function _openid_get_bytes($num_bytes) {
$f =& drupal_static(__FUNCTION__);
$bytes = '';
if (!isset($f)) {
$f = @fopen(OPENID_RAND_SOURCE, "r");
}
if (!$f) {
// pseudorandom used
$bytes = '';
for ($i = 0; $i < $num_bytes; $i += 4) {
$bytes .= pack('L', mt_rand());
}
$bytes = substr($bytes, 0, $num_bytes);
}
else {
$bytes = fread($f, $num_bytes);
}
return $bytes;
}