lambdaEdgeBasicAuth.js

'use strict';

// Configure authentication
const authUser = 'user';
const authPass = 'pass';

exports.handler = async (event) => {
    // Get request and request headers
    const request = event.Records[0].cf.request;
    const headers = request.headers;
    
    // Resolve path index.html
    let urlItems = /^(.*)\/(\?.*|#.*|$)/.exec(request.uri);
    // Replace uri
    if (urlItems != null) {
        request.uri = `${urlItems[1]}/index.html${urlItems[2]}`;
    }
    
    const ignore_list = [
        /\/manifest\.json$/, /\/service-worker\.js$/, /\/precache-manifest\..*\.js$/, /\/graphql\/?$/
    ];
    
    if (ignore_list.reduce((prev, ignore) => prev | ignore.test(request.uri), false)) { // PWA need manifest file always.
        return request;
    }

    // Construct the Basic Auth string
    const authString = 'Basic ' + new Buffer(authUser + ':' + authPass).toString('base64');

    // Require Basic authentication
    if (typeof headers.authorization == 'undefined' || headers.authorization[0].value != authString) {
        const body = 'Unauthorized';
        return {
            status: '401',
            statusDescription: 'Unauthorized',
            body: body,
            headers: {
                'www-authenticate': [{key: 'WWW-Authenticate', value:'Basic'}]
            },
        };
    }
    else {
        // Continue request processing if authentication passed
        return request;
    }
};