Randomize your WiFi MAC address on Ubuntu

#1

Post by paulfurley » Sun, Dec 03, 2017, 12:18 PM UTC

Randomize your WiFi MAC address on Ubuntu
paulfurley.com

Re: Randomize your WiFi MAC address on Ubuntu

#2

Post by pedrocr » Sun, Dec 03, 2017, 12:51 PM UTC

This seems like it should be a default indeed. It does make it harder to assign fixed addresses to your devices in your home network. At least openwrt only seems to have static DHCP leases based on MAC and not on the advertised DHCP name. For most devices this doesn't matter as it does add a DNS entry with whatever IP it assigned. But when you then want to add a firewall rule to port forward something to a device a fixed IP is much nicer.

Re: Randomize your WiFi MAC address on Ubuntu

#3

Post by paulfurley » Sun, Dec 03, 2017, 12:53 PM UTC

pedrocr wrote: post #2

This seems like it should be a default indeed. It does make it harder to assign fixed addresses to your devices in your home network. At least openwrt only seems to have static DHCP leases based on MAC and not on the advertised DHCP name. For most devices this doesn't matter as it does add a DNS entry with whatever IP it assigned. But when you then want to add a firewall rule to port forward something to a device a f…

True - I could update the script to allow for whitelisting certain networks so they receive a stable-forever MAC address..?

Re: Randomize your WiFi MAC address on Ubuntu

#4

Post by pedrocr » Sun, Dec 03, 2017, 12:56 PM UTC

paulfurley wrote: post #3

pedrocr wrote: post #2

This seems like it should be a default indeed. It does make it harder to assign fixed addresses to your devices in your home network. At least openwrt only seems to have static DHCP leases based on MAC and not on the advertised DHCP name. For most devices this doesn't matter as it does add a DNS entry with whatever IP it assigned. But when you then want to add a firewall rule to port forward something to a device a f…

True - I could update the script to allow for whitelisting certain networks so they receive a stable-forever MAC address..?

That would probably make a lot of sense. Can the network manager setting also be changed per network? It would be nice to do this with the normal config in the future.

Re: Randomize your WiFi MAC address on Ubuntu

#5

Post by paulfurley » Sun, Dec 03, 2017, 12:59 PM UTC

pedrocr wrote: post #4

paulfurley wrote: post #3

Earlier quoted context omitted.

True - I could update the script to allow for whitelisting certain networks so they receive a stable-forever MAC address..?

That would probably make a lot of sense. Can the network manager setting also be changed per network? It would be nice to do this with the normal config in the future.

Yes, in network manager 1.4.1+ (ubuntu 17.04+) you can set each network to `random` or `stable` as well as a global default for new networks. This config file updates the global default (but I can't use it yet!): https://gist.github.com/paulfurley/978d4e2e0cceb41d67d017a66...

Re: Randomize your WiFi MAC address on Ubuntu

#6

Post by dbolgheroni » Sun, Dec 03, 2017, 1:31 PM UTC

In OpenBSD, it's just:

  # ifconfig iwn0 lladdr random

Of course, iwn0 is your interface.

Re: Randomize your WiFi MAC address on Ubuntu

#7

Post by diggan » Sun, Dec 03, 2017, 1:36 PM UTC

I've used https://github.com/feross/SpoofMAC in the past, which is a simple python tool for doing just this, cross-platform. Used it a lot in airports and can warmly recommend using it if you're usually dealing with multiple different OSes and don't want to remember how to do it for each.

Re: Randomize your WiFi MAC address on Ubuntu

#8

Post by gingerlime » Sun, Dec 03, 2017, 1:39 PM UTC

diggan wrote: post #7

I've used https://github.com/feross/SpoofMAC in the past, which is a simple python tool for doing just this, cross-platform. Used it a lot in airports and can warmly recommend using it if you're usually dealing with multiple different OSes and don't want to remember how to do it for each.

Looks cool. I wish there was something like this for iPhone/iPad - which is much more likely to be with me everywhere and leak my MAC...

side note/question: do I need to actively connect to a WIFI network for them to know my MAC or does it leak even when my phone scans for neighbouring SSIDs? EDIT: looks like MAC would leak even if I don't connect to any access point, but my Wifi is on... At least according to [0]

EDIT 2: looks like iPhone and Android use MAC randomization when scanning WIFI. (not sure after they connect though). But even this randomization can be defeated[1]?

[0] https://www.crc.id.au/tracking-people-via-wifi-even-when-not... [1] https://www.theregister.co.uk/2017/03/10/mac_address_randomi...

Re: Randomize your WiFi MAC address on Ubuntu

#9

Post by mobilemidget » Sun, Dec 03, 2017, 1:41 PM UTC

Are there any lawyers here that can speak about the legal side of this? I could imagine a wifi provider that offers 30 minutes free wifi e.g. airports, has this covered in their terms and conditions or a country that could consider this as fraudulent?

Re: Randomize your WiFi MAC address on Ubuntu

#10

Post by izacus » Sun, Dec 03, 2017, 1:45 PM UTC

mobilemidget wrote: post #9

Are there any lawyers here that can speak about the legal side of this? I could imagine a wifi provider that offers 30 minutes free wifi e.g. airports, has this covered in their terms and conditions or a country that could consider this as fraudulent?

iPhones and Android phones do this for awhile already. If you read the article you'll notice that the MAC stays the same for a SSID for a working day. This makes sure it doesn't break networking and as a side effect captcha portal limits still work.