Dart

Get Access Token using a Pre-Created JSON Web Token

See more ABN AMRO Examples

Demonstrates how to get an access token using a pre-created JSON Web Token (JWT). Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // We're going to duplicate this CURL statement:
  // curl -X POST https://api-sandbox.abnamro.com/v1/oauth/token \
  // -H "Content-Type: application/x-www-form-urlencoded" \
  // -H "API-Key: xxxxxx" \
  // -d 'client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&grant_type=client_credentials&client_assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ4eHh4eHgiLCJleHAiOiIxNDk5OTQ3NjY4IiwiaXNzIjoibWUiLCJhdWQiOiJodHRwczovL2F1dGgtc2FuZGJveC5hYm5hbXJvLmNvbS9vYXV0aC90b2tlbiJ9.jGwHKG_YjgKpR8NPpaLu6nJ97obeP2vcxg6fOWBKdJ0&scope=tikkie'

  // Load our pre-creaed private key PEM file.
  // Note: Please share your public key along with your app name and developer email id at api.support@nl.abnamro.com. 
  // Token generation will not work unless public key is associated with your app.
  final privkey = CkPrivateKey();

  try {
    privkey.loadPemFile('qa_data/pem/abnAmroPrivateKey.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Create the JWT.
  final jwt = CkJwt();

  // Create the header:
  // {
  //     "typ": "JWT",
  //     "alg": "RS256"
  // }
  final jsonHeader = CkJsonObject();
  jsonHeader.updateString('typ', 'JWT');
  jsonHeader.updateString('alg', 'RS256');

  // Create the payload:
  // {
  //     "nbf": 1499947668,
  //     "exp": 1499948668,
  //     "iss": "me",
  //     "sub": "anApiKey",
  //     "aud": "https://auth-sandbox.abnamro.com/oauth/token"
  // }
  final jsonPayload = CkJsonObject();

  final curDateTime = jwt.genNumericDate(0);

  // Set the "not process before" timestamp to now.
  jsonPayload.addIntAt(-1, 'nbf', curDateTime);

  // Set the timestamp defining an expiration time (end time) for the token
  // to be now + 1 hour (3600 seconds)
  jsonPayload.addIntAt(-1, 'exp', curDateTime + 3600);

  jsonPayload.updateString('iss', 'me');
  jsonPayload.updateString('sub', 'anApiKey');
  jsonPayload.updateString('aud', 'https://auth-sandbox.abnamro.com/oauth/token');

  // Produce the smallest possible JWT:
  jwt.autoCompact = true;

  final String jwtStr;
  try {
    jwtStr = jwt.createJwtPk(jsonHeader.emit(), jsonPayload.emit(), privkey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final http = CkHttp();

  final req = CkHttpRequest();
  req.addParam('client_assertion_type', 'urn:ietf:params:oauth:client-assertion-type:jwt-bearer');
  req.addParam('grant_type', 'client_credentials');
  req.addParam('client_assertion', jwtStr);
  req.addParam('scope', 'tikkie');

  req.httpVerb = 'POST';
  req.contentType = 'application/x-www-form-urlencoded';

  final resp = CkHttpResponse();
  try {
    http.httpReq('https://api-sandbox.abnamro.com/v1/oauth/token', req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  if (resp.statusCode != 200) {
    print(resp.bodyStr);
    return;
  }

  // Get the JSON result:
  // {
  //     "access_token": "{your access token}",
  //     "expires_in": "{duration of validity in seconds}",
  //     "scope": "{scope(s) for which the access token is valid}",
  //     "token_type": "{it is always Bearer}"
  // }
  final json = CkJsonObject();
  json.load(resp.bodyStr);
  print('access_token: ${json.stringOf('access_token')}');
  print('token_type: ${json.stringOf('token_type')}');
  print('expires_in: ${json.stringOf('expires_in')}');
  print('scope: ${json.stringOf('scope')}');
}