Summary
This is a report of Wi-Fi MAC address randomization functionality of iOS14.
- iOS 13: Only Probe Request MAC address is randomized.
- iOS 14: Randomized Probe Request(Broadcast) MAC address is also used by auth/assoc/EAPOL.
- Roaming to identical SSID does not modify MAC address.
- Roaming to identical AP with different SSID modify MAC address.
- Disable/Enable Wi-Fi and rebooting iPhone does not modify MAC address.
Detail
Detail of the investigation.
Assume the STA connected to AP1 (SSID=ssid1, BSSID=bssid1) with MAC address A.
Connected to AP2 with identical SSID (SSID=ssid1, BSSID=bssid2)
=> MAC address stays on A
Modify SSID of AP1 and connect to AP1 (SSID=ssid2, BSSID=bssid1)
=> MAC address is modified to B
Restore AP1 configuration (SSID=ssid1, BSSID=bssid1)
=> MAC address backs to A
Disable/Enable Wi-Fi and connect to AP1 (SSID=ssid1, BSSID=bssid1)
=> MAC address stays on A
Reboot iPhone and connect to AP1 (SSID=ssid1, BSSID=bssid1)
=> MAC address stays on A
※ Tested on iPhone 8 Plus with iOS 14