ks_aes
AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]);
AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]);
AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT);
AES_cbc_encrypt(data, data, len, &ks->ks_aes[1], iv, AES_DECRYPT);