Checksum / CRC scanning

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aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Checksum / CRC scanning

Post by aluigi »

There is an useful script for QuickBMS that allows to perform a full CRC calculation/scanning.

It's very useful if you have an unknown crc and you would like to know on what data it's calculated or, moreover, what polynomial and other settings are used.

http://aluigi.org/papers/bms/crc_scan.bms

I have updated it just today, I added only the "reversed" visualization of the CRC so that you don't need to search your value two times in case it's displayed with a different endianess. This is the only thing I updated.

How to use:

Code: Select all

quickbms.exe crc_scan.bms dump.dat > crc.txt
Where "dump.dat" is the file on which you want to calculate the crc.

Then open crc.txt and search the hexadecimal checksum that you expected, for example the crc located in an archive.
rhhab331
Posts: 5
Joined: Sat Sep 24, 2016 4:45 pm

Re: Checksum / CRC scanning

Post by rhhab331 »

Thanks for the work!
sharlatan
Posts: 6
Joined: Thu May 30, 2019 7:14 pm

Re: Checksum / CRC scanning

Post by sharlatan »

hi. when i use Checksum / CRC scanning script this error show.
error in attach file.
how can i fix it?
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Checksum / CRC scanning

Post by aluigi »

crc_scan.bms must be in the current folder (E:\quickbms)
StreamThread
Posts: 54
Joined: Fri May 27, 2016 2:28 pm

Re: Checksum / CRC scanning

Post by StreamThread »

Similar script for the strings CRC would be very helpful.
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Checksum / CRC scanning

Post by aluigi »

Just dump one of the strings as file and use crc_scan.bms on it.
Once you have found the correct algorithm and settings, you can work on other solutions (it depends by what you want to do).