function backdrop_valid_test_ua

Returns the test prefix if this is an internal request from SimpleTest.

Return value

Either the simpletest prefix (the string "simpletest" followed by any: number of digits) or FALSE if the user agent does not contain a valid HMAC and timestamp.

File

core/includes/bootstrap.inc, line 3459

Functions that need to be loaded on every Backdrop request.

Code

function backdrop_valid_test_ua() {
  // No reason to reset this.
  static $test_prefix;

  if (isset($test_prefix)) {
    return $test_prefix;
  }

  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^(simpletest\d+);(.+);(.+);(.+)$/", $_SERVER['HTTP_USER_AGENT'], $matches)) {
    list(, $prefix, $time, $salt, $hmac) = $matches;
    $check_string = $prefix . ';' . $time . ';' . $salt;
    // We use the salt from settings.php to make the HMAC key, since the
    // database is not yet initialized and we can't access any Backdrop
    // variables. The file properties add more entropy.
    $key = settings_get('hash_salt') . filectime(__FILE__) . fileinode(__FILE__);
    $time_diff = REQUEST_TIME - $time;
    // Since we are making a local request a 5 second time window is allowed,
    // and the HMAC must match.
    if ($time_diff >= 0 && $time_diff <= 5 && $hmac == backdrop_hmac_base64($check_string, $key)) {
      $test_prefix = $prefix;
      return $test_prefix;
    }
  }

  $test_prefix = FALSE;
  return $test_prefix;
}