ref: 5ece9fb8480195b39e604a4aa32b5fa1be185e65
dir: /sys/src/ape/lib/openssl/crypto/aes/README/
This is an OpenSSL-compatible version of AES (also called Rijndael). aes_core.c is basically the same as rijndael-alg-fst.c but with an API that looks like the rest of the OpenSSL symmetric cipher suite.