shootismoke/backend

import { NextFunction, Request, Response } from 'express';

import { IS_DEV } from '../util';

/**
 * Whitelist an endpoint to only IP addresses from easycron.com.
 *
 * @see https://www.easycron.com/ips
 */
const whitelist = [
    '192.99.21.124',
    '167.114.64.88',
    '167.114.64.21',
    '198.27.83.222',
    '2607:5300:60:24de::',
    '2607:5300:60:467c::',
    '2607:5300:60:6558::',
    '2607:5300:60:6515::',
];

/**
 * Check that the request comes form a whitelisted IP address.
 */
export function isWhitelisted(ip: string): boolean {
    return IS_DEV || whitelist.includes(ip);
}

/**
 * Express-like middleware that whitelists the IP address.
 */
export function whitelistIPMiddleware(
    req: Request,
    res: Response,
    next: NextFunction
): void {
    const ip = req.headers['x-forwarded-for'] as string;

    if (!isWhitelisted(ip)) {
        res.status(403);
        res.send({
            status: 'error',
            details: `IP address not whitelisted: ${ip}`,
        });
        res.end();
    } else {
        next();
    }
}