Work was a mess this week, due to an office move and other issues, so I've fallen a bit behind on where I wanted to be on the wireless project. I finally got some time to work on the project late this week. After a run down to the local Fry's, I had all the parts I needed to modify the main board on the WRTSL54GS. I dove into this the other night and found that I was in for more trouble than I expected. First, I pulled out my practice PCB and started soldering again, trying to get warmed up before working on some of the more important parts of the project. Next, I assembled the RS232 adapter and managed to avoid botching the soldering. That made me feel pretty good, so I pressed on... and started wrecking some parts.
The WRTSL54GS uses a very poor antenna in its stock form. It is rated at 1.5 dBi gain, which did not fill me with enthusiasm. So I decided to replace it, but I have a problem The antenna is connected directly to the main board with no way to detach the stock antenna cleanly. Since I was feeling brave after successfully soldering the RS232 adapter, I pulled out the wire cutters and clipped the antenna wire close to the antenna. I wasn't quite brave enough to attempt soldering a new antenna smack in the middle of the board. I had picked up two SMA connectors at Fry's, which I figured would be sufficient. When I attempted to crimp the center pin to the coax cable, I damaged both of them. They would not even come close to sliding up the center of the adapter. Now what? Today, I did another run to Fry's and purchased three more connectors. When I got home, I found that I had the wrong models. The center pins were hollow and I needed the solid ones. So, I needed to salvage the pins I had from the previous night. A bit of dremeling cleaned up one the center pins enough to be usable. Instead of crimping, I soldered the pin to the antenna wire, crimped on the outside of the connector and it all looked pretty good.
Next, I started hooking up the connector to the serial ports on the main board. This sounds straight forward, but Linksys decided to make it more complex. They filled the holes with solder. *sigh* After 30 minutes of messing around the holes were cleared out and I was able to solder in the new head block.
I was a bit nervous again about this because I had to apply a fair bit of heat to get the solder out. I took it up stairs, attached a 10 dBi gain antenna and booted up the router. Sure enough, it booted up cleanly! Needless to say, I'm very happy with this. But was the new antenna working? Fortunately it was. Here's a screen cap of the signal strength.
The SSID of Elune is my access point and WRT is my newly modded router. Both Linksys SSIDs are neighbors, one of which is inviting trouble. Any how, I was on the other side of the house when this cap was taken. Note the huge difference in signal strength of WRT using the new antenna when compared to Elune! Both devices were sitting right next to each other. Mission accomplished.
Here's the modded main board.
Just thought I'd link to my paper on web application security that I did last semester. It's pretty basic and is aimed at a technical audience that is not familiar with web app security.
You can read the document here. <--PDF warning
I'm finally getting close to graduation! My project consists of taking a couple of Linksys routers, hacking the hardware, installing OpenWRT and then dropping the whole thing on an RC vehicle. Voila! A quasi robotic war driving kit!
So what's the point of it really? Well, I took a robotics class and really liked working with hardware. But security is my main interest. Then I thought about doing an audit for rogue wireless access points around a corporate campus. It would take a while to walk around and war walk the campus. I can be a lazy sort, so I try to look for easier way to do things. So why not install the equipment on something that can do about 20 miles an hour? That ought to speed things up! An idea is born.
Really, I've found somewhat similar ideas for this while I've been researching for this project. So while I largely thought of this on my own, I still lose a few points for my lack of originality. But it will be fun and I will learn a lot along the way. That's really what this is about.
The Concept
- Create a mobile wireless detection platform that can cover a wide geographical area quickly.
- Provide near real time feed back to the operator.
- Use GPS to plot the location of detected access points.
- Save data for later analysis.
- Find and use enough information to locate the rogue access point.
- Optionally, use a 2.4 GHz spectrum analyzer while performing the war driving. (I'm not sure how this will work, but I want to check it out.)
Hardware
Most of the project is still scratched out in my notebook, but I will document
more of what I'm doing as I go. I have purchased most of the hardware already. It's been fun to say the least. Here's the bulk of my kit.
I decided on the Kyosho Blizzard EV for the RC platform. It uses treads and has a low center of gravity, which will hopefully keep the shiny side up. More info on its upgraded form here.
Then we get to the wireless gear. I'm still waffling around some on how to set this up, but I think the WRTSL54GS for the Kismet device. I'm kicking around what to do with the lame antenna soldered into it. Unfortunately, it's not like the WRT54GL in the picture which has dual remove able antennae. But I think I can just clip the wire and add an adapter to the end. The idea of soldering a new antenna onto the board is a bit intimidating to me. I'll probably use the WRT54GL to relay information back to me via its wireless connection. I'm working with an old Zaurus PDA and trying to get a Netgear wireless card working on it. It has been a mixed experiment so far.
That's about where I am at so far. The car is assembled and I'm poking around on the WRTSL54GS to see how I can do what I want done. Next steps are:
- Design and fabricate the mounting platform for the wireless gear
- Order and fashion the antenna(s) that I will be using
- Order GPS equipment and mount it to the device
- Assemble the hardware into the completed vehicle
- Install, write, modify and integrate the software I'm researching together.
This all ought to keep me out of trouble for a while.
I'm not much for blogging just for the sake of doing it, but I'm working on a project for school and figured a blog would be a perfect place to log my work.
