AUTHOR EDIT: It was requested that I explain exactly what "Pentesting" is. Pentesting is short for Penetration testing and while it can refer to the process of testing inked writing implements, I am referring to the process of testing a wireless access point, and underlying network, for security flaws.
While I am not a network professional, I can tell you that there are MANY tools used for doing this; some open and some proprietary. I also say that this is a Penetration testing platform because it refers to the lawful testing of your own access point against security flaws....Unless you work for a government agency, in which case you are the law and you can use it to steal network traffic from the bad guys. Now, let's get cracking....no pun intended.
Here's what you'll need.
Raspberry Pi Model B. $35 + shipping (maybe $42 max)
I recommend getting the Model B, because it has an Ethernet port, which is useful if you want to SSH tunnel into it for remote use.
USB to MicroUSB (May come with Battery Pack) Free if you have one or get it in with your battery pack. Otherwise I paid $15 for a Motorola charging cable before I got one with my battery.
Alpha AWUS 036H Wireless Adapter $40
I recommend the Alpha 036H because it is a very cost effective adapter and works well on the distribution you'll be using.
8GB Class 4 SD card (tested) $8 on sale
This is the SD card that I have and it works great. The image consists of a 4.1GB partition and 0.78 GB partition, so 8 GB's to be on the safe side.
You're going to image (dd) to this with pwnpi in this instructable: http://sourceforge.net/projects/pwnpi/
Gigaware Modular Powered USB hubWith an extra male USB for powering the hub $8
I bought this from Radioshack and it works great, but you can use anyone as long as it take it's power from a USB cord not AC adapter.
5000 mAh power pack with 2 USB power ports. Powers is for about an hour. $14 + $6 shipping to New Jersey
I bought this one because it was cheap and works fine. http://www.amazon.com/gp/product/B004P8E612/ref=olp_product_details?ie=UTF8&me=&seller= . It was literally from China, the return adress was the Hong Shu Paint Building. You can also get them from Newtrent and other phone accessory places if you don't want to wait a week for it.
Mouse and Keyboard Free or cheap (depending on if you already own them)
Some little existing knowledge of Linux commands and working with wireless drivers. Knowledge is FREE!
Now that we have our parts and our thinking caps on, let's get to it!
Step 1: Imaging Your SD Card.
Download and unzip it with your program of choice.
Next, we must image our card with a program. I use ImageWriter from the Ubuntu Software Center.
If you're using linux, you can dd it to your card as well.
If you're using windows, you can use https://launchpad.net/win32-image-writer/
At this time, you may want to start charging your battery pack.
Step 2: Powering Up Your Pi
When putting everything in, wait to put your raspberry pi into the battery power pack until everything else is plugged in, because it will boot up immediately.
Step 3: Using Your OS and Tips
From here you can do anything you would normally do.
For an example I enabled a virtual adapter, used wash to check for access points and Reaver to do a WPS bruteforce test against my router.
This little guy works really well...Next we'll analyze what I'm sure everyone is asking.... "What about the battery life!?"
Step 4: Battery Life
The battery pack is 5000 mAh so:
@ 5v it should give 25 watt hours.
The pi should draw 2.6 watts and the Alpha adapter is about 1 W.
25 Wh / 3.6 W = 7 hours
During a test of my adapter ticking away at Reaver full speed ahead, it was only able to last 1 hour.
Past 1 hour it was usable, but was running into problems even initializing the wlan2.
Currently, two aspects need to be improved:
1. Longevity on battery power
2. Heat dissipation, (which can cause the Pi and adapter to slow down if it is in a hot room or enclosed).
Step 5: Results
- Portable, small, fits in a small container.
- Hardware is extensible, robust and has an ethernet controller.
- Inexpensive and modular.
- Perfect for shipping for remote administration and remote physical wireless presence by network security and law enforcement professionals. Especially Law Enforcement in small jurisdictions, who do not have a large budget.
- Poor battery life.
- CPU and adapter chips run hot.
- No case (as of yet).
Step 6: Possibilities for the Future!
While doing this project and thinking about it's capabilities, I realized that this platform had so many more applications, much cooler, than being a portable pen-testing platform that I almost dropped the idea.
Battery powered HTPC.....at about 1/4 of the price of a laptop!!!
Battery operated game emulator or "In the groove" emulator.
On site livestream. Capture live video or audio on location and live stream it over WiFi or 3G.
Switch between a weather monitoring probe on the roof of a taxi, to capturing foot traffic patterns in a city, to anything else by switching SD cards.
Automate things DIY style with full terminals and GUIs on board. Like a cowboy that welcomes people to a store...don't judge.
Strap a few onto RC helicopters and make a mesh network anywhere.
The possibilities are endless and I'm sure I'll think of more cool things once I'm finished typing this, but the idea is that, you don't have to be a rocket scientist to make something cool now. I know I'm not and I did.
RasBMC - http://www.raspbmc.com/download/
PwnPi - http://sourceforge.net/projects/pwnpi/
Hi-Pi - http://www.seclist.us/2012/06/ha-pi-hack-with-raspberrypi.html
In The Groove - http://openitg.gr-p.com/
BATMAN (open mesh network) - http://www.open-mesh.org/projects/open-mesh/wiki