odd.meta

Adventures in code, etc

[odd-meta]

Notes on Changing an Android MAC address

I started investigating how to change MAC addresses on Android devices because things like in-store tracking and massive distributed tracking of mobile devices, and by extension their owners, is probably only going to become more common and more robust.

While this does not address the issue of spewing SSIDs all over the place that might identify a device, it is a step in the direction of more control over unique information devices vomit out into the public space.

So far I have found that I can change the MAC address with commands like ip link set address ... but have run into issues connecting to WPA2 secured access points after performing this command. From a number of packet captures my best guess is Android is still using the burned-in MAC address to calculate a few values for the WPA2 handshake, but sending the actual packets from the spoofed MAC address.  This freaks out the access point, as it should, and triggers a deauthentication packet. This is further supported by the fact that I can get the device to connect to an open network after spoofing the MAC. I have not done any testing with WEP.

Other notes; the MAC address never appears to change in the WiFi > Advanced screen. Turning WiFi off and on again resets the MAC address back to the burned in MAC. Running ifconfig down;ifconfig up; appears to have the same affect. All testing was done on a Nexus S 4G.

I've rolled this into MacSpin; a very simple Android application that I hope to get to a point of working with WPA2 networks. As you might expect this requires a rooted Android device.

[odd-meta]

ThinkGearAM 1_R2.8 hooked to an Arduino Mega 2560

After ordering a ten pack of defective necomimi headsets from NeuroSky I've managed to get the ThinkGearAM chip spewing forth data on the serial line.  Armed with the handy datasheet I removed the ThingGearAM board from the necomimi controller and soldered on wires for the serial line.  I also ended up re-soldering the wires for the electrode and reference clip as they sheared off almost immediately after removing the chip.

After loading a simple sketch to the mega that reads data from Serial1 and prints it to Serial, at 57.6k, I have lines of binary flying past.  Now to actually do something useful with it.  I should note that i had to remove/re-insert the power lines for the ThingGearAM after the mega was loaded up with the sketch to actually make it produce intelligible-looking data.

[odd-meta]

httpfak code posted

This little project was more a learning experience born out of frustration than any kind of directed endeavor.

I was mad because urllib2 wouldn't allow me to specify the exact order of headers it sent to the server.  The data structure that urllib2 stores header data in is a python dict, which by definition has no order.  This was frustrating because I wanted the headers to be in the exact same order as a legitimate browser.  For no other reason than wanting a program to do exactly what I want.  After a cursory, fruitless, search of other python http libraries I decided to quit whining about how hard re-implementing http communication was going to be and just do it.  Thus fawk.py was born.  I tacked on support for storing dumped headers in a file later, and then some basic ssl support after that.  Then rewrote it into some glommed up object oriented mess.

Currently cookie handling is halfway implemented, and I have some more work to do with the ssl portion in terms of parsing cert data for analysis and lulz.

https://github.com/odd-meta/httpfak