reverce crc lookup?

duffstone

Member
Joined
Sep 13, 2013
Messages
188
Has anyone created a tool to reverse the CRC lookup process? I've got an orphaned object in my DB, I can easily delete it if I could get it back into my inventory, problem is I don't remember what object it is.

I've tried several different strings to get to the CRC the core is complaining about but thus far I can't remember what object I was working with. so I have a CRC but can't remember what string I used.

is there a way to go backwards?

-Duff
 

PikkonMG

New Member
Joined
Aug 29, 2013
Messages
14
One thing you got to figure out is it 9/17/33 or 65 bit CRC. CRC polynomial is binary and does it shift from left to right or right to left. You could use some division, just figure out the divisor and go from there on converting to ASCII. If it is hex process is still pretty much the same.
 

duffstone

Member
Joined
Sep 13, 2013
Messages
188
PikkonMG said:
One thing you got to figure out is it 9/17/33 or 65 bit CRC. CRC polynomial is binary and does it shift from left to right or right to left. You could use some division, just figure out the divisor and go from there on converting to ASCII. If it is hex process is still pretty much the same.
I believe it does both a right and left shift from the code I saw, although I'm not going to pretend that I really understand it. What I did manage to glean from it was that it wasn't really possible as bits/bytes are dropped in the shift meaning you can go backwards reliably. - Duff
 

Sytner

Administrator
Staff member
Administrator
Joined
Sep 18, 2010
Messages
426
I wouldn't think there's a way of doing it besides brute force (possibly in a clever way, especially if you can make certain assumptions...). If there was then that would imply you could easily compress and later recover any amount of data into 4-bytes and you would therefore end up very rich indeed...
 
Top Bottom