Sonsivri
 
*
Welcome, Guest. Please login or register.
Did you miss your activation email?
December 04, 2016, 07:16:39 19:16


Login with username, password and session length


Pages: [1]
Print
Author Topic: Looking for USB keyboard logger  (Read 1422 times)
0 Members and 1 Guest are viewing this topic.
DarkClover
Active Member
***
Offline Offline

Posts: 170

Thank You
-Given: 36
-Receive: 60


Still alive...


« on: April 13, 2011, 11:21:14 23:21 »

Hy there,

I want to build a USB keyboard logger. I know there are thousands of devices out there
but I wanna build my own one.

It's planned to save the data onto a SD-card but the problem is, how should I create
the connection between PC-USB and Keyboard.

PC <----USB----> Keyboard.

The communication shouldn't be interrupted. For host I thoughtabout a Vinculum from FTDI
but hoe to make the HID thingy with the computer ?
Logged

Not thinking means to believe what others say!
TRY & ERROR... the fundamental principle our existence is based on
elecgreg
V.I.P
Newbie
*****
Offline Offline

Posts: 17

Thank You
-Given: 14
-Receive: 8


« Reply #1 on: April 14, 2011, 06:33:01 06:33 »

Hello,

You could host the keybord, strip the data from the packets and then emulate a HID device and re transmit the data, you would in effect be creating a new device on the PC. This may or may not be desirable. A work around would be to power up the micro (your host and device?), enumerate the keyboard and then masquerade your new "keyboard" as the orginal keyboard using the descriptors of that device (the one you're now hosting).

An alternative would be to snoop the data lines and write code to strip out the payload, your device would not be visible to the host PC. You would need to strip out enumeration / control characters and find the data packets, remove the headers, CRC and do what you wish with the data.

Attached is a picture of what it looks like to enumerate a HID device, you can see the enumeration and then the sucessive in transactions that get data from the device.
You could look for In transaction signatures and then grab the data.
This trace was made with an Ellisys USB tracker, very helpful for understanding / developing USB devices.

elecgreg
« Last Edit: April 14, 2011, 06:37:47 06:37 by elecgreg » Logged
DarkClover
Active Member
***
Offline Offline

Posts: 170

Thank You
-Given: 36
-Receive: 60


Still alive...


« Reply #2 on: April 15, 2011, 01:35:46 13:35 »

Well,
I'm pending between the sniffing and the host emulation. I think it's not a problem if the system doesn't show the right keyboard
since nobody really is interested in the keyboard type as long as it works correctly.
More it is to emulate HID. I've found some interesting articles about HID and USB on the net which I'll look over this weekend.

And thanks for the hint with Ellisys USB tracker, it really is very helpful. With it I found a problem on another project
which I've searched for the last two weeks.
Logged

Not thinking means to believe what others say!
TRY & ERROR... the fundamental principle our existence is based on
Pages: [1]
Print
Jump to:  


DISCLAIMER
WE DONT HOST ANY ILLEGAL FILES ON THE SERVER
USE CONTACT US TO REPORT ILLEGAL FILES
ADMINISTRATORS CANNOT BE HELD RESPONSIBLE FOR USERS POSTS AND LINKS

... Copyright 2003-2999 Sonsivri.to ...
Powered by SMF 1.1.18 | SMF © 2006-2009, Simple Machines LLC | HarzeM Dilber MC