JWS- Generation in Postman

I was developing APIs that are secured with JWS of the payload. To test these APIs behind the MuleSoft/CloudHub API Manager JWS Policy (a custom policy I create, I will write another blog about it.) I needed to generate the JWS signature sent to the API policy in PostMan.

The steps are very simple

  • Store the private key and KID (Key ID) in the environment variables
  • load the jsrsaasign library
  • Using the private key and library generate the JWS sigature

Simple enough?

var privateKey = pm.environment.get("privateKey");
if(pm.globals.get("jsrsasign-js") == null){
   const loadLibRequest = {
     url: 'http://kjur.github.io/jsrsasign/jsrsasign-latest-all-min.js',
     method: 'GET',
     header: {
       'Accept': '*/*'
    pm.sendRequest(loadLibRequest,(error, response) => {

var sJWS = KJUR.jws.JWS.sign('RS256',sheader,sig,privateKey);

let me know if you have any issues.

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