mbssid_start_ap(dev, apdev, params, fname, ifname, None,
                                     only_start_ap=True)
+
         if non_tx_first:
             dev[1].connect("bss-1", psk="another password", key_mgmt="SAE",
                            ieee80211w="2", beacon_prot="1", scan_freq="2412")
@@ -499,7 +505,17 @@ def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True
             dev[1].connect("bss-1", psk="another password", key_mgmt="SAE",
                            ieee80211w="2", beacon_prot="1", scan_freq="2412")
 
-        bigtk_mismatch = False
+        if invalidate_bigtk:
+            WPA_ALG_BIP_CMAC_128 = 4
+            KEY_FLAG_DEFAULT = 0x02
+            KEY_FLAG_TX = 0x08
+            KEY_FLAG_GROUP = 0x10
+            KEY_FLAG_GROUP_TX_DEFAULT = KEY_FLAG_GROUP | KEY_FLAG_TX | KEY_FLAG_DEFAULT
+
+            # key index 7, as we will have had one update
+            hapd.request('SET_KEY %d %s %d %d %s %s %d' % (WPA_ALG_BIP_CMAC_128, "ff:ff:ff:ff:ff:ff",
+                                                           7, 1, 6*"00", 16*"00", KEY_FLAG_GROUP_TX_DEFAULT))
+
         unexpected_bigtk = False
         try:
             ap_bigtks = get_mac80211_bigtks(hapd)
@@ -509,6 +525,7 @@ def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True
             logger.info(f'BIGTKs dev0: {dev0_bigtks}')
             logger.info(f'BIGTKs dev1: {dev1_bigtks}')
 
+            bigtk_mismatch = False
             if tx_beacon_prot:
                 if dev0_bigtks[0] not in ap_bigtks:
                     bigtk_mismatch = True
@@ -518,8 +535,8 @@ def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True
             if dev1_bigtks[0] not in ap_bigtks:
                 bigtk_mismatch = True
         except HwsimSkip:
-            # We can still check that no beacon loss happened
-            pass
+            # We can still check the beacon loss condition
+            bigtk_mismatch = True if invalidate_bigtk else False
 
         beacon_loss0 = False
         beacon_loss1 = False
@@ -532,12 +549,21 @@ def run_mbssid_beacon_prot(dev, apdev, params, non_tx_first, tx_beacon_prot=True
 
         mbssid_stop_ap(hapd, pid)
 
-        if beacon_loss0:
-            raise Exception("Beacon loss detected on TX BSS")
-        if beacon_loss1:
-            raise Exception("Beacon loss detected on non-TX BSS")
-        if bigtk_mismatch:
-            raise Exception("Installed BIGTKs did not match between AP and STA(s)")
+        if not invalidate_bigtk:
+            if beacon_loss0:
+                raise Exception("Beacon loss detected on TX BSS")
+            if beacon_loss1:
+                raise Exception("Beacon loss detected on non-TX BSS")
+            if bigtk_mismatch:
+                raise Exception("Installed BIGTKs did not match between AP and STA(s)")
+        else:
+            if not beacon_loss0:
+                raise Exception("No beacon loss detected on TX BSS")
+            if not beacon_loss1:
+                raise Exception("No beacon loss detected on non-TX BSS")
+            if not bigtk_mismatch:
+                raise Exception("Installed BIGTKs matched between AP and STA(s)")
+
         if unexpected_bigtk:
             raise Exception("STA on TX-BSSID should not have a BIGTK installed")
     finally:
-- 
2.56.0