if (op->aad_len)
EVP_EncryptUpdate (ctx, NULL, &len, op->aad, op->aad_len);
EVP_EncryptUpdate (ctx, op->dst, &len, op->src, op->len);
if (op->aad_len)
EVP_EncryptUpdate (ctx, NULL, &len, op->aad, op->aad_len);
EVP_EncryptUpdate (ctx, op->dst, &len, op->src, op->len);