For the ultra paranoid... randomizing your MAC address.

I recently wanted to write some python since I've been relegated to the worlds of Java and sometimes C being a college student again.  As a fun and paranoid project, I put together a little script that generates a random mac address and optionally assigns that MAC address to an interface and restarts your network connection.

I initially haven't made it all that complicated or general purpose (for instance, it assumes you're using network-manager, as I guess most of us are now).  The relevant functions are below, but I'd be happy to post the whole script or make it more versatile / general if anyone is interested... post a comment or send me an email.

def mac():
  """
  Returns a randomly generated Unicast MAC Address.

  Returns:
    String - A mac address.
  """
  mac = '';
  i = 0
  count = 6
  while i < count:
    # If the least significant bit of the first bite is onw,
    # ifconfig will fail because those addrs are reserved for multicast
    odd_hex = ['1', '3', '5', '7', '9', 'b', 'd', 'f']
    octet = hex(random.randint(0, 255))
    octet = octet.replace('0x', '')
    if len (octet) == 1:
      octet = '0' + octet
    if (i != 0) or (octet[len(octet)-1] not in odd_hex):
      mac += octet
      if i != 5:
        mac += ':'
      i=i+1
  return mac

 def restartNetwork(iface):
  """
  Assign a random mac address to the given interface and
  restarts network-manager to pick up the changes.

  TODO: error checking for a valid iface.

  Args:
    iface: String representing an assumed valid network interface.
  """
  new_mac = mac()
  subprocess.call(['/etc/init.d/network-manager', 'stop'])
  ifconfig = ['/sbin/ifconfig', iface, 'down']
  subprocess.call(ifconfig)
  #print subprocess.call('/sbin/ifconfig')
  ifconfig = ['/sbin/ifconfig', iface, 'hw','ether', new_mac]
  subprocess.call(ifconfig)
  subprocess.call(['/etc/init.d/network-manager', 'start'])
  print "If everything went as planned, %s should now have " \
    "mac address:" % iface
  print new_mac