Message 2 of 4
21 Apr 17 10:22
Join Date: 08 Sep 2005
Posts To This List: 10157
Simple Keyboard filtering driver
What do you want the filter to do? The kbdfiltr sample is a better starting
point as it has all of the relevant pieces wired in. For drivers below kbdclass
you will not see reads/writes. Instead you hook the keyboard service callback
chain and use it to inspect, inject, and/or reject input
Bent from my phone
From: email@example.com on behalf of firstname.lastname@example.org
Sent: Friday, April 21, 2017 5:32:00 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Simple Keyboard filtering driver
First of all: I'm new when it goes to driver development. I went through
tutorial(s) and I read a lot about drivers and how it should work but since I
don't have knowledge I'm experiencing issues from the very begining... But let
me explain my "simple task"
- I need to write a keyboard filter - HID keyboard.
- I understand that it needs to be in the Kernel space - KMDF - WDF
- I took a solution in VS 2015 for Kernel drivers and I adopted it based on OSR
WDF Filtering driver tutorial
- The driver inf file is based on firefly example from MS (mouse filtering).
More/less the same idea. I've narrowed it to a single specific keyboard
The driver installs on my remote machine without issues. I'm able to deploy it
and I see it in the Device Manager. It is shown as a "Upper Filter" in the
Device Manager. I was able to get Kernel Debug logs (via DbgPrint) and the
driver is created without issues - all statuses were ok. I set my driver as
filter, created device, created queue and "subscribed" my own callbacks for
And the last thing (read/write) callbacks are not called at all.
Driver files visible in Device Manager:
SynTP.sys (this is laptop specific)
Upper Filter: IngacoFltr
Any comments apprieciated ;).
NTDEV is sponsored by OSR
Visit the list online at:
MONTHLY seminars on crash dump analysis, WDF, Windows internals and software
To unsubscribe, visit the List Server section of OSR Online at