Self-Contained C11 SHA-2 Implementation

Last month I wrote a C11 SHA-2 implementation.

Features:

  • Self-contained (no external dependencies)
  • C11 only (platform-agnostic)
  • MIT-licensed
  • Includes test vectors (via make test).

The code is available here.

It includes implementations of the following:

  • SHA-224
  • SHA-256
  • SHA-384
  • SHA-512
  • HMAC-SHA256
  • HMAC-SHA512

This implementation is faster than coreutils, but slower than the assembly-optimized, processor family-specific OpenSSL SHA-2 implementation:

> time -p ./sha256 ~/Videos/8x*avi > /dev/null
rleal 9.39
user 9.10
sys 0.29
> time -p sha256sum ~/Videos/8x*avi > /dev/null
real 12.04
user 11.73
sys 0.31
> time -p openssl sha256 ~/Videos/8x*avi > /dev/null
real 6.36
user 6.01
sys 0.32