Dart

Authorization Code Flow with PKCE for Native Apps

See more Okta OAuth/OIDC Examples

Demonstrates the authorization code flow with Proof Key for Code Exchange (PKCE) for native apps. In Okta, your app should be defined as shown: 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.

  final oauth2 = CkOAuth2();

  // This should be the port in the Login redirect URI for your app.  
  // Your app's Login redirect URI should be "http://localhost:3017/" if the port number is 3017.
  oauth2.listenPort = 3017;

  oauth2.authorizationEndpoint = 'https://{yourOktaDomain}/oauth2/default/v1/authorize';
  oauth2.tokenEndpoint = 'https://{yourOktaDomain}/oauth2/default/v1/token';

  // Replace these with actual values.
  oauth2.clientId = 'OKTA_CLIENT_ID';
  oauth2.clientSecret = 'OKTA_CLIENT_SECRET';

  oauth2.codeChallenge = true;
  oauth2.includeNonce = true;

  // Make sure to include "offline_access" to get a refresh token included in the final JSON response.
  // Add any additional needed scopes separated by space chars.
  oauth2.scope = 'openid offline_access';

  // Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
  final String url;
  try {
    url = oauth2.startAuth();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('URL to load in browser: $url');

  // Launch the system's default browser navigated to the URL.
  try {
    oauth2.launchBrowser(url);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Now wait for the authorization.
  // We'll wait for a max of 60 seconds.
  var numMsWaited = 0;
  while ((numMsWaited < 60000) && (oauth2.authFlowState < 3)) {
    oauth2.sleepMs(100);
    numMsWaited += 100;
  }

  // If there was no response from the browser within 30 seconds, then 
  // the AuthFlowState will be equal to 1 or 2.
  // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
  // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
  // In that case, cancel the background task started in the call to StartAuth.
  if (oauth2.authFlowState < 3) {
    oauth2.cancel();
    print('No response from the browser!');
    return;
  }

  // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
  // The possible AuthFlowState values are:
  // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
  // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
  // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
  if (oauth2.authFlowState == 5) {
    print('OAuth2 failed to complete.');
    print(oauth2.failureInfo);
    return;
  }

  if (oauth2.authFlowState == 4) {
    print('OAuth2 authorization was denied.');
    print(oauth2.accessTokenResponse);
    return;
  }

  if (oauth2.authFlowState != 3) {
    print('Unexpected AuthFlowState:${oauth2.authFlowState}');
    return;
  }

  print('OAuth2 authorization granted!');
  print('Access Token = ${oauth2.accessToken}');

  // Get the full JSON response:
  final json = CkJsonObject();
  json.load(oauth2.accessTokenResponse);
  json.emitCompact = false;
  print(json.emit());

  // The JSON response looks like this:

  // {
  //   "access_token": "eyJraWQi ... Kn4IiEfOw",
  //   "token_type": "Bearer",
  //   "expires_in": 3600,
  //   "scope": "offline_access openid",
  //   "refresh_token": "0jCqotuuUegdjNzB9uuSsfGM2Cu5HnCHUxoJ0yhZ4rs",
  //   "id_token": "eyJraWQiO ... 09WGEq3dTRmQF86PzJg"
  // }

  // Save the JSON to a file for future requests.
  final fac = CkFileAccess();
  fac.writeEntireTextFile('qa_data/tokens/okta.json', json.emit(), 'utf-8', false);
}