Author Topic: Newbie Teensy Question  (Read 2049 times)

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Offline Ro-76

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Newbie Teensy Question
« on: Sun, 05 August 2012, 07:17:26 »
I'm planning to use a teensy to make a small custom keyboard of about 10 keys including some F keys and a few other letters to work with a medical imaging workstation.

I would like have a key toggle through a series of keystrokes with successive presses so that when I hit the key first it will send F1, the next time F2, the next F3 etc.

Is this possible /  difficult?

Thanks

Offline Djuzuh

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Re: Newbie Teensy Question
« Reply #1 on: Sun, 05 August 2012, 07:41:57 »
It's possible, and difficulty depends on your programming skills. I have no tensy experience, but it shouldn't be hard to adapt an existing keyboard code and add an array with all the keypresses and an integer holding the current position.

But people in here can help.
« Last Edit: Sun, 05 August 2012, 07:44:04 by Djuzuh »

Offline braaaiiins

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Re: Newbie Teensy Question
« Reply #2 on: Sun, 05 August 2012, 17:07:20 »
WELCOME!

That's definitely possible and easy to do. The teensy should be able to mimick any keystroke sequence, i'm pretty sure. In fact it can be used for super malicious things since it's automatically recognized as an HID device and doesn't have any drivers to install. There's a fun DEFCON video about it =)

Offline Djuzuh

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Re: Newbie Teensy Question
« Reply #3 on: Sun, 05 August 2012, 17:21:16 »
WELCOME!

That's definitely possible and easy to do. The teensy should be able to mimick any keystroke sequence, i'm pretty sure. In fact it can be used for super malicious things since it's automatically recognized as an HID device and doesn't have any drivers to install. There's a fun DEFCON video about it =)


It has also been used as something more than a POC.

A pentester team break into a system, by sending staffers of the system "free" commercial usb sticks, or usb mouse (or did they drop them on the floor, I don't remember). One of the staffer couldn't resist and plugged it in the office computer. The device worked as mentionned, but after a little time of inactivity, it acted like a keyboard, and send the right keystroke to code/implement a backdoor.

Such a method is completely unavoidable, since it simulates user input on a hardware basis, outside of the PC. At least as long as we don't have signed periphericals (you can't plug a new usb device in before the administrator whitelists it for example). Or smart employees (as if this is possible).

Offline braaaiiins

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Re: Newbie Teensy Question
« Reply #4 on: Sun, 05 August 2012, 17:29:13 »
So true and scary. Makes me weary of using anyone's USB device on my machines.

Offline Ro-76

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Re: Newbie Teensy Question
« Reply #5 on: Fri, 10 August 2012, 07:42:29 »
Great. Thanks for all the replies. I don't have my teensy yet, and TBH, I don't have a lot of programming experience, but I'll give it a try!

I'll report back with any success.

Offline i3oilermaker

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Re: Newbie Teensy Question
« Reply #6 on: Fri, 10 August 2012, 07:49:09 »
I am experimenting too...would love to share our success and failures