Postman - Pre-request Script with JWT (JsonWebToken)

postman-script-jwt.js

function base64url(source) {
	// Encode in classical base64
	encodedSource = CryptoJS.enc.Base64.stringify(source);

	// Remove padding equal characters
	encodedSource = encodedSource.replace(/=+$/, '');

	// Replace characters according to base64url specifications
	encodedSource = encodedSource.replace(/\+/g, '-');
	encodedSource = encodedSource.replace(/\//g, '_');

	return encodedSource;
}

function addIAT(request) {
	var iat = Math.floor(Date.now() / 1000) + 257;
	data.iat = iat;
	return data;
}

let actualDate = new Date().getTime(); 
let expauth = new Date(actualDate + 10*60000)/1000;
let user = "TO_DO";
let pass = "TO_DO";
let appkey = "TO_DO";
let secret_key = "TO_DO";
let url = "TO_DO";

var header = {
	"typ": "JWT",
	"alg": "HS256"
};

var data = {
    "exp": expauth,
    "user": user,
    "pass": pass,
    "appkey": appkey
};

// data = addIAT(data);

var secret = secret_key;

// encode header
var stringifiedHeader = CryptoJS.enc.Utf8.parse(JSON.stringify(header));
var encodedHeader = base64url(stringifiedHeader);

// encode data
var stringifiedData = CryptoJS.enc.Utf8.parse(JSON.stringify(data));
var encodedData = base64url(stringifiedData);

// build token
var token = encodedHeader + "." + encodedData;

// sign token
var signature = CryptoJS.HmacSHA256(token, secret);
signature = base64url(signature);
var signedToken = token + "." + signature;

console.log(signedToken);
let login_request = {
	method: 'GET', 
	url: url,
	header: {
		'Content-Type': 'application/json',
		'Authorization': 'Bearer ' + signedToken
	}
}
pm.sendRequest(login_request, function (err, response) {
    const auth = response.headers.find(it => it.key == 'Authorization')
    if(auth){
        pm.environment.set("token", auth.value.replace("Bearer ", ""));
    } 
});

fabuloso🦘🦘