Steven D'Aprano wrote:
On Mon, 08 Mar 2010 16:09:12 +1300, Gregory Ewing wrote:
Given some known data/crc pairs, how feasible is it to figure out the
polynomial being used to generate the crc?
Google is your friend:
http://www.woodmann.com/fravia/crctut1.htm
That page was interesting to read, especially since I've implemented the
three algorithms - CRC16, CRC32, and the reversed version of CRC16, all
in the long-distant past.
However, if there's anything in there about how to derive the polynomial
algorithm from (a few) samples I missed it entirely. Instead, what it
calls reverse engineering is figuring out how to modify a message to
force it to have a desired CRC value (when the CRC polynomial is already
known).
DaveA
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