JHipster authentication using Postman and JWT

1. Make a POST request to /api/authenticate with the following body: {"password":"admin","username":"admin"}. You will receive the following response: {"id_token":"aabbccddeeff"}
2. Make your subsequent requests using the value of the token received in the previous call and put in into an Authorization: Bearer aabbccddeeff
3. You can check the status of the authentication, making a GET request to /api/authenticate endpoint

The easiest way for me is

1. log into your Jhipster Web app with the admin credential

2. Select Administration > API

3. Then choose any of existing API and click 'Try it out' button

It will list a curl action with the token, now you can grab the token and use it in Postman

If you have deployed a single microservice and you want to test it in isolation you can configure Postman to build a JWT token using a pre-request script.

1. Go to the application-dev.yml file generated by JHipster and grab the base64-secret value:

security:
    authentication:
        jwt:
            # This token must be encoded using Base64 and be at least 256 bits long (you can type `openssl rand -base64 64` on your command line to generate a 512 bits one)
            base64-secret: N2Y2MmFkNzg2ZTI4NTZiZGEwMTZhYTAzOTBhMjgwMzlkMzU2MzRlZjJjZDA2MzQ0NGMxOGFlZThjOWY0MjkzNGVlOGE3ZjkxZGI5ZTQxOGY3MjEwNWUwYTUxMTUxODYxY2U4ZWMzZjVhMjg0NTZkNzlhNWUyMmEyNjQ5NzkxZmI=

2. Put the value in a variable named jhipster_jwt_secret inside the Postman Environment.

3. Configure your pre-request script (this is largely copied from a Gist):

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;
}

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

var payload = {
  "sub": "user",
  "auth": "role"
};

var secret = CryptoJS.enc.Base64.parse(postman.getEnvironmentVariable("jhipster_jwt_secret"));

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

// encode data
var stringifiedPayload = CryptoJS.enc.Utf8.parse(JSON.stringify(payload));
var encodedPayload = base64url(stringifiedPayload);

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

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

postman.setEnvironmentVariable("jwt_token", signedToken);

4. Inside the Authorization tab select "Bearer token" and write {{jwt_token}} in the Token input field.

It is possible to use Postman with a JWT JHipster app.

1. First, authenticate with the JHipster app
2. Inspect any API request for the Authorization header. The JWT token is the value to the right of "Bearer ". You can also find this token in the browser's localStorage under the key jhi-authenticationToken.

3. Edit the headers in Postman and add the Authorization header. The value should look like the following:

   Bearer eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiJydRkZWxsIiwiYXV0aCI6IlJPTEVfQURNSU4sUk9MRV9U0VSIiwiZXhwIjoxNDgzOTg1MDkzfQ.1A13sBvr3KDWxJQpKDKOS33KAVjWIb3mS_qfxLBOCq_LbMwNHnysAai0SNXXgudMOulAnXYN9_Mzlcv1_zctA