Dart
TOTP Authenticator: Duplicate Results of Online Tools

Duplicates the online tool for the Google 2FA Authenticator online tools at
Chilkat Dart Downloads

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.
  // 
  // Note: This example was written on 7-March-2020.  If the online tools have since changed, the instructions provided here may no longer be valid.
  // 

  final crypt = CkCrypt2();

  // ---------------------------------------------------------------------------------------------
  // To duplicate the results of the Authenticator Test at https://rootprojects.org/authenticator/
  // do the following:
  // 1) At the bottom of the screen you will see a URI such as:
  // 
  //    otpauth://totp/ACME%20Co:john@example.com?secret=HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ&issuer=ACME%20Co&algorithm=SHA1&digits=6&period=30
  // 
  //    Use the uppercase secret.  For example:
  var secretKey = 'HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ';

  // 2) DO NOT cick the "Regenerate" button.  The regenerate button will generate a new secret.
  // 
  // 3) Run the following code to generate your 6-digit token.  Compare with the token shown in the picture of the iPhone at https://rootprojects.org/authenticator/
  //      Note: A new token is generated every 30 seconds.  You must generate within the same 30 second interval to get the same result.
  print('Your token is: ${crypt.totp(secretKey, 'base32', '0', '', 30, 6, -1, 'sha1')}');

  // ---------------------------------------------------------------------------------------------
  // To duplicate the results of the Google2FA Playground at https://pragmarx.com/playground/google2fa#/
  // do the following:

  // 1) Copy the 64-byte secret key:
  secretKey = 'OR2VQTRVHB2HO2LCGVWXQSCDK5ZHQS2D3THQ6UXO57XIE7ZHOWS6HDPQ622GU747';

  // 2) Run the same code:
  //    (Note: The online tool generates a new result every 30 seconds.  You must generate and compare within the same 30-second interval.)
  print('Your token is: ${crypt.totp(secretKey, 'base32', '0', '', 30, 6, -1, 'sha1')}');
}