auto-t: hostapd.py: separate GTK and PTK rekeys

REKEY_GTK kicks off the GTK only handshake where REKEY_PTK does
both (via the 4-way). The way this utility was written was causing
hostapd some major issues since both REKEY_GTK and REKEY_PTK was
used.

Instead if address is set only do REKEY_PTK. This will also rekey
the GTK via the 4-way handshake.

If no address is set do REKEY_GTK which will only rekey the GTK.

autotests/util/hostapd.py

@@ -202,11 +202,15 @@ class HostapdCLI(object):
         cmd = self.cmdline + ['req_beacon', addr, request]
         ctx.start_process(cmd).wait()
 
-    def rekey(self, address):
+    def rekey(self, address=None):
+        if address:
+            cmd = 'REKEY_PTK %s' % address
+            self.ctrl_sock.sendall(cmd.encode('utf-8'))
+            self.wait_for_event('EAPOL-4WAY-HS-COMPLETED')
+            return
+
         cmd = 'REKEY_GTK'
         self.ctrl_sock.sendall(cmd.encode('utf-8'))
-        cmd = 'REKEY_PTK %s' % address
-        self.ctrl_sock.sendall(cmd.encode('utf-8'))
 
     @property
     def bssid(self):