File containing its own checksum

security checksum data-integrity
zakovyrya picture zakovyrya · Jul 13, 2009 · Viewed 24.9k times · Source

Is it possible to create a file that will contain its own checksum (MD5, SHA1, whatever)? And to upset jokers I mean checksum in plain, not function calculating it.

Answer

LatinSuD picture LatinSuD · Jul 26, 2011

I created a piece of code in C, then ran bruteforce for less than 2 minutes and got this wonder:

The CRC32 of this string is 4A1C449B

Note the must be no characters (end of line, etc) after the sentence.

You can check it here: http://www.crc-online.com.ar/index.php?d=The+CRC32+of+this+string+is+4A1C449B&en=Calcular+CRC32

This one is also fun:

I killed 56e9dee4 cows and all I got was...

Source code (sorry it's a little messy) here: http://www.latinsud.com/pub/crc32/

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