Implementation of the Serpent cryptographic symmetric encryption algorithm that took second place in the AES contest.
It's built like a tank. - Bruce Shneier
However, it is necessary to make different secure encryption modes and probably in general to turn the written closer to the AES (Rijndael) algorithm in the standard library.
To make sure it works as expected just
zig build test
SERPENT: A Candidate Block Cipher for the Advanced Encryption Standard