ref: 793efcee28211f3670a70e42efd7fa3d9a3ec92d
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.