Calculate the code with given secret and point in time
| public getCode ( $secret, $time = null ) |
public function testKnownTestVectors_sha512()
{
//Known test vectors for SHA512: https://tools.ietf.org/html/rfc6238#page-15
$secret = 'GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQGEZDGNA';
//== base32encode('1234567890123456789012345678901234567890123456789012345678901234')
$tfa = new TwoFactorAuth('Test', 8, 30, 'sha512');
$this->assertEquals('90693936', $tfa->getCode($secret, 59));
$this->assertEquals('25091201', $tfa->getCode($secret, 1111111109));
$this->assertEquals('99943326', $tfa->getCode($secret, 1111111111));
$this->assertEquals('93441116', $tfa->getCode($secret, 1234567890));
$this->assertEquals('38618901', $tfa->getCode($secret, 2000000000));
$this->assertEquals('47863826', $tfa->getCode($secret, 20000000000));
}
<!doctype html>
<html>
<head>
<title>Demo</title>
</head>
<body>
<ol>
<?php
require_once 'loader.php';
Loader::register('../lib', 'RobThree\\Auth');
use RobThree\Auth\TwoFactorAuth;
$tfa = new TwoFactorAuth('MyApp');
echo '<li>First create a secret and associate it with a user';
$secret = $tfa->createSecret();
echo '<li>Next create a QR code and let the user scan it:<br><img src="' . $tfa->getQRCodeImageAsDataUri('My label', $secret) . '"><br>...or display the secret to the user for manual entry: ' . chunk_split($secret, 4, ' ');
$code = $tfa->getCode($secret);
echo '<li>Next, have the user verify the code; at this time the code displayed by a 2FA-app would be: <span style="color:#00c">' . $code . '</span> (but that changes periodically)';
echo '<li>When the code checks out, 2FA can be / is enabled; store (encrypted?) secret with user and have the user verify a code each time a new session is started.';
echo '<li>When aforementioned code (' . $code . ') was entered, the result would be: ' . ($tfa->verifyCode($secret, $code) === true ? '<span style="color:#0c0">OK</span>' : '<span style="color:#c00">FAIL</span>');
?>
</ol>
<p>Note: Make sure your server-time is <a href="http://en.wikipedia.org/wiki/Network_Time_Protocol">NTP-synced</a>! Depending on the $discrepancy allowed your time cannot drift too much from the users' time!</p>
</body>
</html>
