nodeOloRequestSigning.js

const config = require("./config.js");
const dayjs = require("dayjs");
const utc = require("dayjs/plugin/utc");
const crypto = require("crypto");

// activate UTC plugin
dayjs.extend(utc);


function getClientIp(req) {
    return (req.headers["X-Forwarded-For"] ||
            req.headers["x-forwarded-for"] ||
            '').split(',')[0] ||
           req.connection.remoteAddress;
}

function getOloServerAuthHeaders(req, proxyPath) {
    const oloId = config.OLO_CLIENT_ID;
    const oloSecret = config.OLO_SECRET;
    const contentType = req.headers["content-type"] || "application/json";

    // RFC1123Pattern
    const timestamp = `${dayjs.utc().format("ddd, DD MMM YYYY HH:mm:ss")} GMT`;
    const hashedBody = crypto.createHash("sha256")
        .update(req.body || "")
        .digest("base64");

    const signatureString = [
        oloId,
        req.method,
        contentType,
        hashedBody,
        proxyPath,
        timestamp
    ].join("\n");

    console.log(signatureString);

    const hmac = crypto.createHmac("sha256", oloSecret);
    const hashedSignature = hmac.update(signatureString).digest("base64");

    return {
        "Content-Type": contentType,
        "Authorization": `OloSignature ${oloId}:${hashedSignature}`,
        "Date": timestamp,
        "X-Forwarded-For": getClientIp(req),
        "User-Agent": "Olo-Proxy",
    }
}