Awesome

tiny_sha3

Very small, readable implementation of the FIPS 202 and SHA3 hash function. Public domain.

Updated 27-Dec-15:

Added SHAKE128 and SHAKE256 code and test vectors. The code can actually do a XOF of arbitrary size (like "SHAKE512").

Updated 03-Sep-15:

Made the implementation portable. The API is now pretty much the same that OpenSSL uses.

Updated 07-Aug-15:

Now that SHA3 spec is out, I've updated the package to match with the new padding rules. There is literally one line difference between Keccak 3.0 and SHA-3 implementations:

    temp[inlen++] = 0x06;           // XXX Padding Changed from Keccak 3.0

The 0x06 constant there used to be 0x01. But this of course totally breaks compatibility and test vectors had to be revised.

SHA-3 Spec: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf

Cheers,

• markku

Original README.TXT from 19-Nov-11:

Hi.

The SHA-3 competition is nearing it's end and I would personally like to support Keccak as the winner. I have a PhD in hash function cryptanalysis so don't take my word for it, go ahead and look into the code !

Since I couldn't find a compact and/or readable implementation of Keccak anywhere, here's one I cooked up as a service to the curious.

This implementation is intended for study of the algorithm, not for production use.

The code works correctly on 64-bit little-endian platforms with gcc. Like your Linux box. The main.c module contains self-tests for all officially supported hash sizes.

If you're looking for production code, the official multi-megabyte package covers everyting you could possibly need and too much much more: http://keccak.noekeon.org/

Cheers,

• Markku 19-Nov-11

Dr. Markku-Juhani O. Saarinen mjos@iki.fi