Postman Sign JWT Token

postman.js

// https://credentials.workday.com/docs/authentication/

// create JWT header

var alg = postman.getEnvironmentVariable('algorithm');
var jwtHeader = postman.getEnvironmentVariable('jwt-header');
var headerData = JSON.parse(jwtHeader);
headerData.alg = alg;

jwtHeader = JSON.stringify(headerData);

// create JWT claims

var utcNow = new Date();
var early = new Date(utcNow.getTime() - (1 * 60 * 1000));
var oneHour = new Date(utcNow.getTime() + (1 * 60 * 60 * 1000));
var fiveMinutes = new Date(utcNow.getTime() + (5 * 60 * 1000));

var iat = Math.round(utcNow.getTime() / 1000);
var exp = Math.round(fiveMinutes.getTime() / 1000);
var nbf = Math.round(early.getTime() / 1000);

var jsonClaims = postman.getEnvironmentVariable('jwt-claims');
var jsonData = JSON.parse(jsonClaims);
jsonData.email = postman.getEnvironmentVariable('email');
jsonData.nbf = nbf;
jsonData.exp = exp;
jsonData.iat = iat;

var jwtClaims = JSON.stringify(jsonData);

// sign the token

console.log(jwtHeader);
console.log(jwtClaims);

var bwtHeader = btoa(jwtHeader).split('=').join('');
var bwtClaims = btoa(jwtClaims).split('=').join('');
var message = `${bwtHeader}.${bwtClaims}`;
console.log(message);

var secret = postman.getEnvironmentVariable("PRIVATE_KEY");

var hashed = this.CryptoJS.HmacSHA256(message, secret);
var signature = hashed.toString(this.CryptoJS.enc.Base64).split('=').join('');

const jwt = `${message}.${signature}`
console.log(jwt);

postman.setEnvironmentVariable('jwt-token', jwt);