account/src/middleware/client-header.ts

import xmlbuilder from 'xmlbuilder';
import { getValueFromHeaders } from '@/util';
import type express from 'express';

const VALID_CLIENT_ID_SECRET_PAIRS: Record<string, string> = {
	// * 'Key' is the client ID, 'Value' is the client secret
	a2efa818a34fa16b8afbc8a74eba3eda: 'c91cdb5658bd4954ade78533a339cf9a', // * Possibly WiiU exclusive?
	daf6227853bcbdce3d75baee8332b: '3eff548eac636e2bf45bb7b375e7b6b0', // * Possibly 3DS exclusive?
	ea25c66c26b403376b4c5ed94ab9cdea: 'd137be62cb6a2b831cad8c013b92fb55' // * Possibly 3DS exclusive?
};

function nintendoClientHeaderCheck(request: express.Request, response: express.Response, next: express.NextFunction): void {
	response.set('Content-Type', 'text/xml');
	response.set('Server', 'Nintendo 3DS (http)');
	response.set('X-Nintendo-Date', new Date().getTime().toString());

	const clientID = getValueFromHeaders(request.headers, 'x-nintendo-client-id');
	const clientSecret = getValueFromHeaders(request.headers, 'x-nintendo-client-secret');

	if (
		!clientID ||
		!clientSecret ||
		!VALID_CLIENT_ID_SECRET_PAIRS[clientID] ||
		clientSecret !== VALID_CLIENT_ID_SECRET_PAIRS[clientID]
	) {
		response.send(xmlbuilder.create({
			errors: {
				error: {
					cause: 'client_id',
					code: '0004',
					message: 'API application invalid or incorrect application credentials'
				}
			}
		}).end());

		return;
	}

	return next();
}

export default nintendoClientHeaderCheck;