public function PHPGangsta_GoogleAuthenticator::createSecret in TFA Basic plugins 7

Create new secret. 16 characters, randomly chosen from the allowed base32 characters.

Parameters

int $secretLength:

Return value

string

File

includes/googleauthenticator/GoogleAuthenticator.php, line 24

Class

PHPGangsta_GoogleAuthenticator

PHP Class for handling Google Authenticator 2-factor authentication.

Code

public function createSecret($secretLength = 16) {
  $validChars = $this
    ->_getBase32LookupTable();

  // Valid secret lengths are 80 to 640 bits
  if ($secretLength < 16 || $secretLength > 128) {
    throw new Exception('Bad secret length');
  }
  $secret = '';
  $rnd = false;
  if (function_exists('random_bytes')) {
    $rnd = random_bytes($secretLength);
  }
  elseif (function_exists('mcrypt_create_iv')) {
    $rnd = mcrypt_create_iv($secretLength, MCRYPT_DEV_URANDOM);
  }
  elseif (function_exists('openssl_random_pseudo_bytes')) {
    $rnd = openssl_random_pseudo_bytes($secretLength, $cryptoStrong);
    if (!$cryptoStrong) {
      $rnd = false;
    }
  }
  if ($rnd !== false) {
    for ($i = 0; $i < $secretLength; ++$i) {
      $secret .= $validChars[ord($rnd[$i]) & 31];
    }
  }
  else {
    throw new Exception('No source of secure random');
  }
  return $secret;
}