Kong Hmac Postman Pre-Test Script

pre-test-script.js

//Use Postman 7.2+
const cryptojs = require('crypto-js');
const Header = require('postman-collection').Header;
const moment = require('moment');

//values related to creds
const secretKey = 'secret';
const username ='username';

let bodyDigest = cryptojs.SHA256(pm.request.method === 'GET' ? "" : pm.request.body.raw).toString(cryptojs.enc.Base64)
let digestHeaderValue = `SHA-256=${bodyDigest}`;
let dateHeaderValue = moment().utcOffset('+0000').format('ddd, DD MMM YYYY HH:mm:ss G\\MT');

pm.request.headers.append(new Header({
    key: 'Digest',
    value: digestHeaderValue
}));

pm.request.headers.append(new Header({
    key: 'Date',
    value: dateHeaderValue
}));

let requestLine = `${pm.request.method} ${pm.request.url.getPathWithQuery()} HTTP/1.1`
let signingString = [
    `date: ${dateHeaderValue}`,
    `digest: ${digestHeaderValue}`,
    `host: ${pm.request.url.getHost()}`,
    requestLine
].join('\n');

//can remove
console.log('Plain String: '+ signingString)

let signature = cryptojs.HmacSHA256(signingString, secretKey).toString(cryptojs.enc.Base64);
let hmacAuth = `hmac username="${username}", algorithm="hmac-sha256", headers="date digest host request-line", signature="${signature}"`

console.log('Hmac sign: '+ hmacAuth);

pm.request.headers.append(new Header({
    key: 'Authorization',
    value: hmacAuth
}));