Reversing CRC32

algorithm reverse-engineering reverse crc crc32
pat picture pat · Oct 3, 2009 · Viewed 31.3k times · Source

I'm looking for a way to reverse a CRC32 checksum. There are solutions around, but they are either badly written, extremely technical and/or in Assembly. Assembly is (currently) beyond my ken, so I'm hoping someone can piece together an implementation in a higher level language. Ruby is ideal, but I can parse PHP, Python, C, Java, etc.

Any takers?

Answer

Cade Roux picture Cade Roux · Oct 3, 2009

A CRC32 is only reversible if the original string is 4 bytes or less.

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