function _openid_dh_long_to_binary($long) {
$cmp = _openid_math_cmp($long, 0);
if ($cmp < 0) {
return FALSE;
}
if ($cmp == 0) {
return "\0";
}
$bytes = array();
while (_openid_math_cmp($long, 0) > 0) {
array_unshift($bytes, _openid_math_mod($long, 256));
$long = _openid_math_div($long, pow(2, 8));
}
if ($bytes && $bytes[0] > 127) {
array_unshift($bytes, 0);
}
$string = '';
foreach ($bytes as $byte) {
$string .= pack('C', $byte);
}
return $string;
}