(PHP Extension) Google Authenticator Algorithm

Example code implementing the Google Authenticator algorithm.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Generating TOTP Base32 Secret: 
// When you enable 2FA with a TOTP-based authenticator app, Google will provide you with a QR code
// that you can scan using the app. This QR code contains a TOTP base32 secret.
// You can also choose to view and copy the secret manually.

$secretBase32 = 'JBSWY3DPEHPK3PXP';

// Do the following to calculate the 6-digit decimal Google authenticator token for a base32 secret,
// given the current system date/time.
$crypt = new CkCrypt2();
$otp = $crypt->totp($secretBase32,'base32','0','',30,6,-1,'sha1');

print '6-digit decimal token = ' . $otp . "\n";

?>