2008-04-24

Microsoft Advanced Windows Debugging and Troubleshooting Puzzlers

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Over on the Microsoft Advanced Windows Debugging and Troubleshooting blog, they've been posting a "Puzzler" every Monday and providing the answers the following Friday.

The puzzlers are fun to participate in and it is interesting to read people's responses - everyone has their own ideas and own experiences to draw off of.

With the third puzzler, the blog authors have decided to make the challenge a bit more difficult - the latest puzzler requires one to reverse engineer some assembler.

I've not got much experience with reverse engineering assembler - I can read some assembler and can usually get a very basic idea of what a targeted chunk of code is doing. So it was an interesting challenge for me to attempt to C-ify the assembler they provided. It doesn't appear that the authors are posting the responses until they reveal the answer (makes sense to me!). But I thought I'd post hashes of my response, which I'll also post once the NT Debugging blog authors post the answer and submitted comments / responses.

From Sigcheck:


Z:\NTDebuggingPuzzler3>sigcheck -h TheFunc.txt

Sigcheck v1.52
Copyright (C) 2004-2008 Mark Russinovich
Sysinternals - www.sysinternals.com

Z:\NTDebuggingPuzzler3\TheFunc.txt:
Verified: Unsigned
File date: 12:52 PM 4/22/2008
Publisher: n/a
Description: n/a
Product: n/a
Version: n/a
File version: n/a
MD5: 755394f9711b80968f17c8ffcb8f2394
SHA1: e8443f09eef43f2575aa08ba25f68267dba7243e
SHA256: 0e044419ef78f2fa7a8e258098f4f658426a8dc3e8a5b9a121a352c2dbbbfafc


EDIT 2008-04-24: The hashes are for the code that was submitted in my second response (not the entire response - just the code). In my first response, I inadvertently left some garbage in the code (an unnecessary / unused local I had been playing with) and I neglected to remove it before submitting. Not sure how it will all pan out when the comments / responses get posted tomorrow...

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