rijndael_set_key_enc_only
int rijndael_set_key_enc_only(rijndael_ctx *, const u_char *, int);
if (rijndael_set_key_enc_only(&ctx, key, 256) != 0)
int rijndael_set_key_enc_only(rijndael_ctx *, const u_char *, int);
rijndael_set_key_enc_only(&swap_ctxt, (u_char *)key->key,