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