ref: fa2b606f4bf1891b034a655d49f5fe7654ed9afd
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.