SHA3-256 in C

This project is comprised of the singular program sha3-test, which is capable of performing the sponge-based, SHA-3 256 secure hash algorithm on arbitrary amounts of input data.

Design

Credits to Dr. Markku-Juhani O. Saarinen for providing a readable implementation of the SHA-3 library available here: https://github.com/mjosaarinen/tiny_sha3. The code in this project was based on said library, but deviated with several changes made to provide clarity in reference to the original SHA-3/KECCAK standards found here: https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf. More specifically, rewriting significant portions of the library to showcase how exactly the theta, rho, pi, chi, and iota transformations work.

Building

To build the program:

$ make

Or:

$ make all

Usage

Note that the length of the input to hash must be specified using a getopt() command-line option as demonstrated below. To hash a 64-byte input (stdin and stdout are the default for input and output, respectively):

$ ./sha3-test -l 64 [-i input] [-o output]

Additional Program Options

The following getopt() command-line options below are available as well:

-h: Display program help and usage
-v: Display verbose program output (sent to stderr)

Running Tests

Test vectors supplied by NIST are included in this project as well. To run all the tests, just run the following (results are cleaned after):

$ make test