Passive WPA PSK

Each station may have its own PSK (pre-shared key)

When no 802.1X is used, the PSK is used directly as the Pairwise Master Key (PMK). When PSK is passphrase, then PMK = PBKDF2(passphrase, ssid, ssidLength, 4096, 256);

The PTK (Pairwise Transient Key) is a keyed-HMAC function using the PMK on the two MAC addresses and the two nonces from the first two packets of the 4-Way Handshake unique for each session