Postman Pre-Request HMAC256 Signature Generation

postman_prereq_hmac.js

const CryptoJS = require("crypto-js");

const requestBody = pm.request.body.raw;
const secretKey = pm.environment.get("WEBHOOK_SIGNATURE_KEY");

if (requestBody && secretKey) {
    const hmac = CryptoJS.HmacSHA256(requestBody, secretKey).toString();
    pm.environment.set("WEBHOOK_REQ_SIGNATURE", hmac);
    console.log("Generated HMAC Signature:", hmac);
} else {
    console.error("Error: Request body or 'secretKey' environment variable is missing.");
    pm.execution.setNextRequest(null);
}